peerjs/demo/static/peer.js

/*! peerjs.js build:0.0.1, development. Copyright(c) 2013 Michelle Bu <michelle@michellebu.com> */
(function(exports){
var RTCPeerConnection = null;
var getUserMedia = null;
var attachMediaStream = null;
var browserisms = null;

if (navigator.mozGetUserMedia) {
  browserisms = 'Firefox'

  RTCPeerConnection = mozRTCPeerConnection;

  getUserMedia = navigator.mozGetUserMedia.bind(navigator);
  attachMediaStream = function(element, stream) {
    console.log("Attaching media stream");
    element.mozSrcObject = stream;
    element.play();
  };
} else if (navigator.webkitGetUserMedia) {
  browserisms = 'Webkit'

  RTCPeerConnection = webkitRTCPeerConnection;

  getUserMedia = navigator.webkitGetUserMedia.bind(navigator);
  attachMediaStream = function(element, stream) {
    element.src = webkitURL.createObjectURL(stream);
  };
}

exports.RTCPeerConnection = RTCPeerConnection;
exports.getUserMedia = getUserMedia;
exports.attachMediaStream = attachMediaStream;
exports.browserisms = browserisms;
var binaryFeatures = {};
binaryFeatures.useBlobBuilder = (function(){
  try {
    new Blob([]);
    return false;
  } catch (e) {
    return true;
  }
})();

binaryFeatures.useArrayBufferView = !binaryFeatures.useBlobBuilder && (function(){
  try {
    return (new Blob([new Uint8Array([])])).size === 0;
  } catch (e) {
    return true;
  }
})();

exports.binaryFeatures = binaryFeatures;
exports.BlobBuilder = window.WebKitBlobBuilder || window.MozBlobBuilder || window.MSBlobBuilder || window.BlobBuilder;

function BufferBuilder(){
  this._pieces = [];
  this._parts = [];
}

BufferBuilder.prototype.append = function(data) {
  if(typeof data === 'number') {
    this._pieces.push(data);
  } else {
    this._flush();
    this._parts.push(data);
  }
};

BufferBuilder.prototype._flush = function() {
  if (this._pieces.length > 0) {    
    var buf = new Uint8Array(this._pieces);
    if(!binaryFeatures.useArrayBufferView) {
      buf = buf.buffer;
    }
    this._parts.push(buf);
    this._pieces = [];
  }
};

BufferBuilder.prototype.getBuffer = function() {
  this._flush();
  if(binaryFeatures.useBlobBuilder) {
    var builder = new BlobBuilder();
    for(var i = 0, ii = this._parts.length; i < ii; i++) {
      builder.append(this._parts[i]);
    }
    return builder.getBlob();
  } else {
    return new Blob(this._parts);
  }
};
exports.BinaryPack = {
  unpack: function(data){
    var unpacker = new Unpacker(data);
    return unpacker.unpack();
  },
  pack: function(data){
    var packer = new Packer();
    var buffer = packer.pack(data);
    return buffer;
  }
};

function Unpacker (data){
  // Data is ArrayBuffer
  this.index = 0;
  this.dataBuffer = data;
  this.dataView = new Uint8Array(this.dataBuffer);
  this.length = this.dataBuffer.byteLength;
}


Unpacker.prototype.unpack = function(){
  var type = this.unpack_uint8();
  if (type < 0x80){
    var positive_fixnum = type;
    return positive_fixnum;
  } else if ((type ^ 0xe0) < 0x20){
    var negative_fixnum = (type ^ 0xe0) - 0x20;
    return negative_fixnum;
  }
  var size;
  if ((size = type ^ 0xa0) <= 0x0f){
    return this.unpack_raw(size);
  } else if ((size = type ^ 0xb0) <= 0x0f){
    return this.unpack_string(size);
  } else if ((size = type ^ 0x90) <= 0x0f){
    return this.unpack_array(size);
  } else if ((size = type ^ 0x80) <= 0x0f){
    return this.unpack_map(size);
  }
  switch(type){
    case 0xc0:
      return null;
    case 0xc1:
      return undefined;
    case 0xc2:
      return false;
    case 0xc3:
      return true;
    case 0xca:
      return this.unpack_float();
    case 0xcb:
      return this.unpack_double();
    case 0xcc:
      return this.unpack_uint8();
    case 0xcd:
      return this.unpack_uint16();
    case 0xce:
      return this.unpack_uint32();
    case 0xcf:
      return this.unpack_uint64();
    case 0xd0:
      return this.unpack_int8();
    case 0xd1:
      return this.unpack_int16();
    case 0xd2:
      return this.unpack_int32();
    case 0xd3:
      return this.unpack_int64();
    case 0xd4:
      return undefined;
    case 0xd5:
      return undefined;
    case 0xd6:
      return undefined;
    case 0xd7:
      return undefined;
    case 0xd8:
      size = this.unpack_uint16();
      return this.unpack_string(size);
    case 0xd9:
      size = this.unpack_uint32();
      return this.unpack_string(size);
    case 0xda:
      size = this.unpack_uint16();
      return this.unpack_raw(size);
    case 0xdb:
      size = this.unpack_uint32();
      return this.unpack_raw(size);
    case 0xdc:
      size = this.unpack_uint16();
      return this.unpack_array(size);
    case 0xdd:
      size = this.unpack_uint32();
      return this.unpack_array(size);
    case 0xde:
      size = this.unpack_uint16();
      return this.unpack_map(size);
    case 0xdf:
      size = this.unpack_uint32();
      return this.unpack_map(size);
  }
}

Unpacker.prototype.unpack_uint8 = function(){
  var byte = this.dataView[this.index] & 0xff;
  this.index++;
  return byte;
};

Unpacker.prototype.unpack_uint16 = function(){
  var bytes = this.read(2);
  var uint16 =
    ((bytes[0] & 0xff) * 256) + (bytes[1] & 0xff);
  this.index += 2;
  return uint16;
}

Unpacker.prototype.unpack_uint32 = function(){
  var bytes = this.read(4);
  var uint32 =
     ((bytes[0]  * 256 +
       bytes[1]) * 256 +
       bytes[2]) * 256 +
       bytes[3];
  this.index += 4;
  return uint32;
}

Unpacker.prototype.unpack_uint64 = function(){
  var bytes = this.read(8);
  var uint64 =
   ((((((bytes[0]  * 256 +
       bytes[1]) * 256 +
       bytes[2]) * 256 +
       bytes[3]) * 256 +
       bytes[4]) * 256 +
       bytes[5]) * 256 +
       bytes[6]) * 256 +
       bytes[7];
  this.index += 8;
  return uint64;
}


Unpacker.prototype.unpack_int8 = function(){
  var uint8 = this.unpack_uint8();
  return (uint8 < 0x80 ) ? uint8 : uint8 - (1 << 8);
};

Unpacker.prototype.unpack_int16 = function(){
  var uint16 = this.unpack_uint16();
  return (uint16 < 0x8000 ) ? uint16 : uint16 - (1 << 16);
}

Unpacker.prototype.unpack_int32 = function(){
  var uint32 = this.unpack_uint32();
  return (uint32 < Math.pow(2, 31) ) ? uint32 :
    uint32 - Math.pow(2, 32);
}

Unpacker.prototype.unpack_int64 = function(){
  var uint64 = this.unpack_uint64();
  return (uint64 < Math.pow(2, 63) ) ? uint64 :
    uint64 - Math.pow(2, 64);
}

Unpacker.prototype.unpack_raw = function(size){
  if ( this.length < this.index + size){
    throw new Error('BinaryPackFailure: index is out of range'
      + ' ' + this.index + ' ' + size + ' ' + this.length);
  }
  var buf = this.dataBuffer.slice(this.index, this.index + size);
  this.index += size;
  
    //buf = util.bufferToString(buf);
  
  return buf;
}

Unpacker.prototype.unpack_string = function(size){
  var bytes = this.read(size);
  var i = 0, str = '', c, code;
  while(i < size){
    c = bytes[i];
    if ( c < 128){
      str += String.fromCharCode(c);
      i++;
    } else if ((c ^ 0xc0) < 32){
      code = ((c ^ 0xc0) << 6) | (bytes[i+1] & 63);
      str += String.fromCharCode(code);
      i += 2;
    } else {
      code = ((c & 15) << 12) | ((bytes[i+1] & 63) << 6) |
        (bytes[i+2] & 63);
      str += String.fromCharCode(code);
      i += 3;
    }
  }
  this.index += size;
  return str;
}

Unpacker.prototype.unpack_array = function(size){
  var objects = new Array(size);
  for(var i = 0; i < size ; i++){
    objects[i] = this.unpack();
  }
  return objects;
}

Unpacker.prototype.unpack_map = function(size){
  var map = {};
  for(var i = 0; i < size ; i++){
    var key  = this.unpack();
    var value = this.unpack();
    map[key] = value;
  }
  return map;
}

Unpacker.prototype.unpack_float = function(){
  var uint32 = this.unpack_uint32();
  var sign = uint32 >> 31;
  var exp  = ((uint32 >> 23) & 0xff) - 127;
  var fraction = ( uint32 & 0x7fffff ) | 0x800000;
  return (sign == 0 ? 1 : -1) *
    fraction * Math.pow(2, exp - 23);
}

Unpacker.prototype.unpack_double = function(){
  var h32 = this.unpack_uint32();
  var l32 = this.unpack_uint32();
  var sign = h32 >> 31;
  var exp  = ((h32 >> 20) & 0x7ff) - 1023;
  var hfrac = ( h32 & 0xfffff ) | 0x100000;
  var frac = hfrac * Math.pow(2, exp - 20) +
    l32   * Math.pow(2, exp - 52);
  return (sign == 0 ? 1 : -1) * frac;
}

Unpacker.prototype.read = function(length){
  var j = this.index;
  if (j + length <= this.length) {
    return this.dataView.subarray(j, j + length);
  } else {
    throw new Error('BinaryPackFailure: read index out of range');
  }
}
  
function Packer (){
  this.bufferBuilder = new BufferBuilder();
}

Packer.prototype.pack = function(value){
  var type = typeof(value);
  if (type == 'string'){
    this.pack_string(value);
  } else if (type == 'number'){
    if (Math.floor(value) === value){
      this.pack_integer(value);
    } else{
      this.pack_double(value);
    }
  } else if (type == 'boolean'){
    if (value === true){
      this.bufferBuilder.append(0xc3);
    } else if (value === false){
      this.bufferBuilder.append(0xc2);
    }
  } else if (type == 'undefined'){
    this.bufferBuilder.append(0xc0);
  } else if (type == 'object'){
    if (value === null){
      this.bufferBuilder.append(0xc0);
    } else {
      var constructor = value.constructor;
      if (constructor == Array){
        this.pack_array(value);
      } else if (constructor == Blob || constructor == File) {
        this.pack_bin(value);
      } else if (constructor == ArrayBuffer) {
        if(binaryFeatures.useArrayBufferView) {
          this.pack_bin(new Uint8Array(value));
        } else {
          this.pack_bin(value);
        }
      } else if ('BYTES_PER_ELEMENT' in value){
        if(binaryFeatures.useArrayBufferView) {
          this.pack_bin(value);
        } else {
          this.pack_bin(value.buffer);
        }
      } else if (constructor == Object){
        this.pack_object(value);
      } else if (constructor == Date){
        this.pack_string(value.toString());
      } else if (typeof value.toBinaryPack == 'function'){
        this.bufferBuilder.append(value.toBinaryPack());
      } else {
        throw new Error('Type "' + constructor.toString() + '" not yet supported');
      }
    }
  } else {
    throw new Error('Type "' + type + '" not yet supported');
  }
  return this.bufferBuilder.getBuffer();
}


Packer.prototype.pack_bin = function(blob){
  var length = blob.length || blob.byteLength || blob.size;
  if (length <= 0x0f){
    this.pack_uint8(0xa0 + length);
  } else if (length <= 0xffff){
    this.bufferBuilder.append(0xda) ;
    this.pack_uint16(length);
  } else if (length <= 0xffffffff){
    this.bufferBuilder.append(0xdb);
    this.pack_uint32(length);
  } else{
    throw new Error('Invalid length');
    return;
  }
  this.bufferBuilder.append(blob);
}

Packer.prototype.pack_string = function(str){
  var length = str.length;
  if (length <= 0x0f){
    this.pack_uint8(0xb0 + length);
  } else if (length <= 0xffff){
    this.bufferBuilder.append(0xd8) ;
    this.pack_uint16(length);
  } else if (length <= 0xffffffff){
    this.bufferBuilder.append(0xd9);
    this.pack_uint32(length);
  } else{
    throw new Error('Invalid length');
    return;
  }
  this.bufferBuilder.append(str);
}

Packer.prototype.pack_array = function(ary){
  var length = ary.length;
  if (length <= 0x0f){
    this.pack_uint8(0x90 + length);
  } else if (length <= 0xffff){
    this.bufferBuilder.append(0xdc)
    this.pack_uint16(length);
  } else if (length <= 0xffffffff){
    this.bufferBuilder.append(0xdd);
    this.pack_uint32(length);
  } else{
    throw new Error('Invalid length');
  }
  for(var i = 0; i < length ; i++){
    this.pack(ary[i]);
  }
}

Packer.prototype.pack_integer = function(num){
  if ( -0x20 <= num && num <= 0x7f){
    this.bufferBuilder.append(num & 0xff);
  } else if (0x00 <= num && num <= 0xff){
    this.bufferBuilder.append(0xcc);
    this.pack_uint8(num);
  } else if (-0x80 <= num && num <= 0x7f){
    this.bufferBuilder.append(0xd0);
    this.pack_int8(num);
  } else if ( 0x0000 <= num && num <= 0xffff){
    this.bufferBuilder.append(0xcd);
    this.pack_uint16(num);
  } else if (-0x8000 <= num && num <= 0x7fff){
    this.bufferBuilder.append(0xd1);
    this.pack_int16(num);
  } else if ( 0x00000000 <= num && num <= 0xffffffff){
    this.bufferBuilder.append(0xce);
    this.pack_uint32(num);
  } else if (-0x80000000 <= num && num <= 0x7fffffff){
    this.bufferBuilder.append(0xd2);
    this.pack_int32(num);
  } else if (-0x8000000000000000 <= num && num <= 0x7FFFFFFFFFFFFFFF){
    this.bufferBuilder.append(0xd3);
    this.pack_int64(num);
  } else if (0x0000000000000000 <= num && num <= 0xFFFFFFFFFFFFFFFF){
    this.bufferBuilder.append(0xcf);
    this.pack_uint64(num);
  } else{
    throw new Error('Invalid integer');
  }
}

Packer.prototype.pack_double = function(num){
  var sign = 0;
  if (num < 0){
    sign = 1;
    num = -num;
  }
  var exp  = Math.floor(Math.log(num) / Math.LN2);
  var frac0 = num / Math.pow(2, exp) - 1;
  var frac1 = Math.floor(frac0 * Math.pow(2, 52));
  var b32   = Math.pow(2, 32);
  var h32 = (sign << 31) | ((exp+1023) << 20) |
      (frac1 / b32) & 0x0fffff;
  var l32 = frac1 % b32;
  this.bufferBuilder.append(0xcb);
  this.pack_int32(h32);
  this.pack_int32(l32);
}

Packer.prototype.pack_object = function(obj){
  var keys = Object.keys(obj);
  var length = keys.length;
  if (length <= 0x0f){
    this.pack_uint8(0x80 + length);
  } else if (length <= 0xffff){
    this.bufferBuilder.append(0xde);
    this.pack_uint16(length);
  } else if (length <= 0xffffffff){
    this.bufferBuilder.append(0xdf);
    this.pack_uint32(length);
  } else{
    throw new Error('Invalid length');
  }
  for(var prop in obj){
    if (obj.hasOwnProperty(prop)){
      this.pack(prop);
      this.pack(obj[prop]);
    }
  }
}

Packer.prototype.pack_uint8 = function(num){
  this.bufferBuilder.append(num);
}

Packer.prototype.pack_uint16 = function(num){
  this.bufferBuilder.append(num >> 8);
  this.bufferBuilder.append(num & 0xff);
}

Packer.prototype.pack_uint32 = function(num){
  var n = num & 0xffffffff;
  this.bufferBuilder.append((n & 0xff000000) >>> 24);
  this.bufferBuilder.append((n & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((n & 0x0000ff00) >>>  8);
  this.bufferBuilder.append((n & 0x000000ff));
}

Packer.prototype.pack_uint64 = function(num){
  var high = num / Math.pow(2, 32);
  var low  = num % Math.pow(2, 32);
  this.bufferBuilder.append((high & 0xff000000) >>> 24);
  this.bufferBuilder.append((high & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((high & 0x0000ff00) >>>  8);
  this.bufferBuilder.append((high & 0x000000ff));
  this.bufferBuilder.append((low  & 0xff000000) >>> 24);
  this.bufferBuilder.append((low  & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((low  & 0x0000ff00) >>>  8);
  this.bufferBuilder.append((low  & 0x000000ff));
}

Packer.prototype.pack_int8 = function(num){
  this.bufferBuilder.append(num & 0xff);
}

Packer.prototype.pack_int16 = function(num){
  this.bufferBuilder.append((num & 0xff00) >> 8);
  this.bufferBuilder.append(num & 0xff);
}

Packer.prototype.pack_int32 = function(num){
  this.bufferBuilder.append((num >>> 24) & 0xff);
  this.bufferBuilder.append((num & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((num & 0x0000ff00) >>> 8);
  this.bufferBuilder.append((num & 0x000000ff));
}

Packer.prototype.pack_int64 = function(num){
  var high = Math.floor(num / Math.pow(2, 32));
  var low  = num % Math.pow(2, 32);
  this.bufferBuilder.append((high & 0xff000000) >>> 24);
  this.bufferBuilder.append((high & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((high & 0x0000ff00) >>>  8);
  this.bufferBuilder.append((high & 0x000000ff));
  this.bufferBuilder.append((low  & 0xff000000) >>> 24);
  this.bufferBuilder.append((low  & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((low  & 0x0000ff00) >>>  8);
  this.bufferBuilder.append((low  & 0x000000ff));
}
function SinkPeer(options) {
  this._config = options.config || { 'iceServers': [{ 'url': 'stun:stun.l.google.com:19302' }] };
  this._peer = options.source || null;
  this._video = options.video;
  this._data = options.data != undefined ? options.data : true;
  this._audio = options.audio;
  this._pc = null;
  this._id = null;
  this._dc = null;
  this._socket = new WebSocket(options.ws || 'ws://localhost');
  var self = this;
  this._socket.onopen = function() {
    self.socketInit();
  };
  this._handlers = {};

  // Testing firefox.
  // MULTICONNECTION doesn't work still.
  if (browserisms == 'Firefox' && !options.source) {
    if (!SinkPeer.usedPorts) {
      SinkPeer.usedPorts = [];
    }
    this.localPort = randomPort();
    while (SinkPeer.usedPorts.indexOf(this.localPort) != -1) {
      this.localPort = randomPort();
    }
    this.remotePort = randomPort();
    while (this.remotePort == this.localPort ||
        SinkPeer.usedPorts.indexOf(this.localPort) != -1) {
      this.remotePort = randomPort();
    }
    SinkPeer.usedPorts.push(this.remotePort);
    SinkPeer.usedPorts.push(this.localPort);
  }

};


function randomPort() {
  return Math.round(Math.random() * 60535) + 5000;
};


/** Start up websocket communications. */
SinkPeer.prototype.socketInit = function() {
  var self = this;
  // Multiple sinks to one source.
  if (!!this._peer) {
    this._socket.send(JSON.stringify({
      type: 'SINK',
      source: this._peer,
      isms: browserisms
    }));

    this._socket.onmessage = function(event) {
      var message = JSON.parse(event.data);

      switch (message.type) {
        case 'SINK-ID':
          self._id = message.id;
          if (!!self._handlers['ready']) {
            self._handlers['ready'](self._id);
          }
          self.startPeerConnection();
          break;
        case 'OFFER':
          var sdp = message.sdp;
          try {
            sdp = new RTCSessionDescription(message.sdp);
          } catch(e) {
            console.log('Firefox');
          }
          self._pc.setRemoteDescription(sdp, function() {
            console.log('setRemoteDescription: offer');

            // If we also have to set up a stream on the sink end, do so.
            self.handleStream(false, function() {
              self.maybeBrowserisms(false);
            });
          }, function(err) {
            console.log('failed to setRemoteDescription with offer, ', err);
          });
          break;
        case 'CANDIDATE':
          console.log(message.candidate);
          var candidate = new RTCIceCandidate(message.candidate);
          self._pc.addIceCandidate(candidate);
          break;
        case 'PORT':
          if (browserisms && browserisms == 'Firefox') {
            if (!SinkPeer.usedPorts) {
              SinkPeer.usedPorts = [];
            }
            SinkPeer.usedPorts.push(message.local);
            SinkPeer.usedPorts.push(message.remote);
            self._pc.connectDataConnection(message.local, message.remote);
            break;
          }
        case 'DEFAULT':
          console.log('SINK: unrecognized message ', message.type);
          break;
      }
    };

  } else {
    // Otherwise, this sink is the originator to another sink and should wait
    // for an alert.
    this._socket.send(JSON.stringify({
      type: 'SOURCE',
      isms: browserisms
    }));

    this._socket.onmessage = function(event) {
      var message = JSON.parse(event.data);

      switch (message.type) {
        case 'SOURCE-ID':
          self._id = message.id;
          if (!!self._handlers['ready']) {
            self._handlers['ready'](self._id);
          }
          break;
        case 'SINK-CONNECTED':
          self._peer = message.sink;
          self.startPeerConnection();
          self.handleStream(true, function() {
            self.maybeBrowserisms(true);
          });
          break;
        case 'ANSWER':
          var sdp = message.sdp;
          try {
            sdp = new RTCSessionDescription(message.sdp);
          } catch(e) {
            console.log('Firefox');
          }
          self._pc.setRemoteDescription(sdp, function() {
            console.log('setRemoteDescription: answer');
            // Firefoxism
            if (browserisms == 'Firefox') {
              self._pc.connectDataConnection(self.localPort, self.remotePort);
              self._socket.send(JSON.stringify({
                type: 'PORT',
                dst: self._peer,
                remote: self.localPort,
                local: self.remotePort
              }));
            }
            console.log('ORIGINATOR: PeerConnection success');
          }, function(err) {
            console.log('failed to setRemoteDescription, ', err);
          });
          break;
        case 'CANDIDATE':
          console.log(message.candidate);
          var candidate = new RTCIceCandidate(message.candidate);
          self._pc.addIceCandidate(candidate);
          break;
        case 'DEFAULT':
          console.log('ORIGINATOR: message not recognized ', message.type);
      }
    };
  }
  // Makes sure things clean up neatly.
  window.onbeforeunload = function() {
    if (!!self._pc) {
      self._pc.close();
    }
    if (!!self._socket && !!self._peer) {
      self._socket.send(JSON.stringify({ type: 'LEAVE', dst: self._peer }));
      if (!!self._dc) {
        self._dc.close();
      }
    }
  }
};


/** Takes care of ice handlers. */
SinkPeer.prototype.setupIce = function() {
  var self = this;
  this._pc.onicecandidate = function(event) {
    console.log('candidates received');
    if (event.candidate) {
      self._socket.send(JSON.stringify({
        type: 'CANDIDATE',
        candidate: event.candidate,
        dst: self._peer
      }));
    } else {
      console.log("End of candidates.");
    }
  };
};


/** Starts a PeerConnection and sets up handlers. */
SinkPeer.prototype.startPeerConnection = function() {
  this._pc = new RTCPeerConnection(this._config, { optional:[ { RtpDataChannels: true } ]});
  this.setupIce();
  this.setupAudioVideo();
};


/** Decide whether to handle Firefoxisms. */
SinkPeer.prototype.maybeBrowserisms = function(originator) {
  var self = this;
  if (browserisms == 'Firefox' && !this._video && !this._audio && !this._stream) {
    getUserMedia({ audio: true, fake: true }, function(s) {
      self._pc.addStream(s);

      if (originator) {
        self.makeOffer();
      } else {
        self.makeAnswer();
      }

    }, function(err) { console.log('crap'); });
  } else {
    if (originator) {
      this.makeOffer();
    } else {
      this.makeAnswer();
    }
  }
}


/** Create an answer for PC. */
SinkPeer.prototype.makeAnswer = function() {
  var self = this;

  this._pc.createAnswer(function(answer) {
    console.log('createAnswer');
    self._pc.setLocalDescription(answer, function() {
      console.log('setLocalDescription: answer');
      self._socket.send(JSON.stringify({
        type: 'ANSWER',
        src: self._id,
        sdp: answer,
        dst: self._peer
      }));
    }, function(err) {
      console.log('failed to setLocalDescription, ', err)
    });
  }, function(err) {
    console.log('failed to create answer, ', err)
  });
};


/** Create an offer for PC. */
SinkPeer.prototype.makeOffer = function() {
  var self = this;

  this._pc.createOffer(function(offer) {
    console.log('createOffer')
    self._pc.setLocalDescription(offer, function() {
      console.log('setLocalDescription: offer');
      self._socket.send(JSON.stringify({
        type: 'OFFER',
        sdp: offer,
        dst: self._peer,
        src: self._id
      }));
    }, function(err) {
      console.log('failed to setLocalDescription, ', err);
    });
  });
};


/** Sets up A/V stream handler. */
SinkPeer.prototype.setupAudioVideo = function() {
  var self = this;
  console.log('onaddstream handler added');
  this._pc.onaddstream = function(obj) {
    console.log('Remote stream added');
    this._stream = true;
    if (!!self._handlers['remotestream']) {
      self._handlers['remotestream'](obj.type, obj.stream);
    }
  };
};


/** Handle the different types of streams requested by user. */
SinkPeer.prototype.handleStream = function(originator, cb) {
  if (this._data) {
    this.setupDataChannel(originator);
  }
  this.getAudioVideo(originator, cb);
};


/** Get A/V streams. */
SinkPeer.prototype.getAudioVideo = function(originator, cb) {
  var self = this;
  if (this._video) {
    getUserMedia({ video: true }, function(vstream) {
      self._pc.addStream(vstream);
      console.log('Local video stream added');

      if (!!self._handlers['localstream']) {
        self._handlers['localstream']('video', vstream);
      }

      if (self._audio) {
        getUserMedia({ audio: true }, function(astream) {
          self._pc.addStream(astream);
          console.log('Local audio stream added');

          if (!!self._handlers['localstream']) {
            self._handlers['localstream']('audio', astream);
          }

          cb();
        }, function(err) { console.log('Audio cannot start'); cb(); });
      } else {
        cb();
      }
    }, function(err) { console.log('Video cannot start', err); cb(); });
  } else if (this._audio) {
    getUserMedia({ audio: true }, function(astream) {
      self._pc.addStream(astream);

      if (!!self._handlers['localstream']) {
        self._handlers['localstream']('audio', astream);
      }

      cb();
    }, function(err) { console.log('Audio cannot start'); cb(); });
  } else {
    cb();
  }

};


/** Sets up DataChannel handlers. */
SinkPeer.prototype.setupDataChannel = function(originator, cb) {
  var self = this;
  if (originator) {
    /** ORIGINATOR SETUP */
    if (browserisms == 'Webkit') {

      this._pc.onstatechange = function() {
        console.log('State Change: ', self._pc.readyState);
        /*if (self._pc.readyState == 'active') {
          console.log('ORIGINATOR: active state detected');

          self._dc = self._pc.createDataChannel('StreamAPI', { reliable: false });
          self._dc.binaryType = 'blob';

          if (!!self._handlers['connection']) {
            self._handlers['connection'](self._peer);
          }

          self._dc.onmessage = function(e) {
            self.handleDataMessage(e);
          };
        }*/
      }

    } else {
      this._pc.onconnection = function() {
        console.log('ORIGINATOR: onconnection triggered');

        self.startDataChannel();
      };
    }
  } else {
    /** TARGET SETUP */
    this._pc.ondatachannel = function(dc) {
      console.log('SINK: ondatachannel triggered');
      self._dc = dc;
      self._dc.binaryType = 'blob';

      if (!!self._handlers['connection']) {
        self._handlers['connection'](self._peer);
      }

      self._dc.onmessage = function(e) {
        self.handleDataMessage(e);
      };
    };

    this._pc.onconnection = function() {
      console.log('SINK: onconnection triggered');
    };
  }


  this._pc.onclosedconnection = function() {
    // Remove socket handlers perhaps.
  };
};


SinkPeer.prototype.startDataChannel = function() {
  var self = this;
  this._dc = this._pc.createDataChannel(this._peer, { reliable: false });
  this._dc.binaryType = 'blob';

  if (!!this._handlers['connection']) {
    this._handlers['connection'](this._peer);
  }

  this._dc.onmessage = function(e) {
    self.handleDataMessage(e);
  };
};


/** Allows user to send data. */
SinkPeer.prototype.send = function(data) {
  var ab = BinaryPack.pack(data);
  this._dc.send(ab);
}


// Handles a DataChannel message.
// TODO: have these extend Peer, which will impl these generic handlers.
SinkPeer.prototype.handleDataMessage = function(e) {
  var self = this;
  var fr = new FileReader();
  fr.onload = function(evt) {
    var ab = evt.target.result;
    var data = BinaryPack.unpack(ab);
    if (!!self._handlers['data']) {
      self._handlers['data'](data);
    }
  };
  fr.readAsArrayBuffer(e.data);
}


SinkPeer.prototype.on = function(code, cb) {
  this._handlers[code] = cb;
}

exports.Peer = SinkPeer;

})(this);