subsonic-tui/internal/playback/controller.go

package playback

import (
	"io"
	"time"

	"git.dayanhub.com/sagi/subsonic-tui/internal/client"
	"github.com/delucks/go-subsonic"
	"github.com/gopxl/beep/v2"
	"github.com/gopxl/beep/v2/mp3"
	"github.com/gopxl/beep/v2/speaker"
)

type PlaybackState int

const (
	PlaybackStateStopped = iota
	PlaybackStatePaused
	PlaybackStatePlaying
)

type Controller struct {
	client          *client.Client
	stream          beep.StreamSeekCloser
	song            *subsonic.Child
	songElapsedFunc func(song *subsonic.Child, elapsed time.Duration)
	initialFormat   *beep.Format
	currentFormat   *beep.Format
	position        float64
	closeChan       chan bool
	songEndedChan   chan bool
	songEndedFunc   func(song *subsonic.Child)
	ctrl            *beep.Ctrl
	desktopPlayback DesktopPlayback
	queue           *queue
	playbackState   PlaybackState
}

func NewController(client *client.Client) *Controller {
	controller := &Controller{
		client:        client,
		closeChan:     make(chan bool),
		songEndedChan: make(chan bool),
		playbackState: PlaybackStateStopped,
		queue:         newQueue(),
	}
	controller.desktopPlayback = desktopPlayer(controller)
	controller.desktopPlayback.Start()

	go controller.playbackTicker()

	return controller
}

func (c *Controller) State() PlaybackState {
	return c.playbackState
}

func (c *Controller) Play(song *subsonic.Child) {
	if song == nil {
		return
	}

	r, err := c.client.Stream(song.ID)
	if err != nil {
		c.Stop()

		return
	}

	c.Stream(r, song)
}

func (c *Controller) Next() {
	song := c.queue.Next()
	if song != nil {
		c.Play(song)
	}
}

func (c *Controller) AddToQueue(songs []*subsonic.Child) {
	shouldPlay := c.queue.Add(songs...)
	if shouldPlay {
		c.Play(c.queue.GetCurrentSong())
	}

	c.desktopPlayback.OnPlaylistChanged()
}

func (c *Controller) GetQueuePosition() int {
	return c.queue.GetPosition()
}

func (c *Controller) GetCurrentSong() *subsonic.Child {
	return c.queue.GetCurrentSong()
}

func (c *Controller) SetQueue(songs []*subsonic.Child) {
	c.queue.Clear()
	c.Stop()
	c.queue.Set(songs)
	c.Play(c.queue.GetCurrentSong())
	c.desktopPlayback.OnPlaylistChanged()
}

func (c *Controller) SetQueuePosition(position int) {
	s := c.queue.SetPosition(position)
	c.Play(s)
}

func (c *Controller) Prev() {
	song := c.queue.Prev()
	if song != nil {
		c.Play(song)
	}
}

func (c *Controller) GetQueue() []*subsonic.Child {
	return c.queue.Get()
}

func (c *Controller) ClearQueue() {
	c.Stop()
	c.queue.Clear()
	c.desktopPlayback.OnPlayPause()
	c.desktopPlayback.OnSongChanged()
	c.desktopPlayback.OnPlaylistChanged()
}

func (c *Controller) SetSongElapsedFunc(f func(sing *subsonic.Child, elapsed time.Duration)) {
	c.songElapsedFunc = f
}

func (c *Controller) SetSongEndedFunc(f func(song *subsonic.Child)) {
	c.songEndedFunc = f
}

func (c *Controller) Close() error {
	c.Stop()
	c.closeChan <- true

	return nil
}

func (c *Controller) TogglePlayPause() {
	if c.playbackState != PlaybackStateStopped {
		c.ctrl.Paused = !c.ctrl.Paused
		if c.ctrl.Paused {
			c.playbackState = PlaybackStatePaused
		} else {
			c.playbackState = PlaybackStatePlaying
		}
	}

	c.desktopPlayback.OnPlayPause()
}

func (c *Controller) Stop() {
	if c.ctrl == nil {
		return
	}

	speaker.Clear()

	c.ctrl.Paused = true
	c.playbackState = PlaybackStateStopped
	c.ctrl = nil
	c.stream = nil

	c.songElapsedFunc(c.song, time.Duration(0))

	c.song = nil
	c.position = 0
	c.desktopPlayback.OnPlayPause()
	c.desktopPlayback.OnPlaylistChanged()
}

func (c *Controller) playbackTicker() {
	for {
		select {
		case <-c.closeChan:
			return
		case <-c.songEndedChan:
			c.Stop()
			c.Next()
		default:
			if c.playbackState == PlaybackStatePlaying && c.song != nil {
				if c.stream != nil {
					pos := c.stream.Position()
					elapsed := c.currentFormat.SampleRate.D(pos).Round(time.Second)
					c.position = elapsed.Seconds()
					c.songElapsedFunc(c.song, elapsed)
					c.desktopPlayback.OnPositionChanged(int(c.position))
				}
			}
		}
		time.Sleep(time.Second)
	}
}

func (c *Controller) Stream(reader io.Reader, song *subsonic.Child) {
	c.Stop()
	// Ensure artwork cache...
	_, _ = c.client.GetCoverArt(song.CoverArt)

	readerCloser := io.NopCloser(reader)
	decodedMp3, format, err := mp3.Decode(readerCloser)
	decodedMp3.Position()

	if err != nil {
		panic("mp3.NewDecoder failed: " + err.Error())
	}

	if c.initialFormat == nil {
		c.initialFormat = &format
	}

	c.currentFormat = &format

	var stream beep.Streamer = decodedMp3
	if err = speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/10)); err != nil {
		stream = beep.Resample(3, format.SampleRate, c.initialFormat.SampleRate, decodedMp3)
	}

	c.stream = decodedMp3
	c.song = song

	ctrl := &beep.Ctrl{Streamer: stream}
	c.ctrl = ctrl
	c.playbackState = PlaybackStatePlaying

	speaker.Play(beep.Seq(ctrl, beep.Callback(func() {
		c.songEndedFunc(song)
		c.songEndedChan <- true
	})))
	c.desktopPlayback.OnSongChanged()
	c.desktopPlayback.OnPlayPause()
}