Merge branch 'new-api' into dev

.github/workflows/test.yml

@@ -3,7 +3,7 @@ name: test
 
 on:
   push:
-    branches: [master, dev]
+    branches: [dev, master, new-api]
     paths:
       [
         "**.rs",
@@ -37,26 +37,17 @@ on:
 
 env:
   RUST_BACKTRACE: 1
+  RUSTFLAGS: -D warnings
+
+# The layering here is as follows, checking in priority from highest to lowest:
+#  1. absence of errors and warnings on Linux/x86
+#  2. cross compilation on Windows and Linux/ARM
+#  3. absence of lints
+#  4. code formatting
 
 jobs:
-  fmt:
-    name: rustfmt
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@v2
-      - name: Install toolchain
-        uses: actions-rs/toolchain@v1
-        with:
-          profile: minimal
-          toolchain: stable
-          override: true
-          components: rustfmt
-      - run: cargo fmt --all -- --check
-
   test-linux:
-    needs: fmt
-    name: cargo +${{ matrix.toolchain }} build (${{ matrix.os }})
+    name: cargo +${{ matrix.toolchain }} check (${{ matrix.os }})
     runs-on: ${{ matrix.os }}
     continue-on-error: ${{ matrix.experimental }}
     strategy:
@@ -64,14 +55,13 @@ jobs:
       matrix:
         os: [ubuntu-latest]
         toolchain:
-          - 1.57 # MSRV (Minimum supported rust version)
+          - "1.61" # MSRV (Minimum supported rust version)
           - stable
-          - beta
         experimental: [false]
-        # Ignore failures in nightly
+        # Ignore failures in beta
         include:
           - os: ubuntu-latest
-            toolchain: nightly
+            toolchain: beta
             experimental: true
     steps:
       - name: Checkout code
@@ -107,21 +97,24 @@ jobs:
 
       - run: cargo install cargo-hack
       - run: cargo hack --workspace --remove-dev-deps
-      - run: cargo build -p librespot-core --no-default-features
-      - run: cargo build -p librespot-core
-      - run: cargo hack build --each-feature -p librespot-discovery
-      - run: cargo hack build --each-feature -p librespot-playback
-      - run: cargo hack build --each-feature
+      - run: cargo check -p librespot-core --no-default-features
+      - run: cargo check -p librespot-core
+      - run: cargo hack check --each-feature -p librespot-discovery
+      - run: cargo hack check --each-feature -p librespot-playback
+      - run: cargo hack check --each-feature
 
   test-windows:
-    needs: fmt
-    name: cargo build (${{ matrix.os }})
+    needs: test-linux
+    name: cargo +${{ matrix.toolchain }} check (${{ matrix.os }})
     runs-on: ${{ matrix.os }}
+    continue-on-error: false
     strategy:
       fail-fast: false
       matrix:
         os: [windows-latest]
-        toolchain: [stable]
+        toolchain:
+          - "1.61" # MSRV (Minimum supported rust version)
+          - stable
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
@@ -153,20 +146,22 @@ jobs:
 
       - run: cargo install cargo-hack
       - run: cargo hack --workspace --remove-dev-deps
-      - run: cargo build --no-default-features
-      - run: cargo build
+      - run: cargo check --no-default-features
+      - run: cargo check
 
   test-cross-arm:
-    needs: fmt
+    name: cross +${{ matrix.toolchain }} build ${{ matrix.target }}
+    needs: test-linux
     runs-on: ${{ matrix.os }}
     continue-on-error: false
     strategy:
       fail-fast: false
       matrix:
-        include:
-          - os: ubuntu-latest
-            target: armv7-unknown-linux-gnueabihf
-            toolchain: stable
+        os: [ubuntu-latest]
+        target: [armv7-unknown-linux-gnueabihf]
+        toolchain:
+          - "1.61" # MSRV (Minimum supported rust version)
+          - stable
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
@@ -197,3 +192,67 @@ jobs:
         run: cargo install cross || true
       - name: Build
         run: cross build --target ${{ matrix.target }} --no-default-features
+
+  clippy:
+    needs: [test-cross-arm, test-windows]
+    name: cargo +${{ matrix.toolchain }} clippy (${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    continue-on-error: false
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest]
+        toolchain: [stable]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Install toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: ${{ matrix.toolchain }}
+          override: true
+          components: clippy
+
+      - name: Get Rustc version
+        id: get-rustc-version
+        run: echo "::set-output name=version::$(rustc -V)"
+        shell: bash
+
+      - name: Cache Rust dependencies
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.cargo/registry/index
+            ~/.cargo/registry/cache
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-${{ steps.get-rustc-version.outputs.version }}-${{ hashFiles('Cargo.lock') }}
+
+      - name: Install developer package dependencies
+        run: sudo apt-get update && sudo apt-get install libpulse-dev portaudio19-dev libasound2-dev libsdl2-dev gstreamer1.0-dev libgstreamer-plugins-base1.0-dev libavahi-compat-libdnssd-dev
+
+      - run: cargo install cargo-hack
+      - run: cargo hack --workspace --remove-dev-deps
+      - run: cargo clippy -p librespot-core --no-default-features
+      - run: cargo clippy -p librespot-core
+      - run: cargo hack clippy --each-feature -p librespot-discovery
+      - run: cargo hack clippy --each-feature -p librespot-playback
+      - run: cargo hack clippy --each-feature
+
+  fmt:
+    needs: clippy
+    name: cargo +${{ matrix.toolchain }} fmt
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: Install toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+          components: rustfmt
+      - run: cargo fmt --all -- --check

.gitignore

@@ -5,5 +5,4 @@ spotify_appkey.key
 .project
 .history
 *.save
-
-
+*.*~

COMPILING.md

@@ -7,7 +7,7 @@ In order to compile librespot, you will first need to set up a suitable Rust bui
 ### Install Rust
 The easiest, and recommended way to get Rust is to use [rustup](https://rustup.rs). Once that’s installed, Rust's standard tools should be set up and ready to use.
 
-*Note: The current minimum required Rust version at the time of writing is 1.57, you can find the current minimum version specified in the `.github/workflow/test.yml` file.*
+*Note: The current minimum supported Rust version at the time of writing is 1.61.*
 
 #### Additional Rust tools - `rustfmt`
 To ensure a consistent codebase, we utilise [`rustfmt`](https://github.com/rust-lang/rustfmt) and [`clippy`](https://github.com/rust-lang/rust-clippy), which are installed by default with `rustup` these days, else they can be installed manually with:
@@ -15,7 +15,7 @@ To ensure a consistent codebase, we utilise [`rustfmt`](https://github.com/rust-
 rustup component add rustfmt
 rustup component add clippy
 ```
-Using `rustfmt` is not optional, as our CI checks against this repo's rules.
+Using `cargo fmt` and `cargo clippy` is not optional, as our CI checks against this repo's rules.
 
 ### General dependencies
 Along with Rust, you will also require a C compiler.
@@ -63,7 +63,7 @@ sudo dnf install alsa-lib-devel
 The recommended method is to first fork the repo, so that you have a copy that you have read/write access to. After that, it’s a simple case of cloning your fork.
 
 ```bash
-git clone git@github.com:YOURUSERNAME/librespot.git
+git clone git@github.com:YOUR_USERNAME/librespot.git
 ```
 
 ## Compiling & Running

Cargo.toml

@@ -49,18 +49,16 @@ path = "protocol"
 version = "0.4.2"
 
 [dependencies]
-base64 = "0.13"
-env_logger =  {version = "0.9", default-features = false, features = ["termcolor","humantime","atty"]}
+env_logger =  { version = "0.9", default-features = false, features = ["termcolor", "humantime", "atty"] }
 futures-util = { version = "0.3", default_features = false }
-getopts = "0.2.21"
+getopts = "0.2"
 hex = "0.4"
-hyper = "0.14"
 log = "0.4"
-rpassword = "6.0"
+rpassword = "7.0"
+sha1 = "0.10"
 thiserror = "1.0"
-tokio = { version = "1", features = ["rt", "rt-multi-thread", "macros", "signal", "sync", "process"] }
+tokio = { version = "1", features = ["rt", "macros", "signal", "sync", "parking_lot", "process"] }
 url = "2.2"
-sha-1 = "0.9"
 
 [features]
 alsa-backend = ["librespot-playback/alsa-backend"]
@@ -72,7 +70,9 @@ rodiojack-backend = ["librespot-playback/rodiojack-backend"]
 sdl-backend = ["librespot-playback/sdl-backend"]
 gstreamer-backend = ["librespot-playback/gstreamer-backend"]
 
-with-dns-sd = ["librespot-discovery/with-dns-sd"]
+with-dns-sd = ["librespot-core/with-dns-sd", "librespot-discovery/with-dns-sd"]
+
+passthrough-decoder = ["librespot-playback/passthrough-decoder"]
 
 default = ["rodio-backend"]
 

audio/Cargo.toml

@@ -12,10 +12,15 @@ path = "../core"
 version = "0.4.2"
 
 [dependencies]
-aes-ctr = "0.6"
+aes = "0.8"
 byteorder = "1.4"
-bytes = "1.0"
+bytes = "1"
+ctr = "0.9"
+futures-core = "0.3"
+futures-util = "0.3"
+hyper = { version = "0.14", features = ["client"] }
 log = "0.4"
-futures-util = { version = "0.3", default_features = false }
-tempfile = "3.1"
-tokio = { version = "1", features = ["sync", "macros"] }
+parking_lot = { version = "0.12", features = ["deadlock_detection"] }
+tempfile = "3"
+thiserror = "1.0"
+tokio = { version = "1", features = ["macros", "parking_lot", "sync"] }

audio/src/decrypt.rs

@@ -1,8 +1,8 @@
 use std::io;
 
-use aes_ctr::cipher::generic_array::GenericArray;
-use aes_ctr::cipher::{NewStreamCipher, SyncStreamCipher, SyncStreamCipherSeek};
-use aes_ctr::Aes128Ctr;
+use aes::cipher::{KeyIvInit, StreamCipher, StreamCipherSeek};
+
+type Aes128Ctr = ctr::Ctr128BE<aes::Aes128>;
 
 use librespot_core::audio_key::AudioKey;
 
@@ -11,16 +11,20 @@ const AUDIO_AESIV: [u8; 16] = [
 ];
 
 pub struct AudioDecrypt<T: io::Read> {
-    cipher: Aes128Ctr,
+    // a `None` cipher is a convenience to make `AudioDecrypt` pass files unaltered
+    cipher: Option<Aes128Ctr>,
     reader: T,
 }
 
 impl<T: io::Read> AudioDecrypt<T> {
-    pub fn new(key: AudioKey, reader: T) -> AudioDecrypt<T> {
-        let cipher = Aes128Ctr::new(
-            GenericArray::from_slice(&key.0),
-            GenericArray::from_slice(&AUDIO_AESIV),
-        );
+    pub fn new(key: Option<AudioKey>, reader: T) -> AudioDecrypt<T> {
+        let cipher = if let Some(key) = key {
+            Aes128Ctr::new_from_slices(&key.0, &AUDIO_AESIV).ok()
+        } else {
+            // some files are unencrypted
+            None
+        };
+
         AudioDecrypt { cipher, reader }
     }
 }
@@ -29,7 +33,9 @@ impl<T: io::Read> io::Read for AudioDecrypt<T> {
     fn read(&mut self, output: &mut [u8]) -> io::Result<usize> {
         let len = self.reader.read(output)?;
 
-        self.cipher.apply_keystream(&mut output[..len]);
+        if let Some(ref mut cipher) = self.cipher {
+            cipher.apply_keystream(&mut output[..len]);
+        }
 
         Ok(len)
     }
@@ -39,7 +45,9 @@ impl<T: io::Read + io::Seek> io::Seek for AudioDecrypt<T> {
     fn seek(&mut self, pos: io::SeekFrom) -> io::Result<u64> {
         let newpos = self.reader.seek(pos)?;
 
-        self.cipher.seek(newpos);
+        if let Some(ref mut cipher) = self.cipher {
+            cipher.seek(newpos);
+        }
 
         Ok(newpos)
     }

audio/src/fetch/mod.rs

@@ -1,40 +1,82 @@
 mod receive;
 
-use std::cmp::{max, min};
-use std::fs;
-use std::io::{self, Read, Seek, SeekFrom};
-use std::sync::atomic::{self, AtomicUsize};
-use std::sync::{Arc, Condvar, Mutex};
-use std::time::{Duration, Instant};
+use std::{
+    cmp::{max, min},
+    fs,
+    io::{self, Read, Seek, SeekFrom},
+    sync::{
+        atomic::{AtomicBool, AtomicUsize, Ordering},
+        Arc,
+    },
+    time::{Duration, Instant},
+};
 
-use byteorder::{BigEndian, ByteOrder};
-use futures_util::{future, StreamExt, TryFutureExt, TryStreamExt};
-use librespot_core::channel::{ChannelData, ChannelError, ChannelHeaders};
-use librespot_core::session::Session;
-use librespot_core::spotify_id::FileId;
+use futures_util::{future::IntoStream, StreamExt, TryFutureExt};
+use hyper::{client::ResponseFuture, header::CONTENT_RANGE, Body, Response, StatusCode};
+use parking_lot::{Condvar, Mutex};
 use tempfile::NamedTempFile;
+use thiserror::Error;
 use tokio::sync::{mpsc, oneshot};
 
-use self::receive::{audio_file_fetch, request_range};
+use librespot_core::{cdn_url::CdnUrl, Error, FileId, Session};
+
+use self::receive::audio_file_fetch;
+
 use crate::range_set::{Range, RangeSet};
 
+pub type AudioFileResult = Result<(), librespot_core::Error>;
+
+#[derive(Error, Debug)]
+pub enum AudioFileError {
+    #[error("other end of channel disconnected")]
+    Channel,
+    #[error("required header not found")]
+    Header,
+    #[error("streamer received no data")]
+    NoData,
+    #[error("no output available")]
+    Output,
+    #[error("invalid status code {0}")]
+    StatusCode(StatusCode),
+    #[error("wait timeout exceeded")]
+    WaitTimeout,
+}
+
+impl From<AudioFileError> for Error {
+    fn from(err: AudioFileError) -> Self {
+        match err {
+            AudioFileError::Channel => Error::aborted(err),
+            AudioFileError::Header => Error::unavailable(err),
+            AudioFileError::NoData => Error::unavailable(err),
+            AudioFileError::Output => Error::aborted(err),
+            AudioFileError::StatusCode(_) => Error::failed_precondition(err),
+            AudioFileError::WaitTimeout => Error::deadline_exceeded(err),
+        }
+    }
+}
+
 /// The minimum size of a block that is requested from the Spotify servers in one request.
 /// This is the block size that is typically requested while doing a `seek()` on a file.
+/// The Symphonia decoder requires this to be a power of 2 and > 32 kB.
 /// Note: smaller requests can happen if part of the block is downloaded already.
-const MINIMUM_DOWNLOAD_SIZE: usize = 1024 * 16;
+pub const MINIMUM_DOWNLOAD_SIZE: usize = 1024 * 128;
+
+/// The minimum network throughput that we expect. Together with the minimum download size,
+/// this will determine the time we will wait for a response.
+pub const MINIMUM_THROUGHPUT: usize = 8192;
 
 /// The amount of data that is requested when initially opening a file.
 /// Note: if the file is opened to play from the beginning, the amount of data to
 /// read ahead is requested in addition to this amount. If the file is opened to seek to
 /// another position, then only this amount is requested on the first request.
-const INITIAL_DOWNLOAD_SIZE: usize = 1024 * 16;
+pub const INITIAL_DOWNLOAD_SIZE: usize = 1024 * 8;
 
 /// The ping time that is used for calculations before a ping time was actually measured.
-const INITIAL_PING_TIME_ESTIMATE: Duration = Duration::from_millis(500);
+pub const INITIAL_PING_TIME_ESTIMATE: Duration = Duration::from_millis(500);
 
 /// If the measured ping time to the Spotify server is larger than this value, it is capped
 /// to avoid run-away block sizes and pre-fetching.
-const MAXIMUM_ASSUMED_PING_TIME: Duration = Duration::from_millis(1500);
+pub const MAXIMUM_ASSUMED_PING_TIME: Duration = Duration::from_millis(1500);
 
 /// Before playback starts, this many seconds of data must be present.
 /// Note: the calculations are done using the nominal bitrate of the file. The actual amount
@@ -63,7 +105,7 @@ pub const READ_AHEAD_DURING_PLAYBACK_ROUNDTRIPS: f32 = 10.0;
 /// If the amount of data that is pending (requested but not received) is less than a certain amount,
 /// data is pre-fetched in addition to the read ahead settings above. The threshold for requesting more
 /// data is calculated as `<pending bytes> < PREFETCH_THRESHOLD_FACTOR * <ping time> * <nominal data rate>`
-const PREFETCH_THRESHOLD_FACTOR: f32 = 4.0;
+pub const PREFETCH_THRESHOLD_FACTOR: f32 = 4.0;
 
 /// Similar to `PREFETCH_THRESHOLD_FACTOR`, but it also takes the current download rate into account.
 /// The formula used is `<pending bytes> < FAST_PREFETCH_THRESHOLD_FACTOR * <ping time> * <measured download rate>`
@@ -72,16 +114,17 @@ const PREFETCH_THRESHOLD_FACTOR: f32 = 4.0;
 /// the download rate ramps up. However, this comes at the cost that it might hurt ping time if a seek is
 /// performed while downloading. Values smaller than `1.0` cause the download rate to collapse and effectively
 /// only `PREFETCH_THRESHOLD_FACTOR` is in effect. Thus, set to `0.0` if bandwidth saturation is not wanted.
-const FAST_PREFETCH_THRESHOLD_FACTOR: f32 = 1.5;
+pub const FAST_PREFETCH_THRESHOLD_FACTOR: f32 = 1.5;
 
 /// Limit the number of requests that are pending simultaneously before pre-fetching data. Pending
-/// requests share bandwidth. Thus, havint too many requests can lead to the one that is needed next
+/// requests share bandwidth. Thus, having too many requests can lead to the one that is needed next
 /// for playback to be delayed leading to a buffer underrun. This limit has the effect that a new
 /// pre-fetch request is only sent if less than `MAX_PREFETCH_REQUESTS` are pending.
-const MAX_PREFETCH_REQUESTS: usize = 4;
+pub const MAX_PREFETCH_REQUESTS: usize = 4;
 
 /// The time we will wait to obtain status updates on downloading.
-const DOWNLOAD_TIMEOUT: Duration = Duration::from_secs(1);
+pub const DOWNLOAD_TIMEOUT: Duration =
+    Duration::from_secs((MINIMUM_DOWNLOAD_SIZE / MINIMUM_THROUGHPUT) as u64);
 
 pub enum AudioFile {
     Cached(fs::File),
@@ -89,11 +132,20 @@ pub enum AudioFile {
 }
 
 #[derive(Debug)]
-enum StreamLoaderCommand {
+pub struct StreamingRequest {
+    streamer: IntoStream<ResponseFuture>,
+    initial_response: Option<Response<Body>>,
+    offset: usize,
+    length: usize,
+    request_time: Instant,
+}
+
+#[derive(Debug)]
+pub enum StreamLoaderCommand {
     Fetch(Range),     // signal the stream loader to fetch a range of the file
-    RandomAccessMode(), // optimise download strategy for random access
-    StreamMode(),       // optimise download strategy for streaming
-    Close(),            // terminate and don't load any more data
+    RandomAccessMode, // optimise download strategy for random access
+    StreamMode,       // optimise download strategy for streaming
+    Close,            // terminate and don't load any more data
 }
 
 #[derive(Clone)]
@@ -113,33 +165,40 @@ impl StreamLoaderController {
     }
 
     pub fn range_available(&self, range: Range) -> bool {
-        if let Some(ref shared) = self.stream_shared {
-            let download_status = shared.download_status.lock().unwrap();
+        let available = if let Some(ref shared) = self.stream_shared {
+            let download_status = shared.download_status.lock();
+
             range.length
                 <= download_status
                     .downloaded
                     .contained_length_from_value(range.start)
         } else {
             range.length <= self.len() - range.start
-        }
+        };
+
+        available
     }
 
     pub fn range_to_end_available(&self) -> bool {
-        self.stream_shared.as_ref().map_or(true, |shared| {
-            let read_position = shared.read_position.load(atomic::Ordering::Relaxed);
+        match self.stream_shared {
+            Some(ref shared) => {
+                let read_position = shared.read_position.load(Ordering::Acquire);
                 self.range_available(Range::new(read_position, self.len() - read_position))
-        })
+            }
+            None => true,
+        }
     }
 
     pub fn ping_time(&self) -> Duration {
         Duration::from_millis(self.stream_shared.as_ref().map_or(0, |shared| {
-            shared.ping_time_ms.load(atomic::Ordering::Relaxed) as u64
+            shared.ping_time_ms.load(Ordering::Relaxed) as u64
         }))
     }
 
     fn send_stream_loader_command(&self, command: StreamLoaderCommand) {
         if let Some(ref channel) = self.channel_tx {
-            // ignore the error in case the channel has been closed already.
+            // Ignore the error in case the channel has been closed already.
+            // This means that the file was completely downloaded.
             let _ = channel.send(command);
         }
     }
@@ -149,7 +208,7 @@ impl StreamLoaderController {
         self.send_stream_loader_command(StreamLoaderCommand::Fetch(range));
     }
 
-    pub fn fetch_blocking(&self, mut range: Range) {
+    pub fn fetch_blocking(&self, mut range: Range) -> AudioFileResult {
         // signal the stream loader to tech a range of the file and block until it is loaded.
 
         // ensure the range is within the file's bounds.
@@ -162,17 +221,21 @@ impl StreamLoaderController {
         self.fetch(range);
 
         if let Some(ref shared) = self.stream_shared {
-            let mut download_status = shared.download_status.lock().unwrap();
+            let mut download_status = shared.download_status.lock();
+
             while range.length
                 > download_status
                     .downloaded
                     .contained_length_from_value(range.start)
             {
-                download_status = shared
+                if shared
                     .cond
-                    .wait_timeout(download_status, DOWNLOAD_TIMEOUT)
-                    .unwrap()
-                    .0;
+                    .wait_for(&mut download_status, DOWNLOAD_TIMEOUT)
+                    .timed_out()
+                {
+                    return Err(AudioFileError::WaitTimeout.into());
+                }
+
                 if range.length
                     > (download_status
                         .downloaded
@@ -185,41 +248,73 @@ impl StreamLoaderController {
                 }
             }
         }
+
+        Ok(())
     }
 
+    #[allow(dead_code)]
     pub fn fetch_next(&self, length: usize) {
         if let Some(ref shared) = self.stream_shared {
             let range = Range {
-                start: shared.read_position.load(atomic::Ordering::Relaxed),
+                start: shared.read_position.load(Ordering::Acquire),
                 length,
             };
-            self.fetch(range)
+            self.fetch(range);
         }
     }
 
-    pub fn fetch_next_blocking(&self, length: usize) {
-        if let Some(ref shared) = self.stream_shared {
+    #[allow(dead_code)]
+    pub fn fetch_next_blocking(&self, length: usize) -> AudioFileResult {
+        match self.stream_shared {
+            Some(ref shared) => {
                 let range = Range {
-                start: shared.read_position.load(atomic::Ordering::Relaxed),
+                    start: shared.read_position.load(Ordering::Acquire),
                     length,
                 };
-            self.fetch_blocking(range);
+                self.fetch_blocking(range)
+            }
+            None => Ok(()),
+        }
+    }
+
+    pub fn fetch_next_and_wait(
+        &self,
+        request_length: usize,
+        wait_length: usize,
+    ) -> AudioFileResult {
+        match self.stream_shared {
+            Some(ref shared) => {
+                let start = shared.read_position.load(Ordering::Acquire);
+
+                let request_range = Range {
+                    start,
+                    length: request_length,
+                };
+                self.fetch(request_range);
+
+                let wait_range = Range {
+                    start,
+                    length: wait_length,
+                };
+                self.fetch_blocking(wait_range)
+            }
+            None => Ok(()),
         }
     }
 
     pub fn set_random_access_mode(&self) {
         // optimise download strategy for random access
-        self.send_stream_loader_command(StreamLoaderCommand::RandomAccessMode());
+        self.send_stream_loader_command(StreamLoaderCommand::RandomAccessMode);
     }
 
     pub fn set_stream_mode(&self) {
         // optimise download strategy for streaming
-        self.send_stream_loader_command(StreamLoaderCommand::StreamMode());
+        self.send_stream_loader_command(StreamLoaderCommand::StreamMode);
     }
 
     pub fn close(&self) {
         // terminate stream loading and don't load any more data for this file.
-        self.send_stream_loader_command(StreamLoaderCommand::Close());
+        self.send_stream_loader_command(StreamLoaderCommand::Close);
     }
 }
 
@@ -235,19 +330,13 @@ struct AudioFileDownloadStatus {
     downloaded: RangeSet,
 }
 
-#[derive(Copy, Clone, PartialEq, Eq)]
-enum DownloadStrategy {
-    RandomAccess(),
-    Streaming(),
-}
-
 struct AudioFileShared {
-    file_id: FileId,
+    cdn_url: CdnUrl,
     file_size: usize,
-    stream_data_rate: usize,
+    bytes_per_second: usize,
     cond: Condvar,
     download_status: Mutex<AudioFileDownloadStatus>,
-    download_strategy: Mutex<DownloadStrategy>,
+    download_streaming: AtomicBool,
     number_of_open_requests: AtomicUsize,
     ping_time_ms: AtomicUsize,
     read_position: AtomicUsize,
@@ -258,8 +347,7 @@ impl AudioFile {
         session: &Session,
         file_id: FileId,
         bytes_per_second: usize,
-        play_from_beginning: bool,
-    ) -> Result<AudioFile, ChannelError> {
+    ) -> Result<AudioFile, Error> {
         if let Some(file) = session.cache().and_then(|cache| cache.file(file_id)) {
             debug!("File {} already in cache", file_id);
             return Ok(AudioFile::Cached(file));
@@ -268,48 +356,30 @@ impl AudioFile {
         debug!("Downloading file {}", file_id);
 
         let (complete_tx, complete_rx) = oneshot::channel();
-        let mut initial_data_length = if play_from_beginning {
-            INITIAL_DOWNLOAD_SIZE
-                + max(
-                    (READ_AHEAD_DURING_PLAYBACK.as_secs_f32() * bytes_per_second as f32) as usize,
-                    (INITIAL_PING_TIME_ESTIMATE.as_secs_f32()
-                        * READ_AHEAD_DURING_PLAYBACK_ROUNDTRIPS
-                        * bytes_per_second as f32) as usize,
-                )
-        } else {
-            INITIAL_DOWNLOAD_SIZE
-        };
-        if initial_data_length % 4 != 0 {
-            initial_data_length += 4 - (initial_data_length % 4);
-        }
-        let (headers, data) = request_range(session, file_id, 0, initial_data_length).split();
 
-        let streaming = AudioFileStreaming::open(
-            session.clone(),
-            data,
-            initial_data_length,
-            Instant::now(),
-            headers,
-            file_id,
-            complete_tx,
-            bytes_per_second,
-        );
+        let streaming =
+            AudioFileStreaming::open(session.clone(), file_id, complete_tx, bytes_per_second);
 
         let session_ = session.clone();
         session.spawn(complete_rx.map_ok(move |mut file| {
+            debug!("Downloading file {} complete", file_id);
+
             if let Some(cache) = session_.cache() {
-                debug!("File {} complete, saving to cache", file_id);
-                cache.save_file(file_id, &mut file);
+                if let Some(cache_id) = cache.file_path(file_id) {
+                    if let Err(e) = cache.save_file(file_id, &mut file) {
+                        error!("Error caching file {} to {:?}: {}", file_id, cache_id, e);
                     } else {
-                debug!("File {} complete", file_id);
+                        debug!("File {} cached to {:?}", file_id, cache_id);
+                    }
+                }
             }
         }));
 
         Ok(AudioFile::Streaming(streaming.await?))
     }
 
-    pub fn get_stream_loader_controller(&self) -> StreamLoaderController {
-        match self {
+    pub fn get_stream_loader_controller(&self) -> Result<StreamLoaderController, Error> {
+        let controller = match self {
             AudioFile::Streaming(ref stream) => StreamLoaderController {
                 channel_tx: Some(stream.stream_loader_command_tx.clone()),
                 stream_shared: Some(stream.shared.clone()),
@@ -318,9 +388,11 @@ impl AudioFile {
             AudioFile::Cached(ref file) => StreamLoaderController {
                 channel_tx: None,
                 stream_shared: None,
-                file_size: file.metadata().unwrap().len() as usize,
+                file_size: file.metadata()?.len() as usize,
             },
-        }
+        };
+
+        Ok(controller)
     }
 
     pub fn is_cached(&self) -> bool {
@@ -331,53 +403,85 @@ impl AudioFile {
 impl AudioFileStreaming {
     pub async fn open(
         session: Session,
-        initial_data_rx: ChannelData,
-        initial_data_length: usize,
-        initial_request_sent_time: Instant,
-        headers: ChannelHeaders,
         file_id: FileId,
         complete_tx: oneshot::Sender<NamedTempFile>,
-        streaming_data_rate: usize,
-    ) -> Result<AudioFileStreaming, ChannelError> {
-        let (_, data) = headers
-            .try_filter(|(id, _)| future::ready(*id == 0x3))
-            .next()
-            .await
-            .unwrap()?;
+        bytes_per_second: usize,
+    ) -> Result<AudioFileStreaming, Error> {
+        let cdn_url = CdnUrl::new(file_id).resolve_audio(&session).await?;
 
-        let size = BigEndian::read_u32(&data) as usize * 4;
+        if let Ok(url) = cdn_url.try_get_url() {
+            trace!("Streaming from {}", url);
+        }
+
+        // When the audio file is really small, this `download_size` may turn out to be
+        // larger than the audio file we're going to stream later on. This is OK; requesting
+        // `Content-Range` > `Content-Length` will return the complete file with status code
+        // 206 Partial Content.
+        let mut streamer =
+            session
+                .spclient()
+                .stream_from_cdn(&cdn_url, 0, INITIAL_DOWNLOAD_SIZE)?;
+
+        // Get the first chunk with the headers to get the file size.
+        // The remainder of that chunk with possibly also a response body is then
+        // further processed in `audio_file_fetch`.
+        let request_time = Instant::now();
+        let response = streamer.next().await.ok_or(AudioFileError::NoData)??;
+
+        let code = response.status();
+        if code != StatusCode::PARTIAL_CONTENT {
+            debug!(
+                "Opening audio file expected partial content but got: {}",
+                code
+            );
+            return Err(AudioFileError::StatusCode(code).into());
+        }
+
+        let header_value = response
+            .headers()
+            .get(CONTENT_RANGE)
+            .ok_or(AudioFileError::Header)?;
+        let str_value = header_value.to_str()?;
+        let hyphen_index = str_value.find('-').unwrap_or_default();
+        let slash_index = str_value.find('/').unwrap_or_default();
+        let upper_bound: usize = str_value[hyphen_index + 1..slash_index].parse()?;
+        let file_size = str_value[slash_index + 1..].parse()?;
+
+        let initial_request = StreamingRequest {
+            streamer,
+            initial_response: Some(response),
+            offset: 0,
+            length: upper_bound + 1,
+            request_time,
+        };
 
         let shared = Arc::new(AudioFileShared {
-            file_id,
-            file_size: size,
-            stream_data_rate: streaming_data_rate,
+            cdn_url,
+            file_size,
+            bytes_per_second,
             cond: Condvar::new(),
             download_status: Mutex::new(AudioFileDownloadStatus {
                 requested: RangeSet::new(),
                 downloaded: RangeSet::new(),
             }),
-            download_strategy: Mutex::new(DownloadStrategy::RandomAccess()), // start with random access mode until someone tells us otherwise
+            download_streaming: AtomicBool::new(true),
             number_of_open_requests: AtomicUsize::new(0),
-            ping_time_ms: AtomicUsize::new(0),
+            ping_time_ms: AtomicUsize::new(INITIAL_PING_TIME_ESTIMATE.as_millis() as usize),
             read_position: AtomicUsize::new(0),
         });
 
-        let mut write_file = NamedTempFile::new().unwrap();
-        write_file.as_file().set_len(size as u64).unwrap();
-        write_file.seek(SeekFrom::Start(0)).unwrap();
+        let write_file = NamedTempFile::new_in(session.config().tmp_dir.clone())?;
+        write_file.as_file().set_len(file_size as u64)?;
 
-        let read_file = write_file.reopen().unwrap();
+        let read_file = write_file.reopen()?;
 
-        // let (seek_tx, seek_rx) = mpsc::unbounded();
         let (stream_loader_command_tx, stream_loader_command_rx) =
             mpsc::unbounded_channel::<StreamLoaderCommand>();
 
         session.spawn(audio_file_fetch(
             session.clone(),
             shared.clone(),
-            initial_data_rx,
-            initial_request_sent_time,
-            initial_data_length,
+            initial_request,
             write_file,
             stream_loader_command_rx,
             complete_tx,
@@ -401,83 +505,70 @@ impl Read for AudioFileStreaming {
         }
 
         let length = min(output.len(), self.shared.file_size - offset);
+        if length == 0 {
+            return Ok(0);
+        }
 
-        let length_to_request = match *(self.shared.download_strategy.lock().unwrap()) {
-            DownloadStrategy::RandomAccess() => length,
-            DownloadStrategy::Streaming() => {
+        let length_to_request = if self.shared.download_streaming.load(Ordering::Acquire) {
             // Due to the read-ahead stuff, we potentially request more than the actual request demanded.
-                let ping_time_seconds = Duration::from_millis(
-                    self.shared.ping_time_ms.load(atomic::Ordering::Relaxed) as u64,
-                )
+            let ping_time_seconds =
+                Duration::from_millis(self.shared.ping_time_ms.load(Ordering::Relaxed) as u64)
                     .as_secs_f32();
 
             let length_to_request = length
                 + max(
-                        (READ_AHEAD_DURING_PLAYBACK.as_secs_f32()
-                            * self.shared.stream_data_rate as f32) as usize,
+                    (READ_AHEAD_DURING_PLAYBACK.as_secs_f32() * self.shared.bytes_per_second as f32)
+                        as usize,
                     (READ_AHEAD_DURING_PLAYBACK_ROUNDTRIPS
                         * ping_time_seconds
-                            * self.shared.stream_data_rate as f32) as usize,
+                        * self.shared.bytes_per_second as f32) as usize,
                 );
             min(length_to_request, self.shared.file_size - offset)
-            }
+        } else {
+            length
         };
 
         let mut ranges_to_request = RangeSet::new();
         ranges_to_request.add_range(&Range::new(offset, length_to_request));
 
-        let mut download_status = self.shared.download_status.lock().unwrap();
+        let mut download_status = self.shared.download_status.lock();
+
         ranges_to_request.subtract_range_set(&download_status.downloaded);
         ranges_to_request.subtract_range_set(&download_status.requested);
 
         for &range in ranges_to_request.iter() {
             self.stream_loader_command_tx
                 .send(StreamLoaderCommand::Fetch(range))
-                .unwrap();
+                .map_err(|err| io::Error::new(io::ErrorKind::BrokenPipe, err))?;
         }
 
-        if length == 0 {
-            return Ok(0);
-        }
-
-        let mut download_message_printed = false;
         while !download_status.downloaded.contains(offset) {
-            if let DownloadStrategy::Streaming() = *self.shared.download_strategy.lock().unwrap() {
-                if !download_message_printed {
-                    debug!("Stream waiting for download of file position {}. Downloaded ranges: {}. Pending ranges: {}", offset, download_status.downloaded, download_status.requested.minus(&download_status.downloaded));
-                    download_message_printed = true;
-                }
-            }
-            download_status = self
+            if self
                 .shared
                 .cond
-                .wait_timeout(download_status, DOWNLOAD_TIMEOUT)
-                .unwrap()
-                .0;
+                .wait_for(&mut download_status, DOWNLOAD_TIMEOUT)
+                .timed_out()
+            {
+                return Err(io::Error::new(
+                    io::ErrorKind::TimedOut,
+                    Error::deadline_exceeded(AudioFileError::WaitTimeout),
+                ));
+            }
         }
         let available_length = download_status
             .downloaded
             .contained_length_from_value(offset);
-        assert!(available_length > 0);
+
         drop(download_status);
 
-        self.position = self.read_file.seek(SeekFrom::Start(offset as u64)).unwrap();
+        self.position = self.read_file.seek(SeekFrom::Start(offset as u64))?;
         let read_len = min(length, available_length);
         let read_len = self.read_file.read(&mut output[..read_len])?;
 
-        if download_message_printed {
-            debug!(
-                "Read at postion {} completed. {} bytes returned, {} bytes were requested.",
-                offset,
-                read_len,
-                output.len()
-            );
-        }
-
         self.position += read_len as u64;
         self.shared
             .read_position
-            .store(self.position as usize, atomic::Ordering::Relaxed);
+            .store(self.position as usize, Ordering::Release);
 
         Ok(read_len)
     }
@@ -485,11 +576,50 @@ impl Read for AudioFileStreaming {
 
 impl Seek for AudioFileStreaming {
     fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
+        // If we are already at this position, we don't need to switch download mode.
+        // These checks and locks are less expensive than interrupting streaming.
+        let current_position = self.position as i64;
+        let requested_pos = match pos {
+            SeekFrom::Start(pos) => pos as i64,
+            SeekFrom::End(pos) => self.shared.file_size as i64 - pos - 1,
+            SeekFrom::Current(pos) => current_position + pos,
+        };
+        if requested_pos == current_position {
+            return Ok(current_position as u64);
+        }
+
+        // Again if we have already downloaded this part.
+        let available = self
+            .shared
+            .download_status
+            .lock()
+            .downloaded
+            .contains(requested_pos as usize);
+
+        let mut was_streaming = false;
+        if !available {
+            // Ensure random access mode if we need to download this part.
+            // Checking whether we are streaming now is a micro-optimization
+            // to save an atomic load.
+            was_streaming = self.shared.download_streaming.load(Ordering::Acquire);
+            if was_streaming {
+                self.shared
+                    .download_streaming
+                    .store(false, Ordering::Release);
+            }
+        }
+
         self.position = self.read_file.seek(pos)?;
-        // Do not seek past EOF
         self.shared
             .read_position
-            .store(self.position as usize, atomic::Ordering::Relaxed);
+            .store(self.position as usize, Ordering::Release);
+
+        if !available && was_streaming {
+            self.shared
+                .download_streaming
+                .store(true, Ordering::Release);
+        }
+
         Ok(self.position)
     }
 }

audio/src/fetch/receive.rs

@@ -1,57 +1,26 @@
-use std::cmp::{max, min};
-use std::io::{Seek, SeekFrom, Write};
-use std::sync::{atomic, Arc};
-use std::time::{Duration, Instant};
+use std::{
+    cmp::{max, min},
+    io::{Seek, SeekFrom, Write},
+    sync::{atomic::Ordering, Arc},
+    time::{Duration, Instant},
+};
 
-use atomic::Ordering;
-use byteorder::{BigEndian, WriteBytesExt};
 use bytes::Bytes;
 use futures_util::StreamExt;
-use librespot_core::channel::{Channel, ChannelData};
-use librespot_core::session::Session;
-use librespot_core::spotify_id::FileId;
+use hyper::StatusCode;
 use tempfile::NamedTempFile;
 use tokio::sync::{mpsc, oneshot};
 
+use librespot_core::{session::Session, Error};
+
 use crate::range_set::{Range, RangeSet};
 
-use super::{AudioFileShared, DownloadStrategy, StreamLoaderCommand};
 use super::{
+    AudioFileError, AudioFileResult, AudioFileShared, StreamLoaderCommand, StreamingRequest,
     FAST_PREFETCH_THRESHOLD_FACTOR, MAXIMUM_ASSUMED_PING_TIME, MAX_PREFETCH_REQUESTS,
     MINIMUM_DOWNLOAD_SIZE, PREFETCH_THRESHOLD_FACTOR,
 };
 
-pub fn request_range(session: &Session, file: FileId, offset: usize, length: usize) -> Channel {
-    assert!(
-        offset % 4 == 0,
-        "Range request start positions must be aligned by 4 bytes."
-    );
-    assert!(
-        length % 4 == 0,
-        "Range request range lengths must be aligned by 4 bytes."
-    );
-    let start = offset / 4;
-    let end = (offset + length) / 4;
-
-    let (id, channel) = session.channel().allocate();
-
-    let mut data: Vec<u8> = Vec::new();
-    data.write_u16::<BigEndian>(id).unwrap();
-    data.write_u8(0).unwrap();
-    data.write_u8(1).unwrap();
-    data.write_u16::<BigEndian>(0x0000).unwrap();
-    data.write_u32::<BigEndian>(0x00000000).unwrap();
-    data.write_u32::<BigEndian>(0x00009C40).unwrap();
-    data.write_u32::<BigEndian>(0x00020000).unwrap();
-    data.write(&file.0).unwrap();
-    data.write_u32::<BigEndian>(start as u32).unwrap();
-    data.write_u32::<BigEndian>(end as u32).unwrap();
-
-    session.send_packet(0x8, data);
-
-    channel
-}
-
 struct PartialFileData {
     offset: usize,
     data: Bytes,
@@ -65,13 +34,10 @@ enum ReceivedData {
 async fn receive_data(
     shared: Arc<AudioFileShared>,
     file_data_tx: mpsc::UnboundedSender<ReceivedData>,
-    mut data_rx: ChannelData,
-    initial_data_offset: usize,
-    initial_request_length: usize,
-    request_sent_time: Instant,
-) {
-    let mut data_offset = initial_data_offset;
-    let mut request_length = initial_request_length;
+    mut request: StreamingRequest,
+) -> AudioFileResult {
+    let mut offset = request.offset;
+    let mut actual_length = 0;
 
     let old_number_of_request = shared
         .number_of_open_requests
@@ -79,65 +45,80 @@ async fn receive_data(
 
     let mut measure_ping_time = old_number_of_request == 0;
 
-    let result = loop {
-        let data = match data_rx.next().await {
-            Some(Ok(data)) => data,
-            Some(Err(e)) => break Err(e),
-            None => break Ok(()),
-        };
-
-        if measure_ping_time {
-            let mut duration = Instant::now() - request_sent_time;
-            if duration > MAXIMUM_ASSUMED_PING_TIME {
-                duration = MAXIMUM_ASSUMED_PING_TIME;
-            }
-            let _ = file_data_tx.send(ReceivedData::ResponseTime(duration));
-            measure_ping_time = false;
-        }
-        let data_size = data.len();
-        let _ = file_data_tx.send(ReceivedData::Data(PartialFileData {
-            offset: data_offset,
-            data,
-        }));
-        data_offset += data_size;
-        if request_length < data_size {
-            warn!(
-                "Data receiver for range {} (+{}) received more data from server than requested.",
-                initial_data_offset, initial_request_length
-            );
-            request_length = 0;
-        } else {
-            request_length -= data_size;
+    let result: Result<_, Error> = loop {
+        let response = match request.initial_response.take() {
+            Some(data) => data,
+            None => match request.streamer.next().await {
+                Some(Ok(response)) => response,
+                Some(Err(e)) => break Err(e.into()),
+                None => {
+                    if actual_length != request.length {
+                        let msg = format!("did not expect body to contain {} bytes", actual_length);
+                        break Err(Error::data_loss(msg));
                     }
 
-        if request_length == 0 {
                     break Ok(());
                 }
+            },
         };
 
-    if request_length > 0 {
-        let missing_range = Range::new(data_offset, request_length);
+        let code = response.status();
+        if code != StatusCode::PARTIAL_CONTENT {
+            break Err(AudioFileError::StatusCode(code).into());
+        }
 
-        let mut download_status = shared.download_status.lock().unwrap();
+        let body = response.into_body();
+        let data = match hyper::body::to_bytes(body).await {
+            Ok(bytes) => bytes,
+            Err(e) => break Err(e.into()),
+        };
+
+        let data_size = data.len();
+        file_data_tx.send(ReceivedData::Data(PartialFileData { offset, data }))?;
+
+        actual_length += data_size;
+        offset += data_size;
+
+        if measure_ping_time {
+            let mut duration = Instant::now() - request.request_time;
+            if duration > MAXIMUM_ASSUMED_PING_TIME {
+                warn!(
+                    "Ping time {} ms exceeds maximum {}, setting to maximum",
+                    duration.as_millis(),
+                    MAXIMUM_ASSUMED_PING_TIME.as_millis()
+                );
+                duration = MAXIMUM_ASSUMED_PING_TIME;
+            }
+            file_data_tx.send(ReceivedData::ResponseTime(duration))?;
+            measure_ping_time = false;
+        }
+    };
+
+    drop(request.streamer);
+
+    let bytes_remaining = request.length - actual_length;
+    if bytes_remaining > 0 {
+        {
+            let missing_range = Range::new(offset, bytes_remaining);
+            let mut download_status = shared.download_status.lock();
             download_status.requested.subtract_range(&missing_range);
             shared.cond.notify_all();
         }
+    }
 
     shared
         .number_of_open_requests
         .fetch_sub(1, Ordering::SeqCst);
 
-    if result.is_err() {
-        warn!(
-            "Error from channel for data receiver for range {} (+{}).",
-            initial_data_offset, initial_request_length
-        );
-    } else if request_length > 0 {
-        warn!(
-            "Data receiver for range {} (+{}) received less data from server than requested.",
-            initial_data_offset, initial_request_length
+    if let Err(e) = result {
+        error!(
+            "Streamer error requesting range {} +{}: {:?}",
+            request.offset, request.length, e
         );
+        return Err(e);
     }
+
+    Ok(())
 }
 
 struct AudioFileFetch {
@@ -158,68 +139,64 @@ enum ControlFlow {
 }
 
 impl AudioFileFetch {
-    fn get_download_strategy(&mut self) -> DownloadStrategy {
-        *(self.shared.download_strategy.lock().unwrap())
+    fn is_download_streaming(&self) -> bool {
+        self.shared.download_streaming.load(Ordering::Acquire)
     }
 
-    fn download_range(&mut self, mut offset: usize, mut length: usize) {
+    fn download_range(&mut self, offset: usize, mut length: usize) -> AudioFileResult {
         if length < MINIMUM_DOWNLOAD_SIZE {
             length = MINIMUM_DOWNLOAD_SIZE;
         }
 
-        // ensure the values are within the bounds and align them by 4 for the spotify protocol.
-        if offset >= self.shared.file_size {
-            return;
-        }
-
-        if length == 0 {
-            return;
-        }
-
         if offset + length > self.shared.file_size {
             length = self.shared.file_size - offset;
         }
 
-        if offset % 4 != 0 {
-            length += offset % 4;
-            offset -= offset % 4;
-        }
-
-        if length % 4 != 0 {
-            length += 4 - (length % 4);
-        }
-
         let mut ranges_to_request = RangeSet::new();
         ranges_to_request.add_range(&Range::new(offset, length));
 
-        let mut download_status = self.shared.download_status.lock().unwrap();
+        // The iteration that follows spawns streamers fast, without awaiting them,
+        // so holding the lock for the entire scope of this function should be faster
+        // then locking and unlocking multiple times.
+        let mut download_status = self.shared.download_status.lock();
 
         ranges_to_request.subtract_range_set(&download_status.downloaded);
         ranges_to_request.subtract_range_set(&download_status.requested);
 
+        // TODO : refresh cdn_url when the token expired
+
         for range in ranges_to_request.iter() {
-            let (_headers, data) = request_range(
-                &self.session,
-                self.shared.file_id,
+            let streamer = self.session.spclient().stream_from_cdn(
+                &self.shared.cdn_url,
                 range.start,
                 range.length,
-            )
-            .split();
+            )?;
 
             download_status.requested.add_range(range);
 
+            let streaming_request = StreamingRequest {
+                streamer,
+                initial_response: None,
+                offset: range.start,
+                length: range.length,
+                request_time: Instant::now(),
+            };
+
             self.session.spawn(receive_data(
                 self.shared.clone(),
                 self.file_data_tx.clone(),
-                data,
-                range.start,
-                range.length,
-                Instant::now(),
+                streaming_request,
             ));
         }
+
+        Ok(())
     }
 
-    fn pre_fetch_more_data(&mut self, bytes: usize, max_requests_to_send: usize) {
+    fn pre_fetch_more_data(
+        &mut self,
+        bytes: usize,
+        max_requests_to_send: usize,
+    ) -> AudioFileResult {
         let mut bytes_to_go = bytes;
         let mut requests_to_go = max_requests_to_send;
 
@@ -228,14 +205,14 @@ impl AudioFileFetch {
             let mut missing_data = RangeSet::new();
             missing_data.add_range(&Range::new(0, self.shared.file_size));
             {
-                let download_status = self.shared.download_status.lock().unwrap();
+                let download_status = self.shared.download_status.lock();
                 missing_data.subtract_range_set(&download_status.downloaded);
                 missing_data.subtract_range_set(&download_status.requested);
             }
 
             // download data from after the current read position first
             let mut tail_end = RangeSet::new();
-            let read_position = self.shared.read_position.load(Ordering::Relaxed);
+            let read_position = self.shared.read_position.load(Ordering::Acquire);
             tail_end.add_range(&Range::new(
                 read_position,
                 self.shared.file_size - read_position,
@@ -246,7 +223,7 @@ impl AudioFileFetch {
                 let range = tail_end.get_range(0);
                 let offset = range.start;
                 let length = min(range.length, bytes_to_go);
-                self.download_range(offset, length);
+                self.download_range(offset, length)?;
                 requests_to_go -= 1;
                 bytes_to_go -= length;
             } else if !missing_data.is_empty() {
@@ -254,20 +231,21 @@ impl AudioFileFetch {
                 let range = missing_data.get_range(0);
                 let offset = range.start;
                 let length = min(range.length, bytes_to_go);
-                self.download_range(offset, length);
+                self.download_range(offset, length)?;
                 requests_to_go -= 1;
                 bytes_to_go -= length;
             } else {
-                return;
-            }
+                break;
             }
         }
 
-    fn handle_file_data(&mut self, data: ReceivedData) -> ControlFlow {
+        Ok(())
+    }
+
+    fn handle_file_data(&mut self, data: ReceivedData) -> Result<ControlFlow, Error> {
         match data {
             ReceivedData::ResponseTime(response_time) => {
-                // chatty
-                // trace!("Ping time estimated as: {}ms", response_time.as_millis());
+                let old_ping_time_ms = self.shared.ping_time_ms.load(Ordering::Relaxed);
 
                 // prune old response times. Keep at most two so we can push a third.
                 while self.network_response_times.len() >= 3 {
@@ -278,7 +256,8 @@ impl AudioFileFetch {
                 self.network_response_times.push(response_time);
 
                 // stats::median is experimental. So we calculate the median of up to three ourselves.
-                let ping_time = match self.network_response_times.len() {
+                let ping_time_ms = {
+                    let response_time = match self.network_response_times.len() {
                         1 => self.network_response_times[0],
                         2 => (self.network_response_times[0] + self.network_response_times[1]) / 2,
                         3 => {
@@ -288,99 +267,120 @@ impl AudioFileFetch {
                         }
                         _ => unreachable!(),
                     };
+                    response_time.as_millis() as usize
+                };
+
+                // print when the new estimate deviates by more than 10% from the last
+                if f32::abs(
+                    (ping_time_ms as f32 - old_ping_time_ms as f32) / old_ping_time_ms as f32,
+                ) > 0.1
+                {
+                    debug!("Ping time now estimated as: {} ms", ping_time_ms);
+                }
 
                 // store our new estimate for everyone to see
                 self.shared
                     .ping_time_ms
-                    .store(ping_time.as_millis() as usize, Ordering::Relaxed);
+                    .store(ping_time_ms, Ordering::Relaxed);
             }
             ReceivedData::Data(data) => {
-                self.output
-                    .as_mut()
-                    .unwrap()
-                    .seek(SeekFrom::Start(data.offset as u64))
-                    .unwrap();
-                self.output
-                    .as_mut()
-                    .unwrap()
-                    .write_all(data.data.as_ref())
-                    .unwrap();
-
-                let mut download_status = self.shared.download_status.lock().unwrap();
+                match self.output.as_mut() {
+                    Some(output) => {
+                        output.seek(SeekFrom::Start(data.offset as u64))?;
+                        output.write_all(data.data.as_ref())?;
+                    }
+                    None => return Err(AudioFileError::Output.into()),
+                }
 
                 let received_range = Range::new(data.offset, data.data.len());
+
+                let full = {
+                    let mut download_status = self.shared.download_status.lock();
                     download_status.downloaded.add_range(&received_range);
                     self.shared.cond.notify_all();
 
-                let full = download_status.downloaded.contained_length_from_value(0)
-                    >= self.shared.file_size;
-
-                drop(download_status);
+                    download_status.downloaded.contained_length_from_value(0)
+                        >= self.shared.file_size
+                };
 
                 if full {
-                    self.finish();
-                    return ControlFlow::Break;
+                    self.finish()?;
+                    return Ok(ControlFlow::Break);
                 }
             }
         }
-        ControlFlow::Continue
-    }
 
-    fn handle_stream_loader_command(&mut self, cmd: StreamLoaderCommand) -> ControlFlow {
+        Ok(ControlFlow::Continue)
+    }
+
+    fn handle_stream_loader_command(
+        &mut self,
+        cmd: StreamLoaderCommand,
+    ) -> Result<ControlFlow, Error> {
         match cmd {
             StreamLoaderCommand::Fetch(request) => {
-                self.download_range(request.start, request.length);
+                self.download_range(request.start, request.length)?
             }
-            StreamLoaderCommand::RandomAccessMode() => {
-                *(self.shared.download_strategy.lock().unwrap()) = DownloadStrategy::RandomAccess();
-            }
-            StreamLoaderCommand::StreamMode() => {
-                *(self.shared.download_strategy.lock().unwrap()) = DownloadStrategy::Streaming();
-            }
-            StreamLoaderCommand::Close() => return ControlFlow::Break,
-        }
-        ControlFlow::Continue
+            StreamLoaderCommand::RandomAccessMode => self
+                .shared
+                .download_streaming
+                .store(false, Ordering::Release),
+            StreamLoaderCommand::StreamMode => self
+                .shared
+                .download_streaming
+                .store(true, Ordering::Release),
+            StreamLoaderCommand::Close => return Ok(ControlFlow::Break),
         }
 
-    fn finish(&mut self) {
-        let mut output = self.output.take().unwrap();
-        let complete_tx = self.complete_tx.take().unwrap();
+        Ok(ControlFlow::Continue)
+    }
 
-        output.seek(SeekFrom::Start(0)).unwrap();
-        let _ = complete_tx.send(output);
+    fn finish(&mut self) -> AudioFileResult {
+        let output = self.output.take();
+
+        let complete_tx = self.complete_tx.take();
+
+        if let Some(mut output) = output {
+            output.seek(SeekFrom::Start(0))?;
+            if let Some(complete_tx) = complete_tx {
+                complete_tx
+                    .send(output)
+                    .map_err(|_| AudioFileError::Channel)?;
+            }
+        }
+
+        Ok(())
     }
 }
 
 pub(super) async fn audio_file_fetch(
     session: Session,
     shared: Arc<AudioFileShared>,
-    initial_data_rx: ChannelData,
-    initial_request_sent_time: Instant,
-    initial_data_length: usize,
-
+    initial_request: StreamingRequest,
     output: NamedTempFile,
     mut stream_loader_command_rx: mpsc::UnboundedReceiver<StreamLoaderCommand>,
     complete_tx: oneshot::Sender<NamedTempFile>,
-) {
+) -> AudioFileResult {
     let (file_data_tx, mut file_data_rx) = mpsc::unbounded_channel();
 
     {
-        let requested_range = Range::new(0, initial_data_length);
-        let mut download_status = shared.download_status.lock().unwrap();
+        let requested_range = Range::new(
+            initial_request.offset,
+            initial_request.offset + initial_request.length,
+        );
+
+        let mut download_status = shared.download_status.lock();
         download_status.requested.add_range(&requested_range);
     }
 
     session.spawn(receive_data(
         shared.clone(),
         file_data_tx.clone(),
-        initial_data_rx,
-        0,
-        initial_data_length,
-        initial_request_sent_time,
+        initial_request,
     ));
 
     let mut fetch = AudioFileFetch {
-        session,
+        session: session.clone(),
         shared,
         output: Some(output),
 
@@ -392,25 +392,37 @@ pub(super) async fn audio_file_fetch(
     loop {
         tokio::select! {
             cmd = stream_loader_command_rx.recv() => {
-                if cmd.map_or(true, |cmd| fetch.handle_stream_loader_command(cmd) == ControlFlow::Break) {
+                match cmd {
+                        Some(cmd) => {
+                            if fetch.handle_stream_loader_command(cmd)? == ControlFlow::Break {
                                 break;
                             }
+                        }
+                        None => break,
+                    }
+                }
+            data = file_data_rx.recv() => {
+                match data {
+                    Some(data) => {
+                        if fetch.handle_file_data(data)? == ControlFlow::Break {
+                            break;
+                        }
+                    }
+                    None => break,
+                }
             },
-            data = file_data_rx.recv() => {
-                if data.map_or(true, |data| fetch.handle_file_data(data) == ControlFlow::Break) {
-                    break;
-                }
-            }
+            else => (),
         }
 
-        if fetch.get_download_strategy() == DownloadStrategy::Streaming() {
+        if fetch.is_download_streaming() {
             let number_of_open_requests =
                 fetch.shared.number_of_open_requests.load(Ordering::SeqCst);
             if number_of_open_requests < MAX_PREFETCH_REQUESTS {
                 let max_requests_to_send = MAX_PREFETCH_REQUESTS - number_of_open_requests;
 
                 let bytes_pending: usize = {
-                    let download_status = fetch.shared.download_status.lock().unwrap();
+                    let download_status = fetch.shared.download_status.lock();
+
                     download_status
                         .requested
                         .minus(&download_status.downloaded)
@@ -425,7 +437,7 @@ pub(super) async fn audio_file_fetch(
                 let desired_pending_bytes = max(
                     (PREFETCH_THRESHOLD_FACTOR
                         * ping_time_seconds
-                        * fetch.shared.stream_data_rate as f32) as usize,
+                        * fetch.shared.bytes_per_second as f32) as usize,
                     (FAST_PREFETCH_THRESHOLD_FACTOR * ping_time_seconds * download_rate as f32)
                         as usize,
                 );
@@ -434,9 +446,11 @@ pub(super) async fn audio_file_fetch(
                     fetch.pre_fetch_more_data(
                         desired_pending_bytes - bytes_pending,
                         max_requests_to_send,
-                    );
+                    )?;
                 }
             }
         }
     }
+
+    Ok(())
 }

audio/src/lib.rs

@@ -1,5 +1,3 @@
-#![allow(clippy::unused_io_amount, clippy::too_many_arguments)]
-
 #[macro_use]
 extern crate log;
 
@@ -9,8 +7,8 @@ mod fetch;
 mod range_set;
 
 pub use decrypt::AudioDecrypt;
-pub use fetch::{AudioFile, StreamLoaderController};
+pub use fetch::{AudioFile, AudioFileError, StreamLoaderController};
 pub use fetch::{
-    READ_AHEAD_BEFORE_PLAYBACK, READ_AHEAD_BEFORE_PLAYBACK_ROUNDTRIPS, READ_AHEAD_DURING_PLAYBACK,
-    READ_AHEAD_DURING_PLAYBACK_ROUNDTRIPS,
+    MINIMUM_DOWNLOAD_SIZE, READ_AHEAD_BEFORE_PLAYBACK, READ_AHEAD_BEFORE_PLAYBACK_ROUNDTRIPS,
+    READ_AHEAD_DURING_PLAYBACK, READ_AHEAD_DURING_PLAYBACK_ROUNDTRIPS,
 };

audio/src/range_set.rs

@@ -1,6 +1,8 @@
-use std::cmp::{max, min};
-use std::fmt;
-use std::slice::Iter;
+use std::{
+    cmp::{max, min},
+    fmt,
+    slice::Iter,
+};
 
 #[derive(Copy, Clone, Debug)]
 pub struct Range {
@@ -10,7 +12,7 @@ pub struct Range {
 
 impl fmt::Display for Range {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        return write!(f, "[{}, {}]", self.start, self.start + self.length - 1);
+        write!(f, "[{}, {}]", self.start, self.start + self.length - 1)
     }
 }
 
@@ -24,16 +26,16 @@ impl Range {
     }
 }
 
-#[derive(Clone)]
+#[derive(Debug, Clone)]
 pub struct RangeSet {
     ranges: Vec<Range>,
 }
 
 impl fmt::Display for RangeSet {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "(").unwrap();
+        write!(f, "(")?;
         for range in self.ranges.iter() {
-            write!(f, "{}", range).unwrap();
+            write!(f, "{}", range)?;
         }
         write!(f, ")")
     }
@@ -227,7 +229,6 @@ impl RangeSet {
                     self.ranges[self_index].end(),
                     other.ranges[other_index].end(),
                 );
-                assert!(new_start <= new_end);
                 result.add_range(&Range::new(new_start, new_end - new_start));
                 if self.ranges[self_index].end() <= other.ranges[other_index].end() {
                     self_index += 1;

connect/Cargo.toml

@@ -9,14 +9,15 @@ edition = "2018"
 
 [dependencies]
 form_urlencoded = "1.0"
-futures-util = { version = "0.3.5", default_features = false }
+futures-util = "0.3"
 log = "0.4"
-protobuf = "2.14.0"
+protobuf = "2"
 rand = "0.8"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-tokio = { version = "1.0", features = ["macros", "sync"] }
-tokio-stream = "0.1.1"
+thiserror = "1.0"
+tokio = { version = "1", features = ["macros", "parking_lot", "sync"] }
+tokio-stream = "0.1"
 
 [dependencies.librespot-core]
 path = "../core"
@@ -29,10 +30,3 @@ version = "0.4.2"
 [dependencies.librespot-protocol]
 path = "../protocol"
 version = "0.4.2"
-
-[dependencies.librespot-discovery]
-path = "../discovery"
-version = "0.4.2"
-
-[features]
-with-dns-sd = ["librespot-discovery/with-dns-sd"]

connect/src/config.rs

@@ -0,0 +1,20 @@
+use crate::core::config::DeviceType;
+
+#[derive(Clone, Debug)]
+pub struct ConnectConfig {
+    pub name: String,
+    pub device_type: DeviceType,
+    pub initial_volume: Option<u16>,
+    pub has_volume_ctrl: bool,
+}
+
+impl Default for ConnectConfig {
+    fn default() -> ConnectConfig {
+        ConnectConfig {
+            name: "Librespot".to_string(),
+            device_type: DeviceType::default(),
+            initial_volume: Some(50),
+            has_volume_ctrl: true,
+        }
+    }
+}

connect/src/context.rs

@@ -1,7 +1,12 @@
+// TODO : move to metadata
+
 use crate::core::spotify_id::SpotifyId;
 use crate::protocol::spirc::TrackRef;
 
-use serde::Deserialize;
+use serde::{
+    de::{Error, Unexpected},
+    Deserialize,
+};
 
 #[derive(Deserialize, Debug)]
 pub struct StationContext {
@@ -72,17 +77,23 @@ where
     D: serde::Deserializer<'d>,
 {
     let v: Vec<TrackContext> = serde::Deserialize::deserialize(de)?;
-    let track_vec = v
-        .iter()
+    v.iter()
         .map(|v| {
             let mut t = TrackRef::new();
             //  This has got to be the most round about way of doing this.
-            t.set_gid(SpotifyId::from_base62(&v.gid).unwrap().to_raw().to_vec());
+            t.set_gid(
+                SpotifyId::from_base62(&v.gid)
+                    .map_err(|_| {
+                        D::Error::invalid_value(
+                            Unexpected::Str(&v.gid),
+                            &"a Base-62 encoded Spotify ID",
+                        )
+                    })?
+                    .to_raw()
+                    .to_vec(),
+            );
             t.set_uri(v.uri.to_owned());
-
-            t
+            Ok(t)
         })
-        .collect::<Vec<TrackRef>>();
-
-    Ok(track_vec)
+        .collect::<Result<Vec<TrackRef>, D::Error>>()
 }

connect/src/discovery.rs

@@ -1,31 +0,0 @@
-use std::io;
-use std::pin::Pin;
-use std::task::{Context, Poll};
-
-use futures_util::Stream;
-use librespot_core::authentication::Credentials;
-use librespot_core::config::ConnectConfig;
-
-pub struct DiscoveryStream(librespot_discovery::Discovery);
-
-impl Stream for DiscoveryStream {
-    type Item = Credentials;
-
-    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        Pin::new(&mut self.0).poll_next(cx)
-    }
-}
-
-pub fn discovery(
-    config: ConnectConfig,
-    device_id: String,
-    port: u16,
-) -> io::Result<DiscoveryStream> {
-    librespot_discovery::Discovery::builder(device_id)
-        .device_type(config.device_type)
-        .port(port)
-        .name(config.name)
-        .launch()
-        .map(DiscoveryStream)
-        .map_err(|e| io::Error::new(io::ErrorKind::Other, e))
-}

connect/src/lib.rs

@@ -5,10 +5,6 @@ use librespot_core as core;
 use librespot_playback as playback;
 use librespot_protocol as protocol;
 
+pub mod config;
 pub mod context;
-#[deprecated(
-    since = "0.2.1",
-    note = "Please use the crate `librespot_discovery` instead."
-)]
-pub mod discovery;
 pub mod spirc;

core/Cargo.toml

@@ -13,42 +13,54 @@ path = "../protocol"
 version = "0.4.2"
 
 [dependencies]
-aes = "0.6"
+aes = "0.8"
 base64 = "0.13"
 byteorder = "1.4"
-bytes = "1.0"
+bytes = "1"
+dns-sd = { version = "0.1", optional = true }
 form_urlencoded = "1.0"
-futures-core = { version = "0.3", default-features = false }
-futures-util = { version = "0.3", default-features = false, features = ["alloc", "bilock", "unstable", "sink"] }
-hmac = "0.11"
-httparse = "1.3"
+futures-core = "0.3"
+futures-util = { version = "0.3", features = ["alloc", "bilock", "sink", "unstable"] }
+hmac = "0.12"
+httparse = "1.7"
 http = "0.2"
-hyper = { version = "0.14", features = ["client", "tcp", "http1"] }
-hyper-proxy = { version = "0.9.1", default-features = false }
+hyper = { version = "0.14", features = ["client", "http1", "http2", "tcp"] }
+hyper-proxy = { version = "0.9", default-features = false, features = ["rustls"] }
+hyper-rustls = { version = "0.23", features = ["http2"] }
 log = "0.4"
+num = "0.4"
 num-bigint = { version = "0.4", features = ["rand"] }
+num-derive = "0.3"
 num-integer = "0.1"
 num-traits = "0.2"
-once_cell = "1.5.2"
-pbkdf2 = { version = "0.8", default-features = false, features = ["hmac"] }
+once_cell = "1"
+parking_lot = { version = "0.12", features = ["deadlock_detection"] }
+pbkdf2 = { version = "0.11", default-features = false, features = ["hmac"] }
 priority-queue = "1.2"
-protobuf = "2.14.0"
+protobuf = "2"
+quick-xml = { version = "0.23", features = ["serialize"] }
 rand = "0.8"
+rsa = "0.6"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-sha-1 = "0.9"
-shannon = "0.2.0"
-thiserror = "1.0.7"
-tokio = { version = "1.0", features = ["io-util", "net", "rt", "sync"] }
-tokio-stream = "0.1.1"
+sha1 = "0.10"
+shannon = "0.2"
+thiserror = "1.0"
+time = "0.3"
+tokio = { version = "1", features = ["io-util", "macros", "net", "parking_lot", "rt", "sync", "time"] }
+tokio-stream = "0.1"
+tokio-tungstenite = { version = "*", default-features = false, features = ["rustls-tls-native-roots"] }
 tokio-util = { version = "0.7", features = ["codec"] }
-url = "2.1"
-uuid = { version = "1.0", default-features = false, features = ["v4"] }
+url = "2"
+uuid = { version = "1", default-features = false, features = ["v4"] }
 
 [build-dependencies]
 rand = "0.8"
-vergen = "3.0.4"
+vergen = { version = "7", default-features = false, features = ["build", "git"] }
 
 [dev-dependencies]
 env_logger = "0.9"
-tokio = {version = "1.0", features = ["macros"] }
+tokio = { version = "1", features = ["macros", "parking_lot"] }
+
+[features]
+with-dns-sd = ["dns-sd"]

core/build.rs

@@ -1,14 +1,19 @@
-use rand::distributions::Alphanumeric;
-use rand::Rng;
-use std::env;
-use vergen::{generate_cargo_keys, ConstantsFlags};
+use rand::{distributions::Alphanumeric, Rng};
+use vergen::{vergen, Config, ShaKind, TimestampKind};
 
 fn main() {
-    let mut flags = ConstantsFlags::all();
-    flags.toggle(ConstantsFlags::REBUILD_ON_HEAD_CHANGE);
-    generate_cargo_keys(ConstantsFlags::all()).expect("Unable to generate the cargo keys!");
+    let mut config = Config::default();
+    *config.build_mut().kind_mut() = TimestampKind::DateOnly;
+    *config.git_mut().enabled_mut() = true;
+    *config.git_mut().commit_timestamp_mut() = true;
+    *config.git_mut().commit_timestamp_kind_mut() = TimestampKind::DateOnly;
+    *config.git_mut().sha_mut() = true;
+    *config.git_mut().sha_kind_mut() = ShaKind::Short;
+    *config.git_mut().rerun_on_head_change_mut() = true;
 
-    let build_id = match env::var("SOURCE_DATE_EPOCH") {
+    vergen(config).expect("Unable to generate the cargo keys!");
+
+    let build_id = match std::env::var("SOURCE_DATE_EPOCH") {
         Ok(val) => val,
         Err(_) => rand::thread_rng()
             .sample_iter(Alphanumeric)

core/src/apresolve.rs

@@ -1,108 +1,131 @@
-use std::error::Error;
-
-use hyper::client::HttpConnector;
-use hyper::{Body, Client, Method, Request, Uri};
-use hyper_proxy::{Intercept, Proxy, ProxyConnector};
+use hyper::{Body, Method, Request};
 use serde::Deserialize;
-use url::Url;
 
-const APRESOLVE_ENDPOINT: &str = "http://apresolve.spotify.com:80";
-const AP_FALLBACK: &str = "ap.spotify.com:443";
-const AP_BLACKLIST: [&str; 2] = ["ap-gew4.spotify.com", "ap-gue1.spotify.com"];
+use crate::Error;
 
-#[derive(Clone, Debug, Deserialize)]
-struct ApResolveData {
-    ap_list: Vec<String>,
+pub type SocketAddress = (String, u16);
+
+#[derive(Default)]
+pub struct AccessPoints {
+    accesspoint: Vec<SocketAddress>,
+    dealer: Vec<SocketAddress>,
+    spclient: Vec<SocketAddress>,
 }
 
-async fn try_apresolve(
-    proxy: Option<&Url>,
-    ap_port: Option<u16>,
-) -> Result<String, Box<dyn Error>> {
-    let port = ap_port.unwrap_or(443);
+#[derive(Deserialize)]
+pub struct ApResolveData {
+    accesspoint: Vec<String>,
+    dealer: Vec<String>,
+    spclient: Vec<String>,
+}
 
-    let mut req = Request::new(Body::empty());
-    *req.method_mut() = Method::GET;
-    // panic safety: APRESOLVE_ENDPOINT above is valid url.
-    *req.uri_mut() = APRESOLVE_ENDPOINT.parse().expect("invalid AP resolve URL");
+// These addresses probably do some geo-location based traffic management or at least DNS-based
+// load balancing. They are known to fail when the normal resolvers are up, so that's why they
+// should only be used as fallback.
+impl Default for ApResolveData {
+    fn default() -> Self {
+        Self {
+            accesspoint: vec![String::from("ap.spotify.com:443")],
+            dealer: vec![String::from("dealer.spotify.com:443")],
+            spclient: vec![String::from("spclient.wg.spotify.com:443")],
+        }
+    }
+}
 
-    let response = if let Some(url) = proxy {
-        // Panic safety: all URLs are valid URIs
-        let uri = url.to_string().parse().unwrap();
-        let proxy = Proxy::new(Intercept::All, uri);
-        let connector = HttpConnector::new();
-        let proxy_connector = ProxyConnector::from_proxy_unsecured(connector, proxy);
-        Client::builder()
-            .build(proxy_connector)
-            .request(req)
-            .await?
+component! {
+    ApResolver : ApResolverInner {
+        data: AccessPoints = AccessPoints::default(),
+    }
+}
+
+impl ApResolver {
+    // return a port if a proxy URL and/or a proxy port was specified. This is useful even when
+    // there is no proxy, but firewalls only allow certain ports (e.g. 443 and not 4070).
+    pub fn port_config(&self) -> Option<u16> {
+        if self.session().config().proxy.is_some() || self.session().config().ap_port.is_some() {
+            Some(self.session().config().ap_port.unwrap_or(443))
         } else {
-        Client::new().request(req).await?
-    };
+            None
+        }
+    }
 
-    let body = hyper::body::to_bytes(response.into_body()).await?;
+    fn process_data(&self, data: Vec<String>) -> Vec<SocketAddress> {
+        data.into_iter()
+            .filter_map(|ap| {
+                let mut split = ap.rsplitn(2, ':');
+                let port = split.next()?;
+                let host = split.next()?.to_owned();
+                let port: u16 = port.parse().ok()?;
+                if let Some(p) = self.port_config() {
+                    if p != port {
+                        return None;
+                    }
+                }
+                Some((host, port))
+            })
+            .collect()
+    }
+
+    pub async fn try_apresolve(&self) -> Result<ApResolveData, Error> {
+        let req = Request::builder()
+            .method(Method::GET)
+            .uri("http://apresolve.spotify.com/?type=accesspoint&type=dealer&type=spclient")
+            .body(Body::empty())?;
+
+        let body = self.session().http_client().request_body(req).await?;
         let data: ApResolveData = serde_json::from_slice(body.as_ref())?;
 
-    // filter APs that are known to cause channel errors
-    let aps: Vec<String> = data
-        .ap_list
-        .into_iter()
-        .filter_map(|ap| {
-            let host = ap.parse::<Uri>().ok()?.host()?.to_owned();
-            if !AP_BLACKLIST.iter().any(|&blacklisted| host == blacklisted) {
-                Some(ap)
-            } else {
-                warn!("Ignoring blacklisted access point {}", ap);
-                None
+        Ok(data)
     }
+
+    async fn apresolve(&self) {
+        let result = self.try_apresolve().await;
+
+        self.lock(|inner| {
+            let data = match result {
+                Ok(data) => data,
+                Err(e) => {
+                    warn!("Failed to resolve access points, using fallbacks: {}", e);
+                    ApResolveData::default()
+                }
+            };
+
+            inner.data.accesspoint = self.process_data(data.accesspoint);
+            inner.data.dealer = self.process_data(data.dealer);
+            inner.data.spclient = self.process_data(data.spclient);
         })
-        .collect();
-
-    let ap = if ap_port.is_some() || proxy.is_some() {
-        // filter on ports if specified on the command line...
-        aps.into_iter().find_map(|ap| {
-            if ap.parse::<Uri>().ok()?.port()? == port {
-                Some(ap)
-            } else {
-                None
     }
+
+    fn is_empty(&self) -> bool {
+        self.lock(|inner| {
+            inner.data.accesspoint.is_empty()
+                || inner.data.dealer.is_empty()
+                || inner.data.spclient.is_empty()
         })
-    } else {
-        // ...or pick the first on the list
-        aps.into_iter().next()
     }
-    .ok_or("Unable to resolve any viable access points.")?;
 
-    Ok(ap)
-}
+    pub async fn resolve(&self, endpoint: &str) -> Result<SocketAddress, Error> {
+        if self.is_empty() {
+            self.apresolve().await;
+        }
 
-pub async fn apresolve(proxy: Option<&Url>, ap_port: Option<u16>) -> String {
-    try_apresolve(proxy, ap_port).await.unwrap_or_else(|e| {
-        warn!("Failed to resolve Access Point: {}", e);
-        warn!("Using fallback \"{}\"", AP_FALLBACK);
-        AP_FALLBACK.into()
+        self.lock(|inner| {
+            let access_point = match endpoint {
+                // take the first position instead of the last with `pop`, because Spotify returns
+                // access points with ports 4070, 443 and 80 in order of preference from highest
+                // to lowest.
+                "accesspoint" => inner.data.accesspoint.remove(0),
+                "dealer" => inner.data.dealer.remove(0),
+                "spclient" => inner.data.spclient.remove(0),
+                _ => {
+                    return Err(Error::unimplemented(format!(
+                        "No implementation to resolve access point {}",
+                        endpoint
+                    )))
+                }
+            };
+
+            Ok(access_point)
         })
-}
-
-#[cfg(test)]
-mod test {
-    use std::net::ToSocketAddrs;
-
-    use super::try_apresolve;
-
-    #[tokio::test]
-    async fn test_apresolve() {
-        let ap = try_apresolve(None, None).await.unwrap();
-
-        // Assert that the result contains a valid host and port
-        ap.to_socket_addrs().unwrap().next().unwrap();
-    }
-
-    #[tokio::test]
-    async fn test_apresolve_port_443() {
-        let ap = try_apresolve(None, Some(443)).await.unwrap();
-
-        let port = ap.to_socket_addrs().unwrap().next().unwrap().port();
-        assert_eq!(port, 443);
     }
 }

core/src/audio_key.rs

@@ -1,52 +1,85 @@
+use std::{collections::HashMap, io::Write};
+
 use byteorder::{BigEndian, ByteOrder, WriteBytesExt};
 use bytes::Bytes;
-use std::collections::HashMap;
-use std::io::Write;
+use thiserror::Error;
 use tokio::sync::oneshot;
 
-use crate::spotify_id::{FileId, SpotifyId};
-use crate::util::SeqGenerator;
+use crate::{packet::PacketType, util::SeqGenerator, Error, FileId, SpotifyId};
 
 #[derive(Debug, Hash, PartialEq, Eq, Copy, Clone)]
 pub struct AudioKey(pub [u8; 16]);
 
-#[derive(Debug, Hash, PartialEq, Eq, Copy, Clone)]
-pub struct AudioKeyError;
+#[derive(Debug, Error)]
+pub enum AudioKeyError {
+    #[error("audio key error")]
+    AesKey,
+    #[error("other end of channel disconnected")]
+    Channel,
+    #[error("unexpected packet type {0}")]
+    Packet(u8),
+    #[error("sequence {0} not pending")]
+    Sequence(u32),
+}
+
+impl From<AudioKeyError> for Error {
+    fn from(err: AudioKeyError) -> Self {
+        match err {
+            AudioKeyError::AesKey => Error::unavailable(err),
+            AudioKeyError::Channel => Error::aborted(err),
+            AudioKeyError::Sequence(_) => Error::aborted(err),
+            AudioKeyError::Packet(_) => Error::unimplemented(err),
+        }
+    }
+}
 
 component! {
     AudioKeyManager : AudioKeyManagerInner {
         sequence: SeqGenerator<u32> = SeqGenerator::new(0),
-        pending: HashMap<u32, oneshot::Sender<Result<AudioKey, AudioKeyError>>> = HashMap::new(),
+        pending: HashMap<u32, oneshot::Sender<Result<AudioKey, Error>>> = HashMap::new(),
     }
 }
 
 impl AudioKeyManager {
-    pub(crate) fn dispatch(&self, cmd: u8, mut data: Bytes) {
+    pub(crate) fn dispatch(&self, cmd: PacketType, mut data: Bytes) -> Result<(), Error> {
         let seq = BigEndian::read_u32(data.split_to(4).as_ref());
 
-        let sender = self.lock(|inner| inner.pending.remove(&seq));
+        let sender = self
+            .lock(|inner| inner.pending.remove(&seq))
+            .ok_or(AudioKeyError::Sequence(seq))?;
 
-        if let Some(sender) = sender {
         match cmd {
-                0xd => {
+            PacketType::AesKey => {
                 let mut key = [0u8; 16];
                 key.copy_from_slice(data.as_ref());
-                    let _ = sender.send(Ok(AudioKey(key)));
+                sender
+                    .send(Ok(AudioKey(key)))
+                    .map_err(|_| AudioKeyError::Channel)?
             }
-                0xe => {
-                    warn!(
+            PacketType::AesKeyError => {
+                error!(
                     "error audio key {:x} {:x}",
                     data.as_ref()[0],
                     data.as_ref()[1]
                 );
-                    let _ = sender.send(Err(AudioKeyError));
-                }
-                _ => (),
+                sender
+                    .send(Err(AudioKeyError::AesKey.into()))
+                    .map_err(|_| AudioKeyError::Channel)?
             }
+            _ => {
+                trace!(
+                    "Did not expect {:?} AES key packet with data {:#?}",
+                    cmd,
+                    data
+                );
+                return Err(AudioKeyError::Packet(cmd as u8).into());
             }
         }
 
-    pub async fn request(&self, track: SpotifyId, file: FileId) -> Result<AudioKey, AudioKeyError> {
+        Ok(())
+    }
+
+    pub async fn request(&self, track: SpotifyId, file: FileId) -> Result<AudioKey, Error> {
         let (tx, rx) = oneshot::channel();
 
         let seq = self.lock(move |inner| {
@@ -55,17 +88,17 @@ impl AudioKeyManager {
             seq
         });
 
-        self.send_key_request(seq, track, file);
-        rx.await.map_err(|_| AudioKeyError)?
+        self.send_key_request(seq, track, file)?;
+        rx.await?
     }
 
-    fn send_key_request(&self, seq: u32, track: SpotifyId, file: FileId) {
+    fn send_key_request(&self, seq: u32, track: SpotifyId, file: FileId) -> Result<(), Error> {
         let mut data: Vec<u8> = Vec::new();
-        data.write(&file.0).unwrap();
-        data.write(&track.to_raw()).unwrap();
-        data.write_u32::<BigEndian>(seq).unwrap();
-        data.write_u16::<BigEndian>(0x0000).unwrap();
+        data.write_all(&file.0)?;
+        data.write_all(&track.to_raw())?;
+        data.write_u32::<BigEndian>(seq)?;
+        data.write_u16::<BigEndian>(0x0000)?;
 
-        self.session().send_packet(0xc, data)
+        self.session().send_packet(PacketType::RequestKey, data)
     }
 }

core/src/authentication.rs

@@ -7,8 +7,23 @@ use pbkdf2::pbkdf2;
 use protobuf::ProtobufEnum;
 use serde::{Deserialize, Serialize};
 use sha1::{Digest, Sha1};
+use thiserror::Error;
 
-use crate::protocol::authentication::AuthenticationType;
+use crate::{protocol::authentication::AuthenticationType, Error};
+
+#[derive(Debug, Error)]
+pub enum AuthenticationError {
+    #[error("unknown authentication type {0}")]
+    AuthType(u32),
+    #[error("invalid key")]
+    Key,
+}
+
+impl From<AuthenticationError> for Error {
+    fn from(err: AuthenticationError) -> Self {
+        Error::invalid_argument(err)
+    }
+}
 
 /// The credentials are used to log into the Spotify API.
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -46,7 +61,7 @@ impl Credentials {
         username: impl Into<String>,
         encrypted_blob: impl AsRef<[u8]>,
         device_id: impl AsRef<[u8]>,
-    ) -> Credentials {
+    ) -> Result<Credentials, Error> {
         fn read_u8<R: Read>(stream: &mut R) -> io::Result<u8> {
             let mut data = [0u8];
             stream.read_exact(&mut data)?;
@@ -77,6 +92,10 @@ impl Credentials {
 
         let key = {
             let mut key = [0u8; 24];
+            if key.len() < 20 {
+                return Err(AuthenticationError::Key.into());
+            }
+
             pbkdf2::<Hmac<Sha1>>(&secret, username.as_bytes(), 0x100, &mut key[0..20]);
 
             let hash = &Sha1::digest(&key[..20]);
@@ -87,15 +106,13 @@ impl Credentials {
 
         // decrypt data using ECB mode without padding
         let blob = {
-            use aes::cipher::generic_array::typenum::Unsigned;
             use aes::cipher::generic_array::GenericArray;
-            use aes::cipher::{BlockCipher, NewBlockCipher};
+            use aes::cipher::{BlockDecrypt, BlockSizeUser, KeyInit};
 
-            let mut data = base64::decode(encrypted_blob).unwrap();
+            let mut data = base64::decode(encrypted_blob)?;
             let cipher = Aes192::new(GenericArray::from_slice(&key));
-            let block_size = <Aes192 as BlockCipher>::BlockSize::to_usize();
+            let block_size = Aes192::block_size();
 
-            assert_eq!(data.len() % block_size, 0);
             for chunk in data.chunks_exact_mut(block_size) {
                 cipher.decrypt_block(GenericArray::from_mut_slice(chunk));
             }
@@ -109,19 +126,20 @@ impl Credentials {
         };
 
         let mut cursor = io::Cursor::new(blob.as_slice());
-        read_u8(&mut cursor).unwrap();
-        read_bytes(&mut cursor).unwrap();
-        read_u8(&mut cursor).unwrap();
-        let auth_type = read_int(&mut cursor).unwrap();
-        let auth_type = AuthenticationType::from_i32(auth_type as i32).unwrap();
-        read_u8(&mut cursor).unwrap();
-        let auth_data = read_bytes(&mut cursor).unwrap();
+        read_u8(&mut cursor)?;
+        read_bytes(&mut cursor)?;
+        read_u8(&mut cursor)?;
+        let auth_type = read_int(&mut cursor)?;
+        let auth_type = AuthenticationType::from_i32(auth_type as i32)
+            .ok_or(AuthenticationError::AuthType(auth_type))?;
+        read_u8(&mut cursor)?;
+        let auth_data = read_bytes(&mut cursor)?;
 
-        Credentials {
+        Ok(Credentials {
             username,
             auth_type,
             auth_data,
-        }
+        })
     }
 }
 

core/src/cache.rs

@@ -1,15 +1,30 @@
-use std::cmp::Reverse;
-use std::collections::HashMap;
-use std::fs::{self, File};
-use std::io::{self, Error, ErrorKind, Read, Write};
-use std::path::{Path, PathBuf};
-use std::sync::{Arc, Mutex};
-use std::time::SystemTime;
+use std::{
+    cmp::Reverse,
+    collections::HashMap,
+    fs::{self, File},
+    io::{self, Read, Write},
+    path::{Path, PathBuf},
+    sync::Arc,
+    time::SystemTime,
+};
 
+use parking_lot::Mutex;
 use priority_queue::PriorityQueue;
+use thiserror::Error;
 
-use crate::authentication::Credentials;
-use crate::spotify_id::FileId;
+use crate::{authentication::Credentials, error::ErrorKind, Error, FileId};
+
+#[derive(Debug, Error)]
+pub enum CacheError {
+    #[error("audio cache location is not configured")]
+    Path,
+}
+
+impl From<CacheError> for Error {
+    fn from(err: CacheError) -> Self {
+        Error::failed_precondition(err)
+    }
+}
 
 /// Some kind of data structure that holds some paths, the size of these files and a timestamp.
 /// It keeps track of the file sizes and is able to pop the path with the oldest timestamp if
@@ -57,16 +72,17 @@ impl SizeLimiter {
     /// to delete the file in the file system.
     fn pop(&mut self) -> Option<PathBuf> {
         if self.exceeds_limit() {
-            let (next, _) = self
-                .queue
-                .pop()
-                .expect("in_use was > 0, so the queue should have contained an item.");
-            let size = self
-                .sizes
-                .remove(&next)
-                .expect("`queue` and `sizes` should have the same keys.");
+            if let Some((next, _)) = self.queue.pop() {
+                if let Some(size) = self.sizes.remove(&next) {
                     self.in_use -= size;
+                } else {
+                    error!("`queue` and `sizes` should have the same keys.");
+                }
                 Some(next)
+            } else {
+                error!("in_use was > 0, so the queue should have contained an item.");
+                None
+            }
         } else {
             None
         }
@@ -85,11 +101,11 @@ impl SizeLimiter {
             return false;
         }
 
-        let size = self
-            .sizes
-            .remove(file)
-            .expect("`queue` and `sizes` should have the same keys.");
+        if let Some(size) = self.sizes.remove(file) {
             self.in_use -= size;
+        } else {
+            error!("`queue` and `sizes` should have the same keys.");
+        }
 
         true
     }
@@ -173,23 +189,21 @@ impl FsSizeLimiter {
     }
 
     fn add(&self, file: &Path, size: u64) {
-        self.limiter
-            .lock()
-            .unwrap()
-            .add(file, size, SystemTime::now());
+        self.limiter.lock().add(file, size, SystemTime::now())
     }
 
     fn touch(&self, file: &Path) -> bool {
-        self.limiter.lock().unwrap().update(file, SystemTime::now())
+        self.limiter.lock().update(file, SystemTime::now())
     }
 
-    fn remove(&self, file: &Path) {
-        self.limiter.lock().unwrap().remove(file);
+    fn remove(&self, file: &Path) -> bool {
+        self.limiter.lock().remove(file)
     }
 
-    fn prune_internal<F: FnMut() -> Option<PathBuf>>(mut pop: F) {
+    fn prune_internal<F: FnMut() -> Option<PathBuf>>(mut pop: F) -> Result<(), Error> {
         let mut first = true;
         let mut count = 0;
+        let mut last_error = None;
 
         while let Some(file) = pop() {
             if first {
@@ -197,8 +211,10 @@ impl FsSizeLimiter {
                 first = false;
             }
 
-            if let Err(e) = fs::remove_file(&file) {
+            let res = fs::remove_file(&file);
+            if let Err(e) = res {
                 warn!("Could not remove file {:?} from cache dir: {}", file, e);
+                last_error = Some(e);
             } else {
                 count += 1;
             }
@@ -207,21 +223,27 @@ impl FsSizeLimiter {
         if count > 0 {
             info!("Removed {} cache files.", count);
         }
+
+        if let Some(err) = last_error {
+            Err(err.into())
+        } else {
+            Ok(())
+        }
     }
 
-    fn prune(&self) {
-        Self::prune_internal(|| self.limiter.lock().unwrap().pop())
+    fn prune(&self) -> Result<(), Error> {
+        Self::prune_internal(|| self.limiter.lock().pop())
     }
 
-    fn new(path: &Path, limit: u64) -> Self {
+    fn new(path: &Path, limit: u64) -> Result<Self, Error> {
         let mut limiter = SizeLimiter::new(limit);
 
         Self::init_dir(&mut limiter, path);
-        Self::prune_internal(|| limiter.pop());
+        Self::prune_internal(|| limiter.pop())?;
 
-        Self {
+        Ok(Self {
             limiter: Mutex::new(limiter),
-        }
+        })
     }
 }
 
@@ -234,15 +256,13 @@ pub struct Cache {
     size_limiter: Option<Arc<FsSizeLimiter>>,
 }
 
-pub struct RemoveFileError(());
-
 impl Cache {
     pub fn new<P: AsRef<Path>>(
         credentials_path: Option<P>,
         volume_path: Option<P>,
         audio_path: Option<P>,
         size_limit: Option<u64>,
-    ) -> io::Result<Self> {
+    ) -> Result<Self, Error> {
         let mut size_limiter = None;
 
         if let Some(location) = &credentials_path {
@@ -263,8 +283,7 @@ impl Cache {
             fs::create_dir_all(location)?;
 
             if let Some(limit) = size_limit {
-                let limiter = FsSizeLimiter::new(location.as_ref(), limit);
-
+                let limiter = FsSizeLimiter::new(location.as_ref(), limit)?;
                 size_limiter = Some(Arc::new(limiter));
             }
         }
@@ -285,11 +304,11 @@ impl Cache {
         let location = self.credentials_location.as_ref()?;
 
         // This closure is just convencience to enable the question mark operator
-        let read = || {
+        let read = || -> Result<Credentials, Error> {
             let mut file = File::open(location)?;
             let mut contents = String::new();
             file.read_to_string(&mut contents)?;
-            serde_json::from_str(&contents).map_err(|e| Error::new(ErrorKind::InvalidData, e))
+            Ok(serde_json::from_str(&contents)?)
         };
 
         match read() {
@@ -297,7 +316,7 @@ impl Cache {
             Err(e) => {
                 // If the file did not exist, the file was probably not written
                 // before. Otherwise, log the error.
-                if e.kind() != ErrorKind::NotFound {
+                if e.kind != ErrorKind::NotFound {
                     warn!("Error reading credentials from cache: {}", e);
                 }
                 None
@@ -321,19 +340,17 @@ impl Cache {
     pub fn volume(&self) -> Option<u16> {
         let location = self.volume_location.as_ref()?;
 
-        let read = || {
+        let read = || -> Result<u16, Error> {
             let mut file = File::open(location)?;
             let mut contents = String::new();
             file.read_to_string(&mut contents)?;
-            contents
-                .parse()
-                .map_err(|e| Error::new(ErrorKind::InvalidData, e))
+            Ok(contents.parse()?)
         };
 
         match read() {
             Ok(v) => Some(v),
             Err(e) => {
-                if e.kind() != ErrorKind::NotFound {
+                if e.kind != ErrorKind::NotFound {
                     warn!("Error reading volume from cache: {}", e);
                 }
                 None
@@ -350,7 +367,7 @@ impl Cache {
         }
     }
 
-    fn file_path(&self, file: FileId) -> Option<PathBuf> {
+    pub fn file_path(&self, file: FileId) -> Option<PathBuf> {
         match file.to_base16() {
             Ok(name) => self.audio_location.as_ref().map(|location| {
                 let mut path = location.join(&name[0..2]);
@@ -358,7 +375,7 @@ impl Cache {
                 path
             }),
             Err(e) => {
-                warn!("Invalid FileId: {}", e.utf8_error());
+                warn!("Invalid FileId: {}", e);
                 None
             }
         }
@@ -369,12 +386,14 @@ impl Cache {
         match File::open(&path) {
             Ok(file) => {
                 if let Some(limiter) = self.size_limiter.as_deref() {
-                    limiter.touch(&path);
+                    if !limiter.touch(&path) {
+                        error!("limiter could not touch {:?}", path);
+                    }
                 }
                 Some(file)
             }
             Err(e) => {
-                if e.kind() != ErrorKind::NotFound {
+                if e.kind() != io::ErrorKind::NotFound {
                     warn!("Error reading file from cache: {}", e)
                 }
                 None
@@ -382,39 +401,34 @@ impl Cache {
         }
     }
 
-    pub fn save_file<F: Read>(&self, file: FileId, contents: &mut F) {
-        let path = if let Some(path) = self.file_path(file) {
-            path
-        } else {
-            return;
-        };
-        let parent = path.parent().unwrap();
-
-        let result = fs::create_dir_all(parent)
+    pub fn save_file<F: Read>(&self, file: FileId, contents: &mut F) -> Result<PathBuf, Error> {
+        if let Some(path) = self.file_path(file) {
+            if let Some(parent) = path.parent() {
+                if let Ok(size) = fs::create_dir_all(parent)
                     .and_then(|_| File::create(&path))
-            .and_then(|mut file| io::copy(contents, &mut file));
-
-        if let Ok(size) = result {
+                    .and_then(|mut file| io::copy(contents, &mut file))
+                {
                     if let Some(limiter) = self.size_limiter.as_deref() {
                         limiter.add(&path, size);
-                limiter.prune();
+                        limiter.prune()?;
+                    }
+                    return Ok(path);
                 }
             }
         }
+        Err(CacheError::Path.into())
+    }
 
-    pub fn remove_file(&self, file: FileId) -> Result<(), RemoveFileError> {
-        let path = self.file_path(file).ok_or(RemoveFileError(()))?;
+    pub fn remove_file(&self, file: FileId) -> Result<(), Error> {
+        let path = self.file_path(file).ok_or(CacheError::Path)?;
 
-        if let Err(err) = fs::remove_file(&path) {
-            warn!("Unable to remove file from cache: {}", err);
-            Err(RemoveFileError(()))
-        } else {
+        fs::remove_file(&path)?;
         if let Some(limiter) = self.size_limiter.as_deref() {
             limiter.remove(&path);
         }
+
         Ok(())
     }
-    }
 }
 
 #[cfg(test)]

core/src/cdn_url.rs

@@ -0,0 +1,165 @@
+use std::{
+    convert::TryFrom,
+    ops::{Deref, DerefMut},
+};
+
+use protobuf::Message;
+use thiserror::Error;
+use url::Url;
+
+use super::{date::Date, Error, FileId, Session};
+
+use librespot_protocol as protocol;
+use protocol::storage_resolve::StorageResolveResponse as CdnUrlMessage;
+use protocol::storage_resolve::StorageResolveResponse_Result;
+
+#[derive(Debug, Clone)]
+pub struct MaybeExpiringUrl(pub String, pub Option<Date>);
+
+#[derive(Debug, Clone)]
+pub struct MaybeExpiringUrls(pub Vec<MaybeExpiringUrl>);
+
+impl Deref for MaybeExpiringUrls {
+    type Target = Vec<MaybeExpiringUrl>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for MaybeExpiringUrls {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+#[derive(Debug, Error)]
+pub enum CdnUrlError {
+    #[error("all URLs expired")]
+    Expired,
+    #[error("resolved storage is not for CDN")]
+    Storage,
+    #[error("no URLs resolved")]
+    Unresolved,
+}
+
+impl From<CdnUrlError> for Error {
+    fn from(err: CdnUrlError) -> Self {
+        match err {
+            CdnUrlError::Expired => Error::deadline_exceeded(err),
+            CdnUrlError::Storage | CdnUrlError::Unresolved => Error::unavailable(err),
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct CdnUrl {
+    pub file_id: FileId,
+    urls: MaybeExpiringUrls,
+}
+
+impl CdnUrl {
+    pub fn new(file_id: FileId) -> Self {
+        Self {
+            file_id,
+            urls: MaybeExpiringUrls(Vec::new()),
+        }
+    }
+
+    pub async fn resolve_audio(&self, session: &Session) -> Result<Self, Error> {
+        let file_id = self.file_id;
+        let response = session.spclient().get_audio_storage(file_id).await?;
+        let msg = CdnUrlMessage::parse_from_bytes(&response)?;
+        let urls = MaybeExpiringUrls::try_from(msg)?;
+
+        let cdn_url = Self { file_id, urls };
+
+        trace!("Resolved CDN storage: {:#?}", cdn_url);
+
+        Ok(cdn_url)
+    }
+
+    pub fn try_get_url(&self) -> Result<&str, Error> {
+        if self.urls.is_empty() {
+            return Err(CdnUrlError::Unresolved.into());
+        }
+
+        let now = Date::now_utc();
+        let url = self.urls.iter().find(|url| match url.1 {
+            Some(expiry) => now < expiry,
+            None => true,
+        });
+
+        if let Some(url) = url {
+            Ok(&url.0)
+        } else {
+            Err(CdnUrlError::Expired.into())
+        }
+    }
+}
+
+impl TryFrom<CdnUrlMessage> for MaybeExpiringUrls {
+    type Error = crate::Error;
+    fn try_from(msg: CdnUrlMessage) -> Result<Self, Self::Error> {
+        if !matches!(msg.get_result(), StorageResolveResponse_Result::CDN) {
+            return Err(CdnUrlError::Storage.into());
+        }
+
+        let is_expiring = !msg.get_fileid().is_empty();
+
+        let result = msg
+            .get_cdnurl()
+            .iter()
+            .map(|cdn_url| {
+                let url = Url::parse(cdn_url)?;
+
+                if is_expiring {
+                    let expiry_str = if let Some(token) = url
+                        .query_pairs()
+                        .into_iter()
+                        .find(|(key, _value)| key == "__token__")
+                    {
+                        if let Some(mut start) = token.1.find("exp=") {
+                            start += 4;
+                            if token.1.len() >= start {
+                                let slice = &token.1[start..];
+                                if let Some(end) = slice.find('~') {
+                                    // this is the only valid invariant for akamaized.net
+                                    String::from(&slice[..end])
+                                } else {
+                                    String::from(slice)
+                                }
+                            } else {
+                                String::new()
+                            }
+                        } else {
+                            String::new()
+                        }
+                    } else if let Some(query) = url.query() {
+                        let mut items = query.split('_');
+                        if let Some(first) = items.next() {
+                            // this is the only valid invariant for scdn.co
+                            String::from(first)
+                        } else {
+                            String::new()
+                        }
+                    } else {
+                        String::new()
+                    };
+
+                    let mut expiry: i64 = expiry_str.parse()?;
+
+                    expiry -= 5 * 60; // seconds
+
+                    Ok(MaybeExpiringUrl(
+                        cdn_url.to_owned(),
+                        Some(Date::from_timestamp_ms(expiry * 1000)?),
+                    ))
+                } else {
+                    Ok(MaybeExpiringUrl(cdn_url.to_owned(), None))
+                }
+            })
+            .collect::<Result<Vec<MaybeExpiringUrl>, Error>>()?;
+
+        Ok(Self(result))
+    }
+}

core/src/channel.rs

@@ -1,16 +1,20 @@
-use std::collections::HashMap;
-use std::pin::Pin;
-use std::task::{Context, Poll};
-use std::time::Instant;
+use std::{
+    collections::HashMap,
+    fmt,
+    pin::Pin,
+    task::{Context, Poll},
+    time::Instant,
+};
 
 use byteorder::{BigEndian, ByteOrder};
 use bytes::Bytes;
 use futures_core::Stream;
-use futures_util::lock::BiLock;
-use futures_util::{ready, StreamExt};
+use futures_util::{lock::BiLock, ready, StreamExt};
+use num_traits::FromPrimitive;
+use thiserror::Error;
 use tokio::sync::mpsc;
 
-use crate::util::SeqGenerator;
+use crate::{packet::PacketType, util::SeqGenerator, Error};
 
 component! {
     ChannelManager : ChannelManagerInner {
@@ -25,9 +29,21 @@ component! {
 
 const ONE_SECOND_IN_MS: usize = 1000;
 
-#[derive(Debug, Hash, PartialEq, Eq, Copy, Clone)]
+#[derive(Debug, Error, Hash, PartialEq, Eq, Copy, Clone)]
 pub struct ChannelError;
 
+impl From<ChannelError> for Error {
+    fn from(err: ChannelError) -> Self {
+        Error::aborted(err)
+    }
+}
+
+impl fmt::Display for ChannelError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "channel error")
+    }
+}
+
 pub struct Channel {
     receiver: mpsc::UnboundedReceiver<(u8, Bytes)>,
     state: ChannelState,
@@ -68,7 +84,7 @@ impl ChannelManager {
         (seq, channel)
     }
 
-    pub(crate) fn dispatch(&self, cmd: u8, mut data: Bytes) {
+    pub(crate) fn dispatch(&self, cmd: PacketType, mut data: Bytes) -> Result<(), Error> {
         use std::collections::hash_map::Entry;
 
         let id: u16 = BigEndian::read_u16(data.split_to(2).as_ref());
@@ -92,9 +108,14 @@ impl ChannelManager {
             inner.download_measurement_bytes += data.len();
 
             if let Entry::Occupied(entry) = inner.channels.entry(id) {
-                let _ = entry.get().send((cmd, data));
+                entry
+                    .get()
+                    .send((cmd as u8, data))
+                    .map_err(|_| ChannelError)?;
             }
-        });
+
+            Ok(())
+        })
     }
 
     pub fn get_download_rate_estimate(&self) -> usize {
@@ -114,7 +135,8 @@ impl Channel {
     fn recv_packet(&mut self, cx: &mut Context<'_>) -> Poll<Result<Bytes, ChannelError>> {
         let (cmd, packet) = ready!(self.receiver.poll_recv(cx)).ok_or(ChannelError)?;
 
-        if cmd == 0xa {
+        let packet_type = FromPrimitive::from_u8(cmd);
+        if let Some(PacketType::ChannelError) = packet_type {
             let code = BigEndian::read_u16(&packet.as_ref()[..2]);
             error!("channel error: {} {}", packet.len(), code);
 
@@ -139,7 +161,11 @@ impl Stream for Channel {
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         loop {
             match self.state.clone() {
-                ChannelState::Closed => panic!("Polling already terminated channel"),
+                ChannelState::Closed => {
+                    error!("Polling already terminated channel");
+                    return Poll::Ready(None);
+                }
+
                 ChannelState::Header(mut data) => {
                     if data.is_empty() {
                         data = ready!(self.recv_packet(cx))?;
@@ -147,7 +173,6 @@ impl Stream for Channel {
 
                     let length = BigEndian::read_u16(data.split_to(2).as_ref()) as usize;
                     if length == 0 {
-                        assert_eq!(data.len(), 0);
                         self.state = ChannelState::Data;
                     } else {
                         let header_id = data.split_to(1).as_ref()[0];

core/src/component.rs

@@ -1,20 +1,20 @@
 macro_rules! component {
     ($name:ident : $inner:ident { $($key:ident : $ty:ty = $value:expr,)* }) => {
         #[derive(Clone)]
-        pub struct $name(::std::sync::Arc<($crate::session::SessionWeak, ::std::sync::Mutex<$inner>)>);
+        pub struct $name(::std::sync::Arc<($crate::session::SessionWeak, ::parking_lot::Mutex<$inner>)>);
         impl $name {
             #[allow(dead_code)]
             pub(crate) fn new(session: $crate::session::SessionWeak) -> $name {
                 debug!(target:"librespot::component", "new {}", stringify!($name));
 
-                $name(::std::sync::Arc::new((session, ::std::sync::Mutex::new($inner {
+                $name(::std::sync::Arc::new((session, ::parking_lot::Mutex::new($inner {
                     $($key : $value,)*
                 }))))
             }
 
             #[allow(dead_code)]
             fn lock<F: FnOnce(&mut $inner) -> R, R>(&self, f: F) -> R {
-                let mut inner = (self.0).1.lock().expect("Mutex poisoned");
+                let mut inner = (self.0).1.lock();
                 f(&mut inner)
             }
 

core/src/config.rs

@@ -1,23 +1,27 @@
-use std::fmt;
-use std::str::FromStr;
+use std::{fmt, path::PathBuf, str::FromStr};
+
 use url::Url;
 
+const KEYMASTER_CLIENT_ID: &str = "65b708073fc0480ea92a077233ca87bd";
+
 #[derive(Clone, Debug)]
 pub struct SessionConfig {
-    pub user_agent: String,
+    pub client_id: String,
     pub device_id: String,
     pub proxy: Option<Url>,
     pub ap_port: Option<u16>,
+    pub tmp_dir: PathBuf,
 }
 
 impl Default for SessionConfig {
     fn default() -> SessionConfig {
         let device_id = uuid::Uuid::new_v4().as_hyphenated().to_string();
         SessionConfig {
-            user_agent: crate::version::VERSION_STRING.to_string(),
+            client_id: KEYMASTER_CLIENT_ID.to_owned(),
             device_id,
             proxy: None,
             ap_port: None,
+            tmp_dir: std::env::temp_dir(),
         }
     }
 }
@@ -116,24 +120,3 @@ impl Default for DeviceType {
         DeviceType::Speaker
     }
 }
-
-#[derive(Clone, Debug)]
-pub struct ConnectConfig {
-    pub name: String,
-    pub device_type: DeviceType,
-    pub initial_volume: Option<u16>,
-    pub has_volume_ctrl: bool,
-    pub autoplay: bool,
-}
-
-impl Default for ConnectConfig {
-    fn default() -> ConnectConfig {
-        ConnectConfig {
-            name: "Librespot".to_string(),
-            device_type: DeviceType::default(),
-            initial_volume: Some(50),
-            has_volume_ctrl: true,
-            autoplay: false,
-        }
-    }
-}

core/src/connection/codec.rs

@@ -1,12 +1,20 @@
+use std::io;
+
 use byteorder::{BigEndian, ByteOrder};
 use bytes::{BufMut, Bytes, BytesMut};
 use shannon::Shannon;
-use std::io;
+use thiserror::Error;
 use tokio_util::codec::{Decoder, Encoder};
 
 const HEADER_SIZE: usize = 3;
 const MAC_SIZE: usize = 4;
 
+#[derive(Debug, Error)]
+pub enum ApCodecError {
+    #[error("payload was malformed")]
+    Payload,
+}
+
 #[derive(Debug)]
 enum DecodeState {
     Header,
@@ -87,7 +95,10 @@ impl Decoder for ApCodec {
 
                 let mut payload = buf.split_to(size + MAC_SIZE);
 
-                self.decode_cipher.decrypt(payload.get_mut(..size).unwrap());
+                self.decode_cipher
+                    .decrypt(payload.get_mut(..size).ok_or_else(|| {
+                        io::Error::new(io::ErrorKind::InvalidData, ApCodecError::Payload)
+                    })?);
                 let mac = payload.split_off(size);
                 self.decode_cipher.check_mac(mac.as_ref())?;
 

core/src/connection/handshake.rs

@@ -1,16 +1,50 @@
+use std::{env::consts::ARCH, io};
+
 use byteorder::{BigEndian, ByteOrder, WriteBytesExt};
-use hmac::{Hmac, Mac, NewMac};
+use hmac::{Hmac, Mac};
 use protobuf::{self, Message};
 use rand::{thread_rng, RngCore};
-use sha1::Sha1;
-use std::io;
+use rsa::{BigUint, PublicKey};
+use sha1::{Digest, Sha1};
+use thiserror::Error;
 use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
 use tokio_util::codec::{Decoder, Framed};
 
 use super::codec::ApCodec;
-use crate::diffie_hellman::DhLocalKeys;
+
+use crate::{diffie_hellman::DhLocalKeys, version};
+
 use crate::protocol;
-use crate::protocol::keyexchange::{APResponseMessage, ClientHello, ClientResponsePlaintext};
+use crate::protocol::keyexchange::{
+    APResponseMessage, ClientHello, ClientResponsePlaintext, Platform, ProductFlags,
+};
+
+const SERVER_KEY: [u8; 256] = [
+    0xac, 0xe0, 0x46, 0x0b, 0xff, 0xc2, 0x30, 0xaf, 0xf4, 0x6b, 0xfe, 0xc3, 0xbf, 0xbf, 0x86, 0x3d,
+    0xa1, 0x91, 0xc6, 0xcc, 0x33, 0x6c, 0x93, 0xa1, 0x4f, 0xb3, 0xb0, 0x16, 0x12, 0xac, 0xac, 0x6a,
+    0xf1, 0x80, 0xe7, 0xf6, 0x14, 0xd9, 0x42, 0x9d, 0xbe, 0x2e, 0x34, 0x66, 0x43, 0xe3, 0x62, 0xd2,
+    0x32, 0x7a, 0x1a, 0x0d, 0x92, 0x3b, 0xae, 0xdd, 0x14, 0x02, 0xb1, 0x81, 0x55, 0x05, 0x61, 0x04,
+    0xd5, 0x2c, 0x96, 0xa4, 0x4c, 0x1e, 0xcc, 0x02, 0x4a, 0xd4, 0xb2, 0x0c, 0x00, 0x1f, 0x17, 0xed,
+    0xc2, 0x2f, 0xc4, 0x35, 0x21, 0xc8, 0xf0, 0xcb, 0xae, 0xd2, 0xad, 0xd7, 0x2b, 0x0f, 0x9d, 0xb3,
+    0xc5, 0x32, 0x1a, 0x2a, 0xfe, 0x59, 0xf3, 0x5a, 0x0d, 0xac, 0x68, 0xf1, 0xfa, 0x62, 0x1e, 0xfb,
+    0x2c, 0x8d, 0x0c, 0xb7, 0x39, 0x2d, 0x92, 0x47, 0xe3, 0xd7, 0x35, 0x1a, 0x6d, 0xbd, 0x24, 0xc2,
+    0xae, 0x25, 0x5b, 0x88, 0xff, 0xab, 0x73, 0x29, 0x8a, 0x0b, 0xcc, 0xcd, 0x0c, 0x58, 0x67, 0x31,
+    0x89, 0xe8, 0xbd, 0x34, 0x80, 0x78, 0x4a, 0x5f, 0xc9, 0x6b, 0x89, 0x9d, 0x95, 0x6b, 0xfc, 0x86,
+    0xd7, 0x4f, 0x33, 0xa6, 0x78, 0x17, 0x96, 0xc9, 0xc3, 0x2d, 0x0d, 0x32, 0xa5, 0xab, 0xcd, 0x05,
+    0x27, 0xe2, 0xf7, 0x10, 0xa3, 0x96, 0x13, 0xc4, 0x2f, 0x99, 0xc0, 0x27, 0xbf, 0xed, 0x04, 0x9c,
+    0x3c, 0x27, 0x58, 0x04, 0xb6, 0xb2, 0x19, 0xf9, 0xc1, 0x2f, 0x02, 0xe9, 0x48, 0x63, 0xec, 0xa1,
+    0xb6, 0x42, 0xa0, 0x9d, 0x48, 0x25, 0xf8, 0xb3, 0x9d, 0xd0, 0xe8, 0x6a, 0xf9, 0x48, 0x4d, 0xa1,
+    0xc2, 0xba, 0x86, 0x30, 0x42, 0xea, 0x9d, 0xb3, 0x08, 0x6c, 0x19, 0x0e, 0x48, 0xb3, 0x9d, 0x66,
+    0xeb, 0x00, 0x06, 0xa2, 0x5a, 0xee, 0xa1, 0x1b, 0x13, 0x87, 0x3c, 0xd7, 0x19, 0xe6, 0x55, 0xbd,
+];
+
+#[derive(Debug, Error)]
+pub enum HandshakeError {
+    #[error("invalid key length")]
+    InvalidLength,
+    #[error("server key verification failed")]
+    VerificationFailed,
+}
 
 pub async fn handshake<T: AsyncRead + AsyncWrite + Unpin>(
     mut connection: T,
@@ -25,9 +59,37 @@ pub async fn handshake<T: AsyncRead + AsyncWrite + Unpin>(
         .get_diffie_hellman()
         .get_gs()
         .to_owned();
+    let remote_signature = message
+        .get_challenge()
+        .get_login_crypto_challenge()
+        .get_diffie_hellman()
+        .get_gs_signature()
+        .to_owned();
 
+    // Prevent man-in-the-middle attacks: check server signature
+    let n = BigUint::from_bytes_be(&SERVER_KEY);
+    let e = BigUint::new(vec![65537]);
+    let public_key = rsa::RsaPublicKey::new(n, e).map_err(|_| {
+        io::Error::new(
+            io::ErrorKind::InvalidData,
+            HandshakeError::VerificationFailed,
+        )
+    })?;
+
+    let hash = Sha1::digest(&remote_key);
+    let padding = rsa::padding::PaddingScheme::new_pkcs1v15_sign(Some(rsa::hash::Hash::SHA1));
+    public_key
+        .verify(padding, &hash, &remote_signature)
+        .map_err(|_| {
+            io::Error::new(
+                io::ErrorKind::InvalidData,
+                HandshakeError::VerificationFailed,
+            )
+        })?;
+
+    // OK to proceed
     let shared_secret = local_keys.shared_secret(&remote_key);
-    let (challenge, send_key, recv_key) = compute_keys(&shared_secret, &accumulator);
+    let (challenge, send_key, recv_key) = compute_keys(&shared_secret, &accumulator)?;
     let codec = ApCodec::new(&send_key, &recv_key);
 
     client_response(&mut connection, challenge).await?;
@@ -42,14 +104,56 @@ where
     let mut client_nonce = vec![0; 0x10];
     thread_rng().fill_bytes(&mut client_nonce);
 
+    let platform = match std::env::consts::OS {
+        "android" => Platform::PLATFORM_ANDROID_ARM,
+        "freebsd" | "netbsd" | "openbsd" => match ARCH {
+            "x86_64" => Platform::PLATFORM_FREEBSD_X86_64,
+            _ => Platform::PLATFORM_FREEBSD_X86,
+        },
+        "ios" => match ARCH {
+            "aarch64" => Platform::PLATFORM_IPHONE_ARM64,
+            _ => Platform::PLATFORM_IPHONE_ARM,
+        },
+        "linux" => match ARCH {
+            "arm" | "aarch64" => Platform::PLATFORM_LINUX_ARM,
+            "blackfin" => Platform::PLATFORM_LINUX_BLACKFIN,
+            "mips" => Platform::PLATFORM_LINUX_MIPS,
+            "sh" => Platform::PLATFORM_LINUX_SH,
+            "x86_64" => Platform::PLATFORM_LINUX_X86_64,
+            _ => Platform::PLATFORM_LINUX_X86,
+        },
+        "macos" => match ARCH {
+            "ppc" | "ppc64" => Platform::PLATFORM_OSX_PPC,
+            "x86_64" => Platform::PLATFORM_OSX_X86_64,
+            _ => Platform::PLATFORM_OSX_X86,
+        },
+        "windows" => match ARCH {
+            "arm" | "aarch64" => Platform::PLATFORM_WINDOWS_CE_ARM,
+            "x86_64" => Platform::PLATFORM_WIN32_X86_64,
+            _ => Platform::PLATFORM_WIN32_X86,
+        },
+        _ => Platform::PLATFORM_LINUX_X86,
+    };
+
+    #[cfg(debug_assertions)]
+    const PRODUCT_FLAGS: ProductFlags = ProductFlags::PRODUCT_FLAG_DEV_BUILD;
+    #[cfg(not(debug_assertions))]
+    const PRODUCT_FLAGS: ProductFlags = ProductFlags::PRODUCT_FLAG_NONE;
+
     let mut packet = ClientHello::new();
     packet
         .mut_build_info()
-        .set_product(protocol::keyexchange::Product::PRODUCT_PARTNER);
+        // ProductInfo won't push autoplay and perhaps other settings
+        // when set to anything else than PRODUCT_CLIENT
+        .set_product(protocol::keyexchange::Product::PRODUCT_CLIENT);
     packet
         .mut_build_info()
-        .set_platform(protocol::keyexchange::Platform::PLATFORM_LINUX_X86);
-    packet.mut_build_info().set_version(109800078);
+        .mut_product_flags()
+        .push(PRODUCT_FLAGS);
+    packet.mut_build_info().set_platform(platform);
+    packet
+        .mut_build_info()
+        .set_version(version::SPOTIFY_VERSION);
     packet
         .mut_cryptosuites_supported()
         .push(protocol::keyexchange::Cryptosuite::CRYPTO_SUITE_SHANNON);
@@ -66,8 +170,8 @@ where
 
     let mut buffer = vec![0, 4];
     let size = 2 + 4 + packet.compute_size();
-    <Vec<u8> as WriteBytesExt>::write_u32::<BigEndian>(&mut buffer, size).unwrap();
-    packet.write_to_vec(&mut buffer).unwrap();
+    <Vec<u8> as WriteBytesExt>::write_u32::<BigEndian>(&mut buffer, size)?;
+    packet.write_to_vec(&mut buffer)?;
 
     connection.write_all(&buffer[..]).await?;
     Ok(buffer)
@@ -87,8 +191,8 @@ where
 
     let mut buffer = vec![];
     let size = 4 + packet.compute_size();
-    <Vec<u8> as WriteBytesExt>::write_u32::<BigEndian>(&mut buffer, size).unwrap();
-    packet.write_to_vec(&mut buffer).unwrap();
+    <Vec<u8> as WriteBytesExt>::write_u32::<BigEndian>(&mut buffer, size)?;
+    packet.write_to_vec(&mut buffer)?;
 
     connection.write_all(&buffer[..]).await?;
     Ok(())
@@ -102,7 +206,7 @@ where
     let header = read_into_accumulator(connection, 4, acc).await?;
     let size = BigEndian::read_u32(header) as usize;
     let data = read_into_accumulator(connection, size - 4, acc).await?;
-    let message = M::parse_from_bytes(data).unwrap();
+    let message = M::parse_from_bytes(data)?;
     Ok(message)
 }
 
@@ -118,24 +222,26 @@ async fn read_into_accumulator<'a, 'b, T: AsyncRead + Unpin>(
     Ok(&mut acc[offset..])
 }
 
-fn compute_keys(shared_secret: &[u8], packets: &[u8]) -> (Vec<u8>, Vec<u8>, Vec<u8>) {
+fn compute_keys(shared_secret: &[u8], packets: &[u8]) -> io::Result<(Vec<u8>, Vec<u8>, Vec<u8>)> {
     type HmacSha1 = Hmac<Sha1>;
 
     let mut data = Vec::with_capacity(0x64);
     for i in 1..6 {
-        let mut mac =
-            HmacSha1::new_from_slice(shared_secret).expect("HMAC can take key of any size");
+        let mut mac = HmacSha1::new_from_slice(shared_secret).map_err(|_| {
+            io::Error::new(io::ErrorKind::InvalidData, HandshakeError::InvalidLength)
+        })?;
         mac.update(packets);
         mac.update(&[i]);
         data.extend_from_slice(&mac.finalize().into_bytes());
     }
 
-    let mut mac = HmacSha1::new_from_slice(&data[..0x14]).expect("HMAC can take key of any size");
+    let mut mac = HmacSha1::new_from_slice(&data[..0x14])
+        .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, HandshakeError::InvalidLength))?;
     mac.update(packets);
 
-    (
+    Ok((
         mac.finalize().into_bytes().to_vec(),
         data[0x14..0x34].to_vec(),
         data[0x34..0x54].to_vec(),
-    )
+    ))
 }

core/src/connection/mod.rs

@@ -1,23 +1,21 @@
 mod codec;
 mod handshake;
 
-pub use self::codec::ApCodec;
-pub use self::handshake::handshake;
+pub use self::{codec::ApCodec, handshake::handshake};
 
-use std::io::{self, ErrorKind};
-use std::net::ToSocketAddrs;
+use std::io;
 
 use futures_util::{SinkExt, StreamExt};
-use protobuf::{self, Message, ProtobufError};
+use num_traits::FromPrimitive;
+use protobuf::{self, Message};
 use thiserror::Error;
 use tokio::net::TcpStream;
 use tokio_util::codec::Framed;
 use url::Url;
 
-use crate::authentication::Credentials;
+use crate::{authentication::Credentials, packet::PacketType, version, Error};
+
 use crate::protocol::keyexchange::{APLoginFailed, ErrorCode};
-use crate::proxytunnel;
-use crate::version;
 
 pub type Transport = Framed<TcpStream, ApCodec>;
 
@@ -42,13 +40,19 @@ fn login_error_message(code: &ErrorCode) -> &'static str {
 pub enum AuthenticationError {
     #[error("Login failed with reason: {}", login_error_message(.0))]
     LoginFailed(ErrorCode),
-    #[error("Authentication failed: {0}")]
-    IoError(#[from] io::Error),
+    #[error("invalid packet {0}")]
+    Packet(u8),
+    #[error("transport returned no data")]
+    Transport,
 }
 
-impl From<ProtobufError> for AuthenticationError {
-    fn from(e: ProtobufError) -> Self {
-        io::Error::new(ErrorKind::InvalidData, e).into()
+impl From<AuthenticationError> for Error {
+    fn from(err: AuthenticationError) -> Self {
+        match err {
+            AuthenticationError::LoginFailed(_) => Error::permission_denied(err),
+            AuthenticationError::Packet(_) => Error::unimplemented(err),
+            AuthenticationError::Transport => Error::unavailable(err),
+        }
     }
 }
 
@@ -58,50 +62,8 @@ impl From<APLoginFailed> for AuthenticationError {
     }
 }
 
-pub async fn connect(addr: String, proxy: Option<&Url>) -> io::Result<Transport> {
-    let socket = if let Some(proxy_url) = proxy {
-        info!("Using proxy \"{}\"", proxy_url);
-
-        let socket_addr = proxy_url.socket_addrs(|| None).and_then(|addrs| {
-            addrs.into_iter().next().ok_or_else(|| {
-                io::Error::new(
-                    io::ErrorKind::NotFound,
-                    "Can't resolve proxy server address",
-                )
-            })
-        })?;
-        let socket = TcpStream::connect(&socket_addr).await?;
-
-        let uri = addr.parse::<http::Uri>().map_err(|_| {
-            io::Error::new(
-                io::ErrorKind::InvalidData,
-                "Can't parse access point address",
-            )
-        })?;
-        let host = uri.host().ok_or_else(|| {
-            io::Error::new(
-                io::ErrorKind::InvalidInput,
-                "The access point address contains no hostname",
-            )
-        })?;
-        let port = uri.port().ok_or_else(|| {
-            io::Error::new(
-                io::ErrorKind::InvalidInput,
-                "The access point address contains no port",
-            )
-        })?;
-
-        proxytunnel::proxy_connect(socket, host, port.as_str()).await?
-    } else {
-        let socket_addr = addr.to_socket_addrs()?.next().ok_or_else(|| {
-            io::Error::new(
-                io::ErrorKind::NotFound,
-                "Can't resolve access point address",
-            )
-        })?;
-
-        TcpStream::connect(&socket_addr).await?
-    };
+pub async fn connect(host: &str, port: u16, proxy: Option<&Url>) -> io::Result<Transport> {
+    let socket = crate::socket::connect(host, port, proxy).await?;
 
     handshake(socket).await
 }
@@ -110,9 +72,32 @@ pub async fn authenticate(
     transport: &mut Transport,
     credentials: Credentials,
     device_id: &str,
-) -> Result<Credentials, AuthenticationError> {
+) -> Result<Credentials, Error> {
     use crate::protocol::authentication::{APWelcome, ClientResponseEncrypted, CpuFamily, Os};
 
+    let cpu_family = match std::env::consts::ARCH {
+        "blackfin" => CpuFamily::CPU_BLACKFIN,
+        "arm" | "arm64" => CpuFamily::CPU_ARM,
+        "ia64" => CpuFamily::CPU_IA64,
+        "mips" => CpuFamily::CPU_MIPS,
+        "ppc" => CpuFamily::CPU_PPC,
+        "ppc64" => CpuFamily::CPU_PPC_64,
+        "sh" => CpuFamily::CPU_SH,
+        "x86" => CpuFamily::CPU_X86,
+        "x86_64" => CpuFamily::CPU_X86_64,
+        _ => CpuFamily::CPU_UNKNOWN,
+    };
+
+    let os = match std::env::consts::OS {
+        "android" => Os::OS_ANDROID,
+        "freebsd" | "netbsd" | "openbsd" => Os::OS_FREEBSD,
+        "ios" => Os::OS_IPHONE,
+        "linux" => Os::OS_LINUX,
+        "macos" => Os::OS_OSX,
+        "windows" => Os::OS_WINDOWS,
+        _ => Os::OS_UNKNOWN,
+    };
+
     let mut packet = ClientResponseEncrypted::new();
     packet
         .mut_login_credentials()
@@ -123,29 +108,31 @@ pub async fn authenticate(
     packet
         .mut_login_credentials()
         .set_auth_data(credentials.auth_data);
-    packet
-        .mut_system_info()
-        .set_cpu_family(CpuFamily::CPU_UNKNOWN);
-    packet.mut_system_info().set_os(Os::OS_UNKNOWN);
+    packet.mut_system_info().set_cpu_family(cpu_family);
+    packet.mut_system_info().set_os(os);
     packet
         .mut_system_info()
         .set_system_information_string(format!(
-            "librespot_{}_{}",
+            "librespot-{}-{}",
             version::SHA_SHORT,
             version::BUILD_ID
         ));
     packet
         .mut_system_info()
         .set_device_id(device_id.to_string());
-    packet.set_version_string(version::VERSION_STRING.to_string());
+    packet.set_version_string(format!("librespot {}", version::SEMVER));
 
-    let cmd = 0xab;
-    let data = packet.write_to_bytes().unwrap();
+    let cmd = PacketType::Login;
+    let data = packet.write_to_bytes()?;
 
-    transport.send((cmd, data)).await?;
-    let (cmd, data) = transport.next().await.expect("EOF")?;
-    match cmd {
-        0xac => {
+    transport.send((cmd as u8, data)).await?;
+    let (cmd, data) = transport
+        .next()
+        .await
+        .ok_or(AuthenticationError::Transport)??;
+    let packet_type = FromPrimitive::from_u8(cmd);
+    let result = match packet_type {
+        Some(PacketType::APWelcome) => {
             let welcome_data = APWelcome::parse_from_bytes(data.as_ref())?;
 
             let reusable_credentials = Credentials {
@@ -156,13 +143,18 @@ pub async fn authenticate(
 
             Ok(reusable_credentials)
         }
-        0xad => {
+        Some(PacketType::AuthFailure) => {
             let error_data = APLoginFailed::parse_from_bytes(data.as_ref())?;
             Err(error_data.into())
         }
         _ => {
-            let msg = format!("Received invalid packet: {}", cmd);
-            Err(io::Error::new(ErrorKind::InvalidData, msg).into())
-        }
+            trace!(
+                "Did not expect {:?} AES key packet with data {:#?}",
+                cmd,
+                data
+            );
+            Err(AuthenticationError::Packet(cmd))
         }
+    };
+    Ok(result?)
 }

core/src/date.rs

@@ -0,0 +1,81 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use time::{error::ComponentRange, Date as _Date, OffsetDateTime, PrimitiveDateTime, Time};
+
+use crate::Error;
+
+use librespot_protocol as protocol;
+use protocol::metadata::Date as DateMessage;
+
+impl From<ComponentRange> for Error {
+    fn from(err: ComponentRange) -> Self {
+        Error::out_of_range(err)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Date(pub OffsetDateTime);
+
+impl Deref for Date {
+    type Target = OffsetDateTime;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl Date {
+    pub fn as_timestamp_ms(&self) -> i64 {
+        (self.0.unix_timestamp_nanos() / 1_000_000) as i64
+    }
+
+    pub fn from_timestamp_ms(timestamp: i64) -> Result<Self, Error> {
+        let date_time = OffsetDateTime::from_unix_timestamp_nanos(timestamp as i128 * 1_000_000)?;
+        Ok(Self(date_time))
+    }
+
+    pub fn as_utc(&self) -> OffsetDateTime {
+        self.0
+    }
+
+    pub fn from_utc(date_time: PrimitiveDateTime) -> Self {
+        Self(date_time.assume_utc())
+    }
+
+    pub fn now_utc() -> Self {
+        Self(OffsetDateTime::now_utc())
+    }
+}
+
+impl TryFrom<&DateMessage> for Date {
+    type Error = crate::Error;
+    fn try_from(msg: &DateMessage) -> Result<Self, Self::Error> {
+        // Some metadata contains a year, but no month. In that case just set January.
+        let month = if msg.has_month() {
+            msg.get_month() as u8
+        } else {
+            1
+        };
+
+        // Having no day will work, but may be unexpected: it will imply the last day
+        // of the month before. So prevent that, and just set day 1.
+        let day = if msg.has_day() {
+            msg.get_day() as u8
+        } else {
+            1
+        };
+
+        let date = _Date::from_calendar_date(msg.get_year(), month.try_into()?, day)?;
+        let time = Time::from_hms(msg.get_hour() as u8, msg.get_minute() as u8, 0)?;
+        Ok(Self::from_utc(PrimitiveDateTime::new(date, time)))
+    }
+}
+
+impl From<OffsetDateTime> for Date {
+    fn from(datetime: OffsetDateTime) -> Self {
+        Self(datetime)
+    }
+}

core/src/dealer/maps.rs

@@ -0,0 +1,130 @@
+use std::collections::HashMap;
+
+use thiserror::Error;
+
+use crate::Error;
+
+#[derive(Debug, Error)]
+pub enum HandlerMapError {
+    #[error("request was already handled")]
+    AlreadyHandled,
+}
+
+impl From<HandlerMapError> for Error {
+    fn from(err: HandlerMapError) -> Self {
+        Error::aborted(err)
+    }
+}
+
+pub enum HandlerMap<T> {
+    Leaf(T),
+    Branch(HashMap<String, HandlerMap<T>>),
+}
+
+impl<T> Default for HandlerMap<T> {
+    fn default() -> Self {
+        Self::Branch(HashMap::new())
+    }
+}
+
+impl<T> HandlerMap<T> {
+    pub fn insert<'a>(
+        &mut self,
+        mut path: impl Iterator<Item = &'a str>,
+        handler: T,
+    ) -> Result<(), Error> {
+        match self {
+            Self::Leaf(_) => Err(HandlerMapError::AlreadyHandled.into()),
+            Self::Branch(children) => {
+                if let Some(component) = path.next() {
+                    let node = children.entry(component.to_owned()).or_default();
+                    node.insert(path, handler)
+                } else if children.is_empty() {
+                    *self = Self::Leaf(handler);
+                    Ok(())
+                } else {
+                    Err(HandlerMapError::AlreadyHandled.into())
+                }
+            }
+        }
+    }
+
+    pub fn get<'a>(&self, mut path: impl Iterator<Item = &'a str>) -> Option<&T> {
+        match self {
+            Self::Leaf(t) => Some(t),
+            Self::Branch(m) => {
+                let component = path.next()?;
+                m.get(component)?.get(path)
+            }
+        }
+    }
+
+    pub fn remove<'a>(&mut self, mut path: impl Iterator<Item = &'a str>) -> Option<T> {
+        match self {
+            Self::Leaf(_) => match std::mem::take(self) {
+                Self::Leaf(t) => Some(t),
+                _ => unreachable!(),
+            },
+            Self::Branch(map) => {
+                let component = path.next()?;
+                let next = map.get_mut(component)?;
+                let result = next.remove(path);
+                match &*next {
+                    Self::Branch(b) if b.is_empty() => {
+                        map.remove(component);
+                    }
+                    _ => (),
+                }
+                result
+            }
+        }
+    }
+}
+
+pub struct SubscriberMap<T> {
+    subscribed: Vec<T>,
+    children: HashMap<String, SubscriberMap<T>>,
+}
+
+impl<T> Default for SubscriberMap<T> {
+    fn default() -> Self {
+        Self {
+            subscribed: Vec::new(),
+            children: HashMap::new(),
+        }
+    }
+}
+
+impl<T> SubscriberMap<T> {
+    pub fn insert<'a>(&mut self, mut path: impl Iterator<Item = &'a str>, handler: T) {
+        if let Some(component) = path.next() {
+            self.children
+                .entry(component.to_owned())
+                .or_default()
+                .insert(path, handler);
+        } else {
+            self.subscribed.push(handler);
+        }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.children.is_empty() && self.subscribed.is_empty()
+    }
+
+    pub fn retain<'a>(
+        &mut self,
+        mut path: impl Iterator<Item = &'a str>,
+        fun: &mut impl FnMut(&T) -> bool,
+    ) {
+        self.subscribed.retain(|x| fun(x));
+
+        if let Some(next) = path.next() {
+            if let Some(y) = self.children.get_mut(next) {
+                y.retain(path, fun);
+                if y.is_empty() {
+                    self.children.remove(next);
+                }
+            }
+        }
+    }
+}

core/src/dealer/mod.rs

@@ -0,0 +1,612 @@
+mod maps;
+pub mod protocol;
+
+use std::{
+    iter,
+    pin::Pin,
+    sync::{
+        atomic::{self, AtomicBool},
+        Arc,
+    },
+    task::Poll,
+    time::Duration,
+};
+
+use futures_core::{Future, Stream};
+use futures_util::{future::join_all, SinkExt, StreamExt};
+use parking_lot::Mutex;
+use thiserror::Error;
+use tokio::{
+    select,
+    sync::{
+        mpsc::{self, UnboundedReceiver},
+        Semaphore,
+    },
+    task::JoinHandle,
+};
+use tokio_tungstenite::tungstenite;
+use tungstenite::error::UrlError;
+use url::Url;
+
+use self::maps::*;
+use self::protocol::*;
+
+use crate::{
+    socket,
+    util::{keep_flushing, CancelOnDrop, TimeoutOnDrop},
+    Error,
+};
+
+type WsMessage = tungstenite::Message;
+type WsError = tungstenite::Error;
+type WsResult<T> = Result<T, tungstenite::Error>;
+
+const WEBSOCKET_CLOSE_TIMEOUT: Duration = Duration::from_secs(3);
+
+const PING_INTERVAL: Duration = Duration::from_secs(30);
+const PING_TIMEOUT: Duration = Duration::from_secs(3);
+
+const RECONNECT_INTERVAL: Duration = Duration::from_secs(10);
+
+pub struct Response {
+    pub success: bool,
+}
+
+pub struct Responder {
+    key: String,
+    tx: mpsc::UnboundedSender<WsMessage>,
+    sent: bool,
+}
+
+impl Responder {
+    fn new(key: String, tx: mpsc::UnboundedSender<WsMessage>) -> Self {
+        Self {
+            key,
+            tx,
+            sent: false,
+        }
+    }
+
+    // Should only be called once
+    fn send_internal(&mut self, response: Response) {
+        let response = serde_json::json!({
+            "type": "reply",
+            "key": &self.key,
+            "payload": {
+                "success": response.success,
+            }
+        })
+        .to_string();
+
+        if let Err(e) = self.tx.send(WsMessage::Text(response)) {
+            warn!("Wasn't able to reply to dealer request: {}", e);
+        }
+    }
+
+    pub fn send(mut self, response: Response) {
+        self.send_internal(response);
+        self.sent = true;
+    }
+
+    pub fn force_unanswered(mut self) {
+        self.sent = true;
+    }
+}
+
+impl Drop for Responder {
+    fn drop(&mut self) {
+        if !self.sent {
+            self.send_internal(Response { success: false });
+        }
+    }
+}
+
+pub trait IntoResponse {
+    fn respond(self, responder: Responder);
+}
+
+impl IntoResponse for Response {
+    fn respond(self, responder: Responder) {
+        responder.send(self)
+    }
+}
+
+impl<F> IntoResponse for F
+where
+    F: Future<Output = Response> + Send + 'static,
+{
+    fn respond(self, responder: Responder) {
+        tokio::spawn(async move {
+            responder.send(self.await);
+        });
+    }
+}
+
+impl<F, R> RequestHandler for F
+where
+    F: (Fn(Request) -> R) + Send + 'static,
+    R: IntoResponse,
+{
+    fn handle_request(&self, request: Request, responder: Responder) {
+        self(request).respond(responder);
+    }
+}
+
+pub trait RequestHandler: Send + 'static {
+    fn handle_request(&self, request: Request, responder: Responder);
+}
+
+type MessageHandler = mpsc::UnboundedSender<Message>;
+
+// TODO: Maybe it's possible to unregister subscription directly when they
+//       are dropped instead of on next failed attempt.
+pub struct Subscription(UnboundedReceiver<Message>);
+
+impl Stream for Subscription {
+    type Item = Message;
+
+    fn poll_next(
+        mut self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> Poll<Option<Self::Item>> {
+        self.0.poll_recv(cx)
+    }
+}
+
+fn split_uri(s: &str) -> Option<impl Iterator<Item = &'_ str>> {
+    let (scheme, sep, rest) = if let Some(rest) = s.strip_prefix("hm://") {
+        ("hm", '/', rest)
+    } else if let Some(rest) = s.strip_suffix("spotify:") {
+        ("spotify", ':', rest)
+    } else {
+        return None;
+    };
+
+    let rest = rest.trim_end_matches(sep);
+    let split = rest.split(sep);
+
+    Some(iter::once(scheme).chain(split))
+}
+
+#[derive(Debug, Clone, Error)]
+pub enum AddHandlerError {
+    #[error("There is already a handler for the given uri")]
+    AlreadyHandled,
+    #[error("The specified uri {0} is invalid")]
+    InvalidUri(String),
+}
+
+impl From<AddHandlerError> for Error {
+    fn from(err: AddHandlerError) -> Self {
+        match err {
+            AddHandlerError::AlreadyHandled => Error::aborted(err),
+            AddHandlerError::InvalidUri(_) => Error::invalid_argument(err),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Error)]
+pub enum SubscriptionError {
+    #[error("The specified uri is invalid")]
+    InvalidUri(String),
+}
+
+impl From<SubscriptionError> for Error {
+    fn from(err: SubscriptionError) -> Self {
+        Error::invalid_argument(err)
+    }
+}
+
+fn add_handler(
+    map: &mut HandlerMap<Box<dyn RequestHandler>>,
+    uri: &str,
+    handler: impl RequestHandler,
+) -> Result<(), Error> {
+    let split = split_uri(uri).ok_or_else(|| AddHandlerError::InvalidUri(uri.to_string()))?;
+    map.insert(split, Box::new(handler))
+}
+
+fn remove_handler<T>(map: &mut HandlerMap<T>, uri: &str) -> Option<T> {
+    map.remove(split_uri(uri)?)
+}
+
+fn subscribe(
+    map: &mut SubscriberMap<MessageHandler>,
+    uris: &[&str],
+) -> Result<Subscription, Error> {
+    let (tx, rx) = mpsc::unbounded_channel();
+
+    for &uri in uris {
+        let split = split_uri(uri).ok_or_else(|| SubscriptionError::InvalidUri(uri.to_string()))?;
+        map.insert(split, tx.clone());
+    }
+
+    Ok(Subscription(rx))
+}
+
+#[derive(Default)]
+pub struct Builder {
+    message_handlers: SubscriberMap<MessageHandler>,
+    request_handlers: HandlerMap<Box<dyn RequestHandler>>,
+}
+
+macro_rules! create_dealer {
+    ($builder:expr, $shared:ident -> $body:expr) => {
+        match $builder {
+            builder => {
+                let shared = Arc::new(DealerShared {
+                    message_handlers: Mutex::new(builder.message_handlers),
+                    request_handlers: Mutex::new(builder.request_handlers),
+                    notify_drop: Semaphore::new(0),
+                });
+
+                let handle = {
+                    let $shared = Arc::clone(&shared);
+                    tokio::spawn($body)
+                };
+
+                Dealer {
+                    shared,
+                    handle: TimeoutOnDrop::new(handle, WEBSOCKET_CLOSE_TIMEOUT),
+                }
+            }
+        }
+    };
+}
+
+impl Builder {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    pub fn add_handler(&mut self, uri: &str, handler: impl RequestHandler) -> Result<(), Error> {
+        add_handler(&mut self.request_handlers, uri, handler)
+    }
+
+    pub fn subscribe(&mut self, uris: &[&str]) -> Result<Subscription, Error> {
+        subscribe(&mut self.message_handlers, uris)
+    }
+
+    pub fn launch_in_background<Fut, F>(self, get_url: F, proxy: Option<Url>) -> Dealer
+    where
+        Fut: Future<Output = Url> + Send + 'static,
+        F: (FnMut() -> Fut) + Send + 'static,
+    {
+        create_dealer!(self, shared -> run(shared, None, get_url, proxy))
+    }
+
+    pub async fn launch<Fut, F>(self, mut get_url: F, proxy: Option<Url>) -> WsResult<Dealer>
+    where
+        Fut: Future<Output = Url> + Send + 'static,
+        F: (FnMut() -> Fut) + Send + 'static,
+    {
+        let dealer = create_dealer!(self, shared -> {
+            // Try to connect.
+            let url = get_url().await;
+            let tasks = connect(&url, proxy.as_ref(), &shared).await?;
+
+            // If a connection is established, continue in a background task.
+            run(shared, Some(tasks), get_url, proxy)
+        });
+
+        Ok(dealer)
+    }
+}
+
+struct DealerShared {
+    message_handlers: Mutex<SubscriberMap<MessageHandler>>,
+    request_handlers: Mutex<HandlerMap<Box<dyn RequestHandler>>>,
+
+    // Semaphore with 0 permits. By closing this semaphore, we indicate
+    // that the actual Dealer struct has been dropped.
+    notify_drop: Semaphore,
+}
+
+impl DealerShared {
+    fn dispatch_message(&self, msg: Message) {
+        if let Some(split) = split_uri(&msg.uri) {
+            self.message_handlers
+                .lock()
+                .retain(split, &mut |tx| tx.send(msg.clone()).is_ok());
+        }
+    }
+
+    fn dispatch_request(&self, request: Request, send_tx: &mpsc::UnboundedSender<WsMessage>) {
+        // ResponseSender will automatically send "success: false" if it is dropped without an answer.
+        let responder = Responder::new(request.key.clone(), send_tx.clone());
+
+        let split = if let Some(split) = split_uri(&request.message_ident) {
+            split
+        } else {
+            warn!(
+                "Dealer request with invalid message_ident: {}",
+                &request.message_ident
+            );
+            return;
+        };
+
+        {
+            let handler_map = self.request_handlers.lock();
+
+            if let Some(handler) = handler_map.get(split) {
+                handler.handle_request(request, responder);
+                return;
+            }
+        }
+
+        warn!("No handler for message_ident: {}", &request.message_ident);
+    }
+
+    fn dispatch(&self, m: MessageOrRequest, send_tx: &mpsc::UnboundedSender<WsMessage>) {
+        match m {
+            MessageOrRequest::Message(m) => self.dispatch_message(m),
+            MessageOrRequest::Request(r) => self.dispatch_request(r, send_tx),
+        }
+    }
+
+    async fn closed(&self) {
+        if self.notify_drop.acquire().await.is_ok() {
+            error!("should never have gotten a permit");
+        }
+    }
+
+    fn is_closed(&self) -> bool {
+        self.notify_drop.is_closed()
+    }
+}
+
+pub struct Dealer {
+    shared: Arc<DealerShared>,
+    handle: TimeoutOnDrop<()>,
+}
+
+impl Dealer {
+    pub fn add_handler<H>(&self, uri: &str, handler: H) -> Result<(), Error>
+    where
+        H: RequestHandler,
+    {
+        add_handler(&mut self.shared.request_handlers.lock(), uri, handler)
+    }
+
+    pub fn remove_handler(&self, uri: &str) -> Option<Box<dyn RequestHandler>> {
+        remove_handler(&mut self.shared.request_handlers.lock(), uri)
+    }
+
+    pub fn subscribe(&self, uris: &[&str]) -> Result<Subscription, Error> {
+        subscribe(&mut self.shared.message_handlers.lock(), uris)
+    }
+
+    pub async fn close(mut self) {
+        debug!("closing dealer");
+
+        self.shared.notify_drop.close();
+
+        if let Some(handle) = self.handle.take() {
+            if let Err(e) = CancelOnDrop(handle).await {
+                error!("error aborting dealer operations: {}", e);
+            }
+        }
+    }
+}
+
+/// Initializes a connection and returns futures that will finish when the connection is closed/lost.
+async fn connect(
+    address: &Url,
+    proxy: Option<&Url>,
+    shared: &Arc<DealerShared>,
+) -> WsResult<(JoinHandle<()>, JoinHandle<()>)> {
+    let host = address
+        .host_str()
+        .ok_or(WsError::Url(UrlError::NoHostName))?;
+
+    let default_port = match address.scheme() {
+        "ws" => 80,
+        "wss" => 443,
+        _ => return Err(WsError::Url(UrlError::UnsupportedUrlScheme)),
+    };
+
+    let port = address.port().unwrap_or(default_port);
+
+    let stream = socket::connect(host, port, proxy).await?;
+
+    let (mut ws_tx, ws_rx) = tokio_tungstenite::client_async_tls(address, stream)
+        .await?
+        .0
+        .split();
+
+    let (send_tx, mut send_rx) = mpsc::unbounded_channel::<WsMessage>();
+
+    // Spawn a task that will forward messages from the channel to the websocket.
+    let send_task = {
+        let shared = Arc::clone(shared);
+
+        tokio::spawn(async move {
+            let result = loop {
+                select! {
+                    biased;
+                    () = shared.closed() => {
+                        break Ok(None);
+                    }
+                    msg = send_rx.recv() => {
+                        if let Some(msg) = msg {
+                            // New message arrived through channel
+                            if let WsMessage::Close(close_frame) = msg {
+                                break Ok(close_frame);
+                            }
+
+                            if let Err(e) = ws_tx.feed(msg).await  {
+                                break Err(e);
+                            }
+                        } else {
+                            break Ok(None);
+                        }
+                    },
+                    e = keep_flushing(&mut ws_tx) => {
+                        break Err(e)
+                    }
+                    else => (),
+                }
+            };
+
+            send_rx.close();
+
+            // I don't trust in tokio_tungstenite's implementation of Sink::close.
+            let result = match result {
+                Ok(close_frame) => ws_tx.send(WsMessage::Close(close_frame)).await,
+                Err(WsError::AlreadyClosed) | Err(WsError::ConnectionClosed) => ws_tx.flush().await,
+                Err(e) => {
+                    warn!("Dealer finished with an error: {}", e);
+                    ws_tx.send(WsMessage::Close(None)).await
+                }
+            };
+
+            if let Err(e) = result {
+                warn!("Error while closing websocket: {}", e);
+            }
+
+            debug!("Dropping send task");
+        })
+    };
+
+    let shared = Arc::clone(shared);
+
+    // A task that receives messages from the web socket.
+    let receive_task = tokio::spawn(async {
+        let pong_received = AtomicBool::new(true);
+        let send_tx = send_tx;
+        let shared = shared;
+
+        let receive_task = async {
+            let mut ws_rx = ws_rx;
+
+            loop {
+                match ws_rx.next().await {
+                    Some(Ok(msg)) => match msg {
+                        WsMessage::Text(t) => match serde_json::from_str(&t) {
+                            Ok(m) => shared.dispatch(m, &send_tx),
+                            Err(e) => info!("Received invalid message: {}", e),
+                        },
+                        WsMessage::Binary(_) => {
+                            info!("Received invalid binary message");
+                        }
+                        WsMessage::Pong(_) => {
+                            debug!("Received pong");
+                            pong_received.store(true, atomic::Ordering::Relaxed);
+                        }
+                        _ => (), // tungstenite handles Close and Ping automatically
+                    },
+                    Some(Err(e)) => {
+                        warn!("Websocket connection failed: {}", e);
+                        break;
+                    }
+                    None => {
+                        debug!("Websocket connection closed.");
+                        break;
+                    }
+                }
+            }
+        };
+
+        // Sends pings and checks whether a pong comes back.
+        let ping_task = async {
+            use tokio::time::{interval, sleep};
+
+            let mut timer = interval(PING_INTERVAL);
+
+            loop {
+                timer.tick().await;
+
+                pong_received.store(false, atomic::Ordering::Relaxed);
+                if send_tx.send(WsMessage::Ping(vec![])).is_err() {
+                    // The sender is closed.
+                    break;
+                }
+
+                debug!("Sent ping");
+
+                sleep(PING_TIMEOUT).await;
+
+                if !pong_received.load(atomic::Ordering::SeqCst) {
+                    // No response
+                    warn!("Websocket peer does not respond.");
+                    break;
+                }
+            }
+        };
+
+        // Exit this task as soon as one our subtasks fails.
+        // In both cases the connection is probably lost.
+        select! {
+            () = ping_task => (),
+            () = receive_task => ()
+        }
+
+        // Try to take send_task down with us, in case it's still alive.
+        let _ = send_tx.send(WsMessage::Close(None));
+
+        debug!("Dropping receive task");
+    });
+
+    Ok((send_task, receive_task))
+}
+
+/// The main background task for `Dealer`, which coordinates reconnecting.
+async fn run<F, Fut>(
+    shared: Arc<DealerShared>,
+    initial_tasks: Option<(JoinHandle<()>, JoinHandle<()>)>,
+    mut get_url: F,
+    proxy: Option<Url>,
+) where
+    Fut: Future<Output = Url> + Send + 'static,
+    F: (FnMut() -> Fut) + Send + 'static,
+{
+    let init_task = |t| Some(TimeoutOnDrop::new(t, WEBSOCKET_CLOSE_TIMEOUT));
+
+    let mut tasks = if let Some((s, r)) = initial_tasks {
+        (init_task(s), init_task(r))
+    } else {
+        (None, None)
+    };
+
+    while !shared.is_closed() {
+        match &mut tasks {
+            (Some(t0), Some(t1)) => {
+                select! {
+                    () = shared.closed() => break,
+                    r = t0 => {
+                        if let Err(e) = r {
+                            error!("timeout on task 0: {}", e);
+                        }
+                        tasks.0.take();
+                    },
+                    r = t1 => {
+                        if let Err(e) = r {
+                            error!("timeout on task 1: {}", e);
+                        }
+                        tasks.1.take();
+                    }
+                }
+            }
+            _ => {
+                let url = select! {
+                    () = shared.closed() => {
+                        break
+                    },
+                    e = get_url() => e
+                };
+
+                match connect(&url, proxy.as_ref(), &shared).await {
+                    Ok((s, r)) => tasks = (init_task(s), init_task(r)),
+                    Err(e) => {
+                        error!("Error while connecting: {}", e);
+                        tokio::time::sleep(RECONNECT_INTERVAL).await;
+                    }
+                }
+            }
+        }
+    }
+
+    let tasks = tasks.0.into_iter().chain(tasks.1);
+
+    let _ = join_all(tasks).await;
+}

core/src/dealer/protocol.rs

@@ -0,0 +1,39 @@
+use std::collections::HashMap;
+
+use serde::Deserialize;
+
+pub type JsonValue = serde_json::Value;
+pub type JsonObject = serde_json::Map<String, JsonValue>;
+
+#[derive(Clone, Debug, Deserialize)]
+pub struct Payload {
+    pub message_id: i32,
+    pub sent_by_device_id: String,
+    pub command: JsonObject,
+}
+
+#[derive(Clone, Debug, Deserialize)]
+pub struct Request {
+    #[serde(default)]
+    pub headers: HashMap<String, String>,
+    pub message_ident: String,
+    pub key: String,
+    pub payload: Payload,
+}
+
+#[derive(Clone, Debug, Deserialize)]
+pub struct Message {
+    #[serde(default)]
+    pub headers: HashMap<String, String>,
+    pub method: Option<String>,
+    #[serde(default)]
+    pub payloads: Vec<JsonValue>,
+    pub uri: String,
+}
+
+#[derive(Clone, Debug, Deserialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub(super) enum MessageOrRequest {
+    Message(Message),
+    Request(Request),
+}

core/src/error.rs

@@ -0,0 +1,447 @@
+use std::{error, fmt, num::ParseIntError, str::Utf8Error, string::FromUtf8Error};
+
+use base64::DecodeError;
+use http::{
+    header::{InvalidHeaderName, InvalidHeaderValue, ToStrError},
+    method::InvalidMethod,
+    status::InvalidStatusCode,
+    uri::{InvalidUri, InvalidUriParts},
+};
+use protobuf::ProtobufError;
+use thiserror::Error;
+use tokio::sync::{mpsc::error::SendError, oneshot::error::RecvError};
+use url::ParseError;
+
+#[cfg(feature = "with-dns-sd")]
+use dns_sd::DNSError;
+
+#[derive(Debug)]
+pub struct Error {
+    pub kind: ErrorKind,
+    pub error: Box<dyn error::Error + Send + Sync>,
+}
+
+#[derive(Clone, Copy, Debug, Eq, Error, Hash, Ord, PartialEq, PartialOrd)]
+pub enum ErrorKind {
+    #[error("The operation was cancelled by the caller")]
+    Cancelled = 1,
+
+    #[error("Unknown error")]
+    Unknown = 2,
+
+    #[error("Client specified an invalid argument")]
+    InvalidArgument = 3,
+
+    #[error("Deadline expired before operation could complete")]
+    DeadlineExceeded = 4,
+
+    #[error("Requested entity was not found")]
+    NotFound = 5,
+
+    #[error("Attempt to create entity that already exists")]
+    AlreadyExists = 6,
+
+    #[error("Permission denied")]
+    PermissionDenied = 7,
+
+    #[error("No valid authentication credentials")]
+    Unauthenticated = 16,
+
+    #[error("Resource has been exhausted")]
+    ResourceExhausted = 8,
+
+    #[error("Invalid state")]
+    FailedPrecondition = 9,
+
+    #[error("Operation aborted")]
+    Aborted = 10,
+
+    #[error("Operation attempted past the valid range")]
+    OutOfRange = 11,
+
+    #[error("Not implemented")]
+    Unimplemented = 12,
+
+    #[error("Internal error")]
+    Internal = 13,
+
+    #[error("Service unavailable")]
+    Unavailable = 14,
+
+    #[error("Unrecoverable data loss or corruption")]
+    DataLoss = 15,
+
+    #[error("Operation must not be used")]
+    DoNotUse = -1,
+}
+
+#[derive(Debug, Error)]
+struct ErrorMessage(String);
+
+impl fmt::Display for ErrorMessage {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+impl Error {
+    pub fn new<E>(kind: ErrorKind, error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind,
+            error: error.into(),
+        }
+    }
+
+    pub fn aborted<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::Aborted,
+            error: error.into(),
+        }
+    }
+
+    pub fn already_exists<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::AlreadyExists,
+            error: error.into(),
+        }
+    }
+
+    pub fn cancelled<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::Cancelled,
+            error: error.into(),
+        }
+    }
+
+    pub fn data_loss<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::DataLoss,
+            error: error.into(),
+        }
+    }
+
+    pub fn deadline_exceeded<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::DeadlineExceeded,
+            error: error.into(),
+        }
+    }
+
+    pub fn do_not_use<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::DoNotUse,
+            error: error.into(),
+        }
+    }
+
+    pub fn failed_precondition<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::FailedPrecondition,
+            error: error.into(),
+        }
+    }
+
+    pub fn internal<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::Internal,
+            error: error.into(),
+        }
+    }
+
+    pub fn invalid_argument<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::InvalidArgument,
+            error: error.into(),
+        }
+    }
+
+    pub fn not_found<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::NotFound,
+            error: error.into(),
+        }
+    }
+
+    pub fn out_of_range<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::OutOfRange,
+            error: error.into(),
+        }
+    }
+
+    pub fn permission_denied<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::PermissionDenied,
+            error: error.into(),
+        }
+    }
+
+    pub fn resource_exhausted<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::ResourceExhausted,
+            error: error.into(),
+        }
+    }
+
+    pub fn unauthenticated<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::Unauthenticated,
+            error: error.into(),
+        }
+    }
+
+    pub fn unavailable<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::Unavailable,
+            error: error.into(),
+        }
+    }
+
+    pub fn unimplemented<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::Unimplemented,
+            error: error.into(),
+        }
+    }
+
+    pub fn unknown<E>(error: E) -> Error
+    where
+        E: Into<Box<dyn error::Error + Send + Sync>>,
+    {
+        Self {
+            kind: ErrorKind::Unknown,
+            error: error.into(),
+        }
+    }
+}
+
+impl std::error::Error for Error {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        self.error.source()
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(fmt, "{} {{ ", self.kind)?;
+        self.error.fmt(fmt)?;
+        write!(fmt, " }}")
+    }
+}
+
+impl From<DecodeError> for Error {
+    fn from(err: DecodeError) -> Self {
+        Self::new(ErrorKind::FailedPrecondition, err)
+    }
+}
+
+#[cfg(feature = "with-dns-sd")]
+impl From<DNSError> for Error {
+    fn from(err: DNSError) -> Self {
+        Self::new(ErrorKind::Unavailable, err)
+    }
+}
+
+impl From<http::Error> for Error {
+    fn from(err: http::Error) -> Self {
+        if err.is::<InvalidHeaderName>()
+            || err.is::<InvalidHeaderValue>()
+            || err.is::<InvalidMethod>()
+            || err.is::<InvalidUri>()
+            || err.is::<InvalidUriParts>()
+        {
+            return Self::new(ErrorKind::InvalidArgument, err);
+        }
+
+        if err.is::<InvalidStatusCode>() {
+            return Self::new(ErrorKind::FailedPrecondition, err);
+        }
+
+        Self::new(ErrorKind::Unknown, err)
+    }
+}
+
+impl From<hyper::Error> for Error {
+    fn from(err: hyper::Error) -> Self {
+        if err.is_parse() || err.is_parse_too_large() || err.is_parse_status() || err.is_user() {
+            return Self::new(ErrorKind::Internal, err);
+        }
+
+        if err.is_canceled() {
+            return Self::new(ErrorKind::Cancelled, err);
+        }
+
+        if err.is_connect() {
+            return Self::new(ErrorKind::Unavailable, err);
+        }
+
+        if err.is_incomplete_message() {
+            return Self::new(ErrorKind::DataLoss, err);
+        }
+
+        if err.is_body_write_aborted() || err.is_closed() {
+            return Self::new(ErrorKind::Aborted, err);
+        }
+
+        if err.is_timeout() {
+            return Self::new(ErrorKind::DeadlineExceeded, err);
+        }
+
+        Self::new(ErrorKind::Unknown, err)
+    }
+}
+
+impl From<quick_xml::Error> for Error {
+    fn from(err: quick_xml::Error) -> Self {
+        Self::new(ErrorKind::FailedPrecondition, err)
+    }
+}
+
+impl From<serde_json::Error> for Error {
+    fn from(err: serde_json::Error) -> Self {
+        Self::new(ErrorKind::FailedPrecondition, err)
+    }
+}
+
+impl From<std::io::Error> for Error {
+    fn from(err: std::io::Error) -> Self {
+        use std::io::ErrorKind as IoErrorKind;
+        match err.kind() {
+            IoErrorKind::NotFound => Self::new(ErrorKind::NotFound, err),
+            IoErrorKind::PermissionDenied => Self::new(ErrorKind::PermissionDenied, err),
+            IoErrorKind::AddrInUse | IoErrorKind::AlreadyExists => {
+                Self::new(ErrorKind::AlreadyExists, err)
+            }
+            IoErrorKind::AddrNotAvailable
+            | IoErrorKind::ConnectionRefused
+            | IoErrorKind::NotConnected => Self::new(ErrorKind::Unavailable, err),
+            IoErrorKind::BrokenPipe
+            | IoErrorKind::ConnectionReset
+            | IoErrorKind::ConnectionAborted => Self::new(ErrorKind::Aborted, err),
+            IoErrorKind::Interrupted | IoErrorKind::WouldBlock => {
+                Self::new(ErrorKind::Cancelled, err)
+            }
+            IoErrorKind::InvalidData | IoErrorKind::UnexpectedEof => {
+                Self::new(ErrorKind::FailedPrecondition, err)
+            }
+            IoErrorKind::TimedOut => Self::new(ErrorKind::DeadlineExceeded, err),
+            IoErrorKind::InvalidInput => Self::new(ErrorKind::InvalidArgument, err),
+            IoErrorKind::WriteZero => Self::new(ErrorKind::ResourceExhausted, err),
+            _ => Self::new(ErrorKind::Unknown, err),
+        }
+    }
+}
+
+impl From<FromUtf8Error> for Error {
+    fn from(err: FromUtf8Error) -> Self {
+        Self::new(ErrorKind::FailedPrecondition, err)
+    }
+}
+
+impl From<InvalidHeaderValue> for Error {
+    fn from(err: InvalidHeaderValue) -> Self {
+        Self::new(ErrorKind::InvalidArgument, err)
+    }
+}
+
+impl From<InvalidUri> for Error {
+    fn from(err: InvalidUri) -> Self {
+        Self::new(ErrorKind::InvalidArgument, err)
+    }
+}
+
+impl From<ParseError> for Error {
+    fn from(err: ParseError) -> Self {
+        Self::new(ErrorKind::FailedPrecondition, err)
+    }
+}
+
+impl From<ParseIntError> for Error {
+    fn from(err: ParseIntError) -> Self {
+        Self::new(ErrorKind::FailedPrecondition, err)
+    }
+}
+
+impl From<ProtobufError> for Error {
+    fn from(err: ProtobufError) -> Self {
+        Self::new(ErrorKind::FailedPrecondition, err)
+    }
+}
+
+impl From<RecvError> for Error {
+    fn from(err: RecvError) -> Self {
+        Self::new(ErrorKind::Internal, err)
+    }
+}
+
+impl<T> From<SendError<T>> for Error {
+    fn from(err: SendError<T>) -> Self {
+        Self {
+            kind: ErrorKind::Internal,
+            error: ErrorMessage(err.to_string()).into(),
+        }
+    }
+}
+
+impl From<ToStrError> for Error {
+    fn from(err: ToStrError) -> Self {
+        Self::new(ErrorKind::FailedPrecondition, err)
+    }
+}
+
+impl From<Utf8Error> for Error {
+    fn from(err: Utf8Error) -> Self {
+        Self::new(ErrorKind::FailedPrecondition, err)
+    }
+}

core/src/file_id.rs

@@ -0,0 +1,56 @@
+use std::fmt;
+
+use librespot_protocol as protocol;
+
+use crate::{spotify_id::to_base16, Error};
+
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct FileId(pub [u8; 20]);
+
+impl FileId {
+    pub fn from_raw(src: &[u8]) -> FileId {
+        let mut dst = [0u8; 20];
+        dst.clone_from_slice(src);
+        FileId(dst)
+    }
+
+    #[allow(clippy::wrong_self_convention)]
+    pub fn to_base16(&self) -> Result<String, Error> {
+        to_base16(&self.0, &mut [0u8; 40])
+    }
+}
+
+impl fmt::Debug for FileId {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("FileId").field(&self.to_base16()).finish()
+    }
+}
+
+impl fmt::Display for FileId {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(&self.to_base16().unwrap_or_default())
+    }
+}
+
+impl From<&[u8]> for FileId {
+    fn from(src: &[u8]) -> Self {
+        Self::from_raw(src)
+    }
+}
+impl From<&protocol::metadata::Image> for FileId {
+    fn from(image: &protocol::metadata::Image) -> Self {
+        Self::from(image.get_file_id())
+    }
+}
+
+impl From<&protocol::metadata::AudioFile> for FileId {
+    fn from(file: &protocol::metadata::AudioFile) -> Self {
+        Self::from(file.get_file_id())
+    }
+}
+
+impl From<&protocol::metadata::VideoFile> for FileId {
+    fn from(video: &protocol::metadata::VideoFile) -> Self {
+        Self::from(video.get_file_id())
+    }
+}

core/src/http_client.rs

@@ -0,0 +1,164 @@
+use std::env::consts::OS;
+
+use bytes::Bytes;
+use futures_util::{future::IntoStream, FutureExt};
+use http::header::HeaderValue;
+use hyper::{
+    client::{HttpConnector, ResponseFuture},
+    header::USER_AGENT,
+    Body, Client, Request, Response, StatusCode,
+};
+use hyper_proxy::{Intercept, Proxy, ProxyConnector};
+use hyper_rustls::{HttpsConnector, HttpsConnectorBuilder};
+use thiserror::Error;
+use url::Url;
+
+use crate::{
+    version::{FALLBACK_USER_AGENT, SPOTIFY_MOBILE_VERSION, SPOTIFY_VERSION, VERSION_STRING},
+    Error,
+};
+
+#[derive(Debug, Error)]
+pub enum HttpClientError {
+    #[error("Response status code: {0}")]
+    StatusCode(hyper::StatusCode),
+}
+
+impl From<HttpClientError> for Error {
+    fn from(err: HttpClientError) -> Self {
+        match err {
+            HttpClientError::StatusCode(code) => {
+                // not exhaustive, but what reasonably could be expected
+                match code {
+                    StatusCode::GATEWAY_TIMEOUT | StatusCode::REQUEST_TIMEOUT => {
+                        Error::deadline_exceeded(err)
+                    }
+                    StatusCode::GONE
+                    | StatusCode::NOT_FOUND
+                    | StatusCode::MOVED_PERMANENTLY
+                    | StatusCode::PERMANENT_REDIRECT
+                    | StatusCode::TEMPORARY_REDIRECT => Error::not_found(err),
+                    StatusCode::FORBIDDEN | StatusCode::PAYMENT_REQUIRED => {
+                        Error::permission_denied(err)
+                    }
+                    StatusCode::NETWORK_AUTHENTICATION_REQUIRED
+                    | StatusCode::PROXY_AUTHENTICATION_REQUIRED
+                    | StatusCode::UNAUTHORIZED => Error::unauthenticated(err),
+                    StatusCode::EXPECTATION_FAILED
+                    | StatusCode::PRECONDITION_FAILED
+                    | StatusCode::PRECONDITION_REQUIRED => Error::failed_precondition(err),
+                    StatusCode::RANGE_NOT_SATISFIABLE => Error::out_of_range(err),
+                    StatusCode::INTERNAL_SERVER_ERROR
+                    | StatusCode::MISDIRECTED_REQUEST
+                    | StatusCode::SERVICE_UNAVAILABLE
+                    | StatusCode::UNAVAILABLE_FOR_LEGAL_REASONS => Error::unavailable(err),
+                    StatusCode::BAD_REQUEST
+                    | StatusCode::HTTP_VERSION_NOT_SUPPORTED
+                    | StatusCode::LENGTH_REQUIRED
+                    | StatusCode::METHOD_NOT_ALLOWED
+                    | StatusCode::NOT_ACCEPTABLE
+                    | StatusCode::PAYLOAD_TOO_LARGE
+                    | StatusCode::REQUEST_HEADER_FIELDS_TOO_LARGE
+                    | StatusCode::UNSUPPORTED_MEDIA_TYPE
+                    | StatusCode::URI_TOO_LONG => Error::invalid_argument(err),
+                    StatusCode::TOO_MANY_REQUESTS => Error::resource_exhausted(err),
+                    StatusCode::NOT_IMPLEMENTED => Error::unimplemented(err),
+                    _ => Error::unknown(err),
+                }
+            }
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct HttpClient {
+    user_agent: HeaderValue,
+    proxy: Option<Url>,
+    https_connector: HttpsConnector<HttpConnector>,
+}
+
+impl HttpClient {
+    pub fn new(proxy: Option<&Url>) -> Self {
+        let spotify_version = match OS {
+            "android" | "ios" => SPOTIFY_MOBILE_VERSION.to_owned(),
+            _ => SPOTIFY_VERSION.to_string(),
+        };
+
+        let spotify_platform = match OS {
+            "android" => "Android/31",
+            "ios" => "iOS/15.2.1",
+            "macos" => "OSX/0",
+            "windows" => "Win32/0",
+            _ => "Linux/0",
+        };
+
+        let user_agent_str = &format!(
+            "Spotify/{} {} ({})",
+            spotify_version, spotify_platform, VERSION_STRING
+        );
+
+        let user_agent = HeaderValue::from_str(user_agent_str).unwrap_or_else(|err| {
+            error!("Invalid user agent <{}>: {}", user_agent_str, err);
+            HeaderValue::from_static(FALLBACK_USER_AGENT)
+        });
+
+        // configuring TLS is expensive and should be done once per process
+        let https_connector = HttpsConnectorBuilder::new()
+            .with_native_roots()
+            .https_or_http()
+            .enable_http1()
+            .enable_http2()
+            .build();
+
+        Self {
+            user_agent,
+            proxy: proxy.cloned(),
+            https_connector,
+        }
+    }
+
+    pub async fn request(&self, req: Request<Body>) -> Result<Response<Body>, Error> {
+        debug!("Requesting {}", req.uri().to_string());
+
+        let request = self.request_fut(req)?;
+        let response = request.await;
+
+        if let Ok(response) = &response {
+            let code = response.status();
+            if code != StatusCode::OK {
+                return Err(HttpClientError::StatusCode(code).into());
+            }
+        }
+
+        Ok(response?)
+    }
+
+    pub async fn request_body(&self, req: Request<Body>) -> Result<Bytes, Error> {
+        let response = self.request(req).await?;
+        Ok(hyper::body::to_bytes(response.into_body()).await?)
+    }
+
+    pub fn request_stream(&self, req: Request<Body>) -> Result<IntoStream<ResponseFuture>, Error> {
+        Ok(self.request_fut(req)?.into_stream())
+    }
+
+    pub fn request_fut(&self, mut req: Request<Body>) -> Result<ResponseFuture, Error> {
+        let headers_mut = req.headers_mut();
+        headers_mut.insert(USER_AGENT, self.user_agent.clone());
+
+        let request = if let Some(url) = &self.proxy {
+            let proxy_uri = url.to_string().parse()?;
+            let proxy = Proxy::new(Intercept::All, proxy_uri);
+            let proxy_connector = ProxyConnector::from_proxy(self.https_connector.clone(), proxy)?;
+
+            Client::builder().build(proxy_connector).request(req)
+        } else {
+            Client::builder()
+                .http2_adaptive_window(true)
+                .build(self.https_connector.clone())
+                .request(req)
+        };
+
+        Ok(request)
+    }
+}

core/src/keymaster.rs

@@ -1,26 +0,0 @@
-use serde::Deserialize;
-
-use crate::{mercury::MercuryError, session::Session};
-
-#[derive(Deserialize, Debug, Clone)]
-#[serde(rename_all = "camelCase")]
-pub struct Token {
-    pub access_token: String,
-    pub expires_in: u32,
-    pub token_type: String,
-    pub scope: Vec<String>,
-}
-
-pub async fn get_token(
-    session: &Session,
-    client_id: &str,
-    scopes: &str,
-) -> Result<Token, MercuryError> {
-    let url = format!(
-        "hm://keymaster/token/authenticated?client_id={}&scope={}",
-        client_id, scopes
-    );
-    let response = session.mercury().get(url).await?;
-    let data = response.payload.first().expect("Empty payload");
-    serde_json::from_slice(data.as_ref()).map_err(|_| MercuryError)
-}

core/src/lib.rs

@@ -1,27 +1,43 @@
-#![allow(clippy::unused_io_amount)]
-
 #[macro_use]
 extern crate log;
+extern crate num_derive;
 
 use librespot_protocol as protocol;
 
 #[macro_use]
 mod component;
 
-mod apresolve;
+pub mod apresolve;
 pub mod audio_key;
 pub mod authentication;
 pub mod cache;
+pub mod cdn_url;
 pub mod channel;
 pub mod config;
 mod connection;
+pub mod date;
+#[allow(dead_code)]
+mod dealer;
 #[doc(hidden)]
 pub mod diffie_hellman;
-pub mod keymaster;
+pub mod error;
+pub mod file_id;
+mod http_client;
 pub mod mercury;
+pub mod packet;
 mod proxytunnel;
 pub mod session;
+mod socket;
+#[allow(dead_code)]
+pub mod spclient;
 pub mod spotify_id;
+pub mod token;
 #[doc(hidden)]
 pub mod util;
 pub mod version;
+
+pub use config::SessionConfig;
+pub use error::Error;
+pub use file_id::FileId;
+pub use session::Session;
+pub use spotify_id::SpotifyId;

core/src/mercury/mod.rs

@@ -1,9 +1,10 @@
-use std::collections::HashMap;
-use std::future::Future;
-use std::mem;
-use std::pin::Pin;
-use std::task::Context;
-use std::task::Poll;
+use std::{
+    collections::HashMap,
+    future::Future,
+    mem,
+    pin::Pin,
+    task::{Context, Poll},
+};
 
 use byteorder::{BigEndian, ByteOrder};
 use bytes::Bytes;
@@ -11,8 +12,7 @@ use futures_util::FutureExt;
 use protobuf::Message;
 use tokio::sync::{mpsc, oneshot};
 
-use crate::protocol;
-use crate::util::SeqGenerator;
+use crate::{packet::PacketType, protocol, util::SeqGenerator, Error};
 
 mod types;
 pub use self::types::*;
@@ -32,18 +32,18 @@ component! {
 pub struct MercuryPending {
     parts: Vec<Vec<u8>>,
     partial: Option<Vec<u8>>,
-    callback: Option<oneshot::Sender<Result<MercuryResponse, MercuryError>>>,
+    callback: Option<oneshot::Sender<Result<MercuryResponse, Error>>>,
 }
 
 pub struct MercuryFuture<T> {
-    receiver: oneshot::Receiver<Result<T, MercuryError>>,
+    receiver: oneshot::Receiver<Result<T, Error>>,
 }
 
 impl<T> Future for MercuryFuture<T> {
-    type Output = Result<T, MercuryError>;
+    type Output = Result<T, Error>;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        self.receiver.poll_unpin(cx).map_err(|_| MercuryError)?
+        self.receiver.poll_unpin(cx)?
     }
 }
 
@@ -54,7 +54,7 @@ impl MercuryManager {
         seq
     }
 
-    fn request(&self, req: MercuryRequest) -> MercuryFuture<MercuryResponse> {
+    fn request(&self, req: MercuryRequest) -> Result<MercuryFuture<MercuryResponse>, Error> {
         let (tx, rx) = oneshot::channel();
 
         let pending = MercuryPending {
@@ -71,13 +71,13 @@ impl MercuryManager {
         });
 
         let cmd = req.method.command();
-        let data = req.encode(&seq);
+        let data = req.encode(&seq)?;
 
-        self.session().send_packet(cmd, data);
-        MercuryFuture { receiver: rx }
+        self.session().send_packet(cmd, data)?;
+        Ok(MercuryFuture { receiver: rx })
     }
 
-    pub fn get<T: Into<String>>(&self, uri: T) -> MercuryFuture<MercuryResponse> {
+    pub fn get<T: Into<String>>(&self, uri: T) -> Result<MercuryFuture<MercuryResponse>, Error> {
         self.request(MercuryRequest {
             method: MercuryMethod::Get,
             uri: uri.into(),
@@ -86,7 +86,11 @@ impl MercuryManager {
         })
     }
 
-    pub fn send<T: Into<String>>(&self, uri: T, data: Vec<u8>) -> MercuryFuture<MercuryResponse> {
+    pub fn send<T: Into<String>>(
+        &self,
+        uri: T,
+        data: Vec<u8>,
+    ) -> Result<MercuryFuture<MercuryResponse>, Error> {
         self.request(MercuryRequest {
             method: MercuryMethod::Send,
             uri: uri.into(),
@@ -102,7 +106,7 @@ impl MercuryManager {
     pub fn subscribe<T: Into<String>>(
         &self,
         uri: T,
-    ) -> impl Future<Output = Result<mpsc::UnboundedReceiver<MercuryResponse>, MercuryError>> + 'static
+    ) -> impl Future<Output = Result<mpsc::UnboundedReceiver<MercuryResponse>, Error>> + 'static
     {
         let uri = uri.into();
         let request = self.request(MercuryRequest {
@@ -114,7 +118,7 @@ impl MercuryManager {
 
         let manager = self.clone();
         async move {
-            let response = request.await?;
+            let response = request?.await?;
 
             let (tx, rx) = mpsc::unbounded_channel();
 
@@ -124,14 +128,19 @@ impl MercuryManager {
                     if !response.payload.is_empty() {
                         // Old subscription protocol, watch the provided list of URIs
                         for sub in response.payload {
-                            let mut sub =
-                                protocol::pubsub::Subscription::parse_from_bytes(&sub).unwrap();
+                            match protocol::pubsub::Subscription::parse_from_bytes(&sub) {
+                                Ok(mut sub) => {
                                     let sub_uri = sub.take_uri();
 
                                     debug!("subscribed sub_uri={}", sub_uri);
 
                                     inner.subscriptions.push((sub_uri, tx.clone()));
                                 }
+                                Err(e) => {
+                                    error!("could not subscribe to {}: {}", uri, e);
+                                }
+                            }
+                        }
                     } else {
                         // New subscription protocol, watch the requested URI
                         inner.subscriptions.push((uri, tx));
@@ -143,7 +152,28 @@ impl MercuryManager {
         }
     }
 
-    pub(crate) fn dispatch(&self, cmd: u8, mut data: Bytes) {
+    pub fn listen_for<T: Into<String>>(
+        &self,
+        uri: T,
+    ) -> impl Future<Output = mpsc::UnboundedReceiver<MercuryResponse>> + 'static {
+        let uri = uri.into();
+
+        let manager = self.clone();
+        async move {
+            let (tx, rx) = mpsc::unbounded_channel();
+
+            manager.lock(move |inner| {
+                if !inner.invalid {
+                    debug!("listening to uri={}", uri);
+                    inner.subscriptions.push((uri, tx));
+                }
+            });
+
+            rx
+        }
+    }
+
+    pub(crate) fn dispatch(&self, cmd: PacketType, mut data: Bytes) -> Result<(), Error> {
         let seq_len = BigEndian::read_u16(data.split_to(2).as_ref()) as usize;
         let seq = data.split_to(seq_len).as_ref().to_owned();
 
@@ -154,14 +184,17 @@ impl MercuryManager {
 
         let mut pending = match pending {
             Some(pending) => pending,
-            None if cmd == 0xb5 => MercuryPending {
+            None => {
+                if let PacketType::MercuryEvent = cmd {
+                    MercuryPending {
                         parts: Vec::new(),
                         partial: None,
                         callback: None,
-            },
-            None => {
-                warn!("Ignore seq {:?} cmd {:x}", seq, cmd);
-                return;
+                    }
+                } else {
+                    warn!("Ignore seq {:?} cmd {:x}", seq, cmd as u8);
+                    return Err(MercuryError::Command(cmd).into());
+                }
             }
         };
 
@@ -180,10 +213,12 @@ impl MercuryManager {
         }
 
         if flags == 0x1 {
-            self.complete_request(cmd, pending);
+            self.complete_request(cmd, pending)?;
         } else {
             self.lock(move |inner| inner.pending.insert(seq, pending));
         }
+
+        Ok(())
     }
 
     fn parse_part(data: &mut Bytes) -> Vec<u8> {
@@ -191,9 +226,9 @@ impl MercuryManager {
         data.split_to(size).as_ref().to_owned()
     }
 
-    fn complete_request(&self, cmd: u8, mut pending: MercuryPending) {
+    fn complete_request(&self, cmd: PacketType, mut pending: MercuryPending) -> Result<(), Error> {
         let header_data = pending.parts.remove(0);
-        let header = protocol::mercury::Header::parse_from_bytes(&header_data).unwrap();
+        let header = protocol::mercury::Header::parse_from_bytes(&header_data)?;
 
         let response = MercuryResponse {
             uri: header.get_uri().to_string(),
@@ -201,29 +236,33 @@ impl MercuryManager {
             payload: pending.parts,
         };
 
-        if response.status_code >= 500 {
-            panic!("Spotify servers returned an error. Restart librespot.");
-        } else if response.status_code >= 400 {
-            warn!("error {} for uri {}", response.status_code, &response.uri);
+        let status_code = response.status_code;
+        if status_code >= 500 {
+            error!("error {} for uri {}", status_code, &response.uri);
+            Err(MercuryError::Response(response).into())
+        } else if status_code >= 400 {
+            error!("error {} for uri {}", status_code, &response.uri);
             if let Some(cb) = pending.callback {
-                let _ = cb.send(Err(MercuryError));
+                cb.send(Err(MercuryError::Response(response.clone()).into()))
+                    .map_err(|_| MercuryError::Channel)?;
             }
-        } else if cmd == 0xb5 {
-            self.lock(|inner| {
-                let mut found = false;
-
+            Err(MercuryError::Response(response).into())
+        } else if let PacketType::MercuryEvent = cmd {
             // TODO: This is just a workaround to make utf-8 encoded usernames work.
             // A better solution would be to use an uri struct and urlencode it directly
             // before sending while saving the subscription under its unencoded form.
             let mut uri_split = response.uri.split('/');
 
-                let encoded_uri = std::iter::once(uri_split.next().unwrap().to_string())
+            let encoded_uri = std::iter::once(uri_split.next().unwrap_or_default().to_string())
                 .chain(uri_split.map(|component| {
                     form_urlencoded::byte_serialize(component.as_bytes()).collect::<String>()
                 }))
                 .collect::<Vec<String>>()
                 .join("/");
 
+            let mut found = false;
+
+            self.lock(|inner| {
                 inner.subscriptions.retain(|&(ref prefix, ref sub)| {
                     if encoded_uri.starts_with(prefix) {
                         found = true;
@@ -236,13 +275,21 @@ impl MercuryManager {
                         true
                     }
                 });
+            });
 
             if !found {
-                    debug!("unknown subscription uri={}", response.uri);
+                debug!("unknown subscription uri={}", &response.uri);
+                trace!("response pushed over Mercury: {:?}", response);
+                Err(MercuryError::Response(response).into())
+            } else {
+                Ok(())
             }
-            })
         } else if let Some(cb) = pending.callback {
-            let _ = cb.send(Ok(response));
+            cb.send(Ok(response)).map_err(|_| MercuryError::Channel)?;
+            Ok(())
+        } else {
+            error!("can't handle Mercury response: {:?}", response);
+            Err(MercuryError::Response(response).into())
         }
     }
 

core/src/mercury/sender.rs

@@ -1,6 +1,8 @@
 use std::collections::VecDeque;
 
-use super::*;
+use super::{MercuryFuture, MercuryManager, MercuryResponse};
+
+use crate::Error;
 
 pub struct MercurySender {
     mercury: MercuryManager,
@@ -23,12 +25,13 @@ impl MercurySender {
         self.buffered_future.is_none() && self.pending.is_empty()
     }
 
-    pub fn send(&mut self, item: Vec<u8>) {
-        let task = self.mercury.send(self.uri.clone(), item);
+    pub fn send(&mut self, item: Vec<u8>) -> Result<(), Error> {
+        let task = self.mercury.send(self.uri.clone(), item)?;
         self.pending.push_back(task);
+        Ok(())
     }
 
-    pub async fn flush(&mut self) -> Result<(), MercuryError> {
+    pub async fn flush(&mut self) -> Result<(), Error> {
         if self.buffered_future.is_none() {
             self.buffered_future = self.pending.pop_front();
         }

core/src/mercury/types.rs

@@ -1,8 +1,10 @@
-use byteorder::{BigEndian, WriteBytesExt};
-use protobuf::Message;
 use std::io::Write;
 
-use crate::protocol;
+use byteorder::{BigEndian, WriteBytesExt};
+use protobuf::Message;
+use thiserror::Error;
+
+use crate::{packet::PacketType, protocol, Error};
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum MercuryMethod {
@@ -27,8 +29,25 @@ pub struct MercuryResponse {
     pub payload: Vec<Vec<u8>>,
 }
 
-#[derive(Debug, Hash, PartialEq, Eq, Copy, Clone)]
-pub struct MercuryError;
+#[derive(Debug, Error)]
+pub enum MercuryError {
+    #[error("callback receiver was disconnected")]
+    Channel,
+    #[error("error handling packet type: {0:?}")]
+    Command(PacketType),
+    #[error("error handling Mercury response: {0:?}")]
+    Response(MercuryResponse),
+}
+
+impl From<MercuryError> for Error {
+    fn from(err: MercuryError) -> Self {
+        match err {
+            MercuryError::Channel => Error::aborted(err),
+            MercuryError::Command(_) => Error::unimplemented(err),
+            MercuryError::Response(_) => Error::unavailable(err),
+        }
+    }
+}
 
 impl ToString for MercuryMethod {
     fn to_string(&self) -> String {
@@ -43,24 +62,23 @@ impl ToString for MercuryMethod {
 }
 
 impl MercuryMethod {
-    pub fn command(&self) -> u8 {
+    pub fn command(&self) -> PacketType {
+        use PacketType::*;
         match *self {
-            MercuryMethod::Get | MercuryMethod::Send => 0xb2,
-            MercuryMethod::Sub => 0xb3,
-            MercuryMethod::Unsub => 0xb4,
+            MercuryMethod::Get | MercuryMethod::Send => MercuryReq,
+            MercuryMethod::Sub => MercurySub,
+            MercuryMethod::Unsub => MercuryUnsub,
         }
     }
 }
 
 impl MercuryRequest {
-    pub fn encode(&self, seq: &[u8]) -> Vec<u8> {
+    pub fn encode(&self, seq: &[u8]) -> Result<Vec<u8>, Error> {
         let mut packet = Vec::new();
-        packet.write_u16::<BigEndian>(seq.len() as u16).unwrap();
-        packet.write_all(seq).unwrap();
-        packet.write_u8(1).unwrap(); // Flags: FINAL
-        packet
-            .write_u16::<BigEndian>(1 + self.payload.len() as u16)
-            .unwrap(); // Part count
+        packet.write_u16::<BigEndian>(seq.len() as u16)?;
+        packet.write_all(seq)?;
+        packet.write_u8(1)?; // Flags: FINAL
+        packet.write_u16::<BigEndian>(1 + self.payload.len() as u16)?; // Part count
 
         let mut header = protocol::mercury::Header::new();
         header.set_uri(self.uri.clone());
@@ -70,16 +88,14 @@ impl MercuryRequest {
             header.set_content_type(content_type.clone());
         }
 
-        packet
-            .write_u16::<BigEndian>(header.compute_size() as u16)
-            .unwrap();
-        header.write_to_writer(&mut packet).unwrap();
+        packet.write_u16::<BigEndian>(header.compute_size() as u16)?;
+        header.write_to_writer(&mut packet)?;
 
         for p in &self.payload {
-            packet.write_u16::<BigEndian>(p.len() as u16).unwrap();
-            packet.write(p).unwrap();
+            packet.write_u16::<BigEndian>(p.len() as u16)?;
+            packet.write_all(p)?;
         }
 
-        packet
+        Ok(packet)
     }
 }

core/src/packet.rs

@@ -0,0 +1,41 @@
+// Ported from librespot-java. Relicensed under MIT with permission.
+
+use num_derive::{FromPrimitive, ToPrimitive};
+
+#[derive(Debug, Copy, Clone, FromPrimitive, ToPrimitive)]
+pub enum PacketType {
+    SecretBlock = 0x02,
+    Ping = 0x04,
+    StreamChunk = 0x08,
+    StreamChunkRes = 0x09,
+    ChannelError = 0x0a,
+    ChannelAbort = 0x0b,
+    RequestKey = 0x0c,
+    AesKey = 0x0d,
+    AesKeyError = 0x0e,
+    Image = 0x19,
+    CountryCode = 0x1b,
+    Pong = 0x49,
+    PongAck = 0x4a,
+    Pause = 0x4b,
+    ProductInfo = 0x50,
+    LegacyWelcome = 0x69,
+    LicenseVersion = 0x76,
+    Login = 0xab,
+    APWelcome = 0xac,
+    AuthFailure = 0xad,
+    MercuryReq = 0xb2,
+    MercurySub = 0xb3,
+    MercuryUnsub = 0xb4,
+    MercuryEvent = 0xb5,
+    TrackEndedTime = 0x82,
+    UnknownDataAllZeros = 0x1f,
+    PreferredLocale = 0x74,
+    Unknown0x0f = 0x0f,
+    Unknown0x10 = 0x10,
+    Unknown0x4f = 0x4f,
+
+    // TODO - occurs when subscribing with an empty URI. Maybe a MercuryError?
+    // Payload: b"\0\x08\0\0\0\0\0\0\0\0\x01\0\x01\0\x03 \xb0\x06"
+    Unknown0xb6 = 0xb6,
+}

core/src/session.rs

@@ -1,29 +1,41 @@
-use std::future::Future;
-use std::io;
-use std::pin::Pin;
-use std::sync::atomic::{AtomicUsize, Ordering};
-use std::sync::{Arc, RwLock, Weak};
-use std::task::Context;
-use std::task::Poll;
-use std::time::{SystemTime, UNIX_EPOCH};
+use std::{
+    collections::HashMap,
+    future::Future,
+    io,
+    pin::Pin,
+    process::exit,
+    sync::{Arc, Weak},
+    task::{Context, Poll},
+    time::{SystemTime, UNIX_EPOCH},
+};
 
 use byteorder::{BigEndian, ByteOrder};
 use bytes::Bytes;
 use futures_core::TryStream;
 use futures_util::{future, ready, StreamExt, TryStreamExt};
+use num_traits::FromPrimitive;
 use once_cell::sync::OnceCell;
+use parking_lot::RwLock;
+use quick_xml::events::Event;
 use thiserror::Error;
 use tokio::sync::mpsc;
 use tokio_stream::wrappers::UnboundedReceiverStream;
 
-use crate::apresolve::apresolve;
-use crate::audio_key::AudioKeyManager;
-use crate::authentication::Credentials;
-use crate::cache::Cache;
-use crate::channel::ChannelManager;
-use crate::config::SessionConfig;
-use crate::connection::{self, AuthenticationError};
-use crate::mercury::MercuryManager;
+use crate::{
+    apresolve::ApResolver,
+    audio_key::AudioKeyManager,
+    authentication::Credentials,
+    cache::Cache,
+    channel::ChannelManager,
+    config::SessionConfig,
+    connection::{self, AuthenticationError},
+    http_client::HttpClient,
+    mercury::MercuryManager,
+    packet::PacketType,
+    spclient::SpClient,
+    token::TokenProvider,
+    Error,
+};
 
 #[derive(Debug, Error)]
 pub enum SessionError {
@@ -31,103 +43,119 @@ pub enum SessionError {
     AuthenticationError(#[from] AuthenticationError),
     #[error("Cannot create session: {0}")]
     IoError(#[from] io::Error),
+    #[error("Session is not connected")]
+    NotConnected,
+    #[error("packet {0} unknown")]
+    Packet(u8),
 }
 
+impl From<SessionError> for Error {
+    fn from(err: SessionError) -> Self {
+        match err {
+            SessionError::AuthenticationError(_) => Error::unauthenticated(err),
+            SessionError::IoError(_) => Error::unavailable(err),
+            SessionError::NotConnected => Error::unavailable(err),
+            SessionError::Packet(_) => Error::unimplemented(err),
+        }
+    }
+}
+
+pub type UserAttributes = HashMap<String, String>;
+
+#[derive(Debug, Clone, Default)]
+pub struct UserData {
+    pub country: String,
+    pub canonical_username: String,
+    pub attributes: UserAttributes,
+}
+
+#[derive(Debug, Clone, Default)]
 struct SessionData {
-    country: String,
+    client_id: String,
+    connection_id: String,
     time_delta: i64,
-    canonical_username: String,
     invalid: bool,
+    user_data: UserData,
 }
 
 struct SessionInternal {
     config: SessionConfig,
     data: RwLock<SessionData>,
 
-    tx_connection: mpsc::UnboundedSender<(u8, Vec<u8>)>,
+    http_client: HttpClient,
+    tx_connection: OnceCell<mpsc::UnboundedSender<(u8, Vec<u8>)>>,
 
+    apresolver: OnceCell<ApResolver>,
     audio_key: OnceCell<AudioKeyManager>,
     channel: OnceCell<ChannelManager>,
     mercury: OnceCell<MercuryManager>,
+    spclient: OnceCell<SpClient>,
+    token_provider: OnceCell<TokenProvider>,
     cache: Option<Arc<Cache>>,
 
     handle: tokio::runtime::Handle,
-
-    session_id: usize,
 }
 
-static SESSION_COUNTER: AtomicUsize = AtomicUsize::new(0);
-
 #[derive(Clone)]
 pub struct Session(Arc<SessionInternal>);
 
 impl Session {
-    pub async fn connect(
-        config: SessionConfig,
-        credentials: Credentials,
-        cache: Option<Cache>,
-        store_credentials: bool,
-    ) -> Result<(Session, Credentials), SessionError> {
-        let ap = apresolve(config.proxy.as_ref(), config.ap_port).await;
+    pub fn new(config: SessionConfig, cache: Option<Cache>) -> Self {
+        let http_client = HttpClient::new(config.proxy.as_ref());
 
-        info!("Connecting to AP \"{}\"", ap);
-        let mut conn = connection::connect(ap, config.proxy.as_ref()).await?;
+        debug!("new Session");
+
+        let session_data = SessionData {
+            client_id: config.client_id.clone(),
+            ..SessionData::default()
+        };
+
+        Self(Arc::new(SessionInternal {
+            config,
+            data: RwLock::new(session_data),
+            http_client,
+            tx_connection: OnceCell::new(),
+            cache: cache.map(Arc::new),
+            apresolver: OnceCell::new(),
+            audio_key: OnceCell::new(),
+            channel: OnceCell::new(),
+            mercury: OnceCell::new(),
+            spclient: OnceCell::new(),
+            token_provider: OnceCell::new(),
+            handle: tokio::runtime::Handle::current(),
+        }))
+    }
+
+    pub async fn connect(
+        &self,
+        credentials: Credentials,
+        store_credentials: bool,
+    ) -> Result<(), Error> {
+        let ap = self.apresolver().resolve("accesspoint").await?;
+        info!("Connecting to AP \"{}:{}\"", ap.0, ap.1);
+        let mut transport = connection::connect(&ap.0, ap.1, self.config().proxy.as_ref()).await?;
 
         let reusable_credentials =
-            connection::authenticate(&mut conn, credentials, &config.device_id).await?;
+            connection::authenticate(&mut transport, credentials, &self.config().device_id).await?;
         info!("Authenticated as \"{}\" !", reusable_credentials.username);
-        if let Some(cache) = &cache {
+        self.set_username(&reusable_credentials.username);
+        if let Some(cache) = self.cache() {
             if store_credentials {
                 cache.save_credentials(&reusable_credentials);
             }
         }
 
-        let session = Session::create(
-            conn,
-            config,
-            cache,
-            reusable_credentials.username.clone(),
-            tokio::runtime::Handle::current(),
-        );
+        let (tx_connection, rx_connection) = mpsc::unbounded_channel();
+        self.0
+            .tx_connection
+            .set(tx_connection)
+            .map_err(|_| SessionError::NotConnected)?;
 
-        Ok((session, reusable_credentials))
-    }
-
-    fn create(
-        transport: connection::Transport,
-        config: SessionConfig,
-        cache: Option<Cache>,
-        username: String,
-        handle: tokio::runtime::Handle,
-    ) -> Session {
         let (sink, stream) = transport.split();
-
-        let (sender_tx, sender_rx) = mpsc::unbounded_channel();
-        let session_id = SESSION_COUNTER.fetch_add(1, Ordering::Relaxed);
-
-        debug!("new Session[{}]", session_id);
-
-        let session = Session(Arc::new(SessionInternal {
-            config,
-            data: RwLock::new(SessionData {
-                country: String::new(),
-                canonical_username: username,
-                invalid: false,
-                time_delta: 0,
-            }),
-            tx_connection: sender_tx,
-            cache: cache.map(Arc::new),
-            audio_key: OnceCell::new(),
-            channel: OnceCell::new(),
-            mercury: OnceCell::new(),
-            handle,
-            session_id,
-        }));
-
-        let sender_task = UnboundedReceiverStream::new(sender_rx)
+        let sender_task = UnboundedReceiverStream::new(rx_connection)
             .map(Ok)
             .forward(sink);
-        let receiver_task = DispatchTask(stream, session.weak());
+        let receiver_task = DispatchTask(stream, self.weak());
 
         tokio::spawn(async move {
             let result = future::try_join(sender_task, receiver_task).await;
@@ -137,7 +165,13 @@ impl Session {
             }
         });
 
-        session
+        Ok(())
+    }
+
+    pub fn apresolver(&self) -> &ApResolver {
+        self.0
+            .apresolver
+            .get_or_init(|| ApResolver::new(self.weak()))
     }
 
     pub fn audio_key(&self) -> &AudioKeyManager {
@@ -152,14 +186,28 @@ impl Session {
             .get_or_init(|| ChannelManager::new(self.weak()))
     }
 
+    pub fn http_client(&self) -> &HttpClient {
+        &self.0.http_client
+    }
+
     pub fn mercury(&self) -> &MercuryManager {
         self.0
             .mercury
             .get_or_init(|| MercuryManager::new(self.weak()))
     }
 
+    pub fn spclient(&self) -> &SpClient {
+        self.0.spclient.get_or_init(|| SpClient::new(self.weak()))
+    }
+
+    pub fn token_provider(&self) -> &TokenProvider {
+        self.0
+            .token_provider
+            .get_or_init(|| TokenProvider::new(self.weak()))
+    }
+
     pub fn time_delta(&self) -> i64 {
-        self.0.data.read().unwrap().time_delta
+        self.0.data.read().time_delta
     }
 
     pub fn spawn<T>(&self, task: T)
@@ -172,17 +220,38 @@ impl Session {
 
     fn debug_info(&self) {
         debug!(
-            "Session[{}] strong={} weak={}",
-            self.0.session_id,
+            "Session strong={} weak={}",
             Arc::strong_count(&self.0),
             Arc::weak_count(&self.0)
         );
     }
 
-    #[allow(clippy::match_same_arms)]
-    fn dispatch(&self, cmd: u8, data: Bytes) {
-        match cmd {
-            0x4 => {
+    fn check_catalogue(attributes: &UserAttributes) {
+        if let Some(account_type) = attributes.get("type") {
+            if account_type != "premium" {
+                error!("librespot does not support {:?} accounts.", account_type);
+                info!("Please support Spotify and your artists and sign up for a premium account.");
+
+                // TODO: logout instead of exiting
+                exit(1);
+            }
+        }
+    }
+
+    fn dispatch(&self, cmd: u8, data: Bytes) -> Result<(), Error> {
+        use PacketType::*;
+
+        let packet_type = FromPrimitive::from_u8(cmd);
+        let cmd = match packet_type {
+            Some(cmd) => cmd,
+            None => {
+                trace!("Ignoring unknown packet {:x}", cmd);
+                return Err(SessionError::Packet(cmd).into());
+            }
+        };
+
+        match packet_type {
+            Some(Ping) => {
                 let server_timestamp = BigEndian::read_u32(data.as_ref()) as i64;
                 let timestamp = match SystemTime::now().duration_since(UNIX_EPOCH) {
                     Ok(dur) => dur,
@@ -190,66 +259,170 @@ impl Session {
                 }
                 .as_secs() as i64;
 
-                self.0.data.write().unwrap().time_delta = server_timestamp - timestamp;
+                self.0.data.write().time_delta = server_timestamp - timestamp;
 
                 self.debug_info();
-                self.send_packet(0x49, vec![0, 0, 0, 0]);
+                self.send_packet(Pong, vec![0, 0, 0, 0])
             }
-            0x4a => (),
-            0x1b => {
-                let country = String::from_utf8(data.as_ref().to_owned()).unwrap();
+            Some(CountryCode) => {
+                let country = String::from_utf8(data.as_ref().to_owned())?;
                 info!("Country: {:?}", country);
-                self.0.data.write().unwrap().country = country;
+                self.0.data.write().user_data.country = country;
+                Ok(())
             }
+            Some(StreamChunkRes) | Some(ChannelError) => self.channel().dispatch(cmd, data),
+            Some(AesKey) | Some(AesKeyError) => self.audio_key().dispatch(cmd, data),
+            Some(MercuryReq) | Some(MercurySub) | Some(MercuryUnsub) | Some(MercuryEvent) => {
+                self.mercury().dispatch(cmd, data)
+            }
+            Some(ProductInfo) => {
+                let data = std::str::from_utf8(&data)?;
+                let mut reader = quick_xml::Reader::from_str(data);
 
-            0x9 | 0xa => self.channel().dispatch(cmd, data),
-            0xd | 0xe => self.audio_key().dispatch(cmd, data),
-            0xb2..=0xb6 => self.mercury().dispatch(cmd, data),
-            _ => (),
+                let mut buf = Vec::new();
+                let mut current_element = String::new();
+                let mut user_attributes: UserAttributes = HashMap::new();
+
+                loop {
+                    match reader.read_event(&mut buf) {
+                        Ok(Event::Start(ref element)) => {
+                            current_element = std::str::from_utf8(element.name())?.to_owned()
+                        }
+                        Ok(Event::End(_)) => {
+                            current_element = String::new();
+                        }
+                        Ok(Event::Text(ref value)) => {
+                            if !current_element.is_empty() {
+                                let _ = user_attributes.insert(
+                                    current_element.clone(),
+                                    value.unescape_and_decode(&reader)?,
+                                );
+                            }
+                        }
+                        Ok(Event::Eof) => break,
+                        Ok(_) => (),
+                        Err(e) => error!(
+                            "Error parsing XML at position {}: {:?}",
+                            reader.buffer_position(),
+                            e
+                        ),
                     }
                 }
 
-    pub fn send_packet(&self, cmd: u8, data: Vec<u8>) {
-        self.0.tx_connection.send((cmd, data)).unwrap();
+                trace!("Received product info: {:#?}", user_attributes);
+                Self::check_catalogue(&user_attributes);
+
+                self.0.data.write().user_data.attributes = user_attributes;
+                Ok(())
+            }
+            Some(PongAck)
+            | Some(SecretBlock)
+            | Some(LegacyWelcome)
+            | Some(UnknownDataAllZeros)
+            | Some(LicenseVersion) => Ok(()),
+            _ => {
+                trace!("Ignoring {:?} packet with data {:#?}", cmd, data);
+                Err(SessionError::Packet(cmd as u8).into())
+            }
+        }
+    }
+
+    pub fn send_packet(&self, cmd: PacketType, data: Vec<u8>) -> Result<(), Error> {
+        match self.0.tx_connection.get() {
+            Some(tx) => Ok(tx.send((cmd as u8, data))?),
+            None => Err(SessionError::NotConnected.into()),
+        }
     }
 
     pub fn cache(&self) -> Option<&Arc<Cache>> {
         self.0.cache.as_ref()
     }
 
-    fn config(&self) -> &SessionConfig {
+    pub fn config(&self) -> &SessionConfig {
         &self.0.config
     }
 
-    pub fn username(&self) -> String {
-        self.0.data.read().unwrap().canonical_username.clone()
-    }
-
-    pub fn country(&self) -> String {
-        self.0.data.read().unwrap().country.clone()
+    // This clones a fairly large struct, so use a specific getter or setter unless
+    // you need more fields at once, in which case this can spare multiple `read`
+    // locks.
+    pub fn user_data(&self) -> UserData {
+        self.0.data.read().user_data.clone()
     }
 
     pub fn device_id(&self) -> &str {
         &self.config().device_id
     }
 
+    pub fn client_id(&self) -> String {
+        self.0.data.read().client_id.clone()
+    }
+
+    pub fn set_client_id(&self, client_id: &str) {
+        self.0.data.write().client_id = client_id.to_owned();
+    }
+
+    pub fn connection_id(&self) -> String {
+        self.0.data.read().connection_id.clone()
+    }
+
+    pub fn set_connection_id(&self, connection_id: &str) {
+        self.0.data.write().connection_id = connection_id.to_owned();
+    }
+
+    pub fn username(&self) -> String {
+        self.0.data.read().user_data.canonical_username.clone()
+    }
+
+    pub fn set_username(&self, username: &str) {
+        self.0.data.write().user_data.canonical_username = username.to_owned();
+    }
+
+    pub fn country(&self) -> String {
+        self.0.data.read().user_data.country.clone()
+    }
+
+    pub fn set_user_attribute(&self, key: &str, value: &str) -> Option<String> {
+        let mut dummy_attributes = UserAttributes::new();
+        dummy_attributes.insert(key.to_owned(), value.to_owned());
+        Self::check_catalogue(&dummy_attributes);
+
+        self.0
+            .data
+            .write()
+            .user_data
+            .attributes
+            .insert(key.to_owned(), value.to_owned())
+    }
+
+    pub fn set_user_attributes(&self, attributes: UserAttributes) {
+        Self::check_catalogue(&attributes);
+
+        self.0.data.write().user_data.attributes.extend(attributes)
+    }
+
+    pub fn get_user_attribute(&self, key: &str) -> Option<String> {
+        self.0
+            .data
+            .read()
+            .user_data
+            .attributes
+            .get(key)
+            .map(Clone::clone)
+    }
+
     fn weak(&self) -> SessionWeak {
         SessionWeak(Arc::downgrade(&self.0))
     }
 
-    pub fn session_id(&self) -> usize {
-        self.0.session_id
-    }
-
     pub fn shutdown(&self) {
-        debug!("Invalidating session[{}]", self.0.session_id);
-        self.0.data.write().unwrap().invalid = true;
+        debug!("Invalidating session");
+        self.0.data.write().invalid = true;
         self.mercury().shutdown();
         self.channel().shutdown();
     }
 
     pub fn is_invalid(&self) -> bool {
-        self.0.data.read().unwrap().invalid
+        self.0.data.read().invalid
     }
 }
 
@@ -262,13 +435,14 @@ impl SessionWeak {
     }
 
     pub(crate) fn upgrade(&self) -> Session {
-        self.try_upgrade().expect("Session died")
+        self.try_upgrade()
+            .expect("session was dropped and so should have this component")
     }
 }
 
 impl Drop for SessionInternal {
     fn drop(&mut self) {
-        debug!("drop Session[{}]", self.session_id);
+        debug!("drop Session");
     }
 }
 
@@ -303,7 +477,9 @@ where
                 }
             };
 
-            session.dispatch(cmd, data);
+            if let Err(e) = session.dispatch(cmd, data) {
+                error!("could not dispatch command: {}", e);
+            }
         }
     }
 }

core/src/socket.rs

@@ -0,0 +1,34 @@
+use std::{io, net::ToSocketAddrs};
+
+use tokio::net::TcpStream;
+use url::Url;
+
+use crate::proxytunnel;
+
+pub async fn connect(host: &str, port: u16, proxy: Option<&Url>) -> io::Result<TcpStream> {
+    let socket = if let Some(proxy_url) = proxy {
+        info!("Using proxy \"{}\"", proxy_url);
+
+        let socket_addr = proxy_url.socket_addrs(|| None).and_then(|addrs| {
+            addrs.into_iter().next().ok_or_else(|| {
+                io::Error::new(
+                    io::ErrorKind::NotFound,
+                    "Can't resolve proxy server address",
+                )
+            })
+        })?;
+        let socket = TcpStream::connect(&socket_addr).await?;
+
+        proxytunnel::proxy_connect(socket, host, &port.to_string()).await?
+    } else {
+        let socket_addr = (host, port).to_socket_addrs()?.next().ok_or_else(|| {
+            io::Error::new(
+                io::ErrorKind::NotFound,
+                "Can't resolve access point address",
+            )
+        })?;
+
+        TcpStream::connect(&socket_addr).await?
+    };
+    Ok(socket)
+}

core/src/spclient.rs

@@ -0,0 +1,496 @@
+use std::{
+    convert::TryInto,
+    fmt::Write,
+    time::{Duration, Instant},
+};
+
+use bytes::Bytes;
+use futures_util::future::IntoStream;
+use http::header::HeaderValue;
+use hyper::{
+    client::ResponseFuture,
+    header::{ACCEPT, AUTHORIZATION, CONTENT_ENCODING, CONTENT_TYPE, RANGE},
+    Body, HeaderMap, Method, Request,
+};
+use protobuf::Message;
+use rand::Rng;
+use thiserror::Error;
+
+use crate::{
+    apresolve::SocketAddress,
+    cdn_url::CdnUrl,
+    error::ErrorKind,
+    protocol::{
+        canvaz::EntityCanvazRequest,
+        clienttoken_http::{ClientTokenRequest, ClientTokenRequestType, ClientTokenResponse},
+        connect::PutStateRequest,
+        extended_metadata::BatchedEntityRequest,
+    },
+    token::Token,
+    version, Error, FileId, SpotifyId,
+};
+
+component! {
+    SpClient : SpClientInner {
+        accesspoint: Option<SocketAddress> = None,
+        strategy: RequestStrategy = RequestStrategy::default(),
+        client_token: Option<Token> = None,
+    }
+}
+
+pub type SpClientResult = Result<Bytes, Error>;
+
+#[derive(Debug, Error)]
+pub enum SpClientError {
+    #[error("missing attribute {0}")]
+    Attribute(String),
+}
+
+impl From<SpClientError> for Error {
+    fn from(err: SpClientError) -> Self {
+        Self::failed_precondition(err)
+    }
+}
+
+#[derive(Copy, Clone, Debug)]
+pub enum RequestStrategy {
+    TryTimes(usize),
+    Infinitely,
+}
+
+impl Default for RequestStrategy {
+    fn default() -> Self {
+        RequestStrategy::TryTimes(10)
+    }
+}
+
+impl SpClient {
+    pub fn set_strategy(&self, strategy: RequestStrategy) {
+        self.lock(|inner| inner.strategy = strategy)
+    }
+
+    pub async fn flush_accesspoint(&self) {
+        self.lock(|inner| inner.accesspoint = None)
+    }
+
+    pub async fn get_accesspoint(&self) -> Result<SocketAddress, Error> {
+        // Memoize the current access point.
+        let ap = self.lock(|inner| inner.accesspoint.clone());
+        let tuple = match ap {
+            Some(tuple) => tuple,
+            None => {
+                let tuple = self.session().apresolver().resolve("spclient").await?;
+                self.lock(|inner| inner.accesspoint = Some(tuple.clone()));
+                info!(
+                    "Resolved \"{}:{}\" as spclient access point",
+                    tuple.0, tuple.1
+                );
+                tuple
+            }
+        };
+        Ok(tuple)
+    }
+
+    pub async fn base_url(&self) -> Result<String, Error> {
+        let ap = self.get_accesspoint().await?;
+        Ok(format!("https://{}:{}", ap.0, ap.1))
+    }
+
+    pub async fn client_token(&self) -> Result<String, Error> {
+        let client_token = self.lock(|inner| {
+            if let Some(token) = &inner.client_token {
+                if token.is_expired() {
+                    inner.client_token = None;
+                }
+            }
+            inner.client_token.clone()
+        });
+
+        if let Some(client_token) = client_token {
+            return Ok(client_token.access_token);
+        }
+
+        trace!("Client token unavailable or expired, requesting new token.");
+
+        let mut message = ClientTokenRequest::new();
+        message.set_request_type(ClientTokenRequestType::REQUEST_CLIENT_DATA_REQUEST);
+
+        let client_data = message.mut_client_data();
+        client_data.set_client_id(self.session().client_id());
+        client_data.set_client_version(version::SEMVER.to_string());
+
+        let connectivity_data = client_data.mut_connectivity_sdk_data();
+        connectivity_data.set_device_id(self.session().device_id().to_string());
+
+        let platform_data = connectivity_data.mut_platform_specific_data();
+
+        match std::env::consts::OS {
+            "windows" => {
+                let (pe, image_file) = match std::env::consts::ARCH {
+                    "arm" => (448, 452),
+                    "aarch64" => (43620, 452),
+                    "x86_64" => (34404, 34404),
+                    _ => (332, 332), // x86
+                };
+
+                let windows_data = platform_data.mut_desktop_windows();
+                windows_data.set_os_version(10);
+                windows_data.set_os_build(21370);
+                windows_data.set_platform_id(2);
+                windows_data.set_unknown_value_6(9);
+                windows_data.set_image_file_machine(image_file);
+                windows_data.set_pe_machine(pe);
+                windows_data.set_unknown_value_10(true);
+            }
+            "ios" => {
+                let ios_data = platform_data.mut_ios();
+                ios_data.set_user_interface_idiom(0);
+                ios_data.set_target_iphone_simulator(false);
+                ios_data.set_hw_machine("iPhone14,5".to_string());
+                ios_data.set_system_version("15.2.1".to_string());
+            }
+            "android" => {
+                let android_data = platform_data.mut_android();
+                android_data.set_android_version("12.0.0_r26".to_string());
+                android_data.set_api_version(31);
+                android_data.set_device_name("Pixel".to_owned());
+                android_data.set_model_str("GF5KQ".to_owned());
+                android_data.set_vendor("Google".to_owned());
+            }
+            "macos" => {
+                let macos_data = platform_data.mut_desktop_macos();
+                macos_data.set_system_version("Darwin Kernel Version 17.7.0: Fri Oct 30 13:34:27 PDT 2020; root:xnu-4570.71.82.8~1/RELEASE_X86_64".to_string());
+                macos_data.set_hw_model("iMac21,1".to_string());
+                macos_data.set_compiled_cpu_type(std::env::consts::ARCH.to_string());
+            }
+            _ => {
+                let linux_data = platform_data.mut_desktop_linux();
+                linux_data.set_system_name("Linux".to_string());
+                linux_data.set_system_release("5.4.0-56-generic".to_string());
+                linux_data
+                    .set_system_version("#62-Ubuntu SMP Mon Nov 23 19:20:19 UTC 2020".to_string());
+                linux_data.set_hardware(std::env::consts::ARCH.to_string());
+            }
+        }
+
+        let body = message.write_to_bytes()?;
+
+        let request = Request::builder()
+            .method(&Method::POST)
+            .uri("https://clienttoken.spotify.com/v1/clienttoken")
+            .header(ACCEPT, HeaderValue::from_static("application/x-protobuf"))
+            .header(CONTENT_ENCODING, HeaderValue::from_static(""))
+            .body(Body::from(body))?;
+
+        let response = self.session().http_client().request_body(request).await?;
+        let message = ClientTokenResponse::parse_from_bytes(&response)?;
+
+        let client_token = self.lock(|inner| {
+            let access_token = message.get_granted_token().get_token().to_owned();
+
+            let client_token = Token {
+                access_token: access_token.clone(),
+                expires_in: Duration::from_secs(
+                    message
+                        .get_granted_token()
+                        .get_refresh_after_seconds()
+                        .try_into()
+                        .unwrap_or(7200),
+                ),
+                token_type: "client-token".to_string(),
+                scopes: message
+                    .get_granted_token()
+                    .get_domains()
+                    .iter()
+                    .map(|d| d.domain.clone())
+                    .collect(),
+                timestamp: Instant::now(),
+            };
+
+            trace!("Got client token: {:?}", client_token);
+
+            inner.client_token = Some(client_token);
+            access_token
+        });
+
+        Ok(client_token)
+    }
+
+    pub async fn request_with_protobuf(
+        &self,
+        method: &Method,
+        endpoint: &str,
+        headers: Option<HeaderMap>,
+        message: &dyn Message,
+    ) -> SpClientResult {
+        let body = protobuf::text_format::print_to_string(message);
+
+        let mut headers = headers.unwrap_or_else(HeaderMap::new);
+        headers.insert(
+            CONTENT_TYPE,
+            HeaderValue::from_static("application/x-protobuf"),
+        );
+
+        self.request(method, endpoint, Some(headers), Some(body))
+            .await
+    }
+
+    pub async fn request_as_json(
+        &self,
+        method: &Method,
+        endpoint: &str,
+        headers: Option<HeaderMap>,
+        body: Option<String>,
+    ) -> SpClientResult {
+        let mut headers = headers.unwrap_or_else(HeaderMap::new);
+        headers.insert(ACCEPT, HeaderValue::from_static("application/json"));
+
+        self.request(method, endpoint, Some(headers), body).await
+    }
+
+    pub async fn request(
+        &self,
+        method: &Method,
+        endpoint: &str,
+        headers: Option<HeaderMap>,
+        body: Option<String>,
+    ) -> SpClientResult {
+        let mut tries: usize = 0;
+        let mut last_response;
+
+        let body = body.unwrap_or_default();
+
+        loop {
+            tries += 1;
+
+            // Reconnection logic: retrieve the endpoint every iteration, so we can try
+            // another access point when we are experiencing network issues (see below).
+            let mut url = self.base_url().await?;
+            url.push_str(endpoint);
+
+            // Add metrics. There is also an optional `partner` key with a value like
+            // `vodafone-uk` but we've yet to discover how we can find that value.
+            let separator = match url.find('?') {
+                Some(_) => "&",
+                None => "?",
+            };
+            let _ = write!(url, "{}product=0", separator);
+
+            let mut request = Request::builder()
+                .method(method)
+                .uri(url)
+                .body(Body::from(body.clone()))?;
+
+            // Reconnection logic: keep getting (cached) tokens because they might have expired.
+            let token = self
+                .session()
+                .token_provider()
+                .get_token("playlist-read")
+                .await?;
+
+            let headers_mut = request.headers_mut();
+            if let Some(ref hdrs) = headers {
+                *headers_mut = hdrs.clone();
+            }
+            headers_mut.insert(
+                AUTHORIZATION,
+                HeaderValue::from_str(&format!("{} {}", token.token_type, token.access_token,))?,
+            );
+
+            last_response = self.session().http_client().request_body(request).await;
+
+            if last_response.is_ok() {
+                return last_response;
+            }
+
+            // Break before the reconnection logic below, so that the current access point
+            // is retained when max_tries == 1. Leave it up to the caller when to flush.
+            if let RequestStrategy::TryTimes(max_tries) = self.lock(|inner| inner.strategy) {
+                if tries >= max_tries {
+                    break;
+                }
+            }
+
+            // Reconnection logic: drop the current access point if we are experiencing issues.
+            // This will cause the next call to base_url() to resolve a new one.
+            if let Err(ref network_error) = last_response {
+                match network_error.kind {
+                    ErrorKind::Unavailable | ErrorKind::DeadlineExceeded => {
+                        // Keep trying the current access point three times before dropping it.
+                        if tries % 3 == 0 {
+                            self.flush_accesspoint().await
+                        }
+                    }
+                    _ => break, // if we can't build the request now, then we won't ever
+                }
+            }
+
+            // When retrying, avoid hammering the Spotify infrastructure by sleeping a while.
+            // The backoff time is chosen randomly from an ever-increasing range.
+            let max_seconds = u64::pow(tries as u64, 2) * 3;
+            let backoff = Duration::from_secs(rand::thread_rng().gen_range(1..=max_seconds));
+            warn!(
+                "Unable to complete API request, waiting {} seconds before retrying...",
+                backoff.as_secs(),
+            );
+            debug!("Error was: {:?}", last_response);
+            tokio::time::sleep(backoff).await;
+        }
+
+        last_response
+    }
+
+    pub async fn put_connect_state(
+        &self,
+        connection_id: String,
+        state: PutStateRequest,
+    ) -> SpClientResult {
+        let endpoint = format!("/connect-state/v1/devices/{}", self.session().device_id());
+
+        let mut headers = HeaderMap::new();
+        headers.insert("X-Spotify-Connection-Id", connection_id.parse()?);
+
+        self.request_with_protobuf(&Method::PUT, &endpoint, Some(headers), &state)
+            .await
+    }
+
+    pub async fn get_metadata(&self, scope: &str, id: SpotifyId) -> SpClientResult {
+        let endpoint = format!("/metadata/4/{}/{}", scope, id.to_base16()?);
+        self.request(&Method::GET, &endpoint, None, None).await
+    }
+
+    pub async fn get_track_metadata(&self, track_id: SpotifyId) -> SpClientResult {
+        self.get_metadata("track", track_id).await
+    }
+
+    pub async fn get_episode_metadata(&self, episode_id: SpotifyId) -> SpClientResult {
+        self.get_metadata("episode", episode_id).await
+    }
+
+    pub async fn get_album_metadata(&self, album_id: SpotifyId) -> SpClientResult {
+        self.get_metadata("album", album_id).await
+    }
+
+    pub async fn get_artist_metadata(&self, artist_id: SpotifyId) -> SpClientResult {
+        self.get_metadata("artist", artist_id).await
+    }
+
+    pub async fn get_show_metadata(&self, show_id: SpotifyId) -> SpClientResult {
+        self.get_metadata("show", show_id).await
+    }
+
+    pub async fn get_lyrics(&self, track_id: SpotifyId) -> SpClientResult {
+        let endpoint = format!("/color-lyrics/v1/track/{}", track_id.to_base62()?);
+
+        self.request_as_json(&Method::GET, &endpoint, None, None)
+            .await
+    }
+
+    pub async fn get_lyrics_for_image(
+        &self,
+        track_id: SpotifyId,
+        image_id: FileId,
+    ) -> SpClientResult {
+        let endpoint = format!(
+            "/color-lyrics/v2/track/{}/image/spotify:image:{}",
+            track_id.to_base62()?,
+            image_id
+        );
+
+        self.request_as_json(&Method::GET, &endpoint, None, None)
+            .await
+    }
+
+    // TODO: Find endpoint for newer canvas.proto and upgrade to that.
+    pub async fn get_canvases(&self, request: EntityCanvazRequest) -> SpClientResult {
+        let endpoint = "/canvaz-cache/v0/canvases";
+        self.request_with_protobuf(&Method::POST, endpoint, None, &request)
+            .await
+    }
+
+    pub async fn get_extended_metadata(&self, request: BatchedEntityRequest) -> SpClientResult {
+        let endpoint = "/extended-metadata/v0/extended-metadata";
+        self.request_with_protobuf(&Method::POST, endpoint, None, &request)
+            .await
+    }
+
+    pub async fn get_audio_storage(&self, file_id: FileId) -> SpClientResult {
+        let endpoint = format!(
+            "/storage-resolve/files/audio/interactive/{}",
+            file_id.to_base16()?
+        );
+        self.request(&Method::GET, &endpoint, None, None).await
+    }
+
+    pub fn stream_from_cdn(
+        &self,
+        cdn_url: &CdnUrl,
+        offset: usize,
+        length: usize,
+    ) -> Result<IntoStream<ResponseFuture>, Error> {
+        let url = cdn_url.try_get_url()?;
+        let req = Request::builder()
+            .method(&Method::GET)
+            .uri(url)
+            .header(
+                RANGE,
+                HeaderValue::from_str(&format!("bytes={}-{}", offset, offset + length - 1))?,
+            )
+            .body(Body::empty())?;
+
+        let stream = self.session().http_client().request_stream(req)?;
+
+        Ok(stream)
+    }
+
+    pub async fn request_url(&self, url: String) -> SpClientResult {
+        let request = Request::builder()
+            .method(&Method::GET)
+            .uri(url)
+            .body(Body::empty())?;
+
+        self.session().http_client().request_body(request).await
+    }
+
+    // Audio preview in 96 kbps MP3, unencrypted
+    pub async fn get_audio_preview(&self, preview_id: &FileId) -> SpClientResult {
+        let attribute = "audio-preview-url-template";
+        let template = self
+            .session()
+            .get_user_attribute(attribute)
+            .ok_or_else(|| SpClientError::Attribute(attribute.to_string()))?;
+
+        let mut url = template.replace("{id}", &preview_id.to_base16()?);
+        let separator = match url.find('?') {
+            Some(_) => "&",
+            None => "?",
+        };
+        let _ = write!(url, "{}cid={}", separator, self.session().client_id());
+
+        self.request_url(url).await
+    }
+
+    // The first 128 kB of a track, unencrypted
+    pub async fn get_head_file(&self, file_id: FileId) -> SpClientResult {
+        let attribute = "head-files-url";
+        let template = self
+            .session()
+            .get_user_attribute(attribute)
+            .ok_or_else(|| SpClientError::Attribute(attribute.to_string()))?;
+
+        let url = template.replace("{file_id}", &file_id.to_base16()?);
+
+        self.request_url(url).await
+    }
+
+    pub async fn get_image(&self, image_id: FileId) -> SpClientResult {
+        let attribute = "image-url";
+        let template = self
+            .session()
+            .get_user_attribute(attribute)
+            .ok_or_else(|| SpClientError::Attribute(attribute.to_string()))?;
+        let url = template.replace("{file_id}", &image_id.to_base16()?);
+
+        self.request_url(url).await
+    }
+}

core/src/spotify_id.rs

@@ -1,44 +1,81 @@
-#![allow(clippy::wrong_self_convention)]
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt,
+    ops::Deref,
+};
 
-use std::convert::TryInto;
-use std::fmt;
-use std::string::FromUtf8Error;
+use thiserror::Error;
+
+use crate::Error;
+
+use librespot_protocol as protocol;
+
+// re-export FileId for historic reasons, when it was part of this mod
+pub use crate::FileId;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum SpotifyAudioType {
+pub enum SpotifyItemType {
+    Album,
+    Artist,
+    Episode,
+    Playlist,
+    Show,
     Track,
-    Podcast,
-    NonPlayable,
+    Unknown,
 }
 
-impl From<&str> for SpotifyAudioType {
+impl From<&str> for SpotifyItemType {
     fn from(v: &str) -> Self {
         match v {
-            "track" => SpotifyAudioType::Track,
-            "episode" => SpotifyAudioType::Podcast,
-            _ => SpotifyAudioType::NonPlayable,
+            "album" => Self::Album,
+            "artist" => Self::Artist,
+            "episode" => Self::Episode,
+            "playlist" => Self::Playlist,
+            "show" => Self::Show,
+            "track" => Self::Track,
+            _ => Self::Unknown,
         }
     }
 }
 
-impl From<SpotifyAudioType> for &str {
-    fn from(audio_type: SpotifyAudioType) -> &'static str {
-        match audio_type {
-            SpotifyAudioType::Track => "track",
-            SpotifyAudioType::Podcast => "episode",
-            SpotifyAudioType::NonPlayable => "unknown",
+impl From<SpotifyItemType> for &str {
+    fn from(item_type: SpotifyItemType) -> &'static str {
+        match item_type {
+            SpotifyItemType::Album => "album",
+            SpotifyItemType::Artist => "artist",
+            SpotifyItemType::Episode => "episode",
+            SpotifyItemType::Playlist => "playlist",
+            SpotifyItemType::Show => "show",
+            SpotifyItemType::Track => "track",
+            _ => "unknown",
         }
     }
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Clone, Copy, PartialEq, Eq, Hash)]
 pub struct SpotifyId {
     pub id: u128,
-    pub audio_type: SpotifyAudioType,
+    pub item_type: SpotifyItemType,
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-pub struct SpotifyIdError;
+#[derive(Debug, Error, Clone, Copy, PartialEq, Eq)]
+pub enum SpotifyIdError {
+    #[error("ID cannot be parsed")]
+    InvalidId,
+    #[error("not a valid Spotify URI")]
+    InvalidFormat,
+    #[error("URI does not belong to Spotify")]
+    InvalidRoot,
+}
+
+impl From<SpotifyIdError> for Error {
+    fn from(err: SpotifyIdError) -> Self {
+        Error::invalid_argument(err)
+    }
+}
+
+pub type SpotifyIdResult = Result<SpotifyId, Error>;
+pub type NamedSpotifyIdResult = Result<NamedSpotifyId, Error>;
 
 const BASE62_DIGITS: &[u8; 62] = b"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
 const BASE16_DIGITS: &[u8; 16] = b"0123456789abcdef";
@@ -48,11 +85,12 @@ impl SpotifyId {
     const SIZE_BASE16: usize = 32;
     const SIZE_BASE62: usize = 22;
 
-    fn track(n: u128) -> SpotifyId {
-        SpotifyId {
-            id: n,
-            audio_type: SpotifyAudioType::Track,
-        }
+    /// Returns whether this `SpotifyId` is for a playable audio item, if known.
+    pub fn is_playable(&self) -> bool {
+        return matches!(
+            self.item_type,
+            SpotifyItemType::Episode | SpotifyItemType::Track
+        );
     }
 
     /// Parses a base16 (hex) encoded [Spotify ID] into a `SpotifyId`.
@@ -60,29 +98,32 @@ impl SpotifyId {
     /// `src` is expected to be 32 bytes long and encoded using valid characters.
     ///
     /// [Spotify ID]: https://developer.spotify.com/documentation/web-api/#spotify-uris-and-ids
-    pub fn from_base16(src: &str) -> Result<SpotifyId, SpotifyIdError> {
+    pub fn from_base16(src: &str) -> SpotifyIdResult {
         let mut dst: u128 = 0;
 
         for c in src.as_bytes() {
             let p = match c {
                 b'0'..=b'9' => c - b'0',
                 b'a'..=b'f' => c - b'a' + 10,
-                _ => return Err(SpotifyIdError),
+                _ => return Err(SpotifyIdError::InvalidId.into()),
             } as u128;
 
             dst <<= 4;
             dst += p;
         }
 
-        Ok(SpotifyId::track(dst))
+        Ok(Self {
+            id: dst,
+            item_type: SpotifyItemType::Unknown,
+        })
     }
 
-    /// Parses a base62 encoded [Spotify ID] into a `SpotifyId`.
+    /// Parses a base62 encoded [Spotify ID] into a `u128`.
     ///
     /// `src` is expected to be 22 bytes long and encoded using valid characters.
     ///
     /// [Spotify ID]: https://developer.spotify.com/documentation/web-api/#spotify-uris-and-ids
-    pub fn from_base62(src: &str) -> Result<SpotifyId, SpotifyIdError> {
+    pub fn from_base62(src: &str) -> SpotifyIdResult {
         let mut dst: u128 = 0;
 
         for c in src.as_bytes() {
@@ -90,23 +131,29 @@ impl SpotifyId {
                 b'0'..=b'9' => c - b'0',
                 b'a'..=b'z' => c - b'a' + 10,
                 b'A'..=b'Z' => c - b'A' + 36,
-                _ => return Err(SpotifyIdError),
+                _ => return Err(SpotifyIdError::InvalidId.into()),
             } as u128;
 
             dst *= 62;
             dst += p;
         }
 
-        Ok(SpotifyId::track(dst))
+        Ok(Self {
+            id: dst,
+            item_type: SpotifyItemType::Unknown,
+        })
     }
 
-    /// Creates a `SpotifyId` from a copy of `SpotifyId::SIZE` (16) bytes in big-endian order.
+    /// Creates a `u128` from a copy of `SpotifyId::SIZE` (16) bytes in big-endian order.
     ///
-    /// The resulting `SpotifyId` will default to a `SpotifyAudioType::TRACK`.
-    pub fn from_raw(src: &[u8]) -> Result<SpotifyId, SpotifyIdError> {
+    /// The resulting `SpotifyId` will default to a `SpotifyItemType::Unknown`.
+    pub fn from_raw(src: &[u8]) -> SpotifyIdResult {
         match src.try_into() {
-            Ok(dst) => Ok(SpotifyId::track(u128::from_be_bytes(dst))),
-            Err(_) => Err(SpotifyIdError),
+            Ok(dst) => Ok(Self {
+                id: u128::from_be_bytes(dst),
+                item_type: SpotifyItemType::Unknown,
+            }),
+            Err(_) => Err(SpotifyIdError::InvalidId.into()),
         }
     }
 
@@ -115,37 +162,46 @@ impl SpotifyId {
     /// `uri` is expected to be in the canonical form `spotify:{type}:{id}`, where `{type}`
     /// can be arbitrary while `{id}` is a 22-character long, base62 encoded Spotify ID.
     ///
+    /// Note that this should not be used for playlists, which have the form of
+    /// `spotify:user:{owner_username}:playlist:{id}`.
+    ///
     /// [Spotify URI]: https://developer.spotify.com/documentation/web-api/#spotify-uris-and-ids
-    pub fn from_uri(src: &str) -> Result<SpotifyId, SpotifyIdError> {
-        let src = src.strip_prefix("spotify:").ok_or(SpotifyIdError)?;
+    pub fn from_uri(src: &str) -> SpotifyIdResult {
+        let mut uri_parts: Vec<&str> = src.split(':').collect();
 
-        if src.len() <= SpotifyId::SIZE_BASE62 {
-            return Err(SpotifyIdError);
+        // At minimum, should be `spotify:{type}:{id}`
+        if uri_parts.len() < 3 {
+            return Err(SpotifyIdError::InvalidFormat.into());
         }
 
-        let colon_index = src.len() - SpotifyId::SIZE_BASE62 - 1;
-
-        if src.as_bytes()[colon_index] != b':' {
-            return Err(SpotifyIdError);
+        if uri_parts[0] != "spotify" {
+            return Err(SpotifyIdError::InvalidRoot.into());
         }
 
-        let mut id = SpotifyId::from_base62(&src[colon_index + 1..])?;
-        id.audio_type = src[..colon_index].into();
+        let id = uri_parts.pop().unwrap_or_default();
+        if id.len() != Self::SIZE_BASE62 {
+            return Err(SpotifyIdError::InvalidId.into());
+        }
 
-        Ok(id)
+        Ok(Self {
+            item_type: uri_parts.pop().unwrap_or_default().into(),
+            ..Self::from_base62(id)?
+        })
     }
 
     /// Returns the `SpotifyId` as a base16 (hex) encoded, `SpotifyId::SIZE_BASE16` (32)
     /// character long `String`.
-    pub fn to_base16(&self) -> Result<String, FromUtf8Error> {
-        to_base16(&self.to_raw(), &mut [0u8; SpotifyId::SIZE_BASE16])
+    #[allow(clippy::wrong_self_convention)]
+    pub fn to_base16(&self) -> Result<String, Error> {
+        to_base16(&self.to_raw(), &mut [0u8; Self::SIZE_BASE16])
     }
 
     /// Returns the `SpotifyId` as a [canonically] base62 encoded, `SpotifyId::SIZE_BASE62` (22)
     /// character long `String`.
     ///
     /// [canonically]: https://developer.spotify.com/documentation/web-api/#spotify-uris-and-ids
-    pub fn to_base62(&self) -> Result<String, FromUtf8Error> {
+    #[allow(clippy::wrong_self_convention)]
+    pub fn to_base62(&self) -> Result<String, Error> {
         let mut dst = [0u8; 22];
         let mut i = 0;
         let n = self.id;
@@ -183,12 +239,13 @@ impl SpotifyId {
 
         dst.reverse();
 
-        String::from_utf8(dst.to_vec())
+        String::from_utf8(dst.to_vec()).map_err(|_| SpotifyIdError::InvalidId.into())
     }
 
     /// Returns a copy of the `SpotifyId` as an array of `SpotifyId::SIZE` (16) bytes in
     /// big-endian order.
-    pub fn to_raw(&self) -> [u8; SpotifyId::SIZE] {
+    #[allow(clippy::wrong_self_convention)]
+    pub fn to_raw(&self) -> [u8; Self::SIZE] {
         self.id.to_be_bytes()
     }
 
@@ -200,44 +257,260 @@ impl SpotifyId {
     /// be encoded as `unknown`.
     ///
     /// [Spotify URI]: https://developer.spotify.com/documentation/web-api/#spotify-uris-and-ids
-    pub fn to_uri(&self) -> Result<String, FromUtf8Error> {
+    #[allow(clippy::wrong_self_convention)]
+    pub fn to_uri(&self) -> Result<String, Error> {
         // 8 chars for the "spotify:" prefix + 1 colon + 22 chars base62 encoded ID  = 31
-        // + unknown size audio_type.
-        let audio_type: &str = self.audio_type.into();
-        let mut dst = String::with_capacity(31 + audio_type.len());
+        // + unknown size item_type.
+        let item_type: &str = self.item_type.into();
+        let mut dst = String::with_capacity(31 + item_type.len());
         dst.push_str("spotify:");
-        dst.push_str(audio_type);
+        dst.push_str(item_type);
         dst.push(':');
-        let base62 = self.to_base62()?;
-        dst.push_str(&base62);
+        let base_62 = self.to_base62()?;
+        dst.push_str(&base_62);
 
         Ok(dst)
     }
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct FileId(pub [u8; 20]);
-
-impl FileId {
-    pub fn to_base16(&self) -> Result<String, FromUtf8Error> {
-        to_base16(&self.0, &mut [0u8; 40])
-    }
-}
-
-impl fmt::Debug for FileId {
+impl fmt::Debug for SpotifyId {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.debug_tuple("FileId").field(&self.to_base16()).finish()
+        f.debug_tuple("SpotifyId")
+            .field(&self.to_uri().unwrap_or_else(|_| "invalid uri".into()))
+            .finish()
     }
 }
 
-impl fmt::Display for FileId {
+impl fmt::Display for SpotifyId {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.write_str(&self.to_base16().unwrap_or_default())
+        f.write_str(&self.to_uri().unwrap_or_else(|_| "invalid uri".into()))
     }
 }
 
-#[inline]
-fn to_base16(src: &[u8], buf: &mut [u8]) -> Result<String, FromUtf8Error> {
+#[derive(Clone, PartialEq, Eq, Hash)]
+pub struct NamedSpotifyId {
+    pub inner_id: SpotifyId,
+    pub username: String,
+}
+
+impl NamedSpotifyId {
+    pub fn from_uri(src: &str) -> NamedSpotifyIdResult {
+        let uri_parts: Vec<&str> = src.split(':').collect();
+
+        // At minimum, should be `spotify:user:{username}:{type}:{id}`
+        if uri_parts.len() < 5 {
+            return Err(SpotifyIdError::InvalidFormat.into());
+        }
+
+        if uri_parts[0] != "spotify" {
+            return Err(SpotifyIdError::InvalidRoot.into());
+        }
+
+        if uri_parts[1] != "user" {
+            return Err(SpotifyIdError::InvalidFormat.into());
+        }
+
+        Ok(Self {
+            inner_id: SpotifyId::from_uri(src)?,
+            username: uri_parts[2].to_owned(),
+        })
+    }
+
+    pub fn to_uri(&self) -> Result<String, Error> {
+        let item_type: &str = self.inner_id.item_type.into();
+        let mut dst = String::with_capacity(37 + self.username.len() + item_type.len());
+        dst.push_str("spotify:user:");
+        dst.push_str(&self.username);
+        dst.push_str(item_type);
+        dst.push(':');
+        let base_62 = self.to_base62()?;
+        dst.push_str(&base_62);
+
+        Ok(dst)
+    }
+
+    pub fn from_spotify_id(id: SpotifyId, username: String) -> Self {
+        Self {
+            inner_id: id,
+            username,
+        }
+    }
+}
+
+impl Deref for NamedSpotifyId {
+    type Target = SpotifyId;
+    fn deref(&self) -> &Self::Target {
+        &self.inner_id
+    }
+}
+
+impl fmt::Debug for NamedSpotifyId {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("NamedSpotifyId")
+            .field(
+                &self
+                    .inner_id
+                    .to_uri()
+                    .unwrap_or_else(|_| "invalid id".into()),
+            )
+            .finish()
+    }
+}
+
+impl fmt::Display for NamedSpotifyId {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(
+            &self
+                .inner_id
+                .to_uri()
+                .unwrap_or_else(|_| "invalid id".into()),
+        )
+    }
+}
+
+impl TryFrom<&[u8]> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(src: &[u8]) -> Result<Self, Self::Error> {
+        Self::from_raw(src)
+    }
+}
+
+impl TryFrom<&str> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(src: &str) -> Result<Self, Self::Error> {
+        Self::from_base62(src)
+    }
+}
+
+impl TryFrom<String> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(src: String) -> Result<Self, Self::Error> {
+        Self::try_from(src.as_str())
+    }
+}
+
+impl TryFrom<&Vec<u8>> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(src: &Vec<u8>) -> Result<Self, Self::Error> {
+        Self::try_from(src.as_slice())
+    }
+}
+
+impl TryFrom<&protocol::spirc::TrackRef> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(track: &protocol::spirc::TrackRef) -> Result<Self, Self::Error> {
+        match SpotifyId::from_raw(track.get_gid()) {
+            Ok(mut id) => {
+                id.item_type = SpotifyItemType::Track;
+                Ok(id)
+            }
+            Err(_) => SpotifyId::from_uri(track.get_uri()),
+        }
+    }
+}
+
+impl TryFrom<&protocol::metadata::Album> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(album: &protocol::metadata::Album) -> Result<Self, Self::Error> {
+        Ok(Self {
+            item_type: SpotifyItemType::Album,
+            ..Self::from_raw(album.get_gid())?
+        })
+    }
+}
+
+impl TryFrom<&protocol::metadata::Artist> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(artist: &protocol::metadata::Artist) -> Result<Self, Self::Error> {
+        Ok(Self {
+            item_type: SpotifyItemType::Artist,
+            ..Self::from_raw(artist.get_gid())?
+        })
+    }
+}
+
+impl TryFrom<&protocol::metadata::Episode> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(episode: &protocol::metadata::Episode) -> Result<Self, Self::Error> {
+        Ok(Self {
+            item_type: SpotifyItemType::Episode,
+            ..Self::from_raw(episode.get_gid())?
+        })
+    }
+}
+
+impl TryFrom<&protocol::metadata::Track> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(track: &protocol::metadata::Track) -> Result<Self, Self::Error> {
+        Ok(Self {
+            item_type: SpotifyItemType::Track,
+            ..Self::from_raw(track.get_gid())?
+        })
+    }
+}
+
+impl TryFrom<&protocol::metadata::Show> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(show: &protocol::metadata::Show) -> Result<Self, Self::Error> {
+        Ok(Self {
+            item_type: SpotifyItemType::Show,
+            ..Self::from_raw(show.get_gid())?
+        })
+    }
+}
+
+impl TryFrom<&protocol::metadata::ArtistWithRole> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(artist: &protocol::metadata::ArtistWithRole) -> Result<Self, Self::Error> {
+        Ok(Self {
+            item_type: SpotifyItemType::Artist,
+            ..Self::from_raw(artist.get_artist_gid())?
+        })
+    }
+}
+
+impl TryFrom<&protocol::playlist4_external::Item> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(item: &protocol::playlist4_external::Item) -> Result<Self, Self::Error> {
+        Ok(Self {
+            item_type: SpotifyItemType::Track,
+            ..Self::from_uri(item.get_uri())?
+        })
+    }
+}
+
+// Note that this is the unique revision of an item's metadata on a playlist,
+// not the ID of that item or playlist.
+impl TryFrom<&protocol::playlist4_external::MetaItem> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(item: &protocol::playlist4_external::MetaItem) -> Result<Self, Self::Error> {
+        Self::try_from(item.get_revision())
+    }
+}
+
+// Note that this is the unique revision of a playlist, not the ID of that playlist.
+impl TryFrom<&protocol::playlist4_external::SelectedListContent> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(
+        playlist: &protocol::playlist4_external::SelectedListContent,
+    ) -> Result<Self, Self::Error> {
+        Self::try_from(playlist.get_revision())
+    }
+}
+
+// TODO: check meaning and format of this field in the wild. This might be a FileId,
+// which is why we now don't create a separate `Playlist` enum value yet and choose
+// to discard any item type.
+impl TryFrom<&protocol::playlist_annotate3::TranscodedPicture> for SpotifyId {
+    type Error = crate::Error;
+    fn try_from(
+        picture: &protocol::playlist_annotate3::TranscodedPicture,
+    ) -> Result<Self, Self::Error> {
+        Self::from_base62(picture.get_uri())
+    }
+}
+
+pub fn to_base16(src: &[u8], buf: &mut [u8]) -> Result<String, Error> {
     let mut i = 0;
     for v in src {
         buf[i] = BASE16_DIGITS[(v >> 4) as usize];
@@ -245,7 +518,7 @@ fn to_base16(src: &[u8], buf: &mut [u8]) -> Result<String, FromUtf8Error> {
         i += 2;
     }
 
-    String::from_utf8(buf.to_vec())
+    String::from_utf8(buf.to_vec()).map_err(|_| SpotifyIdError::InvalidId.into())
 }
 
 #[cfg(test)]
@@ -254,7 +527,7 @@ mod tests {
 
     struct ConversionCase {
         id: u128,
-        kind: SpotifyAudioType,
+        kind: SpotifyItemType,
         uri: &'static str,
         base16: &'static str,
         base62: &'static str,
@@ -264,7 +537,7 @@ mod tests {
     static CONV_VALID: [ConversionCase; 4] = [
         ConversionCase {
             id: 238762092608182713602505436543891614649,
-            kind: SpotifyAudioType::Track,
+            kind: SpotifyItemType::Track,
             uri: "spotify:track:5sWHDYs0csV6RS48xBl0tH",
             base16: "b39fe8081e1f4c54be38e8d6f9f12bb9",
             base62: "5sWHDYs0csV6RS48xBl0tH",
@@ -274,7 +547,7 @@ mod tests {
         },
         ConversionCase {
             id: 204841891221366092811751085145916697048,
-            kind: SpotifyAudioType::Track,
+            kind: SpotifyItemType::Track,
             uri: "spotify:track:4GNcXTGWmnZ3ySrqvol3o4",
             base16: "9a1b1cfbc6f244569ae0356c77bbe9d8",
             base62: "4GNcXTGWmnZ3ySrqvol3o4",
@@ -284,7 +557,7 @@ mod tests {
         },
         ConversionCase {
             id: 204841891221366092811751085145916697048,
-            kind: SpotifyAudioType::Podcast,
+            kind: SpotifyItemType::Episode,
             uri: "spotify:episode:4GNcXTGWmnZ3ySrqvol3o4",
             base16: "9a1b1cfbc6f244569ae0356c77bbe9d8",
             base62: "4GNcXTGWmnZ3ySrqvol3o4",
@@ -294,8 +567,8 @@ mod tests {
         },
         ConversionCase {
             id: 204841891221366092811751085145916697048,
-            kind: SpotifyAudioType::NonPlayable,
-            uri: "spotify:unknown:4GNcXTGWmnZ3ySrqvol3o4",
+            kind: SpotifyItemType::Show,
+            uri: "spotify:show:4GNcXTGWmnZ3ySrqvol3o4",
             base16: "9a1b1cfbc6f244569ae0356c77bbe9d8",
             base62: "4GNcXTGWmnZ3ySrqvol3o4",
             raw: &[
@@ -307,7 +580,7 @@ mod tests {
     static CONV_INVALID: [ConversionCase; 3] = [
         ConversionCase {
             id: 0,
-            kind: SpotifyAudioType::NonPlayable,
+            kind: SpotifyItemType::Unknown,
             // Invalid ID in the URI.
             uri: "spotify:arbitrarywhatever:5sWHDYs0Bl0tH",
             base16: "ZZZZZ8081e1f4c54be38e8d6f9f12bb9",
@@ -319,7 +592,7 @@ mod tests {
         },
         ConversionCase {
             id: 0,
-            kind: SpotifyAudioType::NonPlayable,
+            kind: SpotifyItemType::Unknown,
             // Missing colon between ID and type.
             uri: "spotify:arbitrarywhatever5sWHDYs0csV6RS48xBl0tH",
             base16: "--------------------",
@@ -331,7 +604,7 @@ mod tests {
         },
         ConversionCase {
             id: 0,
-            kind: SpotifyAudioType::NonPlayable,
+            kind: SpotifyItemType::Unknown,
             // Uri too short
             uri: "spotify:azb:aRS48xBl0tH",
             base16: "--------------------",
@@ -350,7 +623,7 @@ mod tests {
         }
 
         for c in &CONV_INVALID {
-            assert_eq!(SpotifyId::from_base62(c.base62), Err(SpotifyIdError));
+            assert!(SpotifyId::from_base62(c.base62).is_err(),);
         }
     }
 
@@ -359,7 +632,7 @@ mod tests {
         for c in &CONV_VALID {
             let id = SpotifyId {
                 id: c.id,
-                audio_type: c.kind,
+                item_type: c.kind,
             };
 
             assert_eq!(id.to_base62().unwrap(), c.base62);
@@ -373,7 +646,7 @@ mod tests {
         }
 
         for c in &CONV_INVALID {
-            assert_eq!(SpotifyId::from_base16(c.base16), Err(SpotifyIdError));
+            assert!(SpotifyId::from_base16(c.base16).is_err(),);
         }
     }
 
@@ -382,7 +655,7 @@ mod tests {
         for c in &CONV_VALID {
             let id = SpotifyId {
                 id: c.id,
-                audio_type: c.kind,
+                item_type: c.kind,
             };
 
             assert_eq!(id.to_base16().unwrap(), c.base16);
@@ -395,11 +668,11 @@ mod tests {
             let actual = SpotifyId::from_uri(c.uri).unwrap();
 
             assert_eq!(actual.id, c.id);
-            assert_eq!(actual.audio_type, c.kind);
+            assert_eq!(actual.item_type, c.kind);
         }
 
         for c in &CONV_INVALID {
-            assert_eq!(SpotifyId::from_uri(c.uri), Err(SpotifyIdError));
+            assert!(SpotifyId::from_uri(c.uri).is_err());
         }
     }
 
@@ -408,7 +681,7 @@ mod tests {
         for c in &CONV_VALID {
             let id = SpotifyId {
                 id: c.id,
-                audio_type: c.kind,
+                item_type: c.kind,
             };
 
             assert_eq!(id.to_uri().unwrap(), c.uri);
@@ -422,7 +695,7 @@ mod tests {
         }
 
         for c in &CONV_INVALID {
-            assert_eq!(SpotifyId::from_raw(c.raw), Err(SpotifyIdError));
+            assert!(SpotifyId::from_raw(c.raw).is_err());
         }
     }
 }

core/src/token.rs

@@ -0,0 +1,138 @@
+// Ported from librespot-java. Relicensed under MIT with permission.
+
+// Known scopes:
+//   ugc-image-upload, playlist-read-collaborative, playlist-modify-private,
+//   playlist-modify-public, playlist-read-private, user-read-playback-position,
+//   user-read-recently-played, user-top-read, user-modify-playback-state,
+//   user-read-currently-playing, user-read-playback-state, user-read-private, user-read-email,
+//   user-library-modify, user-library-read, user-follow-modify, user-follow-read, streaming,
+//   app-remote-control
+
+use std::time::{Duration, Instant};
+
+use serde::Deserialize;
+use thiserror::Error;
+
+use crate::Error;
+
+component! {
+    TokenProvider : TokenProviderInner {
+        tokens: Vec<Token> = vec![],
+    }
+}
+
+#[derive(Debug, Error)]
+pub enum TokenError {
+    #[error("no tokens available")]
+    Empty,
+}
+
+impl From<TokenError> for Error {
+    fn from(err: TokenError) -> Self {
+        Error::unavailable(err)
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct Token {
+    pub access_token: String,
+    pub expires_in: Duration,
+    pub token_type: String,
+    pub scopes: Vec<String>,
+    pub timestamp: Instant,
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct TokenData {
+    access_token: String,
+    expires_in: u64,
+    token_type: String,
+    scope: Vec<String>,
+}
+
+impl TokenProvider {
+    fn find_token(&self, scopes: Vec<&str>) -> Option<usize> {
+        self.lock(|inner| {
+            for i in 0..inner.tokens.len() {
+                if inner.tokens[i].in_scopes(scopes.clone()) {
+                    return Some(i);
+                }
+            }
+            None
+        })
+    }
+
+    // scopes must be comma-separated
+    pub async fn get_token(&self, scopes: &str) -> Result<Token, Error> {
+        let client_id = self.session().client_id();
+        if client_id.is_empty() {
+            return Err(Error::invalid_argument("Client ID cannot be empty"));
+        }
+
+        if let Some(index) = self.find_token(scopes.split(',').collect()) {
+            let cached_token = self.lock(|inner| inner.tokens[index].clone());
+            if cached_token.is_expired() {
+                self.lock(|inner| inner.tokens.remove(index));
+            } else {
+                return Ok(cached_token);
+            }
+        }
+
+        trace!(
+            "Requested token in scopes {:?} unavailable or expired, requesting new token.",
+            scopes
+        );
+
+        let query_uri = format!(
+            "hm://keymaster/token/authenticated?scope={}&client_id={}&device_id={}",
+            scopes,
+            client_id,
+            self.session().device_id(),
+        );
+        let request = self.session().mercury().get(query_uri)?;
+        let response = request.await?;
+        let data = response.payload.first().ok_or(TokenError::Empty)?.to_vec();
+        let token = Token::from_json(String::from_utf8(data)?)?;
+        trace!("Got token: {:#?}", token);
+        self.lock(|inner| inner.tokens.push(token.clone()));
+        Ok(token)
+    }
+}
+
+impl Token {
+    const EXPIRY_THRESHOLD: Duration = Duration::from_secs(10);
+
+    pub fn from_json(body: String) -> Result<Self, Error> {
+        let data: TokenData = serde_json::from_slice(body.as_ref())?;
+        Ok(Self {
+            access_token: data.access_token,
+            expires_in: Duration::from_secs(data.expires_in),
+            token_type: data.token_type,
+            scopes: data.scope,
+            timestamp: Instant::now(),
+        })
+    }
+
+    pub fn is_expired(&self) -> bool {
+        self.timestamp + (self.expires_in - Self::EXPIRY_THRESHOLD) < Instant::now()
+    }
+
+    pub fn in_scope(&self, scope: &str) -> bool {
+        for s in &self.scopes {
+            if *s == scope {
+                return true;
+            }
+        }
+        false
+    }
+
+    pub fn in_scopes(&self, scopes: Vec<&str>) -> bool {
+        for s in scopes {
+            if !self.in_scope(s) {
+                return false;
+            }
+        }
+        true
+    }
+}

core/src/util.rs

@@ -1,4 +1,97 @@
-use std::mem;
+use std::{
+    future::Future,
+    mem,
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use futures_core::ready;
+use futures_util::{future, FutureExt, Sink, SinkExt};
+use tokio::{task::JoinHandle, time::timeout};
+
+/// Returns a future that will flush the sink, even if flushing is temporarily completed.
+/// Finishes only if the sink throws an error.
+pub(crate) fn keep_flushing<'a, T, S: Sink<T> + Unpin + 'a>(
+    mut s: S,
+) -> impl Future<Output = S::Error> + 'a {
+    future::poll_fn(move |cx| match s.poll_flush_unpin(cx) {
+        Poll::Ready(Err(e)) => Poll::Ready(e),
+        _ => Poll::Pending,
+    })
+}
+
+pub struct CancelOnDrop<T>(pub JoinHandle<T>);
+
+impl<T> Future for CancelOnDrop<T> {
+    type Output = <JoinHandle<T> as Future>::Output;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        self.0.poll_unpin(cx)
+    }
+}
+
+impl<T> Drop for CancelOnDrop<T> {
+    fn drop(&mut self) {
+        self.0.abort();
+    }
+}
+
+pub struct TimeoutOnDrop<T: Send + 'static> {
+    handle: Option<JoinHandle<T>>,
+    timeout: tokio::time::Duration,
+}
+
+impl<T: Send + 'static> TimeoutOnDrop<T> {
+    pub fn new(handle: JoinHandle<T>, timeout: tokio::time::Duration) -> Self {
+        Self {
+            handle: Some(handle),
+            timeout,
+        }
+    }
+
+    pub fn take(&mut self) -> Option<JoinHandle<T>> {
+        self.handle.take()
+    }
+}
+
+impl<T: Send + 'static> Future for TimeoutOnDrop<T> {
+    type Output = <JoinHandle<T> as Future>::Output;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let r = ready!(self
+            .handle
+            .as_mut()
+            .expect("Polled after ready")
+            .poll_unpin(cx));
+        self.handle = None;
+        Poll::Ready(r)
+    }
+}
+
+impl<T: Send + 'static> Drop for TimeoutOnDrop<T> {
+    fn drop(&mut self) {
+        let mut handle = if let Some(handle) = self.handle.take() {
+            handle
+        } else {
+            return;
+        };
+
+        if (&mut handle).now_or_never().is_some() {
+            // Already finished
+            return;
+        }
+
+        match tokio::runtime::Handle::try_current() {
+            Ok(h) => {
+                h.spawn(timeout(self.timeout, CancelOnDrop(handle)));
+            }
+            Err(_) => {
+                // Not in tokio context, can't spawn
+                handle.abort();
+            }
+        }
+    }
+}
 
 pub trait Seq {
     fn next(&self) -> Self;

core/src/version.rs

@@ -1,17 +1,26 @@
 /// Version string of the form "librespot-<sha>"
-pub const VERSION_STRING: &str = concat!("librespot-", env!("VERGEN_SHA_SHORT"));
+pub const VERSION_STRING: &str = concat!("librespot-", env!("VERGEN_GIT_SHA_SHORT"));
 
 /// Generate a timestamp string representing the build date (UTC).
 pub const BUILD_DATE: &str = env!("VERGEN_BUILD_DATE");
 
 /// Short sha of the latest git commit.
-pub const SHA_SHORT: &str = env!("VERGEN_SHA_SHORT");
+pub const SHA_SHORT: &str = env!("VERGEN_GIT_SHA_SHORT");
 
 /// Date of the latest git commit.
-pub const COMMIT_DATE: &str = env!("VERGEN_COMMIT_DATE");
+pub const COMMIT_DATE: &str = env!("VERGEN_GIT_COMMIT_DATE");
 
 /// Librespot crate version.
 pub const SEMVER: &str = env!("CARGO_PKG_VERSION");
 
 /// A random build id.
 pub const BUILD_ID: &str = env!("LIBRESPOT_BUILD_ID");
+
+/// The protocol version of the Spotify desktop client.
+pub const SPOTIFY_VERSION: u64 = 117300517;
+
+/// The protocol version of the Spotify mobile app.
+pub const SPOTIFY_MOBILE_VERSION: &str = "8.6.84";
+
+/// The user agent to fall back to, if one could not be determined dynamically.
+pub const FALLBACK_USER_AGENT: &str = "Spotify/117300517 Linux/0 (librespot)";

core/tests/connect.rs

@@ -1,25 +1,19 @@
 use std::time::Duration;
 
-use librespot_core::authentication::Credentials;
-use librespot_core::config::SessionConfig;
-use librespot_core::session::Session;
-
 use tokio::time::timeout;
 
+use librespot_core::{authentication::Credentials, config::SessionConfig, session::Session};
+
 #[tokio::test]
 async fn test_connection() {
     timeout(Duration::from_secs(30), async {
-        let result = Session::connect(
-            SessionConfig::default(),
-            Credentials::with_password("test", "test"),
-            None,
-            false,
-        )
+        let result = Session::new(SessionConfig::default(), None)
+            .connect(Credentials::with_password("test", "test"), false)
             .await;
 
         match result {
             Ok(_) => panic!("Authentication succeeded despite of bad credentials."),
-            Err(e) => assert_eq!(e.to_string(), "Login failed with reason: Bad credentials"),
+            Err(e) => assert!(!e.to_string().is_empty()), // there should be some error message
         }
     })
     .await

discovery/Cargo.toml

@@ -8,32 +8,32 @@ repository = "https://github.com/librespot-org/librespot"
 edition = "2018"
 
 [dependencies]
-aes-ctr = "0.6"
+aes = "0.8"
 base64 = "0.13"
+cfg-if = "1.0"
+ctr = "0.9"
+dns-sd = { version = "0.1.3", optional = true }
 form_urlencoded = "1.0"
 futures-core = "0.3"
-hmac = "0.11"
-hyper = { version = "0.14", features = ["server", "http1", "tcp"] }
+futures-util = "0.3"
+hmac = "0.12"
+hyper = { version = "0.14", features = ["http1", "server", "tcp"] }
 libmdns = "0.7"
 log = "0.4"
 rand = "0.8"
-serde_json = "1.0.25"
-sha-1 = "0.9"
+serde_json = "1.0"
+sha1 = "0.10"
 thiserror = "1.0"
-tokio = { version = "1.0", features = ["sync", "rt"] }
-
-dns-sd = { version = "0.1.3", optional = true }
+tokio = { version = "1", features = ["parking_lot", "sync", "rt"] }
 
 [dependencies.librespot-core]
 path = "../core"
-default_features = false
 version = "0.4.2"
 
 [dev-dependencies]
 futures = "0.3"
 hex = "0.4"
-simple_logger = "2.1"
-tokio = { version = "1.0", features = ["macros", "rt"] }
+tokio = { version = "1", features = ["macros", "parking_lot", "rt"] }
 
 [features]
-with-dns-sd = ["dns-sd"]
+with-dns-sd = ["dns-sd", "librespot-core/with-dns-sd"]

discovery/examples/discovery.rs

@@ -1,15 +1,9 @@
 use futures::StreamExt;
 use librespot_discovery::DeviceType;
 use sha1::{Digest, Sha1};
-use simple_logger::SimpleLogger;
 
 #[tokio::main(flavor = "current_thread")]
 async fn main() {
-    SimpleLogger::new()
-        .with_level(log::LevelFilter::Debug)
-        .init()
-        .unwrap();
-
     let name = "Librespot";
     let device_id = hex::encode(Sha1::digest(name.as_bytes()));
 

discovery/src/lib.rs

@@ -7,21 +7,23 @@
 //! This library uses mDNS and DNS-SD so that other devices can find it,
 //! and spawns an http server to answer requests of Spotify clients.
 
-#![warn(clippy::all, missing_docs, rust_2018_idioms)]
-
 mod server;
 
-use std::borrow::Cow;
-use std::io;
-use std::pin::Pin;
-use std::task::{Context, Poll};
+use std::{
+    borrow::Cow,
+    io,
+    pin::Pin,
+    task::{Context, Poll},
+};
 
 use futures_core::Stream;
-use librespot_core as core;
 use thiserror::Error;
 
 use self::server::DiscoveryServer;
 
+pub use crate::core::Error;
+use librespot_core as core;
+
 /// Credentials to be used in [`librespot`](`librespot_core`).
 pub use crate::core::authentication::Credentials;
 
@@ -49,13 +51,29 @@ pub struct Builder {
 
 /// Errors that can occur while setting up a [`Discovery`] instance.
 #[derive(Debug, Error)]
-pub enum Error {
-    /// Setting up service discovery via DNS-SD failed.
+pub enum DiscoveryError {
+    #[error("Creating SHA1 block cipher failed")]
+    AesError(#[from] aes::cipher::InvalidLength),
     #[error("Setting up dns-sd failed: {0}")]
     DnsSdError(#[from] io::Error),
-    /// Setting up the http server failed.
-    #[error("Setting up the http server failed: {0}")]
+    #[error("Creating SHA1 HMAC failed for base key {0:?}")]
+    HmacError(Vec<u8>),
+    #[error("Setting up the HTTP server failed: {0}")]
     HttpServerError(#[from] hyper::Error),
+    #[error("Missing params for key {0}")]
+    ParamsError(&'static str),
+}
+
+impl From<DiscoveryError> for Error {
+    fn from(err: DiscoveryError) -> Self {
+        match err {
+            DiscoveryError::AesError(_) => Error::unavailable(err),
+            DiscoveryError::DnsSdError(_) => Error::unavailable(err),
+            DiscoveryError::HmacError(_) => Error::invalid_argument(err),
+            DiscoveryError::HttpServerError(_) => Error::unavailable(err),
+            DiscoveryError::ParamsError(_) => Error::invalid_argument(err),
+        }
+    }
 }
 
 impl Builder {
@@ -97,7 +115,7 @@ impl Builder {
     pub fn launch(self) -> Result<Discovery, Error> {
         let mut port = self.port;
         let name = self.server_config.name.clone().into_owned();
-        let server = DiscoveryServer::new(self.server_config, &mut port)?;
+        let server = DiscoveryServer::new(self.server_config, &mut port)??;
 
         #[cfg(feature = "with-dns-sd")]
         let svc = dns_sd::DNSService::register(
@@ -107,8 +125,7 @@ impl Builder {
             None,
             port,
             &["VERSION=1.0", "CPath=/"],
-        )
-        .map_err(|e| Error::DnsSdError(io::Error::new(io::ErrorKind::Unsupported, e)))?;
+        )?;
 
         #[cfg(not(feature = "with-dns-sd"))]
         let svc = libmdns::Responder::spawn(&tokio::runtime::Handle::current())?.register(

discovery/src/server.rs

@@ -1,26 +1,34 @@
-use std::borrow::Cow;
-use std::collections::BTreeMap;
-use std::convert::Infallible;
-use std::net::{Ipv4Addr, SocketAddr};
-use std::pin::Pin;
-use std::sync::Arc;
-use std::task::{Context, Poll};
+use std::{
+    borrow::Cow,
+    collections::BTreeMap,
+    convert::Infallible,
+    net::{Ipv4Addr, SocketAddr},
+    pin::Pin,
+    sync::Arc,
+    task::{Context, Poll},
+};
 
-use aes_ctr::cipher::generic_array::GenericArray;
-use aes_ctr::cipher::{NewStreamCipher, SyncStreamCipher};
-use aes_ctr::Aes128Ctr;
+use aes::cipher::{KeyIvInit, StreamCipher};
 use futures_core::Stream;
-use hmac::{Hmac, Mac, NewMac};
-use hyper::service::{make_service_fn, service_fn};
-use hyper::{Body, Method, Request, Response, StatusCode};
-use log::{debug, warn};
+use futures_util::{FutureExt, TryFutureExt};
+use hmac::{Hmac, Mac};
+use hyper::{
+    service::{make_service_fn, service_fn},
+    Body, Method, Request, Response, StatusCode,
+};
+use log::{debug, error, warn};
 use serde_json::json;
 use sha1::{Digest, Sha1};
 use tokio::sync::{mpsc, oneshot};
 
-use crate::core::authentication::Credentials;
-use crate::core::config::DeviceType;
-use crate::core::diffie_hellman::DhLocalKeys;
+use super::DiscoveryError;
+
+use crate::{
+    core::config::DeviceType,
+    core::{authentication::Credentials, diffie_hellman::DhLocalKeys, Error},
+};
+
+type Aes128Ctr = ctr::Ctr128BE<aes::Aes128>;
 
 type Params<'a> = BTreeMap<Cow<'a, str>, Cow<'a, str>>;
 
@@ -57,7 +65,7 @@ impl RequestHandler {
             "status": 101,
             "statusString": "ERROR-OK",
             "spotifyError": 0,
-            "version": "2.7.1",
+            "version": crate::core::version::SEMVER,
             "deviceID": (self.config.device_id),
             "remoteName": (self.config.name),
             "activeUser": "",
@@ -76,41 +84,58 @@ impl RequestHandler {
         Response::new(Body::from(body))
     }
 
-    fn handle_add_user(&self, params: &Params<'_>) -> Response<hyper::Body> {
-        let username = params.get("userName").unwrap().as_ref();
-        let encrypted_blob = params.get("blob").unwrap();
-        let client_key = params.get("clientKey").unwrap();
+    fn handle_add_user(&self, params: &Params<'_>) -> Result<Response<hyper::Body>, Error> {
+        let username_key = "userName";
+        let username = params
+            .get(username_key)
+            .ok_or(DiscoveryError::ParamsError(username_key))?
+            .as_ref();
 
-        let encrypted_blob = base64::decode(encrypted_blob.as_bytes()).unwrap();
+        let blob_key = "blob";
+        let encrypted_blob = params
+            .get(blob_key)
+            .ok_or(DiscoveryError::ParamsError(blob_key))?;
 
-        let client_key = base64::decode(client_key.as_bytes()).unwrap();
+        let clientkey_key = "clientKey";
+        let client_key = params
+            .get(clientkey_key)
+            .ok_or(DiscoveryError::ParamsError(clientkey_key))?;
+
+        let encrypted_blob = base64::decode(encrypted_blob.as_bytes())?;
+
+        let client_key = base64::decode(client_key.as_bytes())?;
         let shared_key = self.keys.shared_secret(&client_key);
 
+        let encrypted_blob_len = encrypted_blob.len();
+        if encrypted_blob_len < 16 {
+            return Err(DiscoveryError::HmacError(encrypted_blob.to_vec()).into());
+        }
+
         let iv = &encrypted_blob[0..16];
-        let encrypted = &encrypted_blob[16..encrypted_blob.len() - 20];
-        let cksum = &encrypted_blob[encrypted_blob.len() - 20..encrypted_blob.len()];
+        let encrypted = &encrypted_blob[16..encrypted_blob_len - 20];
+        let cksum = &encrypted_blob[encrypted_blob_len - 20..encrypted_blob_len];
 
         let base_key = Sha1::digest(&shared_key);
         let base_key = &base_key[..16];
 
         let checksum_key = {
-            let mut h =
-                Hmac::<Sha1>::new_from_slice(base_key).expect("HMAC can take key of any size");
+            let mut h = Hmac::<Sha1>::new_from_slice(base_key)
+                .map_err(|_| DiscoveryError::HmacError(base_key.to_vec()))?;
             h.update(b"checksum");
             h.finalize().into_bytes()
         };
 
         let encryption_key = {
-            let mut h =
-                Hmac::<Sha1>::new_from_slice(base_key).expect("HMAC can take key of any size");
+            let mut h = Hmac::<Sha1>::new_from_slice(base_key)
+                .map_err(|_| DiscoveryError::HmacError(base_key.to_vec()))?;
             h.update(b"encryption");
             h.finalize().into_bytes()
         };
 
-        let mut h =
-            Hmac::<Sha1>::new_from_slice(&checksum_key).expect("HMAC can take key of any size");
+        let mut h = Hmac::<Sha1>::new_from_slice(&checksum_key)
+            .map_err(|_| DiscoveryError::HmacError(base_key.to_vec()))?;
         h.update(encrypted);
-        if h.verify(cksum).is_err() {
+        if h.verify_slice(cksum).is_err() {
             warn!("Login error for user {:?}: MAC mismatch", username);
             let result = json!({
                 "status": 102,
@@ -119,22 +144,20 @@ impl RequestHandler {
             });
 
             let body = result.to_string();
-            return Response::new(Body::from(body));
+            return Ok(Response::new(Body::from(body)));
         }
 
         let decrypted = {
             let mut data = encrypted.to_vec();
-            let mut cipher = Aes128Ctr::new(
-                GenericArray::from_slice(&encryption_key[0..16]),
-                GenericArray::from_slice(iv),
-            );
+            let mut cipher = Aes128Ctr::new_from_slices(&encryption_key[0..16], iv)
+                .map_err(DiscoveryError::AesError)?;
             cipher.apply_keystream(&mut data);
             data
         };
 
-        let credentials = Credentials::with_blob(username, &decrypted, &self.config.device_id);
+        let credentials = Credentials::with_blob(username, &decrypted, &self.config.device_id)?;
 
-        self.tx.send(credentials).unwrap();
+        self.tx.send(credentials)?;
 
         let result = json!({
             "status": 101,
@@ -143,7 +166,7 @@ impl RequestHandler {
         });
 
         let body = result.to_string();
-        Response::new(Body::from(body))
+        Ok(Response::new(Body::from(body)))
     }
 
     fn not_found(&self) -> Response<hyper::Body> {
@@ -152,7 +175,10 @@ impl RequestHandler {
         res
     }
 
-    async fn handle(self: Arc<Self>, request: Request<Body>) -> hyper::Result<Response<Body>> {
+    async fn handle(
+        self: Arc<Self>,
+        request: Request<Body>,
+    ) -> Result<hyper::Result<Response<Body>>, Error> {
         let mut params = Params::new();
 
         let (parts, body) = request.into_parts();
@@ -172,11 +198,11 @@ impl RequestHandler {
 
         let action = params.get("action").map(Cow::as_ref);
 
-        Ok(match (parts.method, action) {
+        Ok(Ok(match (parts.method, action) {
             (Method::GET, Some("getInfo")) => self.handle_get_info(),
-            (Method::POST, Some("addUser")) => self.handle_add_user(&params),
+            (Method::POST, Some("addUser")) => self.handle_add_user(&params)?,
             _ => self.not_found(),
-        })
+        }))
     }
 }
 
@@ -186,7 +212,7 @@ pub struct DiscoveryServer {
 }
 
 impl DiscoveryServer {
-    pub fn new(config: Config, port: &mut u16) -> hyper::Result<Self> {
+    pub fn new(config: Config, port: &mut u16) -> Result<hyper::Result<Self>, Error> {
         let (discovery, cred_rx) = RequestHandler::new(config);
         let discovery = Arc::new(discovery);
 
@@ -197,7 +223,14 @@ impl DiscoveryServer {
         let make_service = make_service_fn(move |_| {
             let discovery = discovery.clone();
             async move {
-                Ok::<_, hyper::Error>(service_fn(move |request| discovery.clone().handle(request)))
+                Ok::<_, hyper::Error>(service_fn(move |request| {
+                    discovery
+                        .clone()
+                        .handle(request)
+                        .inspect_err(|e| error!("could not handle discovery request: {}", e))
+                        .and_then(|x| async move { Ok(x) })
+                        .map(Result::unwrap) // guaranteed by `and_then` above
+                }))
             }
         });
 
@@ -209,8 +242,10 @@ impl DiscoveryServer {
         tokio::spawn(async {
             let result = server
                 .with_graceful_shutdown(async {
-                    close_rx.await.unwrap_err();
                     debug!("Shutting down discovery server");
+                    if close_rx.await.is_ok() {
+                        debug!("unable to close discovery Rx channel completely");
+                    }
                 })
                 .await;
 
@@ -219,10 +254,10 @@ impl DiscoveryServer {
             }
         });
 
-        Ok(Self {
+        Ok(Ok(Self {
             cred_rx,
             _close_tx: close_tx,
-        })
+        }))
     }
 }
 

examples/get_token.rs

@@ -1,9 +1,6 @@
 use std::env;
 
-use librespot::core::authentication::Credentials;
-use librespot::core::config::SessionConfig;
-use librespot::core::keymaster;
-use librespot::core::session::Session;
+use librespot::core::{authentication::Credentials, config::SessionConfig, session::Session};
 
 const SCOPES: &str =
     "streaming,user-read-playback-state,user-modify-playback-state,user-read-currently-playing";
@@ -13,21 +10,20 @@ async fn main() {
     let session_config = SessionConfig::default();
 
     let args: Vec<_> = env::args().collect();
-    if args.len() != 4 {
-        eprintln!("Usage: {} USERNAME PASSWORD CLIENT_ID", args[0]);
+    if args.len() != 3 {
+        eprintln!("Usage: {} USERNAME PASSWORD", args[0]);
         return;
     }
 
-    println!("Connecting..");
+    println!("Connecting...");
     let credentials = Credentials::with_password(&args[1], &args[2]);
-    let (session, _) = Session::connect(session_config, credentials, None, false)
-        .await
-        .unwrap();
+    let session = Session::new(session_config, None);
 
-    println!(
+    match session.connect(credentials, false).await {
+        Ok(()) => println!(
             "Token: {:#?}",
-        keymaster::get_token(&session, &args[3], SCOPES)
-            .await
-            .unwrap()
-    );
+            session.token_provider().get_token(SCOPES).await.unwrap()
+        ),
+        Err(e) => println!("Error connecting: {}", e),
+    }
 }

examples/play.rs

@@ -1,13 +1,16 @@
-use std::env;
+use std::{env, process::exit};
 
-use librespot::core::authentication::Credentials;
-use librespot::core::config::SessionConfig;
-use librespot::core::session::Session;
-use librespot::core::spotify_id::SpotifyId;
-use librespot::playback::audio_backend;
-use librespot::playback::config::{AudioFormat, PlayerConfig};
-use librespot::playback::mixer::NoOpVolume;
-use librespot::playback::player::Player;
+use librespot::{
+    core::{
+        authentication::Credentials, config::SessionConfig, session::Session, spotify_id::SpotifyId,
+    },
+    playback::{
+        audio_backend,
+        config::{AudioFormat, PlayerConfig},
+        mixer::NoOpVolume,
+        player::Player,
+    },
+};
 
 #[tokio::main]
 async fn main() {
@@ -26,10 +29,12 @@ async fn main() {
 
     let backend = audio_backend::find(None).unwrap();
 
-    println!("Connecting ..");
-    let (session, _) = Session::connect(session_config, credentials, None, false)
-        .await
-        .unwrap();
+    println!("Connecting...");
+    let session = Session::new(session_config, None);
+    if let Err(e) = session.connect(credentials, false).await {
+        println!("Error connecting: {}", e);
+        exit(1);
+    }
 
     let (mut player, _) = Player::new(player_config, session, Box::new(NoOpVolume), move || {
         backend(None, audio_format)

examples/playlist_tracks.rs

@@ -1,11 +1,11 @@
-use std::env;
-use std::process;
+use std::{env, process::exit};
 
-use librespot::core::authentication::Credentials;
-use librespot::core::config::SessionConfig;
-use librespot::core::session::Session;
-use librespot::core::spotify_id::SpotifyId;
-use librespot::metadata::{Metadata, Playlist, Track};
+use librespot::{
+    core::{
+        authentication::Credentials, config::SessionConfig, session::Session, spotify_id::SpotifyId,
+    },
+    metadata::{Metadata, Playlist, Track},
+};
 
 #[tokio::main]
 async fn main() {
@@ -24,16 +24,18 @@ async fn main() {
             "PLAYLIST should be a playlist URI such as: \
                 \"spotify:playlist:37i9dQZF1DXec50AjHrNTq\""
         );
-        process::exit(1);
+        exit(1);
     });
 
-    let (session, _) = Session::connect(session_config, credentials, None, false)
-        .await
-        .unwrap();
+    let session = Session::new(session_config, None);
+    if let Err(e) = session.connect(credentials, false).await {
+        println!("Error connecting: {}", e);
+        exit(1);
+    }
 
     let plist = Playlist::get(&session, plist_uri).await.unwrap();
     println!("{:?}", plist);
-    for track_id in plist.tracks {
+    for track_id in plist.tracks() {
         let plist_track = Track::get(&session, track_id).await.unwrap();
         println!("track: {} ", plist_track.name);
     }

metadata/Cargo.toml

@@ -9,13 +9,17 @@ edition = "2018"
 
 [dependencies]
 async-trait = "0.1"
-byteorder = "1.3"
-protobuf = "2.14.0"
+byteorder = "1"
+bytes = "1"
 log = "0.4"
+protobuf = "2"
+thiserror = "1"
+uuid = { version = "1", default-features = false }
 
 [dependencies.librespot-core]
 path = "../core"
 version = "0.4.2"
+
 [dependencies.librespot-protocol]
 path = "../protocol"
 version = "0.4.2"

metadata/src/album.rs

@@ -0,0 +1,137 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use crate::{
+    artist::Artists, availability::Availabilities, copyright::Copyrights, external_id::ExternalIds,
+    image::Images, request::RequestResult, restriction::Restrictions, sale_period::SalePeriods,
+    track::Tracks, util::try_from_repeated_message, Metadata,
+};
+
+use librespot_core::{date::Date, Error, Session, SpotifyId};
+
+use librespot_protocol as protocol;
+pub use protocol::metadata::Album_Type as AlbumType;
+use protocol::metadata::Disc as DiscMessage;
+
+#[derive(Debug, Clone)]
+pub struct Album {
+    pub id: SpotifyId,
+    pub name: String,
+    pub artists: Artists,
+    pub album_type: AlbumType,
+    pub label: String,
+    pub date: Date,
+    pub popularity: i32,
+    pub genres: Vec<String>,
+    pub covers: Images,
+    pub external_ids: ExternalIds,
+    pub discs: Discs,
+    pub reviews: Vec<String>,
+    pub copyrights: Copyrights,
+    pub restrictions: Restrictions,
+    pub related: Albums,
+    pub sale_periods: SalePeriods,
+    pub cover_group: Images,
+    pub original_title: String,
+    pub version_title: String,
+    pub type_str: String,
+    pub availability: Availabilities,
+}
+
+#[derive(Debug, Clone)]
+pub struct Albums(pub Vec<SpotifyId>);
+
+impl Deref for Albums {
+    type Target = Vec<SpotifyId>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Disc {
+    pub number: i32,
+    pub name: String,
+    pub tracks: Tracks,
+}
+
+#[derive(Debug, Clone)]
+pub struct Discs(pub Vec<Disc>);
+
+impl Deref for Discs {
+    type Target = Vec<Disc>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl Album {
+    pub fn tracks(&self) -> Tracks {
+        let result = self
+            .discs
+            .iter()
+            .flat_map(|disc| disc.tracks.deref().clone())
+            .collect();
+        Tracks(result)
+    }
+}
+
+#[async_trait]
+impl Metadata for Album {
+    type Message = protocol::metadata::Album;
+
+    async fn request(session: &Session, album_id: SpotifyId) -> RequestResult {
+        session.spclient().get_album_metadata(album_id).await
+    }
+
+    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+        Self::try_from(msg)
+    }
+}
+
+impl TryFrom<&<Self as Metadata>::Message> for Album {
+    type Error = librespot_core::Error;
+    fn try_from(album: &<Self as Metadata>::Message) -> Result<Self, Self::Error> {
+        Ok(Self {
+            id: album.try_into()?,
+            name: album.get_name().to_owned(),
+            artists: album.get_artist().try_into()?,
+            album_type: album.get_field_type(),
+            label: album.get_label().to_owned(),
+            date: album.get_date().try_into()?,
+            popularity: album.get_popularity(),
+            genres: album.get_genre().to_vec(),
+            covers: album.get_cover().into(),
+            external_ids: album.get_external_id().into(),
+            discs: album.get_disc().try_into()?,
+            reviews: album.get_review().to_vec(),
+            copyrights: album.get_copyright().into(),
+            restrictions: album.get_restriction().into(),
+            related: album.get_related().try_into()?,
+            sale_periods: album.get_sale_period().try_into()?,
+            cover_group: album.get_cover_group().get_image().into(),
+            original_title: album.get_original_title().to_owned(),
+            version_title: album.get_version_title().to_owned(),
+            type_str: album.get_type_str().to_owned(),
+            availability: album.get_availability().try_into()?,
+        })
+    }
+}
+
+try_from_repeated_message!(<Album as Metadata>::Message, Albums);
+
+impl TryFrom<&DiscMessage> for Disc {
+    type Error = librespot_core::Error;
+    fn try_from(disc: &DiscMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            number: disc.get_number(),
+            name: disc.get_name().to_owned(),
+            tracks: disc.get_track().try_into()?,
+        })
+    }
+}
+
+try_from_repeated_message!(DiscMessage, Discs);

metadata/src/artist.rs

@@ -0,0 +1,129 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use crate::{request::RequestResult, track::Tracks, util::try_from_repeated_message, Metadata};
+
+use librespot_core::{Error, Session, SpotifyId};
+
+use librespot_protocol as protocol;
+use protocol::metadata::ArtistWithRole as ArtistWithRoleMessage;
+pub use protocol::metadata::ArtistWithRole_ArtistRole as ArtistRole;
+use protocol::metadata::TopTracks as TopTracksMessage;
+
+#[derive(Debug, Clone)]
+pub struct Artist {
+    pub id: SpotifyId,
+    pub name: String,
+    pub top_tracks: CountryTopTracks,
+}
+
+#[derive(Debug, Clone)]
+pub struct Artists(pub Vec<SpotifyId>);
+
+impl Deref for Artists {
+    type Target = Vec<SpotifyId>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct ArtistWithRole {
+    pub id: SpotifyId,
+    pub name: String,
+    pub role: ArtistRole,
+}
+
+#[derive(Debug, Clone)]
+pub struct ArtistsWithRole(pub Vec<ArtistWithRole>);
+
+impl Deref for ArtistsWithRole {
+    type Target = Vec<ArtistWithRole>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct TopTracks {
+    pub country: String,
+    pub tracks: Tracks,
+}
+
+#[derive(Debug, Clone)]
+pub struct CountryTopTracks(pub Vec<TopTracks>);
+
+impl Deref for CountryTopTracks {
+    type Target = Vec<TopTracks>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl CountryTopTracks {
+    pub fn for_country(&self, country: &str) -> Tracks {
+        if let Some(country) = self.0.iter().find(|top_track| top_track.country == country) {
+            return country.tracks.clone();
+        }
+
+        if let Some(global) = self.0.iter().find(|top_track| top_track.country.is_empty()) {
+            return global.tracks.clone();
+        }
+
+        Tracks(vec![]) // none found
+    }
+}
+
+#[async_trait]
+impl Metadata for Artist {
+    type Message = protocol::metadata::Artist;
+
+    async fn request(session: &Session, artist_id: SpotifyId) -> RequestResult {
+        session.spclient().get_artist_metadata(artist_id).await
+    }
+
+    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+        Self::try_from(msg)
+    }
+}
+
+impl TryFrom<&<Self as Metadata>::Message> for Artist {
+    type Error = librespot_core::Error;
+    fn try_from(artist: &<Self as Metadata>::Message) -> Result<Self, Self::Error> {
+        Ok(Self {
+            id: artist.try_into()?,
+            name: artist.get_name().to_owned(),
+            top_tracks: artist.get_top_track().try_into()?,
+        })
+    }
+}
+
+try_from_repeated_message!(<Artist as Metadata>::Message, Artists);
+
+impl TryFrom<&ArtistWithRoleMessage> for ArtistWithRole {
+    type Error = librespot_core::Error;
+    fn try_from(artist_with_role: &ArtistWithRoleMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            id: artist_with_role.try_into()?,
+            name: artist_with_role.get_artist_name().to_owned(),
+            role: artist_with_role.get_role(),
+        })
+    }
+}
+
+try_from_repeated_message!(ArtistWithRoleMessage, ArtistsWithRole);
+
+impl TryFrom<&TopTracksMessage> for TopTracks {
+    type Error = librespot_core::Error;
+    fn try_from(top_tracks: &TopTracksMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            country: top_tracks.get_country().to_owned(),
+            tracks: top_tracks.get_track().try_into()?,
+        })
+    }
+}
+
+try_from_repeated_message!(TopTracksMessage, CountryTopTracks);

metadata/src/audio/file.rs

@@ -0,0 +1,62 @@
+use std::{collections::HashMap, fmt::Debug, ops::Deref};
+
+use librespot_core::FileId;
+
+use librespot_protocol as protocol;
+use protocol::metadata::AudioFile as AudioFileMessage;
+pub use protocol::metadata::AudioFile_Format as AudioFileFormat;
+
+#[derive(Debug, Clone)]
+pub struct AudioFiles(pub HashMap<AudioFileFormat, FileId>);
+
+impl Deref for AudioFiles {
+    type Target = HashMap<AudioFileFormat, FileId>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl AudioFiles {
+    pub fn is_ogg_vorbis(format: AudioFileFormat) -> bool {
+        matches!(
+            format,
+            AudioFileFormat::OGG_VORBIS_320
+                | AudioFileFormat::OGG_VORBIS_160
+                | AudioFileFormat::OGG_VORBIS_96
+        )
+    }
+
+    pub fn is_mp3(format: AudioFileFormat) -> bool {
+        matches!(
+            format,
+            AudioFileFormat::MP3_320
+                | AudioFileFormat::MP3_256
+                | AudioFileFormat::MP3_160
+                | AudioFileFormat::MP3_96
+                | AudioFileFormat::MP3_160_ENC
+        )
+    }
+
+    pub fn is_flac(format: AudioFileFormat) -> bool {
+        matches!(format, AudioFileFormat::FLAC_FLAC)
+    }
+}
+
+impl From<&[AudioFileMessage]> for AudioFiles {
+    fn from(files: &[AudioFileMessage]) -> Self {
+        let audio_files = files
+            .iter()
+            .filter_map(|file| {
+                let file_id = FileId::from(file.get_file_id());
+                if file.has_format() {
+                    Some((file.get_format(), file_id))
+                } else {
+                    trace!("Ignoring file <{}> with unspecified format", file_id);
+                    None
+                }
+            })
+            .collect();
+
+        AudioFiles(audio_files)
+    }
+}

metadata/src/audio/item.rs

@@ -0,0 +1,113 @@
+use std::fmt::Debug;
+
+use crate::{
+    availability::{AudioItemAvailability, Availabilities, UnavailabilityReason},
+    episode::Episode,
+    error::MetadataError,
+    restriction::Restrictions,
+    track::{Track, Tracks},
+};
+
+use super::file::AudioFiles;
+
+use librespot_core::{
+    date::Date, session::UserData, spotify_id::SpotifyItemType, Error, Session, SpotifyId,
+};
+
+pub type AudioItemResult = Result<AudioItem, Error>;
+
+// A wrapper with fields the player needs
+#[derive(Debug, Clone)]
+pub struct AudioItem {
+    pub id: SpotifyId,
+    pub spotify_uri: String,
+    pub files: AudioFiles,
+    pub name: String,
+    pub duration: i32,
+    pub availability: AudioItemAvailability,
+    pub alternatives: Option<Tracks>,
+    pub is_explicit: bool,
+}
+
+impl AudioItem {
+    pub async fn get_file(session: &Session, id: SpotifyId) -> AudioItemResult {
+        match id.item_type {
+            SpotifyItemType::Track => Track::get_audio_item(session, id).await,
+            SpotifyItemType::Episode => Episode::get_audio_item(session, id).await,
+            _ => Err(Error::unavailable(MetadataError::NonPlayable)),
+        }
+    }
+}
+
+#[async_trait]
+pub trait InnerAudioItem {
+    async fn get_audio_item(session: &Session, id: SpotifyId) -> AudioItemResult;
+
+    fn allowed_for_user(
+        user_data: &UserData,
+        restrictions: &Restrictions,
+    ) -> AudioItemAvailability {
+        let country = &user_data.country;
+        let user_catalogue = match user_data.attributes.get("catalogue") {
+            Some(catalogue) => catalogue,
+            None => "premium",
+        };
+
+        for premium_restriction in restrictions.iter().filter(|restriction| {
+            restriction
+                .catalogue_strs
+                .iter()
+                .any(|restricted_catalogue| restricted_catalogue == user_catalogue)
+        }) {
+            if let Some(allowed_countries) = &premium_restriction.countries_allowed {
+                // A restriction will specify either a whitelast *or* a blacklist,
+                // but not both. So restrict availability if there is a whitelist
+                // and the country isn't on it.
+                if allowed_countries.iter().any(|allowed| country == allowed) {
+                    return Ok(());
+                } else {
+                    return Err(UnavailabilityReason::NotWhitelisted);
+                }
+            }
+
+            if let Some(forbidden_countries) = &premium_restriction.countries_forbidden {
+                if forbidden_countries
+                    .iter()
+                    .any(|forbidden| country == forbidden)
+                {
+                    return Err(UnavailabilityReason::Blacklisted);
+                } else {
+                    return Ok(());
+                }
+            }
+        }
+
+        Ok(()) // no restrictions in place
+    }
+
+    fn available(availability: &Availabilities) -> AudioItemAvailability {
+        if availability.is_empty() {
+            // not all items have availability specified
+            return Ok(());
+        }
+
+        if !(availability
+            .iter()
+            .any(|availability| Date::now_utc() >= availability.start))
+        {
+            return Err(UnavailabilityReason::Embargo);
+        }
+
+        Ok(())
+    }
+
+    fn available_for_user(
+        user_data: &UserData,
+        availability: &Availabilities,
+        restrictions: &Restrictions,
+    ) -> AudioItemAvailability {
+        Self::available(availability)?;
+        Self::allowed_for_user(user_data, restrictions)?;
+        Ok(())
+    }
+}

metadata/src/audio/mod.rs

@@ -0,0 +1,5 @@
+pub mod file;
+pub mod item;
+
+pub use file::{AudioFileFormat, AudioFiles};
+pub use item::AudioItem;

metadata/src/availability.rs

@@ -0,0 +1,56 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use thiserror::Error;
+
+use crate::util::try_from_repeated_message;
+
+use librespot_core::date::Date;
+
+use librespot_protocol as protocol;
+use protocol::metadata::Availability as AvailabilityMessage;
+
+pub type AudioItemAvailability = Result<(), UnavailabilityReason>;
+
+#[derive(Debug, Clone)]
+pub struct Availability {
+    pub catalogue_strs: Vec<String>,
+    pub start: Date,
+}
+
+#[derive(Debug, Clone)]
+pub struct Availabilities(pub Vec<Availability>);
+
+impl Deref for Availabilities {
+    type Target = Vec<Availability>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Copy, Clone, Error)]
+pub enum UnavailabilityReason {
+    #[error("blacklist present and country on it")]
+    Blacklisted,
+    #[error("available date is in the future")]
+    Embargo,
+    #[error("required data was not present")]
+    NoData,
+    #[error("whitelist present and country not on it")]
+    NotWhitelisted,
+}
+
+impl TryFrom<&AvailabilityMessage> for Availability {
+    type Error = librespot_core::Error;
+    fn try_from(availability: &AvailabilityMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            catalogue_strs: availability.get_catalogue_str().to_vec(),
+            start: availability.get_start().try_into()?,
+        })
+    }
+}
+
+try_from_repeated_message!(AvailabilityMessage, Availabilities);

metadata/src/content_rating.rs

@@ -0,0 +1,33 @@
+use std::{fmt::Debug, ops::Deref};
+
+use crate::util::from_repeated_message;
+
+use librespot_protocol as protocol;
+use protocol::metadata::ContentRating as ContentRatingMessage;
+
+#[derive(Debug, Clone)]
+pub struct ContentRating {
+    pub country: String,
+    pub tags: Vec<String>,
+}
+
+#[derive(Debug, Clone)]
+pub struct ContentRatings(pub Vec<ContentRating>);
+
+impl Deref for ContentRatings {
+    type Target = Vec<ContentRating>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl From<&ContentRatingMessage> for ContentRating {
+    fn from(content_rating: &ContentRatingMessage) -> Self {
+        Self {
+            country: content_rating.get_country().to_owned(),
+            tags: content_rating.get_tag().to_vec(),
+        }
+    }
+}
+
+from_repeated_message!(ContentRatingMessage, ContentRatings);

metadata/src/copyright.rs

@@ -0,0 +1,34 @@
+use std::{fmt::Debug, ops::Deref};
+
+use crate::util::from_repeated_message;
+
+use librespot_protocol as protocol;
+use protocol::metadata::Copyright as CopyrightMessage;
+pub use protocol::metadata::Copyright_Type as CopyrightType;
+
+#[derive(Debug, Clone)]
+pub struct Copyright {
+    pub copyright_type: CopyrightType,
+    pub text: String,
+}
+
+#[derive(Debug, Clone)]
+pub struct Copyrights(pub Vec<Copyright>);
+
+impl Deref for Copyrights {
+    type Target = Vec<Copyright>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl From<&CopyrightMessage> for Copyright {
+    fn from(copyright: &CopyrightMessage) -> Self {
+        Self {
+            copyright_type: copyright.get_field_type(),
+            text: copyright.get_text().to_owned(),
+        }
+    }
+}
+
+from_repeated_message!(CopyrightMessage, Copyrights);

metadata/src/cover.rs

@@ -1,19 +0,0 @@
-use byteorder::{BigEndian, WriteBytesExt};
-use std::io::Write;
-
-use librespot_core::channel::ChannelData;
-use librespot_core::session::Session;
-use librespot_core::spotify_id::FileId;
-
-pub fn get(session: &Session, file: FileId) -> ChannelData {
-    let (channel_id, channel) = session.channel().allocate();
-    let (_headers, data) = channel.split();
-
-    let mut packet: Vec<u8> = Vec::new();
-    packet.write_u16::<BigEndian>(channel_id).unwrap();
-    packet.write_u16::<BigEndian>(0).unwrap();
-    packet.write(&file.0).unwrap();
-    session.send_packet(0x19, packet);
-
-    data
-}

metadata/src/episode.rs

@@ -0,0 +1,133 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use crate::{
+    audio::{
+        file::AudioFiles,
+        item::{AudioItem, AudioItemResult, InnerAudioItem},
+    },
+    availability::Availabilities,
+    content_rating::ContentRatings,
+    image::Images,
+    request::RequestResult,
+    restriction::Restrictions,
+    util::try_from_repeated_message,
+    video::VideoFiles,
+    Metadata,
+};
+
+use librespot_core::{date::Date, Error, Session, SpotifyId};
+
+use librespot_protocol as protocol;
+pub use protocol::metadata::Episode_EpisodeType as EpisodeType;
+
+#[derive(Debug, Clone)]
+pub struct Episode {
+    pub id: SpotifyId,
+    pub name: String,
+    pub duration: i32,
+    pub audio: AudioFiles,
+    pub description: String,
+    pub number: i32,
+    pub publish_time: Date,
+    pub covers: Images,
+    pub language: String,
+    pub is_explicit: bool,
+    pub show: SpotifyId,
+    pub videos: VideoFiles,
+    pub video_previews: VideoFiles,
+    pub audio_previews: AudioFiles,
+    pub restrictions: Restrictions,
+    pub freeze_frames: Images,
+    pub keywords: Vec<String>,
+    pub allow_background_playback: bool,
+    pub availability: Availabilities,
+    pub external_url: String,
+    pub episode_type: EpisodeType,
+    pub has_music_and_talk: bool,
+    pub content_rating: ContentRatings,
+    pub is_audiobook_chapter: bool,
+}
+
+#[derive(Debug, Clone)]
+pub struct Episodes(pub Vec<SpotifyId>);
+
+impl Deref for Episodes {
+    type Target = Vec<SpotifyId>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[async_trait]
+impl InnerAudioItem for Episode {
+    async fn get_audio_item(session: &Session, id: SpotifyId) -> AudioItemResult {
+        let episode = Self::get(session, id).await?;
+        let availability = Self::available_for_user(
+            &session.user_data(),
+            &episode.availability,
+            &episode.restrictions,
+        );
+
+        Ok(AudioItem {
+            id,
+            spotify_uri: id.to_uri()?,
+            files: episode.audio,
+            name: episode.name,
+            duration: episode.duration,
+            availability,
+            alternatives: None,
+            is_explicit: episode.is_explicit,
+        })
+    }
+}
+
+#[async_trait]
+impl Metadata for Episode {
+    type Message = protocol::metadata::Episode;
+
+    async fn request(session: &Session, episode_id: SpotifyId) -> RequestResult {
+        session.spclient().get_episode_metadata(episode_id).await
+    }
+
+    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+        Self::try_from(msg)
+    }
+}
+
+impl TryFrom<&<Self as Metadata>::Message> for Episode {
+    type Error = librespot_core::Error;
+    fn try_from(episode: &<Self as Metadata>::Message) -> Result<Self, Self::Error> {
+        Ok(Self {
+            id: episode.try_into()?,
+            name: episode.get_name().to_owned(),
+            duration: episode.get_duration().to_owned(),
+            audio: episode.get_audio().into(),
+            description: episode.get_description().to_owned(),
+            number: episode.get_number(),
+            publish_time: episode.get_publish_time().try_into()?,
+            covers: episode.get_cover_image().get_image().into(),
+            language: episode.get_language().to_owned(),
+            is_explicit: episode.get_explicit().to_owned(),
+            show: episode.get_show().try_into()?,
+            videos: episode.get_video().into(),
+            video_previews: episode.get_video_preview().into(),
+            audio_previews: episode.get_audio_preview().into(),
+            restrictions: episode.get_restriction().into(),
+            freeze_frames: episode.get_freeze_frame().get_image().into(),
+            keywords: episode.get_keyword().to_vec(),
+            allow_background_playback: episode.get_allow_background_playback(),
+            availability: episode.get_availability().try_into()?,
+            external_url: episode.get_external_url().to_owned(),
+            episode_type: episode.get_field_type(),
+            has_music_and_talk: episode.get_music_and_talk(),
+            content_rating: episode.get_content_rating().into(),
+            is_audiobook_chapter: episode.get_is_audiobook_chapter(),
+        })
+    }
+}
+
+try_from_repeated_message!(<Episode as Metadata>::Message, Episodes);

metadata/src/error.rs

@@ -0,0 +1,10 @@
+use std::fmt::Debug;
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum MetadataError {
+    #[error("empty response")]
+    Empty,
+    #[error("audio item is non-playable when it should be")]
+    NonPlayable,
+}

metadata/src/external_id.rs

@@ -0,0 +1,33 @@
+use std::{fmt::Debug, ops::Deref};
+
+use crate::util::from_repeated_message;
+
+use librespot_protocol as protocol;
+use protocol::metadata::ExternalId as ExternalIdMessage;
+
+#[derive(Debug, Clone)]
+pub struct ExternalId {
+    pub external_type: String,
+    pub id: String, // this can be anything from a URL to a ISRC, EAN or UPC
+}
+
+#[derive(Debug, Clone)]
+pub struct ExternalIds(pub Vec<ExternalId>);
+
+impl Deref for ExternalIds {
+    type Target = Vec<ExternalId>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl From<&ExternalIdMessage> for ExternalId {
+    fn from(external_id: &ExternalIdMessage) -> Self {
+        Self {
+            external_type: external_id.get_field_type().to_owned(),
+            id: external_id.get_id().to_owned(),
+        }
+    }
+}
+
+from_repeated_message!(ExternalIdMessage, ExternalIds);

metadata/src/image.rs

@@ -0,0 +1,101 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use crate::util::{from_repeated_message, try_from_repeated_message};
+
+use librespot_core::{FileId, SpotifyId};
+
+use librespot_protocol as protocol;
+use protocol::metadata::Image as ImageMessage;
+pub use protocol::metadata::Image_Size as ImageSize;
+use protocol::playlist4_external::PictureSize as PictureSizeMessage;
+use protocol::playlist_annotate3::TranscodedPicture as TranscodedPictureMessage;
+
+#[derive(Debug, Clone)]
+pub struct Image {
+    pub id: FileId,
+    pub size: ImageSize,
+    pub width: i32,
+    pub height: i32,
+}
+
+#[derive(Debug, Clone)]
+pub struct Images(pub Vec<Image>);
+
+impl Deref for Images {
+    type Target = Vec<Image>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct PictureSize {
+    pub target_name: String,
+    pub url: String,
+}
+
+#[derive(Debug, Clone)]
+pub struct PictureSizes(pub Vec<PictureSize>);
+
+impl Deref for PictureSizes {
+    type Target = Vec<PictureSize>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct TranscodedPicture {
+    pub target_name: String,
+    pub uri: SpotifyId,
+}
+
+#[derive(Debug, Clone)]
+pub struct TranscodedPictures(pub Vec<TranscodedPicture>);
+
+impl Deref for TranscodedPictures {
+    type Target = Vec<TranscodedPicture>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl From<&ImageMessage> for Image {
+    fn from(image: &ImageMessage) -> Self {
+        Self {
+            id: image.into(),
+            size: image.get_size(),
+            width: image.get_width(),
+            height: image.get_height(),
+        }
+    }
+}
+
+from_repeated_message!(ImageMessage, Images);
+
+impl From<&PictureSizeMessage> for PictureSize {
+    fn from(size: &PictureSizeMessage) -> Self {
+        Self {
+            target_name: size.get_target_name().to_owned(),
+            url: size.get_url().to_owned(),
+        }
+    }
+}
+
+from_repeated_message!(PictureSizeMessage, PictureSizes);
+
+impl TryFrom<&TranscodedPictureMessage> for TranscodedPicture {
+    type Error = librespot_core::Error;
+    fn try_from(picture: &TranscodedPictureMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            target_name: picture.get_target_name().to_owned(),
+            uri: picture.try_into()?,
+        })
+    }
+}
+
+try_from_repeated_message!(TranscodedPictureMessage, TranscodedPictures);

metadata/src/lib.rs

@@ -1,534 +1,56 @@
-#![allow(clippy::unused_io_amount)]
-
 #[macro_use]
 extern crate log;
 
 #[macro_use]
 extern crate async_trait;
 
-pub mod cover;
-use std::collections::HashMap;
-use std::string::FromUtf8Error;
-
-use librespot_core::mercury::MercuryError;
-use librespot_core::session::Session;
-use librespot_core::spotify_id::{FileId, SpotifyAudioType, SpotifyId, SpotifyIdError};
-use librespot_protocol as protocol;
 use protobuf::Message;
 
-pub use crate::protocol::metadata::AudioFile_Format as FileFormat;
+use librespot_core::{Error, Session, SpotifyId};
 
-fn countrylist_contains(list: &str, country: &str) -> bool {
-    list.chunks(2).any(|cc| cc == country)
-}
+pub mod album;
+pub mod artist;
+pub mod audio;
+pub mod availability;
+pub mod content_rating;
+pub mod copyright;
+pub mod episode;
+pub mod error;
+pub mod external_id;
+pub mod image;
+pub mod playlist;
+mod request;
+pub mod restriction;
+pub mod sale_period;
+pub mod show;
+pub mod track;
+mod util;
+pub mod video;
 
-fn parse_restrictions<'s, I>(restrictions: I, country: &str, catalogue: &str) -> bool
-where
-    I: IntoIterator<Item = &'s protocol::metadata::Restriction>,
-{
-    let mut forbidden = "".to_string();
-    let mut has_forbidden = false;
+pub use error::MetadataError;
+use request::RequestResult;
 
-    let mut allowed = "".to_string();
-    let mut has_allowed = false;
-
-    let rs = restrictions
-        .into_iter()
-        .filter(|r| r.get_catalogue_str().contains(&catalogue.to_owned()));
-
-    for r in rs {
-        if r.has_countries_forbidden() {
-            forbidden.push_str(r.get_countries_forbidden());
-            has_forbidden = true;
-        }
-
-        if r.has_countries_allowed() {
-            allowed.push_str(r.get_countries_allowed());
-            has_allowed = true;
-        }
-    }
-
-    (has_forbidden || has_allowed)
-        && (!has_forbidden || !countrylist_contains(forbidden.as_str(), country))
-        && (!has_allowed || countrylist_contains(allowed.as_str(), country))
-}
-
-// A wrapper with fields the player needs
-#[derive(Debug, Clone)]
-pub struct AudioItem {
-    pub id: SpotifyId,
-    pub uri: String,
-    pub files: HashMap<FileFormat, FileId>,
-    pub name: String,
-    pub duration: i32,
-    pub available: bool,
-    pub alternatives: Option<Vec<SpotifyId>>,
-}
-
-impl AudioItem {
-    pub async fn get_audio_item(session: &Session, id: SpotifyId) -> Result<Self, MercuryError> {
-        match id.audio_type {
-            SpotifyAudioType::Track => Track::get_audio_item(session, id).await,
-            SpotifyAudioType::Podcast => Episode::get_audio_item(session, id).await,
-            SpotifyAudioType::NonPlayable => Err(MercuryError),
-        }
-    }
-}
-
-#[async_trait]
-trait AudioFiles {
-    async fn get_audio_item(session: &Session, id: SpotifyId) -> Result<AudioItem, MercuryError>;
-}
-
-#[async_trait]
-impl AudioFiles for Track {
-    async fn get_audio_item(session: &Session, id: SpotifyId) -> Result<AudioItem, MercuryError> {
-        match id.to_base62() {
-            Err(e) => {
-                warn!("Invalid Track SpotifyId: {}", e);
-                Err(MercuryError)
-            }
-            Ok(uri) => {
-                let item = Self::get(session, id).await?;
-                Ok(AudioItem {
-                    id,
-                    uri: format!("spotify:track:{}", uri),
-                    files: item.files,
-                    name: item.name,
-                    duration: item.duration,
-                    available: item.available,
-                    alternatives: Some(item.alternatives),
-                })
-            }
-        }
-    }
-}
-
-#[async_trait]
-impl AudioFiles for Episode {
-    async fn get_audio_item(session: &Session, id: SpotifyId) -> Result<AudioItem, MercuryError> {
-        match id.to_base62() {
-            Err(e) => {
-                warn!("Invalid Episode SpotifyId: {}", e);
-                Err(MercuryError)
-            }
-            Ok(uri) => {
-                let item = Self::get(session, id).await?;
-                Ok(AudioItem {
-                    id,
-                    uri: format!("spotify:episode:{}", uri),
-                    files: item.files,
-                    name: item.name,
-                    duration: item.duration,
-                    available: item.available,
-                    alternatives: None,
-                })
-            }
-        }
-    }
-}
+pub use album::Album;
+pub use artist::Artist;
+pub use episode::Episode;
+pub use playlist::Playlist;
+pub use show::Show;
+pub use track::Track;
 
 #[async_trait]
 pub trait Metadata: Send + Sized + 'static {
     type Message: protobuf::Message;
 
-    fn request_url(id: SpotifyId) -> Result<String, FromUtf8Error>;
-    fn parse(msg: &Self::Message, session: &Session) -> Result<Self, SpotifyIdError>;
+    // Request a protobuf
+    async fn request(session: &Session, id: SpotifyId) -> RequestResult;
 
-    async fn get(session: &Session, id: SpotifyId) -> Result<Self, MercuryError> {
-        match Self::request_url(id) {
-            Err(e) => {
-                warn!("Invalid SpotifyId: {}", e);
-                Err(MercuryError)
-            }
-            Ok(uri) => {
-                let response = session.mercury().get(uri).await?;
-                match response.payload.first() {
-                    None => {
-                        warn!("Empty payload");
-                        Err(MercuryError)
-                    }
-                    Some(data) => match Self::Message::parse_from_bytes(data) {
-                        Err(e) => {
-                            warn!("Error parsing message from bytes: {}", e);
-                            Err(MercuryError)
-                        }
-                        Ok(msg) => match Self::parse(&msg, session) {
-                            Err(e) => {
-                                warn!("Error parsing message: {:?}", e);
-                                Err(MercuryError)
-                            }
-                            Ok(parsed_msg) => Ok(parsed_msg),
-                        },
-                    },
-                }
-            }
-        }
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct Track {
-    pub id: SpotifyId,
-    pub name: String,
-    pub duration: i32,
-    pub album: SpotifyId,
-    pub artists: Vec<SpotifyId>,
-    pub files: HashMap<FileFormat, FileId>,
-    pub alternatives: Vec<SpotifyId>,
-    pub available: bool,
-}
-
-#[derive(Debug, Clone)]
-pub struct Album {
-    pub id: SpotifyId,
-    pub name: String,
-    pub artists: Vec<SpotifyId>,
-    pub tracks: Vec<SpotifyId>,
-    pub covers: Vec<FileId>,
-}
-
-#[derive(Debug, Clone)]
-pub struct Episode {
-    pub id: SpotifyId,
-    pub name: String,
-    pub external_url: String,
-    pub duration: i32,
-    pub language: String,
-    pub show: SpotifyId,
-    pub files: HashMap<FileFormat, FileId>,
-    pub covers: Vec<FileId>,
-    pub available: bool,
-    pub explicit: bool,
-}
-
-#[derive(Debug, Clone)]
-pub struct Show {
-    pub id: SpotifyId,
-    pub name: String,
-    pub publisher: String,
-    pub episodes: Vec<SpotifyId>,
-    pub covers: Vec<FileId>,
-}
-
-#[derive(Debug, Clone)]
-pub struct Playlist {
-    pub revision: Vec<u8>,
-    pub user: String,
-    pub name: String,
-    pub tracks: Vec<SpotifyId>,
-}
-
-#[derive(Debug, Clone)]
-pub struct Artist {
-    pub id: SpotifyId,
-    pub name: String,
-    pub top_tracks: Vec<SpotifyId>,
-}
-
-impl Metadata for Track {
-    type Message = protocol::metadata::Track;
-
-    fn request_url(id: SpotifyId) -> Result<String, FromUtf8Error> {
-        let id = id.to_base16()?;
-        Ok(format!("hm://metadata/3/track/{}", id))
-    }
-
-    fn parse(msg: &Self::Message, session: &Session) -> Result<Self, SpotifyIdError> {
-        let country = session.country();
-
-        let artists = msg
-            .get_artist()
-            .iter()
-            .filter_map(|artist| {
-                if artist.has_gid() {
-                    SpotifyId::from_raw(artist.get_gid()).ok()
-                } else {
-                    None
-                }
-            })
-            .collect();
-
-        let files = msg
-            .get_file()
-            .iter()
-            .filter_map(|file| {
-                if file.has_file_id() {
-                    let mut dst = [0u8; 20];
-                    dst.clone_from_slice(file.get_file_id());
-                    Some((file.get_format(), FileId(dst)))
-                } else {
-                    None
-                }
-            })
-            .collect();
-
-        Ok(Track {
-            id: SpotifyId::from_raw(msg.get_gid())?,
-            name: msg.get_name().to_owned(),
-            duration: msg.get_duration(),
-            album: SpotifyId::from_raw(msg.get_album().get_gid())?,
-            artists,
-            files,
-            alternatives: msg
-                .get_alternative()
-                .iter()
-                .filter_map(|alt| SpotifyId::from_raw(alt.get_gid()).ok())
-                .collect(),
-            available: parse_restrictions(msg.get_restriction(), &country, "premium"),
-        })
-    }
-}
-
-impl Metadata for Album {
-    type Message = protocol::metadata::Album;
-
-    fn request_url(id: SpotifyId) -> Result<String, FromUtf8Error> {
-        let id = id.to_base16()?;
-        Ok(format!("hm://metadata/3/album/{}", id))
-    }
-
-    fn parse(msg: &Self::Message, _: &Session) -> Result<Self, SpotifyIdError> {
-        let artists = msg
-            .get_artist()
-            .iter()
-            .filter_map(|artist| {
-                if artist.has_gid() {
-                    SpotifyId::from_raw(artist.get_gid()).ok()
-                } else {
-                    None
-                }
-            })
-            .collect();
-
-        let tracks = msg
-            .get_disc()
-            .iter()
-            .flat_map(|disc| disc.get_track())
-            .filter_map(|track| {
-                if track.has_gid() {
-                    SpotifyId::from_raw(track.get_gid()).ok()
-                } else {
-                    None
-                }
-            })
-            .collect();
-
-        let covers = msg
-            .get_cover_group()
-            .get_image()
-            .iter()
-            .filter_map(|image| {
-                if image.has_file_id() {
-                    let mut dst = [0u8; 20];
-                    dst.clone_from_slice(image.get_file_id());
-                    Some(FileId(dst))
-                } else {
-                    None
-                }
-            })
-            .collect();
-
-        Ok(Album {
-            id: SpotifyId::from_raw(msg.get_gid())?,
-            name: msg.get_name().to_owned(),
-            artists,
-            tracks,
-            covers,
-        })
-    }
-}
-
-impl Metadata for Playlist {
-    type Message = protocol::playlist4changes::SelectedListContent;
-
-    fn request_url(id: SpotifyId) -> Result<String, FromUtf8Error> {
-        let id = id.to_base62()?;
-        Ok(format!("hm://playlist/v2/playlist/{}", id))
-    }
-
-    fn parse(msg: &Self::Message, _: &Session) -> Result<Self, SpotifyIdError> {
-        let tracks = msg
-            .get_contents()
-            .get_items()
-            .iter()
-            .filter_map(|item| {
-                let uri_split = item.get_uri().split(':');
-                let uri_parts: Vec<&str> = uri_split.collect();
-                SpotifyId::from_base62(uri_parts[2]).ok()
-            })
-            .collect::<Vec<_>>();
-
-        if tracks.len() != msg.get_length() as usize {
-            warn!(
-                "Got {} tracks, but the playlist should contain {} tracks.",
-                tracks.len(),
-                msg.get_length()
-            );
-        }
-
-        Ok(Playlist {
-            revision: msg.get_revision().to_vec(),
-            name: msg.get_attributes().get_name().to_owned(),
-            tracks,
-            user: msg.get_owner_username().to_string(),
-        })
-    }
-}
-
-impl Metadata for Artist {
-    type Message = protocol::metadata::Artist;
-
-    fn request_url(id: SpotifyId) -> Result<String, FromUtf8Error> {
-        let id = id.to_base16()?;
-        Ok(format!("hm://metadata/3/artist/{}", id))
-    }
-
-    fn parse(msg: &Self::Message, session: &Session) -> Result<Self, SpotifyIdError> {
-        let country = session.country();
-
-        let top_tracks: Vec<SpotifyId> = match msg
-            .get_top_track()
-            .iter()
-            .find(|tt| !tt.has_country() || countrylist_contains(tt.get_country(), &country))
-        {
-            Some(tracks) => tracks
-                .get_track()
-                .iter()
-                .filter_map(|track| {
-                    if track.has_gid() {
-                        SpotifyId::from_raw(track.get_gid()).ok()
-                    } else {
-                        None
-                    }
-                })
-                .collect(),
-            None => Vec::new(),
-        };
-
-        Ok(Artist {
-            id: SpotifyId::from_raw(msg.get_gid())?,
-            name: msg.get_name().to_owned(),
-            top_tracks,
-        })
-    }
-}
-
-// Podcast
-impl Metadata for Episode {
-    type Message = protocol::metadata::Episode;
-
-    fn request_url(id: SpotifyId) -> Result<String, FromUtf8Error> {
-        let id = id.to_base16()?;
-        Ok(format!("hm://metadata/3/episode/{}", id))
-    }
-
-    fn parse(msg: &Self::Message, session: &Session) -> Result<Self, SpotifyIdError> {
-        let country = session.country();
-
-        let files = msg
-            .get_file()
-            .iter()
-            .filter(|file| file.has_file_id())
-            .map(|file| {
-                let mut dst = [0u8; 20];
-                dst.clone_from_slice(file.get_file_id());
-                (file.get_format(), FileId(dst))
-            })
-            .collect();
-
-        let covers = msg
-            .get_covers()
-            .get_image()
-            .iter()
-            .filter(|image| image.has_file_id())
-            .map(|image| {
-                let mut dst = [0u8; 20];
-                dst.clone_from_slice(image.get_file_id());
-                FileId(dst)
-            })
-            .collect();
-
-        Ok(Episode {
-            id: SpotifyId::from_raw(msg.get_gid()).unwrap(),
-            name: msg.get_name().to_owned(),
-            external_url: msg.get_external_url().to_owned(),
-            duration: msg.get_duration().to_owned(),
-            language: msg.get_language().to_owned(),
-            show: SpotifyId::from_raw(msg.get_show().get_gid()).unwrap(),
-            covers,
-            files,
-            available: parse_restrictions(msg.get_restriction(), &country, "premium"),
-            explicit: msg.get_explicit().to_owned(),
-        })
-    }
-}
-
-impl Metadata for Show {
-    type Message = protocol::metadata::Show;
-
-    fn request_url(id: SpotifyId) -> Result<String, FromUtf8Error> {
-        let id = id.to_base16()?;
-        Ok(format!("hm://metadata/3/show/{}", id))
-    }
-
-    fn parse(msg: &Self::Message, _: &Session) -> Result<Self, SpotifyIdError> {
-        let episodes = msg
-            .get_episode()
-            .iter()
-            .filter_map(|episode| {
-                if episode.has_gid() {
-                    SpotifyId::from_raw(episode.get_gid()).ok()
-                } else {
-                    None
-                }
-            })
-            .collect();
-
-        let covers = msg
-            .get_covers()
-            .get_image()
-            .iter()
-            .filter(|image| image.has_file_id())
-            .map(|image| {
-                let mut dst = [0u8; 20];
-                dst.clone_from_slice(image.get_file_id());
-                FileId(dst)
-            })
-            .collect();
-
-        Ok(Show {
-            id: SpotifyId::from_raw(msg.get_gid()).unwrap(),
-            name: msg.get_name().to_owned(),
-            publisher: msg.get_publisher().to_owned(),
-            episodes,
-            covers,
-        })
-    }
-}
-
-struct StrChunks<'s>(&'s str, usize);
-
-trait StrChunksExt {
-    fn chunks(&self, size: usize) -> StrChunks;
-}
-
-impl StrChunksExt for str {
-    fn chunks(&self, size: usize) -> StrChunks {
-        StrChunks(self, size)
-    }
-}
-
-impl<'s> Iterator for StrChunks<'s> {
-    type Item = &'s str;
-    fn next(&mut self) -> Option<&'s str> {
-        let &mut StrChunks(data, size) = self;
-        if data.is_empty() {
-            None
-        } else {
-            let ret = Some(&data[..size]);
-            self.0 = &data[size..];
-            ret
-        }
+    // Request a metadata struct
+    async fn get(session: &Session, id: SpotifyId) -> Result<Self, Error> {
+        let response = Self::request(session, id).await?;
+        let msg = Self::Message::parse_from_bytes(&response)?;
+        trace!("Received metadata: {:#?}", msg);
+        Self::parse(&msg, id)
     }
+
+    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error>;
 }

metadata/src/playlist/annotation.rs

@@ -0,0 +1,87 @@
+use std::convert::{TryFrom, TryInto};
+use std::fmt::Debug;
+
+use protobuf::Message;
+
+use crate::{
+    image::TranscodedPictures,
+    request::{MercuryRequest, RequestResult},
+    Metadata,
+};
+
+use librespot_core::{Error, Session, SpotifyId};
+
+use librespot_protocol as protocol;
+pub use protocol::playlist_annotate3::AbuseReportState;
+
+#[derive(Debug, Clone)]
+pub struct PlaylistAnnotation {
+    pub description: String,
+    pub picture: String,
+    pub transcoded_pictures: TranscodedPictures,
+    pub has_abuse_reporting: bool,
+    pub abuse_report_state: AbuseReportState,
+}
+
+#[async_trait]
+impl Metadata for PlaylistAnnotation {
+    type Message = protocol::playlist_annotate3::PlaylistAnnotation;
+
+    async fn request(session: &Session, playlist_id: SpotifyId) -> RequestResult {
+        let current_user = session.username();
+        Self::request_for_user(session, &current_user, playlist_id).await
+    }
+
+    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+        Ok(Self {
+            description: msg.get_description().to_owned(),
+            picture: msg.get_picture().to_owned(), // TODO: is this a URL or Spotify URI?
+            transcoded_pictures: msg.get_transcoded_picture().try_into()?,
+            has_abuse_reporting: msg.get_is_abuse_reporting_enabled(),
+            abuse_report_state: msg.get_abuse_report_state(),
+        })
+    }
+}
+
+impl PlaylistAnnotation {
+    async fn request_for_user(
+        session: &Session,
+        username: &str,
+        playlist_id: SpotifyId,
+    ) -> RequestResult {
+        let uri = format!(
+            "hm://playlist-annotate/v1/annotation/user/{}/playlist/{}",
+            username,
+            playlist_id.to_base62()?
+        );
+        <Self as MercuryRequest>::request(session, &uri).await
+    }
+
+    #[allow(dead_code)]
+    async fn get_for_user(
+        session: &Session,
+        username: &str,
+        playlist_id: SpotifyId,
+    ) -> Result<Self, Error> {
+        let response = Self::request_for_user(session, username, playlist_id).await?;
+        let msg = <Self as Metadata>::Message::parse_from_bytes(&response)?;
+        Self::parse(&msg, playlist_id)
+    }
+}
+
+impl MercuryRequest for PlaylistAnnotation {}
+
+impl TryFrom<&<PlaylistAnnotation as Metadata>::Message> for PlaylistAnnotation {
+    type Error = librespot_core::Error;
+    fn try_from(
+        annotation: &<PlaylistAnnotation as Metadata>::Message,
+    ) -> Result<Self, Self::Error> {
+        Ok(Self {
+            description: annotation.get_description().to_owned(),
+            picture: annotation.get_picture().to_owned(),
+            transcoded_pictures: annotation.get_transcoded_picture().try_into()?,
+            has_abuse_reporting: annotation.get_is_abuse_reporting_enabled(),
+            abuse_report_state: annotation.get_abuse_report_state(),
+        })
+    }
+}

metadata/src/playlist/attribute.rs

@@ -0,0 +1,196 @@
+use std::{
+    collections::HashMap,
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use crate::{image::PictureSizes, util::from_repeated_enum};
+
+use librespot_core::date::Date;
+
+use librespot_protocol as protocol;
+use protocol::playlist4_external::FormatListAttribute as PlaylistFormatAttributeMessage;
+pub use protocol::playlist4_external::ItemAttributeKind as PlaylistItemAttributeKind;
+use protocol::playlist4_external::ItemAttributes as PlaylistItemAttributesMessage;
+use protocol::playlist4_external::ItemAttributesPartialState as PlaylistPartialItemAttributesMessage;
+pub use protocol::playlist4_external::ListAttributeKind as PlaylistAttributeKind;
+use protocol::playlist4_external::ListAttributes as PlaylistAttributesMessage;
+use protocol::playlist4_external::ListAttributesPartialState as PlaylistPartialAttributesMessage;
+use protocol::playlist4_external::UpdateItemAttributes as PlaylistUpdateItemAttributesMessage;
+use protocol::playlist4_external::UpdateListAttributes as PlaylistUpdateAttributesMessage;
+
+#[derive(Debug, Clone)]
+pub struct PlaylistAttributes {
+    pub name: String,
+    pub description: String,
+    pub picture: Vec<u8>,
+    pub is_collaborative: bool,
+    pub pl3_version: String,
+    pub is_deleted_by_owner: bool,
+    pub client_id: String,
+    pub format: String,
+    pub format_attributes: PlaylistFormatAttribute,
+    pub picture_sizes: PictureSizes,
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistAttributeKinds(pub Vec<PlaylistAttributeKind>);
+
+impl Deref for PlaylistAttributeKinds {
+    type Target = Vec<PlaylistAttributeKind>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+from_repeated_enum!(PlaylistAttributeKind, PlaylistAttributeKinds);
+
+#[derive(Debug, Clone)]
+pub struct PlaylistFormatAttribute(pub HashMap<String, String>);
+
+impl Deref for PlaylistFormatAttribute {
+    type Target = HashMap<String, String>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistItemAttributes {
+    pub added_by: String,
+    pub timestamp: Date,
+    pub seen_at: Date,
+    pub is_public: bool,
+    pub format_attributes: PlaylistFormatAttribute,
+    pub item_id: Vec<u8>,
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistItemAttributeKinds(pub Vec<PlaylistItemAttributeKind>);
+
+impl Deref for PlaylistItemAttributeKinds {
+    type Target = Vec<PlaylistItemAttributeKind>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+from_repeated_enum!(PlaylistItemAttributeKind, PlaylistItemAttributeKinds);
+
+#[derive(Debug, Clone)]
+pub struct PlaylistPartialAttributes {
+    #[allow(dead_code)]
+    values: PlaylistAttributes,
+    #[allow(dead_code)]
+    no_value: PlaylistAttributeKinds,
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistPartialItemAttributes {
+    #[allow(dead_code)]
+    values: PlaylistItemAttributes,
+    #[allow(dead_code)]
+    no_value: PlaylistItemAttributeKinds,
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistUpdateAttributes {
+    pub new_attributes: PlaylistPartialAttributes,
+    pub old_attributes: PlaylistPartialAttributes,
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistUpdateItemAttributes {
+    pub index: i32,
+    pub new_attributes: PlaylistPartialItemAttributes,
+    pub old_attributes: PlaylistPartialItemAttributes,
+}
+
+impl TryFrom<&PlaylistAttributesMessage> for PlaylistAttributes {
+    type Error = librespot_core::Error;
+    fn try_from(attributes: &PlaylistAttributesMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            name: attributes.get_name().to_owned(),
+            description: attributes.get_description().to_owned(),
+            picture: attributes.get_picture().to_owned(),
+            is_collaborative: attributes.get_collaborative(),
+            pl3_version: attributes.get_pl3_version().to_owned(),
+            is_deleted_by_owner: attributes.get_deleted_by_owner(),
+            client_id: attributes.get_client_id().to_owned(),
+            format: attributes.get_format().to_owned(),
+            format_attributes: attributes.get_format_attributes().into(),
+            picture_sizes: attributes.get_picture_size().into(),
+        })
+    }
+}
+
+impl From<&[PlaylistFormatAttributeMessage]> for PlaylistFormatAttribute {
+    fn from(attributes: &[PlaylistFormatAttributeMessage]) -> Self {
+        let format_attributes = attributes
+            .iter()
+            .map(|attribute| {
+                (
+                    attribute.get_key().to_owned(),
+                    attribute.get_value().to_owned(),
+                )
+            })
+            .collect();
+
+        PlaylistFormatAttribute(format_attributes)
+    }
+}
+
+impl TryFrom<&PlaylistItemAttributesMessage> for PlaylistItemAttributes {
+    type Error = librespot_core::Error;
+    fn try_from(attributes: &PlaylistItemAttributesMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            added_by: attributes.get_added_by().to_owned(),
+            timestamp: Date::from_timestamp_ms(attributes.get_timestamp())?,
+            seen_at: Date::from_timestamp_ms(attributes.get_seen_at())?,
+            is_public: attributes.get_public(),
+            format_attributes: attributes.get_format_attributes().into(),
+            item_id: attributes.get_item_id().to_owned(),
+        })
+    }
+}
+impl TryFrom<&PlaylistPartialAttributesMessage> for PlaylistPartialAttributes {
+    type Error = librespot_core::Error;
+    fn try_from(attributes: &PlaylistPartialAttributesMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            values: attributes.get_values().try_into()?,
+            no_value: attributes.get_no_value().into(),
+        })
+    }
+}
+
+impl TryFrom<&PlaylistPartialItemAttributesMessage> for PlaylistPartialItemAttributes {
+    type Error = librespot_core::Error;
+    fn try_from(attributes: &PlaylistPartialItemAttributesMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            values: attributes.get_values().try_into()?,
+            no_value: attributes.get_no_value().into(),
+        })
+    }
+}
+
+impl TryFrom<&PlaylistUpdateAttributesMessage> for PlaylistUpdateAttributes {
+    type Error = librespot_core::Error;
+    fn try_from(update: &PlaylistUpdateAttributesMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            new_attributes: update.get_new_attributes().try_into()?,
+            old_attributes: update.get_old_attributes().try_into()?,
+        })
+    }
+}
+
+impl TryFrom<&PlaylistUpdateItemAttributesMessage> for PlaylistUpdateItemAttributes {
+    type Error = librespot_core::Error;
+    fn try_from(update: &PlaylistUpdateItemAttributesMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            index: update.get_index(),
+            new_attributes: update.get_new_attributes().try_into()?,
+            old_attributes: update.get_old_attributes().try_into()?,
+        })
+    }
+}

metadata/src/playlist/diff.rs

@@ -0,0 +1,29 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+};
+
+use super::operation::PlaylistOperations;
+
+use librespot_core::SpotifyId;
+
+use librespot_protocol as protocol;
+use protocol::playlist4_external::Diff as DiffMessage;
+
+#[derive(Debug, Clone)]
+pub struct PlaylistDiff {
+    pub from_revision: SpotifyId,
+    pub operations: PlaylistOperations,
+    pub to_revision: SpotifyId,
+}
+
+impl TryFrom<&DiffMessage> for PlaylistDiff {
+    type Error = librespot_core::Error;
+    fn try_from(diff: &DiffMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            from_revision: diff.get_from_revision().try_into()?,
+            operations: diff.get_ops().try_into()?,
+            to_revision: diff.get_to_revision().try_into()?,
+        })
+    }
+}

metadata/src/playlist/item.rs

@@ -0,0 +1,105 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use crate::util::try_from_repeated_message;
+
+use super::{
+    attribute::{PlaylistAttributes, PlaylistItemAttributes},
+    permission::Capabilities,
+};
+
+use librespot_core::{date::Date, SpotifyId};
+
+use librespot_protocol as protocol;
+use protocol::playlist4_external::Item as PlaylistItemMessage;
+use protocol::playlist4_external::ListItems as PlaylistItemsMessage;
+use protocol::playlist4_external::MetaItem as PlaylistMetaItemMessage;
+
+#[derive(Debug, Clone)]
+pub struct PlaylistItem {
+    pub id: SpotifyId,
+    pub attributes: PlaylistItemAttributes,
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistItems(pub Vec<PlaylistItem>);
+
+impl Deref for PlaylistItems {
+    type Target = Vec<PlaylistItem>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistItemList {
+    pub position: i32,
+    pub is_truncated: bool,
+    pub items: PlaylistItems,
+    pub meta_items: PlaylistMetaItems,
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistMetaItem {
+    pub revision: SpotifyId,
+    pub attributes: PlaylistAttributes,
+    pub length: i32,
+    pub timestamp: Date,
+    pub owner_username: String,
+    pub has_abuse_reporting: bool,
+    pub capabilities: Capabilities,
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistMetaItems(pub Vec<PlaylistMetaItem>);
+
+impl Deref for PlaylistMetaItems {
+    type Target = Vec<PlaylistMetaItem>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl TryFrom<&PlaylistItemMessage> for PlaylistItem {
+    type Error = librespot_core::Error;
+    fn try_from(item: &PlaylistItemMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            id: item.try_into()?,
+            attributes: item.get_attributes().try_into()?,
+        })
+    }
+}
+
+try_from_repeated_message!(PlaylistItemMessage, PlaylistItems);
+
+impl TryFrom<&PlaylistItemsMessage> for PlaylistItemList {
+    type Error = librespot_core::Error;
+    fn try_from(list_items: &PlaylistItemsMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            position: list_items.get_pos(),
+            is_truncated: list_items.get_truncated(),
+            items: list_items.get_items().try_into()?,
+            meta_items: list_items.get_meta_items().try_into()?,
+        })
+    }
+}
+
+impl TryFrom<&PlaylistMetaItemMessage> for PlaylistMetaItem {
+    type Error = librespot_core::Error;
+    fn try_from(item: &PlaylistMetaItemMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            revision: item.try_into()?,
+            attributes: item.get_attributes().try_into()?,
+            length: item.get_length(),
+            timestamp: Date::from_timestamp_ms(item.get_timestamp())?,
+            owner_username: item.get_owner_username().to_owned(),
+            has_abuse_reporting: item.get_abuse_reporting_enabled(),
+            capabilities: item.get_capabilities().into(),
+        })
+    }
+}
+
+try_from_repeated_message!(PlaylistMetaItemMessage, PlaylistMetaItems);

metadata/src/playlist/list.rs

@@ -0,0 +1,229 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use protobuf::Message;
+
+use crate::{
+    request::{MercuryRequest, RequestResult},
+    util::{from_repeated_enum, try_from_repeated_message},
+    Metadata,
+};
+
+use super::{
+    attribute::PlaylistAttributes, diff::PlaylistDiff, item::PlaylistItemList,
+    permission::Capabilities,
+};
+
+use librespot_core::{
+    date::Date,
+    spotify_id::{NamedSpotifyId, SpotifyId},
+    Error, Session,
+};
+
+use librespot_protocol as protocol;
+use protocol::playlist4_external::GeoblockBlockingType as Geoblock;
+
+#[derive(Debug, Clone)]
+pub struct Geoblocks(Vec<Geoblock>);
+
+impl Deref for Geoblocks {
+    type Target = Vec<Geoblock>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Playlist {
+    pub id: NamedSpotifyId,
+    pub revision: Vec<u8>,
+    pub length: i32,
+    pub attributes: PlaylistAttributes,
+    pub contents: PlaylistItemList,
+    pub diff: Option<PlaylistDiff>,
+    pub sync_result: Option<PlaylistDiff>,
+    pub resulting_revisions: Playlists,
+    pub has_multiple_heads: bool,
+    pub is_up_to_date: bool,
+    pub nonces: Vec<i64>,
+    pub timestamp: Date,
+    pub has_abuse_reporting: bool,
+    pub capabilities: Capabilities,
+    pub geoblocks: Geoblocks,
+}
+
+#[derive(Debug, Clone)]
+pub struct Playlists(pub Vec<SpotifyId>);
+
+impl Deref for Playlists {
+    type Target = Vec<SpotifyId>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct RootPlaylist(pub SelectedListContent);
+
+impl Deref for RootPlaylist {
+    type Target = SelectedListContent;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct SelectedListContent {
+    pub revision: Vec<u8>,
+    pub length: i32,
+    pub attributes: PlaylistAttributes,
+    pub contents: PlaylistItemList,
+    pub diff: Option<PlaylistDiff>,
+    pub sync_result: Option<PlaylistDiff>,
+    pub resulting_revisions: Playlists,
+    pub has_multiple_heads: bool,
+    pub is_up_to_date: bool,
+    pub nonces: Vec<i64>,
+    pub timestamp: Date,
+    pub owner_username: String,
+    pub has_abuse_reporting: bool,
+    pub capabilities: Capabilities,
+    pub geoblocks: Geoblocks,
+}
+
+impl Playlist {
+    #[allow(dead_code)]
+    async fn request_for_user(
+        session: &Session,
+        username: &str,
+        playlist_id: SpotifyId,
+    ) -> RequestResult {
+        let uri = format!(
+            "hm://playlist/user/{}/playlist/{}",
+            username,
+            playlist_id.to_base62()?
+        );
+        <Self as MercuryRequest>::request(session, &uri).await
+    }
+
+    #[allow(dead_code)]
+    pub async fn get_for_user(
+        session: &Session,
+        username: &str,
+        playlist_id: SpotifyId,
+    ) -> Result<Self, Error> {
+        let response = Self::request_for_user(session, username, playlist_id).await?;
+        let msg = <Self as Metadata>::Message::parse_from_bytes(&response)?;
+        Self::parse(&msg, playlist_id)
+    }
+
+    pub fn tracks(&self) -> Vec<SpotifyId> {
+        let tracks = self
+            .contents
+            .items
+            .iter()
+            .map(|item| item.id)
+            .collect::<Vec<_>>();
+
+        let length = tracks.len();
+        let expected_length = self.length as usize;
+        if length != expected_length {
+            warn!(
+                "Got {} tracks, but the list should contain {} tracks.",
+                length, expected_length,
+            );
+        }
+
+        tracks
+    }
+
+    pub fn name(&self) -> &str {
+        &self.attributes.name
+    }
+}
+
+impl MercuryRequest for Playlist {}
+
+#[async_trait]
+impl Metadata for Playlist {
+    type Message = protocol::playlist4_external::SelectedListContent;
+
+    async fn request(session: &Session, playlist_id: SpotifyId) -> RequestResult {
+        let uri = format!("hm://playlist/v2/playlist/{}", playlist_id.to_base62()?);
+        <Self as MercuryRequest>::request(session, &uri).await
+    }
+
+    fn parse(msg: &Self::Message, id: SpotifyId) -> Result<Self, Error> {
+        // the playlist proto doesn't contain the id so we decorate it
+        let playlist = SelectedListContent::try_from(msg)?;
+        let id = NamedSpotifyId::from_spotify_id(id, playlist.owner_username);
+
+        Ok(Self {
+            id,
+            revision: playlist.revision,
+            length: playlist.length,
+            attributes: playlist.attributes,
+            contents: playlist.contents,
+            diff: playlist.diff,
+            sync_result: playlist.sync_result,
+            resulting_revisions: playlist.resulting_revisions,
+            has_multiple_heads: playlist.has_multiple_heads,
+            is_up_to_date: playlist.is_up_to_date,
+            nonces: playlist.nonces,
+            timestamp: playlist.timestamp,
+            has_abuse_reporting: playlist.has_abuse_reporting,
+            capabilities: playlist.capabilities,
+            geoblocks: playlist.geoblocks,
+        })
+    }
+}
+
+impl MercuryRequest for RootPlaylist {}
+
+impl RootPlaylist {
+    #[allow(dead_code)]
+    async fn request_for_user(session: &Session, username: &str) -> RequestResult {
+        let uri = format!("hm://playlist/user/{}/rootlist", username,);
+        <Self as MercuryRequest>::request(session, &uri).await
+    }
+
+    #[allow(dead_code)]
+    pub async fn get_root_for_user(session: &Session, username: &str) -> Result<Self, Error> {
+        let response = Self::request_for_user(session, username).await?;
+        let msg = protocol::playlist4_external::SelectedListContent::parse_from_bytes(&response)?;
+        Ok(Self(SelectedListContent::try_from(&msg)?))
+    }
+}
+
+impl TryFrom<&<Playlist as Metadata>::Message> for SelectedListContent {
+    type Error = librespot_core::Error;
+    fn try_from(playlist: &<Playlist as Metadata>::Message) -> Result<Self, Self::Error> {
+        Ok(Self {
+            revision: playlist.get_revision().to_owned(),
+            length: playlist.get_length(),
+            attributes: playlist.get_attributes().try_into()?,
+            contents: playlist.get_contents().try_into()?,
+            diff: playlist.diff.as_ref().map(TryInto::try_into).transpose()?,
+            sync_result: playlist
+                .sync_result
+                .as_ref()
+                .map(TryInto::try_into)
+                .transpose()?,
+            resulting_revisions: playlist.get_resulting_revisions().try_into()?,
+            has_multiple_heads: playlist.get_multiple_heads(),
+            is_up_to_date: playlist.get_up_to_date(),
+            nonces: playlist.get_nonces().into(),
+            timestamp: Date::from_timestamp_ms(playlist.get_timestamp())?,
+            owner_username: playlist.get_owner_username().to_owned(),
+            has_abuse_reporting: playlist.get_abuse_reporting_enabled(),
+            capabilities: playlist.get_capabilities().into(),
+            geoblocks: playlist.get_geoblock().into(),
+        })
+    }
+}
+
+from_repeated_enum!(Geoblock, Geoblocks);
+try_from_repeated_message!(Vec<u8>, Playlists);

metadata/src/playlist/mod.rs

@@ -0,0 +1,10 @@
+pub mod annotation;
+pub mod attribute;
+pub mod diff;
+pub mod item;
+pub mod list;
+pub mod operation;
+pub mod permission;
+
+pub use annotation::PlaylistAnnotation;
+pub use list::Playlist;

metadata/src/playlist/operation.rs

@@ -0,0 +1,113 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use crate::{
+    playlist::{
+        attribute::{PlaylistUpdateAttributes, PlaylistUpdateItemAttributes},
+        item::PlaylistItems,
+    },
+    util::try_from_repeated_message,
+};
+
+use librespot_protocol as protocol;
+use protocol::playlist4_external::Add as PlaylistAddMessage;
+use protocol::playlist4_external::Mov as PlaylistMoveMessage;
+use protocol::playlist4_external::Op as PlaylistOperationMessage;
+pub use protocol::playlist4_external::Op_Kind as PlaylistOperationKind;
+use protocol::playlist4_external::Rem as PlaylistRemoveMessage;
+
+#[derive(Debug, Clone)]
+pub struct PlaylistOperation {
+    pub kind: PlaylistOperationKind,
+    pub add: PlaylistOperationAdd,
+    pub rem: PlaylistOperationRemove,
+    pub mov: PlaylistOperationMove,
+    pub update_item_attributes: PlaylistUpdateItemAttributes,
+    pub update_list_attributes: PlaylistUpdateAttributes,
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistOperations(pub Vec<PlaylistOperation>);
+
+impl Deref for PlaylistOperations {
+    type Target = Vec<PlaylistOperation>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistOperationAdd {
+    pub from_index: i32,
+    pub items: PlaylistItems,
+    pub add_last: bool,
+    pub add_first: bool,
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistOperationMove {
+    pub from_index: i32,
+    pub length: i32,
+    pub to_index: i32,
+}
+
+#[derive(Debug, Clone)]
+pub struct PlaylistOperationRemove {
+    pub from_index: i32,
+    pub length: i32,
+    pub items: PlaylistItems,
+    pub has_items_as_key: bool,
+}
+
+impl TryFrom<&PlaylistOperationMessage> for PlaylistOperation {
+    type Error = librespot_core::Error;
+    fn try_from(operation: &PlaylistOperationMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            kind: operation.get_kind(),
+            add: operation.get_add().try_into()?,
+            rem: operation.get_rem().try_into()?,
+            mov: operation.get_mov().into(),
+            update_item_attributes: operation.get_update_item_attributes().try_into()?,
+            update_list_attributes: operation.get_update_list_attributes().try_into()?,
+        })
+    }
+}
+
+try_from_repeated_message!(PlaylistOperationMessage, PlaylistOperations);
+
+impl TryFrom<&PlaylistAddMessage> for PlaylistOperationAdd {
+    type Error = librespot_core::Error;
+    fn try_from(add: &PlaylistAddMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            from_index: add.get_from_index(),
+            items: add.get_items().try_into()?,
+            add_last: add.get_add_last(),
+            add_first: add.get_add_first(),
+        })
+    }
+}
+
+impl From<&PlaylistMoveMessage> for PlaylistOperationMove {
+    fn from(mov: &PlaylistMoveMessage) -> Self {
+        Self {
+            from_index: mov.get_from_index(),
+            length: mov.get_length(),
+            to_index: mov.get_to_index(),
+        }
+    }
+}
+
+impl TryFrom<&PlaylistRemoveMessage> for PlaylistOperationRemove {
+    type Error = librespot_core::Error;
+    fn try_from(remove: &PlaylistRemoveMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            from_index: remove.get_from_index(),
+            length: remove.get_length(),
+            items: remove.get_items().try_into()?,
+            has_items_as_key: remove.get_items_as_key(),
+        })
+    }
+}

metadata/src/playlist/permission.rs

@@ -0,0 +1,42 @@
+use std::{fmt::Debug, ops::Deref};
+
+use crate::util::from_repeated_enum;
+
+use librespot_protocol as protocol;
+use protocol::playlist_permission::Capabilities as CapabilitiesMessage;
+use protocol::playlist_permission::PermissionLevel;
+
+#[derive(Debug, Clone)]
+pub struct Capabilities {
+    pub can_view: bool,
+    pub can_administrate_permissions: bool,
+    pub grantable_levels: PermissionLevels,
+    pub can_edit_metadata: bool,
+    pub can_edit_items: bool,
+    pub can_cancel_membership: bool,
+}
+
+#[derive(Debug, Clone)]
+pub struct PermissionLevels(pub Vec<PermissionLevel>);
+
+impl Deref for PermissionLevels {
+    type Target = Vec<PermissionLevel>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl From<&CapabilitiesMessage> for Capabilities {
+    fn from(playlist: &CapabilitiesMessage) -> Self {
+        Self {
+            can_view: playlist.get_can_view(),
+            can_administrate_permissions: playlist.get_can_administrate_permissions(),
+            grantable_levels: playlist.get_grantable_level().into(),
+            can_edit_metadata: playlist.get_can_edit_metadata(),
+            can_edit_items: playlist.get_can_edit_items(),
+            can_cancel_membership: playlist.get_can_cancel_membership(),
+        }
+    }
+}
+
+from_repeated_enum!(PermissionLevel, PermissionLevels);

metadata/src/request.rs

@@ -0,0 +1,37 @@
+use std::fmt::Write;
+
+use crate::MetadataError;
+
+use librespot_core::{Error, Session};
+
+pub type RequestResult = Result<bytes::Bytes, Error>;
+
+#[async_trait]
+pub trait MercuryRequest {
+    async fn request(session: &Session, uri: &str) -> RequestResult {
+        let mut metrics_uri = uri.to_owned();
+
+        let separator = match metrics_uri.find('?') {
+            Some(_) => "&",
+            None => "?",
+        };
+        let _ = write!(metrics_uri, "{}country={}", separator, session.country());
+
+        if let Some(product) = session.get_user_attribute("type") {
+            let _ = write!(metrics_uri, "&product={}", product);
+        }
+
+        trace!("Requesting {}", metrics_uri);
+
+        let request = session.mercury().get(metrics_uri)?;
+        let response = request.await?;
+        match response.payload.first() {
+            Some(data) => {
+                let data = data.to_vec().into();
+                trace!("Received metadata: {:?}", data);
+                Ok(data)
+            }
+            None => Err(Error::unavailable(MetadataError::Empty)),
+        }
+    }
+}

metadata/src/restriction.rs

@@ -0,0 +1,104 @@
+use std::{fmt::Debug, ops::Deref};
+
+use crate::util::{from_repeated_enum, from_repeated_message};
+
+use protocol::metadata::Restriction as RestrictionMessage;
+
+use librespot_protocol as protocol;
+pub use protocol::metadata::Restriction_Catalogue as RestrictionCatalogue;
+pub use protocol::metadata::Restriction_Type as RestrictionType;
+
+#[derive(Debug, Clone)]
+pub struct Restriction {
+    pub catalogues: RestrictionCatalogues,
+    pub restriction_type: RestrictionType,
+    pub catalogue_strs: Vec<String>,
+    pub countries_allowed: Option<Vec<String>>,
+    pub countries_forbidden: Option<Vec<String>>,
+}
+
+#[derive(Debug, Clone)]
+pub struct Restrictions(pub Vec<Restriction>);
+
+impl Deref for Restrictions {
+    type Target = Vec<Restriction>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct RestrictionCatalogues(pub Vec<RestrictionCatalogue>);
+
+impl Deref for RestrictionCatalogues {
+    type Target = Vec<RestrictionCatalogue>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl Restriction {
+    fn parse_country_codes(country_codes: &str) -> Vec<String> {
+        country_codes
+            .chunks(2)
+            .map(|country_code| country_code.to_owned())
+            .collect()
+    }
+}
+
+impl From<&RestrictionMessage> for Restriction {
+    fn from(restriction: &RestrictionMessage) -> Self {
+        let countries_allowed = if restriction.has_countries_allowed() {
+            Some(Self::parse_country_codes(
+                restriction.get_countries_allowed(),
+            ))
+        } else {
+            None
+        };
+
+        let countries_forbidden = if restriction.has_countries_forbidden() {
+            Some(Self::parse_country_codes(
+                restriction.get_countries_forbidden(),
+            ))
+        } else {
+            None
+        };
+
+        Self {
+            catalogues: restriction.get_catalogue().into(),
+            restriction_type: restriction.get_field_type(),
+            catalogue_strs: restriction.get_catalogue_str().to_vec(),
+            countries_allowed,
+            countries_forbidden,
+        }
+    }
+}
+
+from_repeated_message!(RestrictionMessage, Restrictions);
+from_repeated_enum!(RestrictionCatalogue, RestrictionCatalogues);
+
+struct StrChunks<'s>(&'s str, usize);
+
+trait StrChunksExt {
+    fn chunks(&self, size: usize) -> StrChunks;
+}
+
+impl StrChunksExt for str {
+    fn chunks(&self, size: usize) -> StrChunks {
+        StrChunks(self, size)
+    }
+}
+
+impl<'s> Iterator for StrChunks<'s> {
+    type Item = &'s str;
+    fn next(&mut self) -> Option<&'s str> {
+        let &mut StrChunks(data, size) = self;
+        if data.is_empty() {
+            None
+        } else {
+            let ret = Some(&data[..size]);
+            self.0 = &data[size..];
+            ret
+        }
+    }
+}

metadata/src/sale_period.rs

@@ -0,0 +1,42 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use crate::{restriction::Restrictions, util::try_from_repeated_message};
+
+use librespot_core::date::Date;
+
+use librespot_protocol as protocol;
+use protocol::metadata::SalePeriod as SalePeriodMessage;
+
+#[derive(Debug, Clone)]
+pub struct SalePeriod {
+    pub restrictions: Restrictions,
+    pub start: Date,
+    pub end: Date,
+}
+
+#[derive(Debug, Clone)]
+pub struct SalePeriods(pub Vec<SalePeriod>);
+
+impl Deref for SalePeriods {
+    type Target = Vec<SalePeriod>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl TryFrom<&SalePeriodMessage> for SalePeriod {
+    type Error = librespot_core::Error;
+    fn try_from(sale_period: &SalePeriodMessage) -> Result<Self, Self::Error> {
+        Ok(Self {
+            restrictions: sale_period.get_restriction().into(),
+            start: sale_period.get_start().try_into()?,
+            end: sale_period.get_end().try_into()?,
+        })
+    }
+}
+
+try_from_repeated_message!(SalePeriodMessage, SalePeriods);

metadata/src/show.rs

@@ -0,0 +1,74 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+};
+
+use crate::{
+    availability::Availabilities, copyright::Copyrights, episode::Episodes, image::Images,
+    restriction::Restrictions, Metadata, RequestResult,
+};
+
+use librespot_core::{Error, Session, SpotifyId};
+
+use librespot_protocol as protocol;
+pub use protocol::metadata::Show_ConsumptionOrder as ShowConsumptionOrder;
+pub use protocol::metadata::Show_MediaType as ShowMediaType;
+
+#[derive(Debug, Clone)]
+pub struct Show {
+    pub id: SpotifyId,
+    pub name: String,
+    pub description: String,
+    pub publisher: String,
+    pub language: String,
+    pub is_explicit: bool,
+    pub covers: Images,
+    pub episodes: Episodes,
+    pub copyrights: Copyrights,
+    pub restrictions: Restrictions,
+    pub keywords: Vec<String>,
+    pub media_type: ShowMediaType,
+    pub consumption_order: ShowConsumptionOrder,
+    pub availability: Availabilities,
+    pub trailer_uri: SpotifyId,
+    pub has_music_and_talk: bool,
+    pub is_audiobook: bool,
+}
+
+#[async_trait]
+impl Metadata for Show {
+    type Message = protocol::metadata::Show;
+
+    async fn request(session: &Session, show_id: SpotifyId) -> RequestResult {
+        session.spclient().get_show_metadata(show_id).await
+    }
+
+    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+        Self::try_from(msg)
+    }
+}
+
+impl TryFrom<&<Self as Metadata>::Message> for Show {
+    type Error = librespot_core::Error;
+    fn try_from(show: &<Self as Metadata>::Message) -> Result<Self, Self::Error> {
+        Ok(Self {
+            id: show.try_into()?,
+            name: show.get_name().to_owned(),
+            description: show.get_description().to_owned(),
+            publisher: show.get_publisher().to_owned(),
+            language: show.get_language().to_owned(),
+            is_explicit: show.get_explicit(),
+            covers: show.get_cover_image().get_image().into(),
+            episodes: show.get_episode().try_into()?,
+            copyrights: show.get_copyright().into(),
+            restrictions: show.get_restriction().into(),
+            keywords: show.get_keyword().to_vec(),
+            media_type: show.get_media_type(),
+            consumption_order: show.get_consumption_order(),
+            availability: show.get_availability().try_into()?,
+            trailer_uri: SpotifyId::from_uri(show.get_trailer_uri())?,
+            has_music_and_talk: show.get_music_and_talk(),
+            is_audiobook: show.get_is_audiobook(),
+        })
+    }
+}

metadata/src/track.rs

@@ -0,0 +1,149 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt::Debug,
+    ops::Deref,
+};
+
+use uuid::Uuid;
+
+use crate::{
+    artist::{Artists, ArtistsWithRole},
+    audio::{
+        file::AudioFiles,
+        item::{AudioItem, AudioItemResult, InnerAudioItem},
+    },
+    availability::{Availabilities, UnavailabilityReason},
+    content_rating::ContentRatings,
+    external_id::ExternalIds,
+    restriction::Restrictions,
+    sale_period::SalePeriods,
+    util::try_from_repeated_message,
+    Metadata, RequestResult,
+};
+
+use librespot_core::{date::Date, Error, Session, SpotifyId};
+use librespot_protocol as protocol;
+
+#[derive(Debug, Clone)]
+pub struct Track {
+    pub id: SpotifyId,
+    pub name: String,
+    pub album: SpotifyId,
+    pub artists: Artists,
+    pub number: i32,
+    pub disc_number: i32,
+    pub duration: i32,
+    pub popularity: i32,
+    pub is_explicit: bool,
+    pub external_ids: ExternalIds,
+    pub restrictions: Restrictions,
+    pub files: AudioFiles,
+    pub alternatives: Tracks,
+    pub sale_periods: SalePeriods,
+    pub previews: AudioFiles,
+    pub tags: Vec<String>,
+    pub earliest_live_timestamp: Date,
+    pub has_lyrics: bool,
+    pub availability: Availabilities,
+    pub licensor: Uuid,
+    pub language_of_performance: Vec<String>,
+    pub content_ratings: ContentRatings,
+    pub original_title: String,
+    pub version_title: String,
+    pub artists_with_role: ArtistsWithRole,
+}
+
+#[derive(Debug, Clone)]
+pub struct Tracks(pub Vec<SpotifyId>);
+
+impl Deref for Tracks {
+    type Target = Vec<SpotifyId>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[async_trait]
+impl InnerAudioItem for Track {
+    async fn get_audio_item(session: &Session, id: SpotifyId) -> AudioItemResult {
+        let track = Self::get(session, id).await?;
+        let alternatives = {
+            if track.alternatives.is_empty() {
+                None
+            } else {
+                Some(track.alternatives.clone())
+            }
+        };
+
+        // TODO: check meaning of earliest_live_timestamp in
+        let availability = if Date::now_utc() < track.earliest_live_timestamp {
+            Err(UnavailabilityReason::Embargo)
+        } else {
+            Self::available_for_user(
+                &session.user_data(),
+                &track.availability,
+                &track.restrictions,
+            )
+        };
+
+        Ok(AudioItem {
+            id,
+            spotify_uri: id.to_uri()?,
+            files: track.files,
+            name: track.name,
+            duration: track.duration,
+            availability,
+            alternatives,
+            is_explicit: track.is_explicit,
+        })
+    }
+}
+
+#[async_trait]
+impl Metadata for Track {
+    type Message = protocol::metadata::Track;
+
+    async fn request(session: &Session, track_id: SpotifyId) -> RequestResult {
+        session.spclient().get_track_metadata(track_id).await
+    }
+
+    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+        Self::try_from(msg)
+    }
+}
+
+impl TryFrom<&<Self as Metadata>::Message> for Track {
+    type Error = librespot_core::Error;
+    fn try_from(track: &<Self as Metadata>::Message) -> Result<Self, Self::Error> {
+        Ok(Self {
+            id: track.try_into()?,
+            name: track.get_name().to_owned(),
+            album: track.get_album().try_into()?,
+            artists: track.get_artist().try_into()?,
+            number: track.get_number(),
+            disc_number: track.get_disc_number(),
+            duration: track.get_duration(),
+            popularity: track.get_popularity(),
+            is_explicit: track.get_explicit(),
+            external_ids: track.get_external_id().into(),
+            restrictions: track.get_restriction().into(),
+            files: track.get_file().into(),
+            alternatives: track.get_alternative().try_into()?,
+            sale_periods: track.get_sale_period().try_into()?,
+            previews: track.get_preview().into(),
+            tags: track.get_tags().to_vec(),
+            earliest_live_timestamp: Date::from_timestamp_ms(track.get_earliest_live_timestamp())?,
+            has_lyrics: track.get_has_lyrics(),
+            availability: track.get_availability().try_into()?,
+            licensor: Uuid::from_slice(track.get_licensor().get_uuid())
+                .unwrap_or_else(|_| Uuid::nil()),
+            language_of_performance: track.get_language_of_performance().to_vec(),
+            content_ratings: track.get_content_rating().into(),
+            original_title: track.get_original_title().to_owned(),
+            version_title: track.get_version_title().to_owned(),
+            artists_with_role: track.get_artist_with_role().try_into()?,
+        })
+    }
+}
+
+try_from_repeated_message!(<Track as Metadata>::Message, Tracks);

metadata/src/util.rs

@@ -0,0 +1,39 @@
+macro_rules! from_repeated_message {
+    ($src:ty, $dst:ty) => {
+        impl From<&[$src]> for $dst {
+            fn from(src: &[$src]) -> Self {
+                let result = src.iter().map(From::from).collect();
+                Self(result)
+            }
+        }
+    };
+}
+
+pub(crate) use from_repeated_message;
+
+macro_rules! from_repeated_enum {
+    ($src:ty, $dst:ty) => {
+        impl From<&[$src]> for $dst {
+            fn from(src: &[$src]) -> Self {
+                let result = src.iter().map(|x| <$src>::from(*x)).collect();
+                Self(result)
+            }
+        }
+    };
+}
+
+pub(crate) use from_repeated_enum;
+
+macro_rules! try_from_repeated_message {
+    ($src:ty, $dst:ty) => {
+        impl TryFrom<&[$src]> for $dst {
+            type Error = librespot_core::Error;
+            fn try_from(src: &[$src]) -> Result<Self, Self::Error> {
+                let result: Result<Vec<_>, _> = src.iter().map(TryFrom::try_from).collect();
+                Ok(Self(result?))
+            }
+        }
+    };
+}
+
+pub(crate) use try_from_repeated_message;

metadata/src/video.rs

@@ -0,0 +1,20 @@
+use std::{fmt::Debug, ops::Deref};
+
+use crate::util::from_repeated_message;
+
+use librespot_core::FileId;
+
+use librespot_protocol as protocol;
+use protocol::metadata::VideoFile as VideoFileMessage;
+
+#[derive(Debug, Clone)]
+pub struct VideoFiles(pub Vec<FileId>);
+
+impl Deref for VideoFiles {
+    type Target = Vec<FileId>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+from_repeated_message!(VideoFileMessage, VideoFiles);

playback/Cargo.toml

@@ -18,15 +18,14 @@ path = "../metadata"
 version = "0.4.2"
 
 [dependencies]
-futures-executor = "0.3"
-futures-util = { version = "0.3", default_features = false, features = ["alloc"] }
+byteorder = "1"
+futures-util = "0.3"
 log = "0.4"
 parking_lot = { version = "0.12", features = ["deadlock_detection"] }
-byteorder = "1.4"
-shell-words = "1.0.0"
-tokio = { version = "1", features = ["sync", "parking_lot"] }
-zerocopy = { version = "0.6" }
-thiserror = { version = "1" }
+shell-words = "1.1"
+thiserror = "1"
+tokio = { version = "1", features = ["parking_lot", "rt", "rt-multi-thread", "sync"] }
+zerocopy = "0.6"
 
 # Backends
 alsa            = { version = "0.6", optional = true }
@@ -44,9 +43,11 @@ glib            = { version = "0.15", optional = true }
 rodio           = { version = "0.15", optional = true, default-features = false }
 cpal            = { version = "0.13", optional = true }
 
-# Decoder
-lewton = "0.10"
-ogg = "0.8"
+# Container and audio decoder
+symphonia = { version = "0.5", default-features = false, features = ["mp3", "ogg", "vorbis"] }
+
+# Legacy Ogg container decoder for the passthrough decoder
+ogg = { version = "0.8", optional = true }
 
 # Dithering
 rand = { version = "0.8", features = ["small_rng"] }
@@ -61,3 +62,5 @@ rodio-backend = ["rodio", "cpal"]
 rodiojack-backend = ["rodio", "cpal/jack"]
 sdl-backend = ["sdl2"]
 gstreamer-backend = ["gstreamer", "gstreamer-app", "gstreamer-audio", "glib"]
+
+passthrough-decoder = ["ogg"]

playback/src/audio_backend/gstreamer.rs

@@ -141,10 +141,10 @@ impl Sink for GstreamerSink {
         self.appsrc.send_event(FlushStop::new(true));
         self.bufferpool
             .set_active(true)
-            .map_err(|e| SinkError::OnWrite(e.to_string()))?;
+            .map_err(|e| SinkError::StateChange(e.to_string()))?;
         self.pipeline
             .set_state(State::Playing)
-            .map_err(|e| SinkError::OnWrite(e.to_string()))?;
+            .map_err(|e| SinkError::StateChange(e.to_string()))?;
         Ok(())
     }
 
@@ -153,10 +153,10 @@ impl Sink for GstreamerSink {
         self.appsrc.send_event(FlushStart::new());
         self.pipeline
             .set_state(State::Paused)
-            .map_err(|e| SinkError::OnWrite(e.to_string()))?;
+            .map_err(|e| SinkError::StateChange(e.to_string()))?;
         self.bufferpool
             .set_active(false)
-            .map_err(|e| SinkError::OnWrite(e.to_string()))?;
+            .map_err(|e| SinkError::StateChange(e.to_string()))?;
         Ok(())
     }
 

playback/src/audio_backend/mod.rs

@@ -13,6 +13,8 @@ pub enum SinkError {
     OnWrite(String),
     #[error("Audio Sink Error Invalid Parameters: {0}")]
     InvalidParams(String),
+    #[error("Audio Sink Error Changing State: {0}")]
+    StateChange(String),
 }
 
 pub type SinkResult<T> = Result<T, SinkError>;
@@ -71,7 +73,7 @@ macro_rules! sink_as_bytes {
                         self.write_bytes(samples_s16.as_bytes())
                     }
                 },
-                AudioPacket::OggData(samples) => self.write_bytes(&samples),
+                AudioPacket::Raw(samples) => self.write_bytes(&samples),
             }
         }
     };

playback/src/audio_backend/rodio.rs

@@ -186,6 +186,17 @@ pub fn open(host: cpal::Host, device: Option<String>, format: AudioFormat) -> Ro
 }
 
 impl Sink for RodioSink {
+    fn start(&mut self) -> SinkResult<()> {
+        self.rodio_sink.play();
+        Ok(())
+    }
+
+    fn stop(&mut self) -> SinkResult<()> {
+        self.rodio_sink.sleep_until_end();
+        self.rodio_sink.pause();
+        Ok(())
+    }
+
     fn write(&mut self, packet: AudioPacket, converter: &mut Converter) -> SinkResult<()> {
         let samples = packet
             .samples()

playback/src/audio_backend/sdl.rs

@@ -95,7 +95,7 @@ impl Sink for SdlSink {
         let samples = packet
             .samples()
             .map_err(|e| SinkError::OnWrite(e.to_string()))?;
-        match self {
+        let result = match self {
             Self::F32(queue) => {
                 let samples_f32: &[f32] = &converter.f64_to_f32(samples);
                 drain_sink!(queue, AudioFormat::F32.size());
@@ -111,9 +111,8 @@ impl Sink for SdlSink {
                 drain_sink!(queue, AudioFormat::S16.size());
                 queue.queue_audio(samples_s16)
             }
-        }
-        .map_err(SinkError::OnWrite)?;
-        Ok(())
+        };
+        result.map_err(SinkError::OnWrite)
     }
 }
 

playback/src/decoder/lewton_decoder.rs

@@ -1,46 +0,0 @@
-use super::{AudioDecoder, AudioPacket, DecoderError, DecoderResult};
-
-use lewton::audio::AudioReadError::AudioIsHeader;
-use lewton::inside_ogg::OggStreamReader;
-use lewton::samples::InterleavedSamples;
-use lewton::OggReadError::NoCapturePatternFound;
-use lewton::VorbisError::{BadAudio, OggError};
-
-use std::io::{Read, Seek};
-
-pub struct VorbisDecoder<R: Read + Seek>(OggStreamReader<R>);
-
-impl<R> VorbisDecoder<R>
-where
-    R: Read + Seek,
-{
-    pub fn new(input: R) -> DecoderResult<VorbisDecoder<R>> {
-        let reader =
-            OggStreamReader::new(input).map_err(|e| DecoderError::LewtonDecoder(e.to_string()))?;
-        Ok(VorbisDecoder(reader))
-    }
-}
-
-impl<R> AudioDecoder for VorbisDecoder<R>
-where
-    R: Read + Seek,
-{
-    fn seek(&mut self, absgp: u64) -> DecoderResult<()> {
-        self.0
-            .seek_absgp_pg(absgp)
-            .map_err(|e| DecoderError::LewtonDecoder(e.to_string()))?;
-        Ok(())
-    }
-
-    fn next_packet(&mut self) -> DecoderResult<Option<AudioPacket>> {
-        loop {
-            match self.0.read_dec_packet_generic::<InterleavedSamples<f32>>() {
-                Ok(Some(packet)) => return Ok(Some(AudioPacket::samples_from_f32(packet.samples))),
-                Ok(None) => return Ok(None),
-                Err(BadAudio(AudioIsHeader)) => (),
-                Err(OggError(NoCapturePatternFound)) => (),
-                Err(e) => return Err(DecoderError::LewtonDecoder(e.to_string())),
-            }
-        }
-    }
-}

playback/src/decoder/mod.rs

@@ -1,26 +1,30 @@
+use std::ops::Deref;
+
 use thiserror::Error;
 
-mod lewton_decoder;
-pub use lewton_decoder::VorbisDecoder;
-
+#[cfg(feature = "passthrough-decoder")]
 mod passthrough_decoder;
+#[cfg(feature = "passthrough-decoder")]
 pub use passthrough_decoder::PassthroughDecoder;
 
+mod symphonia_decoder;
+pub use symphonia_decoder::SymphoniaDecoder;
+
 #[derive(Error, Debug)]
 pub enum DecoderError {
-    #[error("Lewton Decoder Error: {0}")]
-    LewtonDecoder(String),
     #[error("Passthrough Decoder Error: {0}")]
     PassthroughDecoder(String),
+    #[error("Symphonia Decoder Error: {0}")]
+    SymphoniaDecoder(String),
 }
 
 pub type DecoderResult<T> = Result<T, DecoderError>;
 
 #[derive(Error, Debug)]
 pub enum AudioPacketError {
-    #[error("Decoder OggData Error: Can't return OggData on Samples")]
-    OggData,
-    #[error("Decoder Samples Error: Can't return Samples on OggData")]
+    #[error("Decoder Raw Error: Can't return Raw on Samples")]
+    Raw,
+    #[error("Decoder Samples Error: Can't return Samples on Raw")]
     Samples,
 }
 
@@ -28,25 +32,20 @@ pub type AudioPacketResult<T> = Result<T, AudioPacketError>;
 
 pub enum AudioPacket {
     Samples(Vec<f64>),
-    OggData(Vec<u8>),
+    Raw(Vec<u8>),
 }
 
 impl AudioPacket {
-    pub fn samples_from_f32(f32_samples: Vec<f32>) -> Self {
-        let f64_samples = f32_samples.iter().map(|sample| *sample as f64).collect();
-        AudioPacket::Samples(f64_samples)
-    }
-
     pub fn samples(&self) -> AudioPacketResult<&[f64]> {
         match self {
             AudioPacket::Samples(s) => Ok(s),
-            AudioPacket::OggData(_) => Err(AudioPacketError::OggData),
+            AudioPacket::Raw(_) => Err(AudioPacketError::Raw),
         }
     }
 
-    pub fn oggdata(&self) -> AudioPacketResult<&[u8]> {
+    pub fn raw(&self) -> AudioPacketResult<&[u8]> {
         match self {
-            AudioPacket::OggData(d) => Ok(d),
+            AudioPacket::Raw(d) => Ok(d),
             AudioPacket::Samples(_) => Err(AudioPacketError::Samples),
         }
     }
@@ -54,12 +53,37 @@ impl AudioPacket {
     pub fn is_empty(&self) -> bool {
         match self {
             AudioPacket::Samples(s) => s.is_empty(),
-            AudioPacket::OggData(d) => d.is_empty(),
+            AudioPacket::Raw(d) => d.is_empty(),
         }
     }
 }
 
-pub trait AudioDecoder {
-    fn seek(&mut self, absgp: u64) -> DecoderResult<()>;
-    fn next_packet(&mut self) -> DecoderResult<Option<AudioPacket>>;
+#[derive(Debug, Clone)]
+pub struct AudioPacketPosition {
+    pub position_ms: u32,
+    pub skipped: bool,
+}
+
+impl Deref for AudioPacketPosition {
+    type Target = u32;
+    fn deref(&self) -> &Self::Target {
+        &self.position_ms
+    }
+}
+
+pub trait AudioDecoder {
+    fn seek(&mut self, position_ms: u32) -> Result<u32, DecoderError>;
+    fn next_packet(&mut self) -> DecoderResult<Option<(AudioPacketPosition, AudioPacket)>>;
+}
+
+impl From<DecoderError> for librespot_core::error::Error {
+    fn from(err: DecoderError) -> Self {
+        librespot_core::error::Error::aborted(err)
+    }
+}
+
+impl From<symphonia::core::errors::Error> for DecoderError {
+    fn from(err: symphonia::core::errors::Error) -> Self {
+        Self::SymphoniaDecoder(err.to_string())
+    }
 }

playback/src/decoder/passthrough_decoder.rs

@@ -1,8 +1,18 @@
 // Passthrough decoder for librespot
-use super::{AudioDecoder, AudioPacket, DecoderError, DecoderResult};
+use std::{
+    io::{Read, Seek},
+    time::{SystemTime, UNIX_EPOCH},
+};
+
+// TODO: move this to the Symphonia Ogg demuxer
 use ogg::{OggReadError, Packet, PacketReader, PacketWriteEndInfo, PacketWriter};
-use std::io::{Read, Seek};
-use std::time::{SystemTime, UNIX_EPOCH};
+
+use super::{AudioDecoder, AudioPacket, AudioPacketPosition, DecoderError, DecoderResult};
+
+use crate::{
+    metadata::audio::{AudioFileFormat, AudioFiles},
+    MS_PER_PAGE, PAGES_PER_MS,
+};
 
 fn get_header<T>(code: u8, rdr: &mut PacketReader<T>) -> DecoderResult<Box<[u8]>>
 where
@@ -16,7 +26,7 @@ where
     debug!("Vorbis header type {}", &pkt_type);
 
     if pkt_type != code {
-        return Err(DecoderError::PassthroughDecoder("Invalid Data".to_string()));
+        return Err(DecoderError::PassthroughDecoder("Invalid Data".into()));
     }
 
     Ok(pck.data.into_boxed_slice())
@@ -36,7 +46,14 @@ pub struct PassthroughDecoder<R: Read + Seek> {
 
 impl<R: Read + Seek> PassthroughDecoder<R> {
     /// Constructs a new Decoder from a given implementation of `Read + Seek`.
-    pub fn new(rdr: R) -> DecoderResult<Self> {
+    pub fn new(rdr: R, format: AudioFileFormat) -> DecoderResult<Self> {
+        if !AudioFiles::is_ogg_vorbis(format) {
+            return Err(DecoderError::PassthroughDecoder(format!(
+                "Passthrough decoder is not implemented for format {:?}",
+                format
+            )));
+        }
+
         let mut rdr = PacketReader::new(rdr);
         let since_epoch = SystemTime::now()
             .duration_since(UNIX_EPOCH)
@@ -65,10 +82,16 @@ impl<R: Read + Seek> PassthroughDecoder<R> {
             bos: false,
         })
     }
+
+    fn position_pcm_to_ms(position_pcm: u64) -> u32 {
+        (position_pcm as f64 * MS_PER_PAGE) as u32
+    }
 }
 
 impl<R: Read + Seek> AudioDecoder for PassthroughDecoder<R> {
-    fn seek(&mut self, absgp: u64) -> DecoderResult<()> {
+    fn seek(&mut self, position_ms: u32) -> Result<u32, DecoderError> {
+        let absgp = (position_ms as f64 * PAGES_PER_MS) as u64;
+
         // add an eos to previous stream if missing
         if self.bos && !self.eos {
             match self.rdr.read_packet() {
@@ -101,20 +124,20 @@ impl<R: Read + Seek> AudioDecoder for PassthroughDecoder<R> {
                     .map_err(|e| DecoderError::PassthroughDecoder(e.to_string()))?;
                 match pck {
                     Some(pck) => {
-                        self.ofsgp_page = pck.absgp_page();
-                        debug!("Seek to offset page {}", self.ofsgp_page);
-                        Ok(())
+                        let new_page = pck.absgp_page();
+                        self.ofsgp_page = new_page;
+                        debug!("Seek to offset page {}", new_page);
+                        let new_position_ms = Self::position_pcm_to_ms(new_page);
+                        Ok(new_position_ms)
                     }
-                    None => Err(DecoderError::PassthroughDecoder(
-                        "Packet is None".to_string(),
-                    )),
+                    None => Err(DecoderError::PassthroughDecoder("Packet is None".into())),
                 }
             }
             Err(e) => Err(DecoderError::PassthroughDecoder(e.to_string())),
         }
     }
 
-    fn next_packet(&mut self) -> DecoderResult<Option<AudioPacket>> {
+    fn next_packet(&mut self) -> DecoderResult<Option<(AudioPacketPosition, AudioPacket)>> {
         // write headers if we are (re)starting
         if !self.bos {
             self.wtr
@@ -184,8 +207,15 @@ impl<R: Read + Seek> AudioDecoder for PassthroughDecoder<R> {
             let data = self.wtr.inner_mut();
 
             if !data.is_empty() {
-                let ogg_data = AudioPacket::OggData(std::mem::take(data));
-                return Ok(Some(ogg_data));
+                let position_ms = Self::position_pcm_to_ms(pckgp_page);
+                let packet_position = AudioPacketPosition {
+                    position_ms,
+                    skipped: false,
+                };
+
+                let ogg_data = AudioPacket::Raw(std::mem::take(data));
+
+                return Ok(Some((packet_position, ogg_data)));
             }
         }
     }

playback/src/decoder/symphonia_decoder.rs

@@ -0,0 +1,226 @@
+use std::io;
+
+use symphonia::{
+    core::{
+        audio::SampleBuffer,
+        codecs::{Decoder, DecoderOptions},
+        errors::Error,
+        formats::{FormatOptions, FormatReader, SeekMode, SeekTo},
+        io::{MediaSource, MediaSourceStream, MediaSourceStreamOptions},
+        meta::{StandardTagKey, Value},
+        units::Time,
+    },
+    default::{
+        codecs::{Mp3Decoder, VorbisDecoder},
+        formats::{Mp3Reader, OggReader},
+    },
+};
+
+use super::{AudioDecoder, AudioPacket, AudioPacketPosition, DecoderError, DecoderResult};
+
+use crate::{
+    metadata::audio::{AudioFileFormat, AudioFiles},
+    player::NormalisationData,
+    NUM_CHANNELS, PAGES_PER_MS, SAMPLE_RATE,
+};
+
+pub struct SymphoniaDecoder {
+    format: Box<dyn FormatReader>,
+    decoder: Box<dyn Decoder>,
+    sample_buffer: Option<SampleBuffer<f64>>,
+}
+
+impl SymphoniaDecoder {
+    pub fn new<R>(input: R, file_format: AudioFileFormat) -> DecoderResult<Self>
+    where
+        R: MediaSource + 'static,
+    {
+        let mss_opts = MediaSourceStreamOptions {
+            buffer_len: librespot_audio::MINIMUM_DOWNLOAD_SIZE,
+        };
+        let mss = MediaSourceStream::new(Box::new(input), mss_opts);
+
+        let format_opts = FormatOptions {
+            enable_gapless: true,
+            ..Default::default()
+        };
+
+        let format: Box<dyn FormatReader> = if AudioFiles::is_ogg_vorbis(file_format) {
+            Box::new(OggReader::try_new(mss, &format_opts)?)
+        } else if AudioFiles::is_mp3(file_format) {
+            Box::new(Mp3Reader::try_new(mss, &format_opts)?)
+        } else {
+            return Err(DecoderError::SymphoniaDecoder(format!(
+                "Unsupported format: {:?}",
+                file_format
+            )));
+        };
+
+        let track = format.default_track().ok_or_else(|| {
+            DecoderError::SymphoniaDecoder("Could not retrieve default track".into())
+        })?;
+
+        let decoder_opts: DecoderOptions = Default::default();
+        let decoder: Box<dyn Decoder> = if AudioFiles::is_ogg_vorbis(file_format) {
+            Box::new(VorbisDecoder::try_new(&track.codec_params, &decoder_opts)?)
+        } else if AudioFiles::is_mp3(file_format) {
+            Box::new(Mp3Decoder::try_new(&track.codec_params, &decoder_opts)?)
+        } else {
+            return Err(DecoderError::SymphoniaDecoder(format!(
+                "Unsupported decoder: {:?}",
+                file_format
+            )));
+        };
+
+        let rate = decoder.codec_params().sample_rate.ok_or_else(|| {
+            DecoderError::SymphoniaDecoder("Could not retrieve sample rate".into())
+        })?;
+        if rate != SAMPLE_RATE {
+            return Err(DecoderError::SymphoniaDecoder(format!(
+                "Unsupported sample rate: {}",
+                rate
+            )));
+        }
+
+        let channels = decoder.codec_params().channels.ok_or_else(|| {
+            DecoderError::SymphoniaDecoder("Could not retrieve channel configuration".into())
+        })?;
+        if channels.count() != NUM_CHANNELS as usize {
+            return Err(DecoderError::SymphoniaDecoder(format!(
+                "Unsupported number of channels: {}",
+                channels
+            )));
+        }
+
+        Ok(Self {
+            format,
+            decoder,
+
+            // We set the sample buffer when decoding the first full packet,
+            // whose duration is also the ideal sample buffer size.
+            sample_buffer: None,
+        })
+    }
+
+    pub fn normalisation_data(&mut self) -> Option<NormalisationData> {
+        let mut metadata = self.format.metadata();
+
+        // Advance to the latest metadata revision.
+        // None means we hit the latest.
+        loop {
+            if metadata.pop().is_none() {
+                break;
+            }
+        }
+
+        let tags = metadata.current()?.tags();
+
+        if tags.is_empty() {
+            None
+        } else {
+            let mut data = NormalisationData::default();
+
+            for tag in tags {
+                if let Value::Float(value) = tag.value {
+                    match tag.std_key {
+                        Some(StandardTagKey::ReplayGainAlbumGain) => data.album_gain_db = value,
+                        Some(StandardTagKey::ReplayGainAlbumPeak) => data.album_peak = value,
+                        Some(StandardTagKey::ReplayGainTrackGain) => data.track_gain_db = value,
+                        Some(StandardTagKey::ReplayGainTrackPeak) => data.track_peak = value,
+                        _ => (),
+                    }
+                }
+            }
+
+            Some(data)
+        }
+    }
+
+    fn ts_to_ms(&self, ts: u64) -> u32 {
+        let time_base = self.decoder.codec_params().time_base;
+        let seeked_to_ms = match time_base {
+            Some(time_base) => {
+                let time = time_base.calc_time(ts);
+                (time.seconds as f64 + time.frac) * 1000.
+            }
+            // Fallback in the unexpected case that the format has no base time set.
+            None => (ts as f64 * PAGES_PER_MS),
+        };
+        seeked_to_ms as u32
+    }
+}
+
+impl AudioDecoder for SymphoniaDecoder {
+    fn seek(&mut self, position_ms: u32) -> Result<u32, DecoderError> {
+        let seconds = position_ms as u64 / 1000;
+        let frac = (position_ms as f64 % 1000.) / 1000.;
+        let time = Time::new(seconds, frac);
+
+        // `track_id: None` implies the default track ID (of the container, not of Spotify).
+        let seeked_to_ts = self.format.seek(
+            SeekMode::Accurate,
+            SeekTo::Time {
+                time,
+                track_id: None,
+            },
+        )?;
+
+        // Seeking is a `FormatReader` operation, so the decoder cannot reliably
+        // know when a seek took place. Reset it to avoid audio glitches.
+        self.decoder.reset();
+
+        Ok(self.ts_to_ms(seeked_to_ts.actual_ts))
+    }
+
+    fn next_packet(&mut self) -> DecoderResult<Option<(AudioPacketPosition, AudioPacket)>> {
+        let mut skipped = false;
+
+        loop {
+            let packet = match self.format.next_packet() {
+                Ok(packet) => packet,
+                Err(Error::IoError(err)) => {
+                    if err.kind() == io::ErrorKind::UnexpectedEof {
+                        return Ok(None);
+                    } else {
+                        return Err(DecoderError::SymphoniaDecoder(err.to_string()));
+                    }
+                }
+                Err(err) => {
+                    return Err(err.into());
+                }
+            };
+
+            let position_ms = self.ts_to_ms(packet.ts());
+            let packet_position = AudioPacketPosition {
+                position_ms,
+                skipped,
+            };
+
+            match self.decoder.decode(&packet) {
+                Ok(decoded) => {
+                    let sample_buffer = match self.sample_buffer.as_mut() {
+                        Some(buffer) => buffer,
+                        None => {
+                            let spec = *decoded.spec();
+                            let duration = decoded.capacity() as u64;
+                            self.sample_buffer.insert(SampleBuffer::new(duration, spec))
+                        }
+                    };
+
+                    sample_buffer.copy_interleaved_ref(decoded);
+                    let samples = AudioPacket::Samples(sample_buffer.samples().to_vec());
+
+                    return Ok(Some((packet_position, samples)));
+                }
+                Err(Error::DecodeError(_)) => {
+                    // The packet failed to decode due to corrupted or invalid data, get a new
+                    // packet and try again.
+                    warn!("Skipping malformed audio packet at {} ms", position_ms);
+                    skipped = true;
+                    continue;
+                }
+                Err(err) => return Err(err.into()),
+            }
+        }
+    }
+}

playback/src/mixer/alsamixer.rs

@@ -201,7 +201,7 @@ impl Mixer for AlsaMixer {
             mapped_volume = LogMapping::linear_to_mapped(mapped_volume, self.db_range);
         }
 
-        self.config.volume_ctrl.to_unmapped(mapped_volume)
+        self.config.volume_ctrl.as_unmapped(mapped_volume)
     }
 
     fn set_volume(&self, volume: u16) {

playback/src/mixer/mappings.rs

@@ -3,7 +3,7 @@ use crate::player::db_to_ratio;
 
 pub trait MappedCtrl {
     fn to_mapped(&self, volume: u16) -> f64;
-    fn to_unmapped(&self, mapped_volume: f64) -> u16;
+    fn as_unmapped(&self, mapped_volume: f64) -> u16;
 
     fn db_range(&self) -> f64;
     fn set_db_range(&mut self, new_db_range: f64);
@@ -49,7 +49,7 @@ impl MappedCtrl for VolumeCtrl {
         mapped_volume
     }
 
-    fn to_unmapped(&self, mapped_volume: f64) -> u16 {
+    fn as_unmapped(&self, mapped_volume: f64) -> u16 {
         // More than just an optimization, this ensures that zero mapped volume
         // is unmapped to non-negative real numbers (otherwise the log and cubic
         // equations would respectively return -inf and -1/9.)

playback/src/mixer/softmixer.rs

@@ -26,7 +26,7 @@ impl Mixer for SoftMixer {
 
     fn volume(&self) -> u16 {
         let mapped_volume = f64::from_bits(self.volume.load(Ordering::Relaxed));
-        self.volume_ctrl.to_unmapped(mapped_volume)
+        self.volume_ctrl.as_unmapped(mapped_volume)
     }
 
     fn set_volume(&self, volume: u16) {