/*
 *  Copyright (c) 2017 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
});

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

exports.shimRTCIceCandidate = shimRTCIceCandidate;
exports.shimMaxMessageSize = shimMaxMessageSize;
exports.shimSendThrowTypeError = shimSendThrowTypeError;
exports.shimConnectionState = shimConnectionState;
exports.removeAllowExtmapMixed = removeAllowExtmapMixed;

var _sdp = require('sdp');

var _sdp2 = _interopRequireDefault(_sdp);

var _utils = require('./utils');

var utils = _interopRequireWildcard(_utils);

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function shimRTCIceCandidate(window) {
  // foundation is arbitrarily chosen as an indicator for full support for
  // https://w3c.github.io/webrtc-pc/#rtcicecandidate-interface
  if (!window.RTCIceCandidate || window.RTCIceCandidate && 'foundation' in window.RTCIceCandidate.prototype) {
    return;
  }

  var NativeRTCIceCandidate = window.RTCIceCandidate;
  window.RTCIceCandidate = function RTCIceCandidate(args) {
    // Remove the a= which shouldn't be part of the candidate string.
    if ((typeof args === 'undefined' ? 'undefined' : _typeof(args)) === 'object' && args.candidate && args.candidate.indexOf('a=') === 0) {
      args = JSON.parse(JSON.stringify(args));
      args.candidate = args.candidate.substr(2);
    }

    if (args.candidate && args.candidate.length) {
      // Augment the native candidate with the parsed fields.
      var nativeCandidate = new NativeRTCIceCandidate(args);
      var parsedCandidate = _sdp2.default.parseCandidate(args.candidate);
      var augmentedCandidate = Object.assign(nativeCandidate, parsedCandidate);

      // Add a serializer that does not serialize the extra attributes.
      augmentedCandidate.toJSON = function toJSON() {
        return {
          candidate: augmentedCandidate.candidate,
          sdpMid: augmentedCandidate.sdpMid,
          sdpMLineIndex: augmentedCandidate.sdpMLineIndex,
          usernameFragment: augmentedCandidate.usernameFragment
        };
      };
      return augmentedCandidate;
    }
    return new NativeRTCIceCandidate(args);
  };
  window.RTCIceCandidate.prototype = NativeRTCIceCandidate.prototype;

  // Hook up the augmented candidate in onicecandidate and
  // addEventListener('icecandidate', ...)
  utils.wrapPeerConnectionEvent(window, 'icecandidate', function (e) {
    if (e.candidate) {
      Object.defineProperty(e, 'candidate', {
        value: new window.RTCIceCandidate(e.candidate),
        writable: 'false'
      });
    }
    return e;
  });
}

function shimMaxMessageSize(window) {
  if (!window.RTCPeerConnection) {
    return;
  }
  var browserDetails = utils.detectBrowser(window);

  if (!('sctp' in window.RTCPeerConnection.prototype)) {
    Object.defineProperty(window.RTCPeerConnection.prototype, 'sctp', {
      get: function get() {
        return typeof this._sctp === 'undefined' ? null : this._sctp;
      }
    });
  }

  var sctpInDescription = function sctpInDescription(description) {
    if (!description || !description.sdp) {
      return false;
    }
    var sections = _sdp2.default.splitSections(description.sdp);
    sections.shift();
    return sections.some(function (mediaSection) {
      var mLine = _sdp2.default.parseMLine(mediaSection);
      return mLine && mLine.kind === 'application' && mLine.protocol.indexOf('SCTP') !== -1;
    });
  };

  var getRemoteFirefoxVersion = function getRemoteFirefoxVersion(description) {
    // TODO: Is there a better solution for detecting Firefox?
    var match = description.sdp.match(/mozilla...THIS_IS_SDPARTA-(\d+)/);
    if (match === null || match.length < 2) {
      return -1;
    }
    var version = parseInt(match[1], 10);
    // Test for NaN (yes, this is ugly)
    return version !== version ? -1 : version;
  };

  var getCanSendMaxMessageSize = function getCanSendMaxMessageSize(remoteIsFirefox) {
    // Every implementation we know can send at least 64 KiB.
    // Note: Although Chrome is technically able to send up to 256 KiB, the
    //       data does not reach the other peer reliably.
    //       See: https://bugs.chromium.org/p/webrtc/issues/detail?id=8419
    var canSendMaxMessageSize = 65536;
    if (browserDetails.browser === 'firefox') {
      if (browserDetails.version < 57) {
        if (remoteIsFirefox === -1) {
          // FF < 57 will send in 16 KiB chunks using the deprecated PPID
          // fragmentation.
          canSendMaxMessageSize = 16384;
        } else {
          // However, other FF (and RAWRTC) can reassemble PPID-fragmented
          // messages. Thus, supporting ~2 GiB when sending.
          canSendMaxMessageSize = 2147483637;
        }
      } else if (browserDetails.version < 60) {
        // Currently, all FF >= 57 will reset the remote maximum message size
        // to the default value when a data channel is created at a later
        // stage. :(
        // See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831
        canSendMaxMessageSize = browserDetails.version === 57 ? 65535 : 65536;
      } else {
        // FF >= 60 supports sending ~2 GiB
        canSendMaxMessageSize = 2147483637;
      }
    }
    return canSendMaxMessageSize;
  };

  var getMaxMessageSize = function getMaxMessageSize(description, remoteIsFirefox) {
    // Note: 65536 bytes is the default value from the SDP spec. Also,
    //       every implementation we know supports receiving 65536 bytes.
    var maxMessageSize = 65536;

    // FF 57 has a slightly incorrect default remote max message size, so
    // we need to adjust it here to avoid a failure when sending.
    // See: https://bugzilla.mozilla.org/show_bug.cgi?id=1425697
    if (browserDetails.browser === 'firefox' && browserDetails.version === 57) {
      maxMessageSize = 65535;
    }

    var match = _sdp2.default.matchPrefix(description.sdp, 'a=max-message-size:');
    if (match.length > 0) {
      maxMessageSize = parseInt(match[0].substr(19), 10);
    } else if (browserDetails.browser === 'firefox' && remoteIsFirefox !== -1) {
      // If the maximum message size is not present in the remote SDP and
      // both local and remote are Firefox, the remote peer can receive
      // ~2 GiB.
      maxMessageSize = 2147483637;
    }
    return maxMessageSize;
  };

  var origSetRemoteDescription = window.RTCPeerConnection.prototype.setRemoteDescription;
  window.RTCPeerConnection.prototype.setRemoteDescription = function setRemoteDescription() {
    this._sctp = null;
    // Chrome decided to not expose .sctp in plan-b mode.
    // As usual, adapter.js has to do an 'ugly worakaround'
    // to cover up the mess.
    if (browserDetails.browser === 'chrome' && browserDetails.version >= 76) {
      var _getConfiguration = this.getConfiguration(),
          sdpSemantics = _getConfiguration.sdpSemantics;

      if (sdpSemantics === 'plan-b') {
        Object.defineProperty(this, 'sctp', {
          get: function get() {
            return typeof this._sctp === 'undefined' ? null : this._sctp;
          },

          enumerable: true,
          configurable: true
        });
      }
    }

    if (sctpInDescription(arguments[0])) {
      // Check if the remote is FF.
      var isFirefox = getRemoteFirefoxVersion(arguments[0]);

      // Get the maximum message size the local peer is capable of sending
      var canSendMMS = getCanSendMaxMessageSize(isFirefox);

      // Get the maximum message size of the remote peer.
      var remoteMMS = getMaxMessageSize(arguments[0], isFirefox);

      // Determine final maximum message size
      var maxMessageSize = void 0;
      if (canSendMMS === 0 && remoteMMS === 0) {
        maxMessageSize = Number.POSITIVE_INFINITY;
      } else if (canSendMMS === 0 || remoteMMS === 0) {
        maxMessageSize = Math.max(canSendMMS, remoteMMS);
      } else {
        maxMessageSize = Math.min(canSendMMS, remoteMMS);
      }

      // Create a dummy RTCSctpTransport object and the 'maxMessageSize'
      // attribute.
      var sctp = {};
      Object.defineProperty(sctp, 'maxMessageSize', {
        get: function get() {
          return maxMessageSize;
        }
      });
      this._sctp = sctp;
    }

    return origSetRemoteDescription.apply(this, arguments);
  };
}

function shimSendThrowTypeError(window) {
  if (!(window.RTCPeerConnection && 'createDataChannel' in window.RTCPeerConnection.prototype)) {
    return;
  }

  // Note: Although Firefox >= 57 has a native implementation, the maximum
  //       message size can be reset for all data channels at a later stage.
  //       See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831

  function wrapDcSend(dc, pc) {
    var origDataChannelSend = dc.send;
    dc.send = function send() {
      var data = arguments[0];
      var length = data.length || data.size || data.byteLength;
      if (dc.readyState === 'open' && pc.sctp && length > pc.sctp.maxMessageSize) {
        throw new TypeError('Message too large (can send a maximum of ' + pc.sctp.maxMessageSize + ' bytes)');
      }
      return origDataChannelSend.apply(dc, arguments);
    };
  }
  var origCreateDataChannel = window.RTCPeerConnection.prototype.createDataChannel;
  window.RTCPeerConnection.prototype.createDataChannel = function createDataChannel() {
    var dataChannel = origCreateDataChannel.apply(this, arguments);
    wrapDcSend(dataChannel, this);
    return dataChannel;
  };
  utils.wrapPeerConnectionEvent(window, 'datachannel', function (e) {
    wrapDcSend(e.channel, e.target);
    return e;
  });
}

/* shims RTCConnectionState by pretending it is the same as iceConnectionState.
 * See https://bugs.chromium.org/p/webrtc/issues/detail?id=6145#c12
 * for why this is a valid hack in Chrome. In Firefox it is slightly incorrect
 * since DTLS failures would be hidden. See
 * https://bugzilla.mozilla.org/show_bug.cgi?id=1265827
 * for the Firefox tracking bug.
 */
function shimConnectionState(window) {
  if (!window.RTCPeerConnection || 'connectionState' in window.RTCPeerConnection.prototype) {
    return;
  }
  var proto = window.RTCPeerConnection.prototype;
  Object.defineProperty(proto, 'connectionState', {
    get: function get() {
      return {
        completed: 'connected',
        checking: 'connecting'
      }[this.iceConnectionState] || this.iceConnectionState;
    },

    enumerable: true,
    configurable: true
  });
  Object.defineProperty(proto, 'onconnectionstatechange', {
    get: function get() {
      return this._onconnectionstatechange || null;
    },
    set: function set(cb) {
      if (this._onconnectionstatechange) {
        this.removeEventListener('connectionstatechange', this._onconnectionstatechange);
        delete this._onconnectionstatechange;
      }
      if (cb) {
        this.addEventListener('connectionstatechange', this._onconnectionstatechange = cb);
      }
    },

    enumerable: true,
    configurable: true
  });

  ['setLocalDescription', 'setRemoteDescription'].forEach(function (method) {
    var origMethod = proto[method];
    proto[method] = function () {
      if (!this._connectionstatechangepoly) {
        this._connectionstatechangepoly = function (e) {
          var pc = e.target;
          if (pc._lastConnectionState !== pc.connectionState) {
            pc._lastConnectionState = pc.connectionState;
            var newEvent = new Event('connectionstatechange', e);
            pc.dispatchEvent(newEvent);
          }
          return e;
        };
        this.addEventListener('iceconnectionstatechange', this._connectionstatechangepoly);
      }
      return origMethod.apply(this, arguments);
    };
  });
}

function removeAllowExtmapMixed(window) {
  /* remove a=extmap-allow-mixed for webrtc.org < M71 */
  if (!window.RTCPeerConnection) {
    return;
  }
  var browserDetails = utils.detectBrowser(window);
  if (browserDetails.browser === 'chrome' && browserDetails.version >= 71) {
    return;
  }
  if (browserDetails.browser === 'safari' && browserDetails.version >= 605) {
    return;
  }
  var nativeSRD = window.RTCPeerConnection.prototype.setRemoteDescription;
  window.RTCPeerConnection.prototype.setRemoteDescription = function setRemoteDescription(desc) {
    if (desc && desc.sdp && desc.sdp.indexOf('\na=extmap-allow-mixed') !== -1) {
      desc.sdp = desc.sdp.split('\n').filter(function (line) {
        return line.trim() !== 'a=extmap-allow-mixed';
      }).join('\n');
    }
    return nativeSRD.apply(this, arguments);
  };
}