Refactor player and spirc

src/player.rs

@@ -1,77 +1,41 @@
+use futures::sync::oneshot;
 use futures::{future, Future};
-use futures::sync::mpsc;
-use std;
 use std::borrow::Cow;
 use std::io::{Read, Seek};
-use std::sync::{Mutex, Arc, MutexGuard};
+use std::mem;
 use std::thread;
-use vorbis;
+use std;
+use vorbis::{self, VorbisError};
 
-use audio_file::AudioFile;
-use audio_decrypt::AudioDecrypt;
 use audio_backend::Sink;
+use audio_decrypt::AudioDecrypt;
+use audio_file::AudioFile;
 use metadata::{FileFormat, Track};
 use session::{Bitrate, Session};
 use util::{self, SpotifyId, Subfile};
-pub use spirc::PlayStatus;
-
-#[cfg(not(feature = "with-tremor"))]
-fn vorbis_time_seek_ms<R>(decoder: &mut vorbis::Decoder<R>, ms: i64) -> Result<(), vorbis::VorbisError> where R: Read + Seek {
-    decoder.time_seek(ms as f64 / 1000f64)
-}
-
-#[cfg(not(feature = "with-tremor"))]
-fn vorbis_time_tell_ms<R>(decoder: &mut vorbis::Decoder<R>) -> Result<i64, vorbis::VorbisError> where R: Read + Seek {
-    decoder.time_tell().map(|t| (t * 1000f64) as i64)
-}
-
-#[cfg(feature = "with-tremor")]
-fn vorbis_time_seek_ms<R>(decoder: &mut vorbis::Decoder<R>, ms: i64) -> Result<(), vorbis::VorbisError> where R: Read + Seek {
-    decoder.time_seek(ms)
-}
-
-#[cfg(feature = "with-tremor")]
-fn vorbis_time_tell_ms<R>(decoder: &mut vorbis::Decoder<R>) -> Result<i64, vorbis::VorbisError> where R: Read + Seek {
-    decoder.time_tell()
-}
 
 #[derive(Clone)]
 pub struct Player {
-    state: Arc<Mutex<PlayerState>>,
-    observers: Arc<Mutex<Vec<mpsc::UnboundedSender<PlayerState>>>>,
-
     commands: std::sync::mpsc::Sender<PlayerCommand>,
 }
 
-#[derive(Clone)]
-pub struct PlayerState {
-    pub status: PlayStatus,
-    pub position_ms: u32,
-    pub position_measured_at: i64,
-    pub update_time: i64,
-    pub volume: u16,
-    pub track: Option<SpotifyId>,
-
-    pub end_of_track: bool,
-}
-
 struct PlayerInternal {
-    state: Arc<Mutex<PlayerState>>,
-    observers: Arc<Mutex<Vec<mpsc::UnboundedSender<PlayerState>>>>,
-
     session: Session,
     commands: std::sync::mpsc::Receiver<PlayerCommand>,
+
+    state: PlayerState,
+    volume: u16,
+    sink: Box<Sink>,
 }
 
-#[derive(Debug)]
+//#[derive(Debug)]
 enum PlayerCommand {
-    Load(SpotifyId, bool, u32),
+    Load(SpotifyId, bool, u32, oneshot::Sender<()>),
     Play,
     Pause,
     Volume(u16),
     Stop,
     Seek(u32),
-    SeekAt(u32, i64),
 }
 
 impl Player {
@@ -79,31 +43,21 @@ impl Player {
         where F: FnOnce() -> Box<Sink> + Send + 'static {
         let (cmd_tx, cmd_rx) = std::sync::mpsc::channel();
 
-        let state = Arc::new(Mutex::new(PlayerState {
-            status: PlayStatus::kPlayStatusStop,
-            position_ms: 0,
-            position_measured_at: 0,
-            update_time: util::now_ms(),
-            volume: 0xFFFF,
-            track: None,
-            end_of_track: false,
-        }));
-
-        let observers = Arc::new(Mutex::new(Vec::new()));
-
-        let internal = PlayerInternal {
-            session: session,
-            commands: cmd_rx,
-            state: state.clone(),
-            observers: observers.clone(),
-        };
+        thread::spawn(move || {
+            let internal = PlayerInternal {
+                session: session,
+                commands: cmd_rx,
 
-        thread::spawn(move || internal.run(sink_builder()));
+                state: PlayerState::Stopped,
+                volume: 0xFFFF,
+                sink: sink_builder(),
+            };
+
+            internal.run();
+        });
 
         Player {
             commands: cmd_tx,
-            state: state,
-            observers: observers,
         }
     }
 
@@ -111,8 +65,13 @@ impl Player {
         self.commands.send(cmd).unwrap();
     }
 
-    pub fn load(&self, track: SpotifyId, start_playing: bool, position_ms: u32) {
-        self.command(PlayerCommand::Load(track, start_playing, position_ms));
+    pub fn load(&self, track: SpotifyId, start_playing: bool, position_ms: u32)
+        -> oneshot::Receiver<()>
+    {
+        let (tx, rx) = oneshot::channel();
+        self.command(PlayerCommand::Load(track, start_playing, position_ms, tx));
+
+        rx
     }
 
     pub fn play(&self) {
@@ -131,322 +90,310 @@ impl Player {
         self.command(PlayerCommand::Seek(position_ms));
     }
 
-    pub fn seek_at(&self, position_ms: u32, measured_at: i64) {
-        self.command(PlayerCommand::SeekAt(position_ms, measured_at));
-    }
-
-    pub fn state(&self) -> PlayerState {
-        self.state.lock().unwrap().clone()
-    }
-
     pub fn volume(&self, vol: u16) {
         self.command(PlayerCommand::Volume(vol));
     }
-
-    pub fn observe(&self) -> mpsc::UnboundedReceiver<PlayerState> {
-        let (tx, rx) = mpsc::unbounded();
-        self.observers.lock().unwrap().push(tx);
-
-        rx
-    }
 }
 
-fn apply_volume(volume: u16, data: &[i16]) -> Cow<[i16]> {
-    // Fast path when volume is 100%
-    if volume == 0xFFFF {
-        Cow::Borrowed(data)
-    } else {
-        Cow::Owned(data.iter()
-                       .map(|&x| {
-                           (x as i32
-                            * volume as i32
-                            / 0xFFFF) as i16
-                       })
-                       .collect())
-    }
+type Decoder = vorbis::Decoder<Subfile<AudioDecrypt<AudioFile>>>;
+enum PlayerState {
+    Stopped,
+    Paused {
+        decoder: Decoder,
+        end_of_track: oneshot::Sender<()>,
+    },
+    Playing {
+        decoder: Decoder,
+        end_of_track: oneshot::Sender<()>,
+    },
+
+    Invalid,
 }
 
-fn find_available_alternative<'a>(session: &Session, track: &'a Track) -> Option<Cow<'a, Track>> {
-    if track.available {
-        Some(Cow::Borrowed(track))
-    } else {
-        let alternatives = track.alternatives
-            .iter()
-            .map(|alt_id| {
-                session.metadata().get::<Track>(*alt_id)
-            });
-        let alternatives = future::join_all(alternatives).wait().unwrap();
-
-        alternatives.into_iter().find(|alt| alt.available).map(Cow::Owned)
+impl PlayerState {
+    fn is_playing(&self) -> bool {
+        use self::PlayerState::*;
+        match *self {
+            Stopped | Paused { .. } => false,
+            Playing { .. } => true,
+            Invalid => panic!("invalid state"),
+        }
     }
-}
-
-fn load_track(session: &Session, track_id: SpotifyId)
-    -> Option<vorbis::Decoder<Subfile<AudioDecrypt<AudioFile>>>>
-{
-    let track = session.metadata().get::<Track>(track_id).wait().unwrap();
-
-    info!("Loading track \"{}\"", track.name);
 
-    let track = match find_available_alternative(session, &track) {
-        Some(track) => track,
-        None => {
-            warn!("Track \"{}\" is not available", track.name);
-            return None;
+    fn decoder(&mut self) -> Option<&mut Decoder> {
+        use self::PlayerState::*;
+        match *self {
+            Stopped => None,
+            Paused { ref mut decoder, .. } |
+            Playing { ref mut decoder, .. } => Some(decoder),
+            Invalid => panic!("invalid state"),
         }
-    };
-
-    let format = match session.config().bitrate {
-        Bitrate::Bitrate96 => FileFormat::OGG_VORBIS_96,
-        Bitrate::Bitrate160 => FileFormat::OGG_VORBIS_160,
-        Bitrate::Bitrate320 => FileFormat::OGG_VORBIS_320,
-    };
-
+    }
 
+    fn signal_end_of_track(self) {
+        use self::PlayerState::*;
+        match self {
+            Paused { end_of_track, .. } |
+            Playing { end_of_track, .. } => {
+                end_of_track.complete(())
+            }
 
-    let file_id = match track.files.get(&format) {
-        Some(&file_id) => file_id,
-        None => {
-            warn!("Track \"{}\" is not available in format {:?}", track.name, format);
-            return None;
+            Stopped => warn!("signal_end_of_track from stopped state"),
+            Invalid => panic!("invalid state"),
         }
-    };
-
-    let key = session.audio_key().request(track.id, file_id).wait().unwrap();
-
-    let (open, _) = session.audio_file().open(file_id);
-    let encrypted_file = open.wait().unwrap();
-
-    let audio_file = Subfile::new(AudioDecrypt::new(key, encrypted_file), 0xa7);
-    let decoder = vorbis::Decoder::new(audio_file).unwrap();
-
-    Some(decoder)
-}
+    }
 
-fn run_onstart(session: &Session) {
-    match session.config().onstart {
-        Some(ref program) => util::run_program(program),
-        None => {},
-    };
-}
+    fn paused_to_playing(&mut self) {
+        use self::PlayerState::*;
+        match ::std::mem::replace(self, Invalid) {
+            Paused { decoder, end_of_track } => {
+                *self = Playing {
+                    decoder: decoder,
+                    end_of_track: end_of_track,
+                };
+            }
+            _ => panic!("invalid state"),
+        }
+    }
 
-fn run_onstop(session: &Session) {
-    match session.config().onstop {
-        Some(ref program) => util::run_program(program),
-        None => {},
-    };
+    fn playing_to_paused(&mut self) {
+        use self::PlayerState::*;
+        match ::std::mem::replace(self, Invalid) {
+            Playing { decoder, end_of_track } => {
+                *self = Paused {
+                    decoder: decoder,
+                    end_of_track: end_of_track,
+                };
+            }
+            _ => panic!("invalid state"),
+        }
+    }
 }
 
 impl PlayerInternal {
-    fn run(self, mut sink: Box<Sink>) {
-        let mut decoder = None;
-
+    fn run(mut self) {
         loop {
-            let playing = self.state.lock().unwrap().status == PlayStatus::kPlayStatusPlay;
-            let cmd = if playing {
+            let cmd = if self.state.is_playing() {
                 self.commands.try_recv().ok()
             } else {
                 Some(self.commands.recv().unwrap())
             };
 
-            match cmd {
-                Some(PlayerCommand::Load(track_id, play, position)) => {
-                    self.update(|state| {
-                        if state.status == PlayStatus::kPlayStatusPlay {
-                            sink.stop().unwrap();
-                            run_onstop(&self.session);
-                        }
-                        state.end_of_track = false;
-                        state.status = PlayStatus::kPlayStatusPause;
-                        state.position_ms = position;
-                        state.position_measured_at = util::now_ms();
-                        state.track = Some(track_id);
-                        true
-                    });
-                    drop(decoder);
-
-                    decoder = match load_track(&self.session, track_id) {
-                        Some(mut decoder) => {
-                            match vorbis_time_seek_ms(&mut decoder, position as i64) {
-                                Ok(_) => (),
-                                Err(err) => error!("Vorbis error: {:?}", err),
-                            }
+            if let Some(cmd) = cmd {
+                self.handle_command(cmd);
+            }
 
-                            self.update(|state| {
-                                state.status = if play {
-                                    run_onstart(&self.session);
-                                    sink.start().unwrap();
-                                    PlayStatus::kPlayStatusPlay
-                                } else {
-                                    PlayStatus::kPlayStatusPause
-                                };
-                                state.position_ms = position;
-                                state.position_measured_at = util::now_ms();
-
-                                true
-                            });
-
-                            info!("Load Done");
-                            Some(decoder)
-                        }
+            let packet = if let PlayerState::Playing { ref mut decoder, .. } = self.state {
+                Some(decoder.packets().next())
+            } else { None };
 
-                        None => {
-                            self.update(|state| {
-                                state.status = PlayStatus::kPlayStatusStop;
-                                state.end_of_track = true;
-                                true
-                            });
+            if let Some(packet) = packet {
+                self.handle_packet(packet);
+            }
+        }
+    }
 
-                            None
-                        }
+    fn handle_packet(&mut self, packet: Option<Result<vorbis::Packet, VorbisError>>) {
+        match packet {
+            Some(Ok(mut packet)) => {
+                if self.volume < 0xFFFF {
+                    for x in packet.data.iter_mut() {
+                        *x = (*x as i32 * self.volume as i32 / 0xFFFF) as i16;
                     }
+                }
 
+                self.sink.write(&packet.data).unwrap();
+            }
+
+            Some(Err(vorbis::VorbisError::Hole)) => (),
+            Some(Err(e)) => panic!("Vorbis error {:?}", e),
+            None => {
+                self.sink.stop().unwrap();
+                self.run_onstop();
+
+                let old_state = mem::replace(&mut self.state, PlayerState::Stopped);
+                old_state.signal_end_of_track();
+            }
+        }
+    }
 
+    fn handle_command(&mut self, cmd: PlayerCommand) {
+        //debug!("command={:?}", cmd);
+        match cmd {
+            PlayerCommand::Load(track_id, play, position, end_of_track) => {
+                if self.state.is_playing() {
+                    self.sink.stop().unwrap();
                 }
-                Some(PlayerCommand::Seek(position)) => {
-                    match vorbis_time_seek_ms(decoder.as_mut().unwrap(), position as i64) {
-                        Ok(_) => (),
-                        Err(err) => error!("Vorbis error: {:?}", err),
+
+                match self.load_track(track_id, position as i64) {
+                    Some(decoder) => {
+                        if play {
+                            if !self.state.is_playing() {
+                                self.run_onstart();
+                            }
+                            self.sink.start().unwrap();
+
+                            self.state = PlayerState::Playing {
+                                decoder: decoder,
+                                end_of_track: end_of_track,
+                            };
+                        } else {
+                            if self.state.is_playing() {
+                                self.run_onstop();
+                            }
+
+                            self.state = PlayerState::Paused {
+                                decoder: decoder,
+                                end_of_track: end_of_track,
+                            };
+                        }
                     }
-                    self.update(|state| {
-                        state.position_ms = vorbis_time_tell_ms(decoder.as_mut().unwrap()).unwrap() as u32;
-                        state.position_measured_at = util::now_ms();
 
-                        true
-                    });
+                    None => {
+                        if self.state.is_playing() {
+                            self.run_onstop();
+                        }
+                    }
                 }
-                Some(PlayerCommand::SeekAt(position, measured_at)) => {
-                    let position = (util::now_ms() - measured_at + position as i64) as u32;
+            }
 
-                    match vorbis_time_seek_ms(decoder.as_mut().unwrap(), position as i64) {
+            PlayerCommand::Seek(position) => {
+                if let Some(decoder) = self.state.decoder() {
+                    match vorbis_time_seek_ms(decoder, position as i64) {
                         Ok(_) => (),
                         Err(err) => error!("Vorbis error: {:?}", err),
                     }
-                    self.update(|state| {
-                        state.position_ms = vorbis_time_tell_ms(decoder.as_mut().unwrap()).unwrap() as u32;
-                        state.position_measured_at = util::now_ms();
-
-                        true
-                    });
-                }
-                Some(PlayerCommand::Play) => {
-                    self.update(|state| {
-                        state.status = PlayStatus::kPlayStatusPlay;
-                        state.position_ms = vorbis_time_tell_ms(decoder.as_mut().unwrap()).unwrap() as u32;
-                        state.position_measured_at = util::now_ms();
-                        true
-                    });
-
-                    run_onstart(&self.session);
-                    sink.start().unwrap();
-                }
-                Some(PlayerCommand::Pause) => {
-                    self.update(|state| {
-                        state.status = PlayStatus::kPlayStatusPause;
-                        state.update_time = util::now_ms();
-                        state.position_ms = decoder.as_mut().map(|d| vorbis_time_tell_ms(d).unwrap()).unwrap_or(0) as u32;
-                        state.position_measured_at = util::now_ms();
-                        true
-                    });
-
-                    sink.stop().unwrap();
-                    run_onstop(&self.session);
-                }
-                Some(PlayerCommand::Volume(vol)) => {
-                    self.update(|state| {
-                        state.volume = vol;
-                        false
-                    });
-                }
-                Some(PlayerCommand::Stop) => {
-                    self.update(|state| {
-                        if state.status == PlayStatus::kPlayStatusPlay {
-                            state.status = PlayStatus::kPlayStatusPause;
-                        }
-                        state.position_ms = 0;
-                        state.position_measured_at = util::now_ms();
-                        true
-                    });
-
-                    sink.stop().unwrap();
-                    run_onstop(&self.session);
-                    decoder = None;
+                } else {
+                    warn!("Player::seek called from invalid state");
                 }
-                None => (),
             }
 
-            if self.state.lock().unwrap().status == PlayStatus::kPlayStatusPlay {
-                let packet = decoder.as_mut().unwrap().packets().next();
+            PlayerCommand::Play => {
+                if let PlayerState::Paused { .. } = self.state {
+                    self.state.paused_to_playing();
 
-                match packet {
-                    Some(Ok(packet)) => {
-                        let buffer = apply_volume(self.state.lock().unwrap().volume,
-                                                  &packet.data);
-                        sink.write(&buffer).unwrap();
+                    self.run_onstart();
+                    self.sink.start().unwrap();
+                } else {
+                    warn!("Player::play called from invalid state");
+                }
+            }
 
-                        self.update(|state| {
-                            state.position_ms = vorbis_time_tell_ms(decoder.as_mut().unwrap()).unwrap() as u32;
-                            state.position_measured_at = util::now_ms();
+            PlayerCommand::Pause => {
+                if let PlayerState::Playing { .. } = self.state {
+                    self.state.playing_to_paused();
+
+                    self.sink.stop().unwrap();
+                    self.run_onstop();
+                } else {
+                    warn!("Player::pause called from invalid state");
+                }
+            }
 
-                            false
-                        });
+            PlayerCommand::Stop => {
+                match self.state {
+                    PlayerState::Playing { .. } => {
+                        self.sink.stop().unwrap();
+                        self.run_onstop();
+                        self.state = PlayerState::Stopped;
                     }
-                    Some(Err(vorbis::VorbisError::Hole)) => (),
-                    Some(Err(e)) => panic!("Vorbis error {:?}", e),
-                    None => {
-                        self.update(|state| {
-                            state.status = PlayStatus::kPlayStatusStop;
-                            state.end_of_track = true;
-                            true
-                        });
-
-                        sink.stop().unwrap();
-                        run_onstop(&self.session);
-                        decoder = None;
+                    PlayerState::Paused { .. } => {
+                        self.state = PlayerState::Stopped;
+                    },
+                    PlayerState::Stopped => {
+                        warn!("Player::stop called from invalid state");
                     }
+                    PlayerState::Invalid => panic!("invalid state"),
                 }
             }
-        }
-    }
 
-    fn update<F>(&self, f: F)
-        where F: FnOnce(&mut MutexGuard<PlayerState>) -> bool
-    {
-        let mut guard = self.state.lock().unwrap();
-        let update = f(&mut guard);
-
-        if update {
-            let observers = self.observers.lock().unwrap();
-
-            guard.update_time = util::now_ms();
-            let state = guard.clone();
-            drop(guard);
-
-            for observer in observers.iter() {
-                observer.send(state.clone()).unwrap();
+            PlayerCommand::Volume(vol) => {
+                self.volume = vol;
             }
         }
     }
-}
 
-impl PlayerState {
-    pub fn status(&self) -> PlayStatus {
-        self.status
+    fn run_onstart(&self) {
+        match self.session.config().onstart {
+            Some(ref program) => util::run_program(program),
+            None => {},
+        };
     }
 
-    pub fn position(&self) -> (u32, i64) {
-        (self.position_ms, self.position_measured_at)
+    fn run_onstop(&self) {
+        match self.session.config().onstop {
+            Some(ref program) => util::run_program(program),
+            None => {},
+        };
     }
 
-    pub fn volume(&self) -> u16 {
-        self.volume
+    fn find_available_alternative<'a>(&self, track: &'a Track) -> Option<Cow<'a, Track>> {
+        if track.available {
+            Some(Cow::Borrowed(track))
+        } else {
+            let alternatives = track.alternatives
+                .iter()
+                .map(|alt_id| {
+                    self.session.metadata().get::<Track>(*alt_id)
+                });
+            let alternatives = future::join_all(alternatives).wait().unwrap();
+
+            alternatives.into_iter().find(|alt| alt.available).map(Cow::Owned)
+        }
     }
 
-    pub fn update_time(&self) -> i64 {
-        self.update_time
-    }
+    fn load_track(&self, track_id: SpotifyId, position: i64) -> Option<Decoder> {
+        let track = self.session.metadata().get::<Track>(track_id).wait().unwrap();
+
+        info!("Loading track \"{}\"", track.name);
+
+        let track = match self.find_available_alternative(&track) {
+            Some(track) => track,
+            None => {
+                warn!("Track \"{}\" is not available", track.name);
+                return None;
+            }
+        };
 
-    pub fn end_of_track(&self) -> bool {
-        self.end_of_track
+        let format = match self.session.config().bitrate {
+            Bitrate::Bitrate96 => FileFormat::OGG_VORBIS_96,
+            Bitrate::Bitrate160 => FileFormat::OGG_VORBIS_160,
+            Bitrate::Bitrate320 => FileFormat::OGG_VORBIS_320,
+        };
+
+        let file_id = match track.files.get(&format) {
+            Some(&file_id) => file_id,
+            None => {
+                warn!("Track \"{}\" is not available in format {:?}", track.name, format);
+                return None;
+            }
+        };
+
+        let key = self.session.audio_key().request(track.id, file_id).wait().unwrap();
+
+        let (open, _) = self.session.audio_file().open(file_id);
+        let encrypted_file = open.wait().unwrap();
+
+        let audio_file = Subfile::new(AudioDecrypt::new(key, encrypted_file), 0xa7);
+        let mut decoder = vorbis::Decoder::new(audio_file).unwrap();
+
+        match vorbis_time_seek_ms(&mut decoder, position) {
+            Ok(_) => (),
+            Err(err) => error!("Vorbis error: {:?}", err),
+        }
+
+        info!("Track \"{}\" loaded", track.name);
+
+        Some(decoder)
     }
 }
+
+#[cfg(not(feature = "with-tremor"))]
+fn vorbis_time_seek_ms<R>(decoder: &mut vorbis::Decoder<R>, ms: i64) -> Result<(), vorbis::VorbisError> where R: Read + Seek {
+    decoder.time_seek(ms as f64 / 1000f64)
+}
+
+#[cfg(feature = "with-tremor")]
+fn vorbis_time_seek_ms<R>(decoder: &mut vorbis::Decoder<R>, ms: i64) -> Result<(), vorbis::VorbisError> where R: Read + Seek {
+    decoder.time_seek(ms)
+}

src/spirc.rs

@@ -1,19 +1,18 @@
-use protobuf::{self, Message, RepeatedField};
-use std::borrow::Cow;
-use futures::{Future, Stream, Sink, Async, Poll};
-use futures::stream::BoxStream;
+use futures::future;
 use futures::sink::BoxSink;
-use futures::sync::mpsc;
+use futures::stream::BoxStream;
+use futures::sync::{oneshot, mpsc};
+use futures::{Future, Stream, Sink, Async, Poll, BoxFuture};
+use protobuf::{self, Message};
 
 use mercury::MercuryError;
-use player::{Player, PlayerState};
+use player::Player;
 use session::Session;
 use util::{now_ms, SpotifyId, SeqGenerator};
 use version;
 
 use protocol;
-pub use protocol::spirc::PlayStatus;
-use protocol::spirc::{MessageType, Frame, DeviceState};
+use protocol::spirc::{PlayStatus, State, MessageType, Frame, DeviceState};
 
 pub struct SpircTask {
     player: Player,
@@ -22,21 +21,12 @@ pub struct SpircTask {
 
     ident: String,
     device: DeviceState,
-
-    repeat: bool,
-    shuffle: bool,
-
-    last_command_ident: String,
-    last_command_msgid: u32,
-
-    tracks: Vec<SpotifyId>,
-    index: u32,
+    state: State,
 
     subscription: BoxStream<Frame, MercuryError>,
     sender: BoxSink<Frame, MercuryError>,
-
-    updates: mpsc::UnboundedReceiver<PlayerState>,
     commands: mpsc::UnboundedReceiver<SpircCommand>,
+    end_of_track: BoxFuture<(), oneshot::Canceled>,
 
     shutdown: bool,
 }
@@ -49,6 +39,17 @@ pub struct Spirc {
     commands: mpsc::UnboundedSender<SpircCommand>,
 }
 
+fn initial_state() -> State {
+    protobuf_init!(protocol::spirc::State::new(), {
+        repeat: false,
+        shuffle: false,
+
+        status: PlayStatus::kPlayStatusStop,
+        position_ms: 0,
+        position_measured_at: 0,
+    })
+}
+
 fn initial_device_state(name: String, volume: u16) -> DeviceState {
     protobuf_init!(DeviceState::new(), {
         sw_version: version::version_string(),
@@ -56,12 +57,10 @@ fn initial_device_state(name: String, volume: u16) -> DeviceState {
         can_play: true,
         volume: volume as u32,
         name: name,
-        error_code: 0,
-        became_active_at: 0,
         capabilities => [
             @{
                 typ: protocol::spirc::CapabilityType::kCanBePlayer,
-                intValue => [0]
+                intValue => [1]
             },
             @{
                 typ: protocol::spirc::CapabilityType::kDeviceType,
@@ -127,8 +126,6 @@ impl Spirc {
             Ok(frame.write_to_bytes().unwrap())
         }));
 
-        let updates = player.observe();
-
         let (cmd_tx, cmd_rx) = mpsc::unbounded();
 
         let volume = 0xFFFF;
@@ -141,21 +138,14 @@ impl Spirc {
             sequence: SeqGenerator::new(1),
 
             ident: ident,
-            device: device,
-
-            repeat: false,
-            shuffle: false,
-
-            last_command_ident: String::new(),
-            last_command_msgid: 0,
 
-            tracks: Vec::new(),
-            index: 0,
+            device: device,
+            state: initial_state(),
 
             subscription: subscription,
             sender: sender,
-            updates: updates,
             commands: cmd_rx,
+            end_of_track: future::empty().boxed(),
 
             shutdown: false,
         };
@@ -164,7 +154,7 @@ impl Spirc {
             commands: cmd_tx,
         };
 
-        task.notify(true, None);
+        task.hello();
 
         (spirc, task)
     }
@@ -192,15 +182,6 @@ impl Future for SpircTask {
                     Async::NotReady => (),
                 }
 
-                match self.updates.poll().unwrap() {
-                    Async::Ready(Some(state)) => {
-                        progress = true;
-                        self.handle_update(state);
-                    }
-                    Async::Ready(None) => panic!("player terminated"),
-                    Async::NotReady => (),
-                }
-
                 match self.commands.poll().unwrap() {
                     Async::Ready(Some(command)) => {
                         progress = true;
@@ -209,6 +190,17 @@ impl Future for SpircTask {
                     Async::Ready(None) => (),
                     Async::NotReady => (),
                 }
+
+                match self.end_of_track.poll() {
+                    Ok(Async::Ready(())) => {
+                        progress = true;
+                        self.handle_end_of_track();
+                    }
+                    Ok(Async::NotReady) => (),
+                    Err(oneshot::Canceled) => {
+                        self.end_of_track = future::empty().boxed()
+                    }
+                }
             }
 
             let poll_sender = self.sender.poll_complete().unwrap();
@@ -219,7 +211,6 @@ impl Future for SpircTask {
             }
 
             if !progress {
-
                 return Ok(Async::NotReady);
             }
         }
@@ -227,24 +218,12 @@ impl Future for SpircTask {
 }
 
 impl SpircTask {
-    fn handle_update(&mut self, player_state: PlayerState) {
-        let end_of_track = player_state.end_of_track();
-        if end_of_track {
-            self.index = (self.index + 1) % self.tracks.len() as u32;
-            let track = self.tracks[self.index as usize];
-            self.player.load(track, true, 0);
-        } else {
-            self.notify_with_player_state(false, None, &player_state);
-        }
-    }
-
     fn handle_command(&mut self, cmd: SpircCommand) {
         match cmd {
             SpircCommand::Shutdown => {
                 CommandSender::new(self, MessageType::kMessageTypeGoodbye).send();
                 self.shutdown = true;
                 self.commands.close();
-                self.updates.close();
             }
         }
     }
@@ -262,142 +241,188 @@ impl SpircTask {
             return;
         }
 
-        if frame.get_recipient().len() > 0 {
-            self.last_command_ident = frame.get_ident().to_owned();
-            self.last_command_msgid = frame.get_seq_nr();
-        }
-
         match frame.get_typ() {
             MessageType::kMessageTypeHello => {
-                self.notify(false, Some(frame.get_ident()));
+                self.notify(Some(frame.get_ident()));
             }
+
             MessageType::kMessageTypeLoad => {
                 if !self.device.get_is_active() {
                     self.device.set_is_active(true);
                     self.device.set_became_active_at(now_ms());
                 }
 
-                self.reload_tracks(&frame);
-                if self.tracks.len() > 0 {
+                self.update_tracks(&frame);
+
+                if self.state.get_track().len() > 0 {
+                    self.state.set_position_ms(frame.get_state().get_position_ms());
+                    self.state.set_position_measured_at(now_ms() as u64);
+
                     let play = frame.get_state().get_status() == PlayStatus::kPlayStatusPlay;
-                    let track = self.tracks[self.index as usize];
-                    let position = frame.get_state().get_position_ms();
-                    self.player.load(track, play, position);
+                    self.load_track(play);
                 } else {
-                    self.notify(false, Some(frame.get_ident()));
+                    self.state.set_status(PlayStatus::kPlayStatusStop);
                 }
+
+                self.notify(None);
             }
+
             MessageType::kMessageTypePlay => {
-                self.player.play();
+                if self.state.get_status() == PlayStatus::kPlayStatusPause {
+                    self.player.play();
+                    self.state.set_status(PlayStatus::kPlayStatusPlay);
+                    self.state.set_position_measured_at(now_ms() as u64);
+                }
+
+                self.notify(None);
             }
+
             MessageType::kMessageTypePause => {
-                self.player.pause();
+                if self.state.get_status() == PlayStatus::kPlayStatusPlay {
+                    self.player.pause();
+                    self.state.set_status(PlayStatus::kPlayStatusPause);
+
+                    let now = now_ms() as u64;
+                    let position = self.state.get_position_ms();
+
+                    let diff = now - self.state.get_position_measured_at();
+
+                    self.state.set_position_ms(position + diff as u32);
+                    self.state.set_position_measured_at(now);
+                }
+
+                self.notify(None);
             }
+
             MessageType::kMessageTypeNext => {
-                self.index = (self.index + 1) % self.tracks.len() as u32;
-                let track = self.tracks[self.index as usize];
-                self.player.load(track, true, 0);
+                let current_index = self.state.get_playing_track_index();
+                let new_index = (current_index + 1) % (self.state.get_track().len() as u32);
+
+                self.state.set_playing_track_index(new_index);
+                self.state.set_position_ms(0);
+                self.state.set_position_measured_at(now_ms() as u64);
+
+                self.load_track(true);
+                self.notify(None);
             }
+
             MessageType::kMessageTypePrev => {
-                self.index = (self.index - 1) % self.tracks.len() as u32;
-                let track = self.tracks[self.index as usize];
-                self.player.load(track, true, 0);
+                // Previous behaves differently based on the position
+                // Under 3s it goes to the previous song
+                // Over 3s it seeks to zero
+                if self.position() < 3000 {
+                    let current_index = self.state.get_playing_track_index();
+                    let new_index = (current_index - 1) % (self.state.get_track().len() as u32);
+
+                    self.state.set_playing_track_index(new_index);
+                    self.state.set_position_ms(0);
+                    self.state.set_position_measured_at(now_ms() as u64);
+
+                    self.load_track(true);
+                } else {
+                    self.state.set_position_ms(0);
+                    self.state.set_position_measured_at(now_ms() as u64);
+                    self.player.seek(0);
+                }
+                self.notify(None);
             }
+
             MessageType::kMessageTypeSeek => {
-                self.player.seek(frame.get_position());
+                let position = frame.get_position();
+
+                self.state.set_position_ms(position);
+                self.state.set_position_measured_at(now_ms() as u64);
+                self.player.seek(position);
+                self.notify(None);
             }
+
             MessageType::kMessageTypeReplace => {
-                self.reload_tracks(&frame);
+                self.update_tracks(&frame);
+                self.notify(None);
             }
+
+            MessageType::kMessageTypeVolume => {
+                let volume = frame.get_volume();
+                self.device.set_volume(volume);
+                self.player.volume(volume as u16);
+                self.notify(None);
+            }
+
             MessageType::kMessageTypeNotify => {
-                if self.device.get_is_active() && frame.get_device_state().get_is_active() {
+                if self.device.get_is_active() &&
+                    frame.get_device_state().get_is_active()
+                {
                     self.device.set_is_active(false);
+                    self.state.set_status(PlayStatus::kPlayStatusStop);
                     self.player.stop();
                 }
             }
-            MessageType::kMessageTypeVolume => {
-                let volume = frame.get_volume();
-                self.player.volume(volume as u16);
-                self.device.set_volume(volume);
-                self.notify(false, None);
-            }
-            MessageType::kMessageTypeGoodbye => (),
+
             _ => (),
         }
     }
 
-    fn reload_tracks(&mut self, ref frame: &protocol::spirc::Frame) {
-        self.index = frame.get_state().get_playing_track_index();
-        self.tracks = frame.get_state()
-                           .get_track()
-                           .iter()
-                           .filter(|track| track.has_gid())
-                           .map(|track| SpotifyId::from_raw(track.get_gid()))
-                           .collect();
+    fn handle_end_of_track(&mut self) {
+        let current_index = self.state.get_playing_track_index();
+        let new_index = (current_index + 1) % (self.state.get_track().len() as u32);
+
+        self.state.set_playing_track_index(new_index);
+        self.state.set_position_ms(0);
+        self.state.set_position_measured_at(now_ms() as u64);
+
+        self.load_track(true);
+        self.notify(None);
     }
 
-    fn notify(&mut self, hello: bool, recipient: Option<&str>) {
-        let mut cs = CommandSender::new(self,
-                                        if hello {
-                                            MessageType::kMessageTypeHello
-                                        } else {
-                                            MessageType::kMessageTypeNotify
-                                        });
-        if let Some(s) = recipient {
-            cs = cs.recipient(&s);
-        }
-        cs.send();
+    fn position(&mut self) -> u32 {
+        let diff = now_ms() as u64 - self.state.get_position_measured_at();
+        self.state.get_position_ms() + diff as u32
     }
 
-    fn notify_with_player_state(&mut self,
-                                hello: bool,
-                                recipient: Option<&str>,
-                                player_state: &PlayerState) {
-        let mut cs = CommandSender::new(self,
-                                        if hello {
-                                            MessageType::kMessageTypeHello
-                                        } else {
-                                            MessageType::kMessageTypeNotify
-                                        })
-                         .player_state(player_state);
-        if let Some(s) = recipient {
-            cs = cs.recipient(&s);
-        }
-        cs.send();
+    fn update_tracks(&mut self, ref frame: &protocol::spirc::Frame) {
+        let index = frame.get_state().get_playing_track_index();
+        let tracks = frame.get_state().get_track();
+
+        self.state.set_playing_track_index(index);
+        self.state.set_track(tracks.into_iter().map(Clone::clone).collect());
     }
 
-    fn spirc_state(&self, player_state: &PlayerState) -> protocol::spirc::State {
-        let (position_ms, position_measured_at) = player_state.position();
+    fn load_track(&mut self, play: bool) {
+        let index = self.state.get_playing_track_index();
+        let track = {
+            let gid = self.state.get_track()[index as usize].get_gid();
+            SpotifyId::from_raw(gid)
+        };
 
-        protobuf_init!(protocol::spirc::State::new(), {
-            status: player_state.status(),
-            position_ms: position_ms,
-            position_measured_at: position_measured_at as u64,
+        let position = self.state.get_position_ms();
 
-            playing_track_index: self.index,
-            track: self.tracks.iter().map(|track| {
-                protobuf_init!(protocol::spirc::TrackRef::new(), {
-                    gid: track.to_raw().to_vec()
-                })
-            }).collect(),
+        let end_of_track = self.player.load(track, play, position);
 
-            shuffle: self.shuffle,
-            repeat: self.repeat,
+        self.state.set_status(PlayStatus::kPlayStatusPlay);
+        self.end_of_track = end_of_track.boxed();
+    }
 
-            playing_from_fallback: true,
+    fn hello(&mut self) {
+        CommandSender::new(self, MessageType::kMessageTypeHello).send();
+    }
 
-            last_command_ident: self.last_command_ident.clone(),
-            last_command_msgid: self.last_command_msgid
-        })
+    fn notify(&mut self, recipient: Option<&str>) {
+        let mut cs = CommandSender::new(self, MessageType::kMessageTypeNotify);
+        if let Some(s) = recipient {
+            cs = cs.recipient(&s);
+        }
+        cs.send();
+    }
+
+    fn spirc_state(&self) -> protocol::spirc::State {
+        self.state.clone()
     }
 }
 
 struct CommandSender<'a> {
     spirc: &'a mut SpircTask,
     cmd: MessageType,
-    recipient: Option<&'a str>,
-    player_state: Option<&'a PlayerState>,
-    state: Option<protocol::spirc::State>,
+    recipient: Option<String>,
 }
 
 impl<'a> CommandSender<'a> {
@@ -406,64 +431,34 @@ impl<'a> CommandSender<'a> {
             spirc: spirc,
             cmd: cmd,
             recipient: None,
-            player_state: None,
-            state: None,
         }
     }
 
-    fn recipient(mut self, r: &'a str) -> CommandSender {
-        self.recipient = Some(r);
-        self
-    }
-
-    fn player_state(mut self, s: &'a PlayerState) -> CommandSender {
-        self.player_state = Some(s);
-        self
-    }
-
-    #[allow(dead_code)]
-    fn state(mut self, s: protocol::spirc::State) -> CommandSender<'a> {
-        self.state = Some(s);
+    fn recipient(mut self, r: &str) -> CommandSender<'a> {
+        self.recipient = Some(r.to_owned());
         self
     }
 
     fn send(self) {
-        let state = self.player_state.map_or_else(|| {
-            Cow::Owned(self.spirc.player.state())
-        }, |s| {
-            Cow::Borrowed(s)
-        });
-
         let mut frame = protobuf_init!(Frame::new(), {
             version: 1,
             ident: self.spirc.ident.clone(),
             protocol_version: "2.0.0",
             seq_nr: self.spirc.sequence.get(),
             typ: self.cmd,
-            recipient: RepeatedField::from_vec(
-                self.recipient.map(|r| vec![r.to_owned()] ).unwrap_or(vec![])
-                ),
             device_state: self.spirc.device.clone(),
-            state_update_id: state.update_time()
+            state_update_id: now_ms(),
         });
 
+        if let Some(recipient) = self.recipient {
+            frame.mut_recipient().push(recipient.to_owned());
+        }
+
         if self.spirc.device.get_is_active() {
-            frame.set_state(self.spirc.spirc_state(&state));
+            frame.set_state(self.spirc.spirc_state());
         }
 
         let ready = self.spirc.sender.start_send(frame).unwrap().is_ready();
         assert!(ready);
     }
 }
-
-#[allow(dead_code)]
-fn track_ids_to_state<I: Iterator<Item = SpotifyId>>(track_ids: I) -> protocol::spirc::State {
-    let tracks: Vec<protocol::spirc::TrackRef> =
-        track_ids.map(|i| {
-                     protobuf_init!(protocol::spirc::TrackRef::new(), { gid: i.to_raw().to_vec()})
-                 })
-                 .collect();
-    protobuf_init!(protocol::spirc::State::new(), {
-                    track: RepeatedField::from_vec(tracks)
-                })
-}