#[macro_use] extern crate log;
extern crate env_logger;
extern crate futures;
extern crate getopts;
extern crate librespot;
extern crate rpassword;
extern crate tokio_core;
extern crate tokio_io;
extern crate tokio_signal;
extern crate crypto;

use env_logger::LogBuilder;
use futures::{Future, Async, Poll, Stream};
use futures::sync::mpsc::UnboundedReceiver;
use std::env;
use std::io::{self, stderr, Write};
use std::path::PathBuf;
use std::process::exit;
use std::str::FromStr;
use tokio_core::reactor::{Handle, Core};
use tokio_io::IoStream;
use std::mem;
use crypto::digest::Digest;
use crypto::sha1::Sha1;

use librespot::core::authentication::{get_credentials, Credentials};
use librespot::core::cache::Cache;
use librespot::core::config::{DeviceType, SessionConfig, ConnectConfig};
use librespot::core::session::Session;
use librespot::core::version;

use librespot::playback::audio_backend::{self, Sink, BACKENDS};
use librespot::playback::config::{Bitrate, PlayerConfig};
use librespot::connect::discovery::{discovery, DiscoveryStream};
use librespot::playback::mixer::{self, Mixer};
use librespot::playback::player::{Player, PlayerEvent};
use librespot::connect::spirc::{Spirc, SpircTask};

mod player_event_handler;
use player_event_handler::run_program_on_events;

fn device_id(name: &str) -> String {
    let mut h = Sha1::new();
    h.input_str(name);
    h.result_str()
}

fn usage(program: &str, opts: &getopts::Options) -> String {
    let brief = format!("Usage: {} [options]", program);
    opts.usage(&brief)
}

fn setup_logging(verbose: bool) {
    let mut builder = LogBuilder::new();
    match env::var("RUST_LOG") {
        Ok(config) => {
            builder.parse(&config);
            builder.init().unwrap();

            if verbose {
                warn!("`--verbose` flag overidden by `RUST_LOG` environment variable");
            }
        }
        Err(_) => {
            if verbose {
                builder.parse("mdns=info,librespot=trace");
            } else {
                builder.parse("mdns=info,librespot=info");
            }
            builder.init().unwrap();
        }
    }
}

fn list_backends() {
    println!("Available Backends : ");
    for (&(name, _), idx) in BACKENDS.iter().zip(0..) {
        if idx == 0 {
            println!("- {} (default)", name);
        } else {
            println!("- {}", name);
        }
    }
}

#[derive(Clone)]
struct Setup {
    backend: fn(Option<String>) -> Box<Sink>,
    device: Option<String>,

    mixer: fn() -> Box<Mixer>,

    cache: Option<Cache>,
    player_config: PlayerConfig,
    session_config: SessionConfig,
    connect_config: ConnectConfig,
    credentials: Option<Credentials>,
    enable_discovery: bool,
    zeroconf_port: u16,
    player_event_program: Option<String>,
}

fn setup(args: &[String]) -> Setup {
    let mut opts = getopts::Options::new();
    opts.optopt("c", "cache", "Path to a directory where files will be cached.", "CACHE")
        .optflag("", "disable-audio-cache", "Disable caching of the audio data.")
        .reqopt("n", "name", "Device name", "NAME")
        .optopt("", "device-type", "Displayed device type", "DEVICE_TYPE")
        .optopt("b", "bitrate", "Bitrate (96, 160 or 320). Defaults to 160", "BITRATE")
        .optopt("", "onevent", "Run PROGRAM when playback is about to begin.", "PROGRAM")
        .optflag("v", "verbose", "Enable verbose output")
        .optopt("u", "username", "Username to sign in with", "USERNAME")
        .optopt("p", "password", "Password", "PASSWORD")
        .optflag("", "disable-discovery", "Disable discovery mode")
        .optopt("", "backend", "Audio backend to use. Use '?' to list options", "BACKEND")
        .optopt("", "device", "Audio device to use. Use '?' to list options if using portaudio", "DEVICE")
        .optopt("", "mixer", "Mixer to use", "MIXER")
        .optopt("", "initial-volume", "Initial volume in %, once connected (must be from 0 to 100)", "VOLUME")
        .optopt("", "zeroconf-port", "The port the internal server advertised over zeroconf uses.", "ZEROCONF_PORT")
        .optflag("", "enable-volume-normalisation", "Play all tracks at the same volume")
        .optopt("", "normalisation-pregain", "Pregain (dB) applied by volume normalisation", "PREGAIN");

    let matches = match opts.parse(&args[1..]) {
        Ok(m) => m,
        Err(f) => {
            writeln!(stderr(), "error: {}\n{}", f.to_string(), usage(&args[0], &opts)).unwrap();
            exit(1);
        }
    };

    let verbose = matches.opt_present("verbose");
    setup_logging(verbose);

    info!("librespot {} ({}). Built on {}. Build ID: {}",
             version::short_sha(),
             version::commit_date(),
             version::short_now(),
             version::build_id());

    let backend_name = matches.opt_str("backend");
    if backend_name == Some("?".into()) {
        list_backends();
        exit(0);
    }

    let backend = audio_backend::find(backend_name)
        .expect("Invalid backend");

    let device = matches.opt_str("device");

    let mixer_name = matches.opt_str("mixer");
    let mixer = mixer::find(mixer_name.as_ref())
        .expect("Invalid mixer");

    let initial_volume = matches
        .opt_str("initial-volume")
        .map(|volume| {
            let volume = volume.parse::<i32>().unwrap();
            if volume < 0 || volume > 100 {
                panic!("Initial volume must be in the range 0-100");
            }
            volume * 0xFFFF / 100
        })
        .unwrap_or(0x8000);

    let zeroconf_port =
    matches.opt_str("zeroconf-port")
           .map(|port| port.parse::<u16>().unwrap())
           .unwrap_or(0);

    let name = matches.opt_str("name").unwrap();
    let use_audio_cache = !matches.opt_present("disable-audio-cache");

    let cache = matches.opt_str("c").map(|cache_location| {
        Cache::new(PathBuf::from(cache_location), use_audio_cache)
    });

    let credentials = {
        let cached_credentials = cache.as_ref().and_then(Cache::credentials);

        let password = |username: &String| -> String {
            write!(stderr(), "Password for {}: ", username).unwrap();
            stderr().flush().unwrap();
            rpassword::read_password().unwrap()
        };

        get_credentials(
            matches.opt_str("username"),
            matches.opt_str("password"),
            cached_credentials,
            password
        )
    };

    let session_config = {
        let device_id = device_id(&name);

        SessionConfig {
            user_agent: version::version_string(),
            device_id: device_id,
        }
    };

    let player_config = {
        let bitrate = matches.opt_str("b").as_ref()
            .map(|bitrate| Bitrate::from_str(bitrate).expect("Invalid bitrate"))
            .unwrap_or(Bitrate::default());

        PlayerConfig {
            bitrate: bitrate,
            normalisation: matches.opt_present("enable-volume-normalisation"),
            normalisation_pregain: matches.opt_str("normalisation-pregain")
                .map(|pregain| pregain.parse::<f32>().expect("Invalid pregain float value"))
                .unwrap_or(PlayerConfig::default().normalisation_pregain),
        }
    };

    let connect_config = {
        let device_type = matches.opt_str("device-type").as_ref()
            .map(|device_type| DeviceType::from_str(device_type).expect("Invalid device type"))
            .unwrap_or(DeviceType::default());

        ConnectConfig {
            name: name,
            device_type: device_type,
            volume: initial_volume,
        }
    };

    let enable_discovery = !matches.opt_present("disable-discovery");

    Setup {
        backend: backend,
        cache: cache,
        session_config: session_config,
        player_config: player_config,
        connect_config: connect_config,
        credentials: credentials,
        device: device,
        enable_discovery: enable_discovery,
        zeroconf_port: zeroconf_port,
        mixer: mixer,
        player_event_program: matches.opt_str("onevent"),
    }
}

struct Main {
    cache: Option<Cache>,
    player_config: PlayerConfig,
    session_config: SessionConfig,
    connect_config: ConnectConfig,
    backend: fn(Option<String>) -> Box<Sink>,
    device: Option<String>,
    mixer: fn() -> Box<Mixer>,
    handle: Handle,

    discovery: Option<DiscoveryStream>,
    signal: IoStream<()>,

    spirc: Option<Spirc>,
    spirc_task: Option<SpircTask>,
    connect: Box<Future<Item=Session, Error=io::Error>>,

    shutdown: bool,

    player_event_channel: Option<UnboundedReceiver<PlayerEvent>>,
    player_event_program: Option<String>,
}

impl Main {
    fn new(handle: Handle, setup: Setup) -> Main {
        let mut task = Main {
            handle: handle.clone(),
            cache: setup.cache,
            session_config: setup.session_config,
            player_config: setup.player_config,
            connect_config: setup.connect_config,
            backend: setup.backend,
            device: setup.device,
            mixer: setup.mixer,

            connect: Box::new(futures::future::empty()),
            discovery: None,
            spirc: None,
            spirc_task: None,
            shutdown: false,
            signal: Box::new(tokio_signal::ctrl_c(&handle).flatten_stream()),

            player_event_channel: None,
            player_event_program: setup.player_event_program,
        };

        if setup.enable_discovery {
            let config = task.connect_config.clone();
            let device_id = task.session_config.device_id.clone();

            task.discovery = Some(discovery(&handle, config, device_id, setup.zeroconf_port).unwrap());
        }

        if let Some(credentials) = setup.credentials {
            task.credentials(credentials);
        }

        task
    }

    fn credentials(&mut self, credentials: Credentials) {
        let config = self.session_config.clone();
        let handle = self.handle.clone();

        let connection = Session::connect(config, credentials, self.cache.clone(), handle);

        self.connect = connection;
        self.spirc = None;
        let task = mem::replace(&mut self.spirc_task, None);
        if let Some(task) = task {
            self.handle.spawn(task);
        }
    }
}

impl Future for Main {
    type Item = ();
    type Error = ();

    fn poll(&mut self) -> Poll<(), ()> {
        loop {
            let mut progress = false;

            if let Some(Async::Ready(Some(creds))) = self.discovery.as_mut().map(|d| d.poll().unwrap()) {
                if let Some(ref spirc) = self.spirc {
                    spirc.shutdown();
                }
                self.credentials(creds);

                progress = true;
            }

            if let Async::Ready(session) = self.connect.poll().unwrap() {
                self.connect = Box::new(futures::future::empty());
                let device = self.device.clone();
                let mixer = (self.mixer)();
                let player_config = self.player_config.clone();
                let connect_config = self.connect_config.clone();

                let audio_filter = mixer.get_audio_filter();
                let backend = self.backend;
                let (player, event_channel) = Player::new(player_config, session.clone(), audio_filter, move || {
                    (backend)(device)
                });

                let (spirc, spirc_task) = Spirc::new(connect_config, session, player, mixer);
                self.spirc = Some(spirc);
                self.spirc_task = Some(spirc_task);
                self.player_event_channel = Some(event_channel);

                progress = true;
            }

            if let Async::Ready(Some(())) = self.signal.poll().unwrap() {
                if !self.shutdown {
                    if let Some(ref spirc) = self.spirc {
                        spirc.shutdown();
                    }
                    self.shutdown = true;
                } else {
                    return Ok(Async::Ready(()));
                }

                progress = true;
            }

            if let Some(ref mut spirc_task) = self.spirc_task {
                if let Async::Ready(()) = spirc_task.poll().unwrap() {
                    if self.shutdown {
                        return Ok(Async::Ready(()));
                    } else {
                        panic!("Spirc shut down unexpectedly");
                    }
                }
            }

            if let Some(ref mut player_event_channel) = self.player_event_channel {
                if let Async::Ready(Some(event)) = player_event_channel.poll().unwrap() {
                    if let Some(ref program) = self.player_event_program {
                        run_program_on_events(event, program);
                    }
                }
            }

            if !progress {
                return Ok(Async::NotReady);
            }
        }
    }
}

fn main() {
    if env::var("RUST_BACKTRACE").is_err() {
        env::set_var("RUST_BACKTRACE", "full")
    }
    let mut core = Core::new().unwrap();
    let handle = core.handle();

    let args: Vec<String> = std::env::args().collect();

    core.run(Main::new(handle, setup(&args))).unwrap()
}