/*
 *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree.
 */
/* eslint-env node */
'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.fixNegotiationNeeded = fixNegotiationNeeded;
exports.shimAddTrackRemoveTrack = shimAddTrackRemoveTrack;
exports.shimAddTrackRemoveTrackWithNative = shimAddTrackRemoveTrackWithNative;
Object.defineProperty(exports, "shimGetDisplayMedia", {
  enumerable: true,
  get: function get() {
    return _getdisplaymedia.shimGetDisplayMedia;
  }
});
exports.shimGetSendersWithDtmf = shimGetSendersWithDtmf;
exports.shimGetStats = shimGetStats;
Object.defineProperty(exports, "shimGetUserMedia", {
  enumerable: true,
  get: function get() {
    return _getusermedia.shimGetUserMedia;
  }
});
exports.shimMediaStream = shimMediaStream;
exports.shimOnTrack = shimOnTrack;
exports.shimPeerConnection = shimPeerConnection;
exports.shimSenderReceiverGetStats = shimSenderReceiverGetStats;
var utils = _interopRequireWildcard(require("../utils.js"));
var _getusermedia = require("./getusermedia");
var _getdisplaymedia = require("./getdisplaymedia");
function _getRequireWildcardCache(nodeInterop) { if (typeof WeakMap !== "function") return null; var cacheBabelInterop = new WeakMap(); var cacheNodeInterop = new WeakMap(); return (_getRequireWildcardCache = function _getRequireWildcardCache(nodeInterop) { return nodeInterop ? cacheNodeInterop : cacheBabelInterop; })(nodeInterop); }
function _interopRequireWildcard(obj, nodeInterop) { if (!nodeInterop && obj && obj.__esModule) { return obj; } if (obj === null || _typeof(obj) !== "object" && typeof obj !== "function") { return { "default": obj }; } var cache = _getRequireWildcardCache(nodeInterop); if (cache && cache.has(obj)) { return cache.get(obj); } var newObj = {}; var hasPropertyDescriptor = Object.defineProperty && Object.getOwnPropertyDescriptor; for (var key in obj) { if (key !== "default" && Object.prototype.hasOwnProperty.call(obj, key)) { var desc = hasPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : null; if (desc && (desc.get || desc.set)) { Object.defineProperty(newObj, key, desc); } else { newObj[key] = obj[key]; } } } newObj["default"] = obj; if (cache) { cache.set(obj, newObj); } return newObj; }
function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return _typeof(key) === "symbol" ? key : String(key); }
function _toPrimitive(input, hint) { if (_typeof(input) !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (_typeof(res) !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
function _typeof(obj) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (obj) { return typeof obj; } : function (obj) { return obj && "function" == typeof Symbol && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }, _typeof(obj); }
function shimMediaStream(window) {
  window.MediaStream = window.MediaStream || window.webkitMediaStream;
}
function shimOnTrack(window) {
  if (_typeof(window) === 'object' && window.RTCPeerConnection && !('ontrack' in window.RTCPeerConnection.prototype)) {
    Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
      get: function get() {
        return this._ontrack;
      },
      set: function set(f) {
        if (this._ontrack) {
          this.removeEventListener('track', this._ontrack);
        }
        this.addEventListener('track', this._ontrack = f);
      },
      enumerable: true,
      configurable: true
    });
    var origSetRemoteDescription = window.RTCPeerConnection.prototype.setRemoteDescription;
    window.RTCPeerConnection.prototype.setRemoteDescription = function setRemoteDescription() {
      var _this = this;
      if (!this._ontrackpoly) {
        this._ontrackpoly = function (e) {
          // onaddstream does not fire when a track is added to an existing
          // stream. But stream.onaddtrack is implemented so we use that.
          e.stream.addEventListener('addtrack', function (te) {
            var receiver;
            if (window.RTCPeerConnection.prototype.getReceivers) {
              receiver = _this.getReceivers().find(function (r) {
                return r.track && r.track.id === te.track.id;
              });
            } else {
              receiver = {
                track: te.track
              };
            }
            var event = new Event('track');
            event.track = te.track;
            event.receiver = receiver;
            event.transceiver = {
              receiver: receiver
            };
            event.streams = [e.stream];
            _this.dispatchEvent(event);
          });
          e.stream.getTracks().forEach(function (track) {
            var receiver;
            if (window.RTCPeerConnection.prototype.getReceivers) {
              receiver = _this.getReceivers().find(function (r) {
                return r.track && r.track.id === track.id;
              });
            } else {
              receiver = {
                track: track
              };
            }
            var event = new Event('track');
            event.track = track;
            event.receiver = receiver;
            event.transceiver = {
              receiver: receiver
            };
            event.streams = [e.stream];
            _this.dispatchEvent(event);
          });
        };
        this.addEventListener('addstream', this._ontrackpoly);
      }
      return origSetRemoteDescription.apply(this, arguments);
    };
  } else {
    // even if RTCRtpTransceiver is in window, it is only used and
    // emitted in unified-plan. Unfortunately this means we need
    // to unconditionally wrap the event.
    utils.wrapPeerConnectionEvent(window, 'track', function (e) {
      if (!e.transceiver) {
        Object.defineProperty(e, 'transceiver', {
          value: {
            receiver: e.receiver
          }
        });
      }
      return e;
    });
  }
}
function shimGetSendersWithDtmf(window) {
  // Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
  if (_typeof(window) === 'object' && window.RTCPeerConnection && !('getSenders' in window.RTCPeerConnection.prototype) && 'createDTMFSender' in window.RTCPeerConnection.prototype) {
    var shimSenderWithDtmf = function shimSenderWithDtmf(pc, track) {
      return {
        track: track,
        get dtmf() {
          if (this._dtmf === undefined) {
            if (track.kind === 'audio') {
              this._dtmf = pc.createDTMFSender(track);
            } else {
              this._dtmf = null;
            }
          }
          return this._dtmf;
        },
        _pc: pc
      };
    };

    // augment addTrack when getSenders is not available.
    if (!window.RTCPeerConnection.prototype.getSenders) {
      window.RTCPeerConnection.prototype.getSenders = function getSenders() {
        this._senders = this._senders || [];
        return this._senders.slice(); // return a copy of the internal state.
      };

      var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
      window.RTCPeerConnection.prototype.addTrack = function addTrack(track, stream) {
        var sender = origAddTrack.apply(this, arguments);
        if (!sender) {
          sender = shimSenderWithDtmf(this, track);
          this._senders.push(sender);
        }
        return sender;
      };
      var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
      window.RTCPeerConnection.prototype.removeTrack = function removeTrack(sender) {
        origRemoveTrack.apply(this, arguments);
        var idx = this._senders.indexOf(sender);
        if (idx !== -1) {
          this._senders.splice(idx, 1);
        }
      };
    }
    var origAddStream = window.RTCPeerConnection.prototype.addStream;
    window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
      var _this2 = this;
      this._senders = this._senders || [];
      origAddStream.apply(this, [stream]);
      stream.getTracks().forEach(function (track) {
        _this2._senders.push(shimSenderWithDtmf(_this2, track));
      });
    };
    var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
    window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
      var _this3 = this;
      this._senders = this._senders || [];
      origRemoveStream.apply(this, [stream]);
      stream.getTracks().forEach(function (track) {
        var sender = _this3._senders.find(function (s) {
          return s.track === track;
        });
        if (sender) {
          // remove sender
          _this3._senders.splice(_this3._senders.indexOf(sender), 1);
        }
      });
    };
  } else if (_typeof(window) === 'object' && window.RTCPeerConnection && 'getSenders' in window.RTCPeerConnection.prototype && 'createDTMFSender' in window.RTCPeerConnection.prototype && window.RTCRtpSender && !('dtmf' in window.RTCRtpSender.prototype)) {
    var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
    window.RTCPeerConnection.prototype.getSenders = function getSenders() {
      var _this4 = this;
      var senders = origGetSenders.apply(this, []);
      senders.forEach(function (sender) {
        return sender._pc = _this4;
      });
      return senders;
    };
    Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
      get: function get() {
        if (this._dtmf === undefined) {
          if (this.track.kind === 'audio') {
            this._dtmf = this._pc.createDTMFSender(this.track);
          } else {
            this._dtmf = null;
          }
        }
        return this._dtmf;
      }
    });
  }
}
function shimGetStats(window) {
  if (!window.RTCPeerConnection) {
    return;
  }
  var origGetStats = window.RTCPeerConnection.prototype.getStats;
  window.RTCPeerConnection.prototype.getStats = function getStats() {
    var _this5 = this;
    var _arguments = Array.prototype.slice.call(arguments),
      selector = _arguments[0],
      onSucc = _arguments[1],
      onErr = _arguments[2];

    // If selector is a function then we are in the old style stats so just
    // pass back the original getStats format to avoid breaking old users.
    if (arguments.length > 0 && typeof selector === 'function') {
      return origGetStats.apply(this, arguments);
    }

    // When spec-style getStats is supported, return those when called with
    // either no arguments or the selector argument is null.
    if (origGetStats.length === 0 && (arguments.length === 0 || typeof selector !== 'function')) {
      return origGetStats.apply(this, []);
    }
    var fixChromeStats_ = function fixChromeStats_(response) {
      var standardReport = {};
      var reports = response.result();
      reports.forEach(function (report) {
        var standardStats = {
          id: report.id,
          timestamp: report.timestamp,
          type: {
            localcandidate: 'local-candidate',
            remotecandidate: 'remote-candidate'
          }[report.type] || report.type
        };
        report.names().forEach(function (name) {
          standardStats[name] = report.stat(name);
        });
        standardReport[standardStats.id] = standardStats;
      });
      return standardReport;
    };

    // shim getStats with maplike support
    var makeMapStats = function makeMapStats(stats) {
      return new Map(Object.keys(stats).map(function (key) {
        return [key, stats[key]];
      }));
    };
    if (arguments.length >= 2) {
      var successCallbackWrapper_ = function successCallbackWrapper_(response) {
        onSucc(makeMapStats(fixChromeStats_(response)));
      };
      return origGetStats.apply(this, [successCallbackWrapper_, selector]);
    }

    // promise-support
    return new Promise(function (resolve, reject) {
      origGetStats.apply(_this5, [function (response) {
        resolve(makeMapStats(fixChromeStats_(response)));
      }, reject]);
    }).then(onSucc, onErr);
  };
}
function shimSenderReceiverGetStats(window) {
  if (!(_typeof(window) === 'object' && window.RTCPeerConnection && window.RTCRtpSender && window.RTCRtpReceiver)) {
    return;
  }

  // shim sender stats.
  if (!('getStats' in window.RTCRtpSender.prototype)) {
    var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
    if (origGetSenders) {
      window.RTCPeerConnection.prototype.getSenders = function getSenders() {
        var _this6 = this;
        var senders = origGetSenders.apply(this, []);
        senders.forEach(function (sender) {
          return sender._pc = _this6;
        });
        return senders;
      };
    }
    var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
    if (origAddTrack) {
      window.RTCPeerConnection.prototype.addTrack = function addTrack() {
        var sender = origAddTrack.apply(this, arguments);
        sender._pc = this;
        return sender;
      };
    }
    window.RTCRtpSender.prototype.getStats = function getStats() {
      var sender = this;
      return this._pc.getStats().then(function (result) {
        return (
          /* Note: this will include stats of all senders that
           *   send a track with the same id as sender.track as
           *   it is not possible to identify the RTCRtpSender.
           */
          utils.filterStats(result, sender.track, true)
        );
      });
    };
  }

  // shim receiver stats.
  if (!('getStats' in window.RTCRtpReceiver.prototype)) {
    var origGetReceivers = window.RTCPeerConnection.prototype.getReceivers;
    if (origGetReceivers) {
      window.RTCPeerConnection.prototype.getReceivers = function getReceivers() {
        var _this7 = this;
        var receivers = origGetReceivers.apply(this, []);
        receivers.forEach(function (receiver) {
          return receiver._pc = _this7;
        });
        return receivers;
      };
    }
    utils.wrapPeerConnectionEvent(window, 'track', function (e) {
      e.receiver._pc = e.srcElement;
      return e;
    });
    window.RTCRtpReceiver.prototype.getStats = function getStats() {
      var receiver = this;
      return this._pc.getStats().then(function (result) {
        return utils.filterStats(result, receiver.track, false);
      });
    };
  }
  if (!('getStats' in window.RTCRtpSender.prototype && 'getStats' in window.RTCRtpReceiver.prototype)) {
    return;
  }

  // shim RTCPeerConnection.getStats(track).
  var origGetStats = window.RTCPeerConnection.prototype.getStats;
  window.RTCPeerConnection.prototype.getStats = function getStats() {
    if (arguments.length > 0 && arguments[0] instanceof window.MediaStreamTrack) {
      var track = arguments[0];
      var sender;
      var receiver;
      var err;
      this.getSenders().forEach(function (s) {
        if (s.track === track) {
          if (sender) {
            err = true;
          } else {
            sender = s;
          }
        }
      });
      this.getReceivers().forEach(function (r) {
        if (r.track === track) {
          if (receiver) {
            err = true;
          } else {
            receiver = r;
          }
        }
        return r.track === track;
      });
      if (err || sender && receiver) {
        return Promise.reject(new DOMException('There are more than one sender or receiver for the track.', 'InvalidAccessError'));
      } else if (sender) {
        return sender.getStats();
      } else if (receiver) {
        return receiver.getStats();
      }
      return Promise.reject(new DOMException('There is no sender or receiver for the track.', 'InvalidAccessError'));
    }
    return origGetStats.apply(this, arguments);
  };
}
function shimAddTrackRemoveTrackWithNative(window) {
  // shim addTrack/removeTrack with native variants in order to make
  // the interactions with legacy getLocalStreams behave as in other browsers.
  // Keeps a mapping stream.id => [stream, rtpsenders...]
  window.RTCPeerConnection.prototype.getLocalStreams = function getLocalStreams() {
    var _this8 = this;
    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
    return Object.keys(this._shimmedLocalStreams).map(function (streamId) {
      return _this8._shimmedLocalStreams[streamId][0];
    });
  };
  var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
  window.RTCPeerConnection.prototype.addTrack = function addTrack(track, stream) {
    if (!stream) {
      return origAddTrack.apply(this, arguments);
    }
    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
    var sender = origAddTrack.apply(this, arguments);
    if (!this._shimmedLocalStreams[stream.id]) {
      this._shimmedLocalStreams[stream.id] = [stream, sender];
    } else if (this._shimmedLocalStreams[stream.id].indexOf(sender) === -1) {
      this._shimmedLocalStreams[stream.id].push(sender);
    }
    return sender;
  };
  var origAddStream = window.RTCPeerConnection.prototype.addStream;
  window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
    var _this9 = this;
    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
    stream.getTracks().forEach(function (track) {
      var alreadyExists = _this9.getSenders().find(function (s) {
        return s.track === track;
      });
      if (alreadyExists) {
        throw new DOMException('Track already exists.', 'InvalidAccessError');
      }
    });
    var existingSenders = this.getSenders();
    origAddStream.apply(this, arguments);
    var newSenders = this.getSenders().filter(function (newSender) {
      return existingSenders.indexOf(newSender) === -1;
    });
    this._shimmedLocalStreams[stream.id] = [stream].concat(newSenders);
  };
  var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
  window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
    delete this._shimmedLocalStreams[stream.id];
    return origRemoveStream.apply(this, arguments);
  };
  var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
  window.RTCPeerConnection.prototype.removeTrack = function removeTrack(sender) {
    var _this10 = this;
    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
    if (sender) {
      Object.keys(this._shimmedLocalStreams).forEach(function (streamId) {
        var idx = _this10._shimmedLocalStreams[streamId].indexOf(sender);
        if (idx !== -1) {
          _this10._shimmedLocalStreams[streamId].splice(idx, 1);
        }
        if (_this10._shimmedLocalStreams[streamId].length === 1) {
          delete _this10._shimmedLocalStreams[streamId];
        }
      });
    }
    return origRemoveTrack.apply(this, arguments);
  };
}
function shimAddTrackRemoveTrack(window, browserDetails) {
  if (!window.RTCPeerConnection) {
    return;
  }
  // shim addTrack and removeTrack.
  if (window.RTCPeerConnection.prototype.addTrack && browserDetails.version >= 65) {
    return shimAddTrackRemoveTrackWithNative(window);
  }

  // also shim pc.getLocalStreams when addTrack is shimmed
  // to return the original streams.
  var origGetLocalStreams = window.RTCPeerConnection.prototype.getLocalStreams;
  window.RTCPeerConnection.prototype.getLocalStreams = function getLocalStreams() {
    var _this11 = this;
    var nativeStreams = origGetLocalStreams.apply(this);
    this._reverseStreams = this._reverseStreams || {};
    return nativeStreams.map(function (stream) {
      return _this11._reverseStreams[stream.id];
    });
  };
  var origAddStream = window.RTCPeerConnection.prototype.addStream;
  window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
    var _this12 = this;
    this._streams = this._streams || {};
    this._reverseStreams = this._reverseStreams || {};
    stream.getTracks().forEach(function (track) {
      var alreadyExists = _this12.getSenders().find(function (s) {
        return s.track === track;
      });
      if (alreadyExists) {
        throw new DOMException('Track already exists.', 'InvalidAccessError');
      }
    });
    // Add identity mapping for consistency with addTrack.
    // Unless this is being used with a stream from addTrack.
    if (!this._reverseStreams[stream.id]) {
      var newStream = new window.MediaStream(stream.getTracks());
      this._streams[stream.id] = newStream;
      this._reverseStreams[newStream.id] = stream;
      stream = newStream;
    }
    origAddStream.apply(this, [stream]);
  };
  var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
  window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
    this._streams = this._streams || {};
    this._reverseStreams = this._reverseStreams || {};
    origRemoveStream.apply(this, [this._streams[stream.id] || stream]);
    delete this._reverseStreams[this._streams[stream.id] ? this._streams[stream.id].id : stream.id];
    delete this._streams[stream.id];
  };
  window.RTCPeerConnection.prototype.addTrack = function addTrack(track, stream) {
    var _this13 = this;
    if (this.signalingState === 'closed') {
      throw new DOMException('The RTCPeerConnection\'s signalingState is \'closed\'.', 'InvalidStateError');
    }
    var streams = [].slice.call(arguments, 1);
    if (streams.length !== 1 || !streams[0].getTracks().find(function (t) {
      return t === track;
    })) {
      // this is not fully correct but all we can manage without
      // [[associated MediaStreams]] internal slot.
      throw new DOMException('The adapter.js addTrack polyfill only supports a single ' + ' stream which is associated with the specified track.', 'NotSupportedError');
    }
    var alreadyExists = this.getSenders().find(function (s) {
      return s.track === track;
    });
    if (alreadyExists) {
      throw new DOMException('Track already exists.', 'InvalidAccessError');
    }
    this._streams = this._streams || {};
    this._reverseStreams = this._reverseStreams || {};
    var oldStream = this._streams[stream.id];
    if (oldStream) {
      // this is using odd Chrome behaviour, use with caution:
      // https://bugs.chromium.org/p/webrtc/issues/detail?id=7815
      // Note: we rely on the high-level addTrack/dtmf shim to
      // create the sender with a dtmf sender.
      oldStream.addTrack(track);

      // Trigger ONN async.
      Promise.resolve().then(function () {
        _this13.dispatchEvent(new Event('negotiationneeded'));
      });
    } else {
      var newStream = new window.MediaStream([track]);
      this._streams[stream.id] = newStream;
      this._reverseStreams[newStream.id] = stream;
      this.addStream(newStream);
    }
    return this.getSenders().find(function (s) {
      return s.track === track;
    });
  };

  // replace the internal stream id with the external one and
  // vice versa.
  function replaceInternalStreamId(pc, description) {
    var sdp = description.sdp;
    Object.keys(pc._reverseStreams || []).forEach(function (internalId) {
      var externalStream = pc._reverseStreams[internalId];
      var internalStream = pc._streams[externalStream.id];
      sdp = sdp.replace(new RegExp(internalStream.id, 'g'), externalStream.id);
    });
    return new RTCSessionDescription({
      type: description.type,
      sdp: sdp
    });
  }
  function replaceExternalStreamId(pc, description) {
    var sdp = description.sdp;
    Object.keys(pc._reverseStreams || []).forEach(function (internalId) {
      var externalStream = pc._reverseStreams[internalId];
      var internalStream = pc._streams[externalStream.id];
      sdp = sdp.replace(new RegExp(externalStream.id, 'g'), internalStream.id);
    });
    return new RTCSessionDescription({
      type: description.type,
      sdp: sdp
    });
  }
  ['createOffer', 'createAnswer'].forEach(function (method) {
    var nativeMethod = window.RTCPeerConnection.prototype[method];
    var methodObj = _defineProperty({}, method, function () {
      var _this14 = this;
      var args = arguments;
      var isLegacyCall = arguments.length && typeof arguments[0] === 'function';
      if (isLegacyCall) {
        return nativeMethod.apply(this, [function (description) {
          var desc = replaceInternalStreamId(_this14, description);
          args[0].apply(null, [desc]);
        }, function (err) {
          if (args[1]) {
            args[1].apply(null, err);
          }
        }, arguments[2]]);
      }
      return nativeMethod.apply(this, arguments).then(function (description) {
        return replaceInternalStreamId(_this14, description);
      });
    });
    window.RTCPeerConnection.prototype[method] = methodObj[method];
  });
  var origSetLocalDescription = window.RTCPeerConnection.prototype.setLocalDescription;
  window.RTCPeerConnection.prototype.setLocalDescription = function setLocalDescription() {
    if (!arguments.length || !arguments[0].type) {
      return origSetLocalDescription.apply(this, arguments);
    }
    arguments[0] = replaceExternalStreamId(this, arguments[0]);
    return origSetLocalDescription.apply(this, arguments);
  };

  // TODO: mangle getStats: https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamstats-streamidentifier

  var origLocalDescription = Object.getOwnPropertyDescriptor(window.RTCPeerConnection.prototype, 'localDescription');
  Object.defineProperty(window.RTCPeerConnection.prototype, 'localDescription', {
    get: function get() {
      var description = origLocalDescription.get.apply(this);
      if (description.type === '') {
        return description;
      }
      return replaceInternalStreamId(this, description);
    }
  });
  window.RTCPeerConnection.prototype.removeTrack = function removeTrack(sender) {
    var _this15 = this;
    if (this.signalingState === 'closed') {
      throw new DOMException('The RTCPeerConnection\'s signalingState is \'closed\'.', 'InvalidStateError');
    }
    // We can not yet check for sender instanceof RTCRtpSender
    // since we shim RTPSender. So we check if sender._pc is set.
    if (!sender._pc) {
      throw new DOMException('Argument 1 of RTCPeerConnection.removeTrack ' + 'does not implement interface RTCRtpSender.', 'TypeError');
    }
    var isLocal = sender._pc === this;
    if (!isLocal) {
      throw new DOMException('Sender was not created by this connection.', 'InvalidAccessError');
    }

    // Search for the native stream the senders track belongs to.
    this._streams = this._streams || {};
    var stream;
    Object.keys(this._streams).forEach(function (streamid) {
      var hasTrack = _this15._streams[streamid].getTracks().find(function (track) {
        return sender.track === track;
      });
      if (hasTrack) {
        stream = _this15._streams[streamid];
      }
    });
    if (stream) {
      if (stream.getTracks().length === 1) {
        // if this is the last track of the stream, remove the stream. This
        // takes care of any shimmed _senders.
        this.removeStream(this._reverseStreams[stream.id]);
      } else {
        // relying on the same odd chrome behaviour as above.
        stream.removeTrack(sender.track);
      }
      this.dispatchEvent(new Event('negotiationneeded'));
    }
  };
}
function shimPeerConnection(window, browserDetails) {
  if (!window.RTCPeerConnection && window.webkitRTCPeerConnection) {
    // very basic support for old versions.
    window.RTCPeerConnection = window.webkitRTCPeerConnection;
  }
  if (!window.RTCPeerConnection) {
    return;
  }

  // shim implicit creation of RTCSessionDescription/RTCIceCandidate
  if (browserDetails.version < 53) {
    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate'].forEach(function (method) {
      var nativeMethod = window.RTCPeerConnection.prototype[method];
      var methodObj = _defineProperty({}, method, function () {
        arguments[0] = new (method === 'addIceCandidate' ? window.RTCIceCandidate : window.RTCSessionDescription)(arguments[0]);
        return nativeMethod.apply(this, arguments);
      });
      window.RTCPeerConnection.prototype[method] = methodObj[method];
    });
  }
}

// Attempt to fix ONN in plan-b mode.
function fixNegotiationNeeded(window, browserDetails) {
  utils.wrapPeerConnectionEvent(window, 'negotiationneeded', function (e) {
    var pc = e.target;
    if (browserDetails.version < 72 || pc.getConfiguration && pc.getConfiguration().sdpSemantics === 'plan-b') {
      if (pc.signalingState !== 'stable') {
        return;
      }
    }
    return e;
  });
}