const _ = require('underscore');
const Peer = require('./Peer.js');
const debug = require('debug')('peer-calls:peer');
const dispatcher = require('../dispatcher/dispatcher.js');
const notify = require('../action/notify.js');

let peers = {};

/**
 * @param {Socket} socket
 * @param {User} user
 * @param {String} user.id
 * @param {Boolean} [initiator=false]
 * @param {MediaStream} [stream]
 */
function create({ socket, user, initiator, stream }) {
  debug('create peer: %s', user.id);
  notify.warn('Connecting to peer...');

  if (peers[user.id]) {
    notify.info('Cleaning up old connection...');
    destroy(user.id);
  }

  let peer = peers[user.id] = Peer.init({
    initiator: '/#' + socket.id === initiator,
    stream,
    config: {
      iceServers: [{
        url: 'stun:23.21.150.121',
        urls: 'stun:23.21.150.121'
      }, {
        url: 'turn:numb.viagenie.ca',
        credential: 'muazkh',
        username: 'webrtc@live.com'
      }]
    }
  });

  peer.once('error', err => {
    debug('peer: %s, error %s', user.id, err.stack);
    notify.error('A peer connection error occurred');
    destroy(user.id);
  });

  peer.on('signal', signal => {
    debug('peer: %s, signal: %o', user.id, signal);

    let payload = { userId: user.id, signal };
    socket.emit('signal', payload);
  });

  peer.once('connect', () => {
    debug('peer: %s, connect', user.id);
    notify.warn('Peer connection established');
    dispatcher.dispatch({ type: 'play' });
  });

  peer.on('stream', stream => {
    debug('peer: %s, stream', user.id);
    dispatcher.dispatch({
      type: 'add-stream',
      userId: user.id,
      stream
    });
  });

  peer.once('close', () => {
    debug('peer: %s, close', user.id);
    notify.error('Peer connection closed');
    dispatcher.dispatch({
      type: 'remove-stream',
      userId: user.id
    });

    // make sure some other peer with different id didn't take place between
    // calling `destroy()` and `close` event
    if (peers[user.id] === peer) delete peers[user.id];
  });
}

function get(userId) {
  return peers[userId];
}

function getIds() {
  return _.map(peers, (peer, id) => id);
}

function clear() {
  debug('clear');
  _.each(peers, (_, userId) => destroy(userId));
  peers = {};
}

function destroy(userId) {
  debug('destroy peer: %s', userId);
  let peer = peers[userId];
  if (!peer) return debug('peer: %s peer not found', userId);
  peer.destroy();
  delete peers[userId];
}

module.exports = { create, get, getIds, destroy, clear };