1 files changed, 158 insertions, 0 deletions

diff --git a/music/playqueue.go b/music/playqueue.go
new file mode 100644
index 0000000..d6182ed
--- /dev/null
+++ b/music/playqueue.go
@@ -0,0 +1,158 @@
+package music
+
+import (
+        "fmt"
+        "path/filepath"
+        "time"
+
+        "github.com/delucks/go-subsonic"
+        "github.com/faiface/beep"
+        "github.com/faiface/beep/flac"
+        "github.com/faiface/beep/mp3"
+        "github.com/faiface/beep/speaker"
+        "github.com/faiface/beep/vorbis"
+)
+
+type Queue struct {
+        songs    []*subsonic.Child
+        isPaused bool
+
+        sub                *subsonic.Client
+        speakerInitialized bool
+        oldSampleRate      beep.SampleRate
+        onChange           func(newSong *subsonic.Child, isPaused bool)
+}
+
+func NewQueue(client *subsonic.Client) *Queue {
+        return &Queue{
+                sub:                client,
+                speakerInitialized: false,
+        }
+}
+
+func (q *Queue) SetClient(client *subsonic.Client) {
+        q.Clear()
+        q.sub = client
+}
+
+func (p *Queue) GetSongs() []*subsonic.Child {
+        return p.songs
+}
+
+func (q *Queue) Append(s *subsonic.Child) {
+        q.songs = append(q.songs, s)
+}
+
+func (q *Queue) Clear() {
+        q.songs = make([]*subsonic.Child, 0)
+        speaker.Clear()
+}
+
+func (q *Queue) PlaySong(s *subsonic.Child) error {
+        rc, err := Download2(q.sub, s.ID)
+        if err != nil {
+                return err
+        }
+
+        var ssc beep.StreamSeekCloser
+        var format beep.Format
+
+        switch filepath.Ext(s.Path) {
+        case ".mp3":
+                ssc, format, err = mp3.Decode(rc)
+        case ".ogg":
+                fallthrough
+        case ".oga":
+                ssc, format, err = vorbis.Decode(rc)
+        case ".flac":
+                ssc, format, err = flac.Decode(rc)
+        default:
+                return fmt.Errorf("unknown file type: %s", filepath.Ext(s.Path))
+        }
+
+        if err != nil {
+                return err
+        }
+
+        streamer, err := q.setupSpeaker(ssc, format)
+        if err != nil {
+                return err
+        }
+        speaker.Clear()
+        speaker.Play(beep.Seq(streamer, beep.Callback(func() { go q.Next() })))
+
+        if q.onChange != nil {
+                q.onChange(s, false)
+        }
+
+        return nil
+}
+
+func (q *Queue) Play() error {
+        if len(q.songs) == 0 {
+                return fmt.Errorf("the queue is empty")
+        }
+
+        s := q.songs[0]
+        q.PlaySong(s)
+
+        return nil
+}
+
+func (q *Queue) Next() error {
+        q.Stop()
+
+        if len(q.songs) == 0 {
+                return nil
+        }
+
+        q.songs = q.songs[1:]
+
+        if len(q.songs) == 0 {
+                if q.onChange != nil {
+                        q.onChange(nil, false)
+                }
+                return nil
+        }
+
+        return q.Play()
+}
+
+func (q *Queue) Stop() {
+        speaker.Clear()
+}
+
+func (q *Queue) SetOnChangeCallback(f func(newSong *subsonic.Child, isPlaying bool)) {
+        q.onChange = f
+}
+
+func (q *Queue) TogglePause() {
+        if q.isPaused {
+                speaker.Unlock()
+        } else {
+                speaker.Lock()
+        }
+
+        q.isPaused = !q.isPaused
+
+        if q.onChange != nil {
+                if len(q.songs) > 0 {
+                        q.onChange(q.songs[0], q.isPaused)
+                }
+        }
+}
+
+func (p *Queue) setupSpeaker(s beep.Streamer, format beep.Format) (beep.Streamer, error) {
+        if !p.speakerInitialized {
+                err := speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/10))
+                if err != nil {
+                        return nil, fmt.Errorf("speaker.Init: %v", err)
+                }
+                p.speakerInitialized = true
+                p.oldSampleRate = format.SampleRate
+
+                return s, nil
+        } else {
+                return beep.Resample(4, format.SampleRate, p.oldSampleRate, s), nil
+        }
+}