dndmusicbot/events.go

package main

import (
	"context"
	"dndmusicbot/ffmpeg"
	discordspeaker "dndmusicbot/speaker"
	"encoding/json"
	"fmt"
	"log"
	"net/url"
	"os"
	"time"

	"github.com/faiface/beep/mp3"
	"github.com/google/uuid"
	"github.com/kataras/go-events"
	"golang.org/x/time/rate"
)

type SongInfo struct {
	Playlist     uuid.UUID `json:"playlist"`
	PlaylistName string    `json:"playlistname"`
	Title        string    `json:"current"`
	Channel      string    `json:"channel"`
	Position     int       `json:"position"`
	Length       int       `json:"len"`
	Pause        bool      `json:"pause"`
	Song         string    `json:"song"`
}

var l = rate.Sometimes{Interval: 1 * time.Second}

func init() {
	log.Println("events.go loading...")
	app.events = events.New()

	app.events.On("load_playlist", app.loadPlaylist)
	app.events.On("add_playlist", app.addPlaylist)

	app.events.On("preload_song", app.preloadSong)
	app.events.On("song_over", app.songOver)
	//app.events.On("song_position", app.songPosition)
	app.events.On("ambiance_play", app.ambiancePlay)
	app.events.On("ambiance_stop", app.ambianceStop)

	app.events.On("stop", app.stop)
	app.events.On("next", app.nextSong)
	app.events.On("prev", app.prevSong)

	//app.events.On("tick", app.checkQueue)
	app.events.On("tick", app.songPosition)
	app.events.On("tick", app.checkTimeleft)
}

func (app *App) songInfoEvent(event string) map[string]interface{} {
	msg := make(map[string]interface{})
	msg["event"] = event

	var title, channel string

	switch current := app.queue.Current().(type) {
	case *ffmpeg.PCM:
		title = current.Player.Title
		channel = current.Player.Channel
	}

	var plid uuid.UUID
	var pltitle string

	if app.playlist != nil {
		plid = app.playlist.Id
		pltitle = app.playlist.Title
	}

	var song string

	if app.active != nil && len(app.active) > 0 {
		song = app.active[app.plidx]
	}

	msg["payload"] = SongInfo{
		Playlist:     plid,
		PlaylistName: pltitle,
		Title:        title,
		Channel:      channel,
		Position:     app.queue.Position(),
		Length:       app.queue.Len(),
		Pause:        !app.queue.IsPlaying(),
		Song:         song,
	}

	return msg
}

func (app *App) ambiancePlay(payload ...interface{}) {
	if !(len(payload) > 0) {
		log.Println("ambiance_play called without a payload.")
		return
	}

	var fn string
	switch data := payload[0].(type) {
	case json.RawMessage:
		var err error
		err = json.Unmarshal(data, &fn)
		if err != nil {
			log.Println(err)
			return
		}
	default:
		log.Println("loadPlaylist called with invalid payload.")
		return
	}

	f, err := os.Open(fmt.Sprintf("./ambiance/%s.mp3", fn))
	if err != nil {
		log.Fatal(err)
	}

	play, _, err := mp3.Decode(f)
	if err != nil {
		log.Fatal(err)
	}

	discordspeaker.Pause(false)
	discordspeaker.Lock()
	if app.ambiance.IsPlaying() {
		app.ambiance.Reset()
	}
	app.ambiance.Add(play)
	discordspeaker.Unlock()

	msg := make(map[string]interface{})
	out := make(map[string]interface{})

	app.curamb = fn

	msg["event"] = "ambiance_play"
	out["type"] = fn
	msg["payload"] = out
	ws_msg <- msg
}

func (app *App) ambianceStop(payload ...interface{}) {
	log.Println("Stopping ambiance")
	discordspeaker.Lock()
	app.ambiance.Reset()
	discordspeaker.Unlock()

	msg := make(map[string]interface{})
	msg["event"] = "ambiance_stop"
	ws_msg <- msg

}

func (app *App) songPosition(payload ...interface{}) {
	if !app.queue.IsPlaying() {
		return
	}

	l.Do(func() {
		msg := make(map[string]interface{})
		out := make(map[string]interface{})

		msg["event"] = "song_position"
		if app.queue != nil {
			out["len"] = app.queue.Len()
			out["position"] = app.queue.Position()
		}

		msg["payload"] = out
		ws_msg <- msg
	})

}

func (app *App) checkQueue(payload ...interface{}) {
	if !app.queue.IsPlaying() {
		return
	}

	// This needs some tweaking.
	if app.queue.playing && !app.next && app.queue.QLen() == 0 {

		log.Println("Queue is 0. It should never be 0..")
		ctx, cancel := context.WithTimeout(context.Background(), 4*time.Second)
		defer cancel()

		select {
		case <-ctx.Done():
			if app.queue.QLen() == 0 {
				log.Println("Queue is still 0. Queueing a song.")
				app.events.Emit("next")
			}
			log.Println("Seems queue is filled, doing nothing.")
		}
	}
}

func (app *App) checkTimeleft(payload ...interface{}) {
	if !app.queue.IsPlaying() {
		return
	}
	timeleft := app.queue.Len() - app.queue.Position()
	if timeleft <= 10000 && timeleft > 0 && !app.next {
		app.events.Emit("preload_song")
	}
}

func (app *App) songOver(payload ...interface{}) {
	log.Println("song_over event received")

	msg := app.songInfoEvent("song_info")
	ws_msg <- msg

	app.next = false
}

func (app *App) stop(payload ...interface{}) {
	log.Println("stop event received")
	discordspeaker.Lock()
	app.queue.Reset()
	discordspeaker.Unlock()

	msg := make(map[string]interface{})
	msg["event"] = "stop"

	ws_msg <- msg

}

func (app *App) prevSong(payload ...interface{}) {
	log.Println("prev_song event received")
	song := app.GetPrevSong(app.active)
	f, err := ffmpeg.NewPCM(song, sampleRate, channels)
	if err != nil {
		log.Println("Unable to start new ffmpeg")
		return
	}

	discordspeaker.Lock()
	app.queue.Reset()
	app.queue.Add(f)
	discordspeaker.Unlock()

	msg := app.songInfoEvent("song_info")
	ws_msg <- msg
}

func (app *App) nextSong(payload ...interface{}) {
	log.Println("next_song event received")
	song := app.GetNextSong(app.active)
	f, err := ffmpeg.NewPCM(song, sampleRate, channels)
	if err != nil {
		log.Println("Unable to start new ffmpeg")
		return
	}

	for {
		time.Sleep(1 * time.Second)
		if app.queue.QLen() == 0 {
			log.Println("retrying...")
			song = app.GetSong(app.active)
		} else {
			break
		}
	}

	discordspeaker.Lock()
	app.queue.Reset()
	app.queue.Add(f)
	discordspeaker.Unlock()

	msg := app.songInfoEvent("song_info")
	ws_msg <- msg
}

func (app *App) addPlaylist(payload ...interface{}) {
	if !(len(payload) > 0) {
		log.Println("addPlaylist called without a payload.")
		return
	}

	log.Println("add_playlist event received")

	var data map[string]string
	switch js := payload[0].(type) {
	case json.RawMessage:
		json.Unmarshal(js, &data)
	default:
		log.Println("newPlaylist called with invalid payload.")
		return
	}

	plurl, ok := data["url"]
	if !ok {
		log.Println("addPlaylist without url")
		return
	}
	pltitle, ok := data["title"]
	if !ok {
		log.Println("addPlaylist without title")
		return
	}

	pl, err := url.Parse(plurl)
	if err != nil {
		log.Println("addPlaylist invalid url")
		return
	}

	plid := pl.Query().Get("list")
	if plid == "" {
		log.Println("addPlaylist missing list in url")
		return
	}

	_, err = app.Playlist(plid)
	if err != nil {
		log.Println("Error getting youtube playlist info,", plid)
	}

	id, err := app.AddPlaylist(pltitle, plid)
	if err != nil {
		log.Println("Error getting youtube playlist info,", plid)
	}

	msg := make(map[string]interface{})

	msg["event"] = "new_playlist"
	msg["payload"] = map[string]string{"url": id.String(), "title": pltitle}

	ws_msg <- msg
}

func (app *App) loadPlaylist(payload ...interface{}) {
	log.Println("load_playlist event received")

	if !(len(payload) > 0) {
		log.Println("loadPlaylist called without a payload.")
		return
	}

	var id uuid.UUID
	switch data := payload[0].(type) {
	case json.RawMessage:
		var err error
		var tmp string

		json.Unmarshal(data, &tmp)
		id, err = uuid.Parse(tmp)
		if err != nil {
			log.Println("Unable to parse UUID,", err)
		}
	case uuid.UUID:
		id = data
	default:
		log.Println("loadPlaylist called with invalid payload.")
		return
	}

	log.Println("Loading new playlist: ", id)
	pl, err := app.GetPlaylist(id)
	if err != nil {
		log.Println("Unable to find playlist with id,", id)
		return
	}

	app.plm.Lock()
	app.playlist = pl
	app.plm.Unlock()

	app.next = true
	discordspeaker.Pause(false)

	list, err := app.Playlist(pl.Url)
	if err != nil {
		log.Println("Error getting playlist info,", id)
		return
	}

	list, err = ShufflePlaylist(list)
	if err != nil {
		log.Println("Unable to shuffle playlist")
		return
	}

	app.active = list

	song := app.GetNextSong(list)
	f, err := ffmpeg.NewPCM(song, sampleRate, channels)
	if err != nil {
		log.Println("Unable to start new ffmpeg")
		return
	}

	discordspeaker.Lock()
	app.queue.Reset()
	app.queue.Add(f)
	discordspeaker.Unlock()

	app.next = false

	msg := app.songInfoEvent("song_info")
	ws_msg <- msg
	log.Println("Added song", song)
}

func (app *App) preloadSong(payload ...interface{}) {
	log.Println("preload_song event received")
	app.next = true
	discordspeaker.Pause(false)

	var song string
	switch current := app.queue.Current().(type) {
	case *ffmpeg.PCM:
		for {
			song = app.GetNextSong(app.active)
			if current.Uri != song {
				break
			}
			log.Println("Got same song, try again!")
		}
	default:
		song = app.GetNextSong(app.active)
	}

	f, err := ffmpeg.NewPCM(song, sampleRate, channels)
	if err != nil {
		log.Fatal(err)
	}

	discordspeaker.Lock()
	app.queue.Add(f)
	discordspeaker.Unlock()

	log.Println("Added song.", song)
}