message Frame {
    optional uint32 version = 0x1;
    optional string ident = 0x2;
    optional string protocol_version = 0x3;
    optional uint32 seq_nr = 0x4;
    optional MessageType typ = 0x5;
    optional DeviceState device_state = 0x7;
    optional Goodbye goodbye = 0xb;
    optional State state = 0xc;
    optional uint32 position = 0xd;
    optional uint32 volume = 0xe;
    optional int64 state_update_id = 0x11;
    repeated string recipient = 0x12;
    optional bytes context_player_state = 0x13;
}

enum MessageType {
    kMessageTypeHello = 0x1;
    kMessageTypeGoodbye = 0x2;
    kMessageTypeProbe = 0x3;
    kMessageTypeNotify = 0xa;
    kMessageTypeLoad = 0x14;
    kMessageTypePlay = 0x15;
    kMessageTypePause = 0x16;
    kMessageTypePlayPause = 0x17;
    kMessageTypeSeek = 0x18;
    kMessageTypePrev = 0x19;
    kMessageTypeNext = 0x1a;
    kMessageTypeVolume = 0x1b;
    kMessageTypeShuffle = 0x1c;
    kMessageTypeRepeat = 0x1d;
    kMessageTypeVolumeDown = 0x1f;
    kMessageTypeVolumeUp = 0x20;
    kMessageTypeReplace = 0x21;
    kMessageTypeLogout = 0x22;
    kMessageTypeAction = 0x23;
}

message DeviceState {
    optional string sw_version = 0x1;
    optional bool is_active = 0xa;
    optional bool can_play = 0xb;
    optional uint32 volume = 0xc;
    optional string name = 0xd;
    optional uint32 error_code = 0xe;
    optional int64 became_active_at = 0xf;
    optional string error_message = 0x10;
    repeated Capability capabilities = 0x11;
    repeated string local_uris = 0x12;
    repeated int32 enc_key = 0x13;
}

message Capability {
    optional CapabilityType typ = 0x1;
    repeated int64 intValue = 0x2;
    repeated string stringValue = 0x3;
}

enum CapabilityType {
    kSupportedContexts = 0x1;
    kCanBePlayer = 0x2;
    kRestrictToLocal = 0x3;
    kDeviceType = 0x4;
    kGaiaEqConnectId = 0x5;
    kSupportsLogout = 0x6;
    kIsObservable = 0x7;
    kVolumeSteps = 0x8;
    kSupportedTypes = 0x9;
}

message Goodbye {
    optional string reason = 0x1;
}

message State {
    optional string context_uri = 0x2;
    optional uint32 index = 0x3;
    optional uint32 position_ms = 0x4;
    optional PlayStatus status = 0x5;
    optional uint64 position_measured_at = 0x7;
    optional string context_description = 0x8;
    optional bool shuffle = 0xd;
    optional bool repeat = 0xe;
    optional string last_command_ident = 0x14;
    optional uint32 last_command_msgid = 0x15;
    optional bool playing_from_fallback = 0x18;
    optional uint32 row = 0x19;
    optional uint32 playing_track_index = 0x1a;
    repeated TrackRef track = 0x1b;
    optional Ad ad = 0x1c;
}

enum PlayStatus {
    kPlayStatusStop = 0x0;
    kPlayStatusPlay = 0x1;
    kPlayStatusPause = 0x2;
    kPlayStatusLoading = 0x3;
}

message TrackRef {
    optional bytes gid = 0x1;
    optional string uri = 0x2;
    optional bool queued = 0x3;
    optional string context = 0x4;
}

message Ad {
    optional int32 next = 0x1;
    optional bytes ogg_fid = 0x2;
    optional bytes image_fid = 0x3;
    optional int32 duration = 0x4;
    optional string click_url = 0x5;
    optional string impression_url = 0x6;
    optional string product = 0x7;
    optional string advertiser = 0x8;
    optional bytes gid = 0x9;
}