dndmusicbot/queue.go

package main

import (
	"log"

	"github.com/faiface/beep"
	"github.com/kataras/go-events"

	discordspeaker "dndmusicbot/speaker"
)

type Ambiance struct {
	Type string
	URL  string
}

func init() {
	app.ambiance = new(Queue)
	app.ambiance.Events = app.events
	discordspeaker.Play(app.ambiance)

	app.queue = new(Queue)
	app.queue.Events = app.events
	discordspeaker.Play(app.queue)

	log.Println("queue.go done.")
}

type Queue struct {
	streamers []beep.StreamSeekCloser
	Events    events.EventEmmiter
	playing   bool
}

func (q Queue) IsPlaying() bool {
	return q.playing
}

func (q *Queue) Add(streamers ...beep.StreamSeekCloser) {
	q.playing = true
	q.streamers = append(q.streamers, streamers...)
}

func (q Queue) QLen() int {
	return len(q.streamers)
}

func (q Queue) Len() int {
	if len(q.streamers) > 0 {
		return q.streamers[0].Len()
	} else {
		return 0
	}
}

func (q Queue) Current() beep.StreamSeekCloser {
	if len(q.streamers) > 0 {
		return q.streamers[0]
	} else {
		return nil
	}
}

func (q *Queue) Reset() {
	q.playing = false
	for _, stream := range q.streamers {
		stream.Close()
	}
	q.streamers = nil
}

func (q *Queue) Stream(samples [][2]float64) (n int, ok bool) {
	// We use the filled variable to track how many samples we've
	// successfully filled already. We loop until all samples are filled.
	filled := 0

	for filled < len(samples) {
		// There are no streamers in the queue, so we stream silence.
		if len(q.streamers) == 0 {
			for i := range samples[filled:] {
				samples[i][0] = 0
				samples[i][1] = 0
			}
			break
		}

		// We stream from the first streamer in the queue.
		n, ok := q.streamers[0].Stream(samples[filled:])
		// If it's drained, we pop it from the queue, thus continuing with
		// the next streamer.
		if !ok {
			q.streamers = q.streamers[1:]
			q.Events.Emit("song_over", nil)
		}
		// We update the number of filled samples.
		filled += n
	}
	return len(samples), true
}

func (q *Queue) Err() error {
	return nil
}

func (q *Queue) Position() int {
	if len(q.streamers) > 0 {
		return q.streamers[0].Position()
	} else {
		return 0
	}
}