dndmusicbot/events.go

package main

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

	"github.com/faiface/beep"
	"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,omitempty"`
	PlaylistName string    `json:"playlistname,omitempty"`
	Title        string    `json:"current,omitempty"`
	Channel      string    `json:"channel,omitempty"`
	Position     int       `json:"position"`
	Length       int       `json:"len,omitempty"`
	Pause        bool      `json:"pause"`
	Song         string    `json:"song,omitempty"`
}

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.songInfo)
	app.events.On("song_start", app.songInfo)
	//app.events.On("song_position", app.songPosition)

	app.events.On("ambiance_play", app.ambiancePlay)
	app.events.On("ambiance_stop", app.ambianceStop)
	app.events.On("ambiance_add", app.ambianceAdd)

	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

	msg["payload"] = SongInfo{
		Playlist:     app.queue.Current().Playlist.Id,
		PlaylistName: app.queue.Current().Playlist.Title,
		Title:        app.queue.Current().Title,
		Channel:      app.queue.Current().Channel,
		Position:     0,
		Length:       app.queue.Len(),
		Pause:        !app.queue.IsPlaying(),
		Song:         app.queue.Current().VideoID,
	}

	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()
	app.ambiance.Clear()
	loop := beep.Loop(-1, play)
	app.ambiance.Add(loop)
	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.Clear()
	discordspeaker.Unlock()

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

}

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

	log.Println("ambiance_add 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
	}

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

	err := ytdl.DownloadAmbiance(amburl, ambtitle)
	if err != nil {
		log.Println(err)
		return
	}

	msg := make(map[string]interface{})
	out := make(map[string]interface{})
	msg["event"] = "ambiance_add"
	out["type"] = ambtitle
	msg["payload"] = out
	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"
		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) songInfo(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")

	app.queue.Prev()

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

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

	app.queue.Next()

	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
	}

	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.queue.Reset()

	go func() {
		for _, vid := range list {
			ytinfo, err := app.Video(vid)
			if err != nil {
				log.Println(err)
				continue
			}

			_, yt, err := app.cache.GetOrCreateBytes(vid+".txt", func() ([]byte, error) {
				uri, err := ytdl.NewYTdl(vid)
				if err != nil {
					return nil, err
				}
				return uri, nil
			})

			ff, err := ffmpeg.NewPCM(string(yt), sampleRate, channels)
			if err != nil {
				log.Println(err)
				continue
			}

			song := &Song{
				Title:    ytinfo.Title,
				Channel:  ytinfo.Channel,
				VideoID:  vid,
				Length:   ytinfo.Len,
				PCM:      ff,
				Playlist: *pl,
				DLuri:    string(yt),
			}
			app.queue.Add(song)
		}
	}()
}

func (app *App) preloadSong(payload ...interface{}) {
	app.queue.Preload()
}