const VoiceWebSocket = require('./VoiceWebSocket');
const VoiceUDP = require('./VoiceUDPClient');
const Constants = require('../../util/Constants');
const AudioPlayer = require('./player/AudioPlayer');
const VoiceReceiver = require('./receiver/VoiceReceiver');
const EventEmitter = require('events').EventEmitter;
const fs = require('fs');

/**
 * Represents a connection to a Voice Channel in Discord.
 * ```js
 * // obtained using:
 * voiceChannel.join().then(connection => {
 *
 * });
 * ```
 * @extends {EventEmitter}
 */
class VoiceConnection extends EventEmitter {

  constructor(pendingConnection) {
    super();
    /**
     * The Voice Manager that instantiated this connection
     * @type {ClientVoiceManager}
     */
    this.voiceManager = pendingConnection.voiceManager;

    /**
     * The voice channel this connection is currently serving
     * @type {VoiceChannel}
     */
    this.channel = pendingConnection.channel;

    this.receivers = [];

    /**
     * The authentication data needed to connect to the voice server
     * @type {object}
     */
    this.authentication = pendingConnection.data;

    this.player = new AudioPlayer(this);

    this.player.on('debug', m => {
      this.emit('debug', `audio player - ${m}`);
    });

    this.player.on('error', e => {
      this.emit('warn', e);
      this.player.cleanup();
    });

    this.ssrcMap = new Map();

    /**
     * Object that wraps contains the `ws` and `udp` sockets of this voice connection
     * @type {object}
     */
    this.sockets = {};
    this.connect();
  }

  setSpeaking(value) {
    if (this.speaking === value) return;
    this.speaking = value;
    this.sockets.ws.sendPacket({
      op: Constants.VoiceOPCodes.SPEAKING,
      d: {
        speaking: true,
        delay: 0,
      },
    })
    .catch(e => {
      this.emit('debug', e);
    });
  }

  disconnect() {
    this.emit('closing');
    this.voiceManager.client.ws.send({
      op: Constants.OPCodes.VOICE_STATE_UPDATE,
      d: {
        guild_id: this.channel.guild.id,
        channel_id: null,
        self_mute: false,
        self_deaf: false,
      },
    });
    this.emit('disconnected');
  }

  connect() {
    if (this.sockets.ws) {
      throw new Error('There is already an existing WebSocket connection!');
    }
    if (this.sockets.udp) {
      throw new Error('There is already an existing UDP connection!');
    }
    this.sockets.ws = new VoiceWebSocket(this);
    this.sockets.udp = new VoiceUDP(this);
    this.sockets.ws.on('error', e => this.emit('error', e));
    this.sockets.udp.on('error', e => this.emit('error', e));
    this.sockets.ws.once('ready', d => {
      this.authentication.port = d.port;
      this.authentication.ssrc = d.ssrc;
      this.sockets.udp.findEndpointAddress()
        .then(address => {
          this.sockets.udp.createUDPSocket(address);
        })
        .catch(e => this.emit('error', e));
    });
    this.sockets.ws.once('sessionDescription', (mode, secret) => {
      this.authentication.encryptionMode = mode;
      this.authentication.secretKey = secret;
      this.emit('ready');
    });
    this.sockets.ws.on('speaking', data => {
      const guild = this.channel.guild;
      const user = this.voiceManager.client.users.get(data.user_id);
      this.ssrcMap.set(+data.ssrc, user);
      if (!data.speaking) {
        for (const receiver of this.receivers) {
          const opusStream = receiver.opusStreams.get(user.id);
          const pcmStream = receiver.pcmStreams.get(user.id);
          if (opusStream) {
            opusStream.push(null);
            opusStream.open = false;
            receiver.opusStreams.delete(user.id);
          }
          if (pcmStream) {
            pcmStream.push(null);
            pcmStream.open = false;
            receiver.pcmStreams.delete(user.id);
          }
        }
      }
      /**
       * Emitted whenever a user starts/stops speaking
       * @event VoiceConnection#speaking
       * @param {User} user The user that has started/stopped speaking
       * @param {boolean} speaking Whether or not the user is speaking
       */
      if (this.ready) this.emit('speaking', user, data.speaking);
      guild._memberSpeakUpdate(data.user_id, data.speaking);
    });
  }

  playFile(file, options) {
    return this.playStream(fs.createReadStream(file), options);
  }

  playStream(stream, { seek = 0, volume = 1, passes = 1 } = {}) {
    const options = { seek, volume, passes };
    return this.player.playUnknownStream(stream, options);
  }

  playConvertedStream(stream, { seek = 0, volume = 1, passes = 1 } = {}) {
    const options = { seek, volume, passes };
    return this.player.playPCMStream(stream, options);
  }

  createReceiver() {
    const receiver = new VoiceReceiver(this);
    this.receivers.push(receiver);
    return receiver;
  }

}

module.exports = VoiceConnection;