bigbluebutton-Github/bigbluebutton-html5/imports/api/audio/client/bridge/sip.js

import browser from 'browser-detect';
import BaseAudioBridge from './base';
import logger from '/imports/startup/client/logger';
import {
  fetchWebRTCMappedStunTurnServers,
  getMappedFallbackStun,
} from '/imports/utils/fetchStunTurnServers';
import {
  isUnifiedPlan,
  toUnifiedPlan,
  toPlanB,
  stripMDnsCandidates,
  analyzeSdp,
  logSelectedCandidate,
} from '/imports/utils/sdpUtils';
import { Tracker } from 'meteor/tracker';
import VoiceCallStates from '/imports/api/voice-call-states';
import CallStateOptions from '/imports/api/voice-call-states/utils/callStates';
import Auth from '/imports/ui/services/auth';

const MEDIA = Meteor.settings.public.media;
const MEDIA_TAG = MEDIA.mediaTag;
const CALL_TRANSFER_TIMEOUT = MEDIA.callTransferTimeout;
const CALL_HANGUP_TIMEOUT = MEDIA.callHangupTimeout;
const CALL_HANGUP_MAX_RETRIES = MEDIA.callHangupMaximumRetries;
const IPV4_FALLBACK_DOMAIN = Meteor.settings.public.app.ipv4FallbackDomain;
const CALL_CONNECT_TIMEOUT = 20000;
const ICE_NEGOTIATION_TIMEOUT = 20000;
const AUDIO_SESSION_NUM_KEY = 'AudioSessionNumber';
const USER_AGENT_RECONNECTION_ATTEMPTS = 7;
const USER_AGENT_RECONNECTION_DELAY_MS = 5000;
const USER_AGENT_CONNECTION_TIMEOUT_MS = 5000;
const ICE_GATHERING_TIMEOUT = MEDIA.iceGatheringTimeout || 5000;

const getAudioSessionNumber = () => {
  let currItem = parseInt(sessionStorage.getItem(AUDIO_SESSION_NUM_KEY), 10);
  if (!currItem) {
    currItem = 0;
  }

  currItem += 1;
  sessionStorage.setItem(AUDIO_SESSION_NUM_KEY, currItem);
  return currItem;
};


/**
  * Get error code from SIP.js websocket messages.
 */
const getErrorCode = (error) => {
  try {
    if (!error) return error;

    const match = error.message.match(/code: \d+/g);

    const _codeArray = match[0].split(':');

    return parseInt(_codeArray[1].trim(), 10);
  } catch (e) {
    return 0;
  }
};

class SIPSession {
  constructor(user, userData, protocol, hostname,
    baseCallStates, baseErrorCodes, reconnectAttempt) {
    this.user = user;
    this.userData = userData;
    this.protocol = protocol;
    this.hostname = hostname;
    this.baseCallStates = baseCallStates;
    this.baseErrorCodes = baseErrorCodes;
    this.reconnectAttempt = reconnectAttempt;
    this.currentSession = null;
    this.remoteStream = null;
    this.inputDeviceId = null;
    this._hangupFlag = false;
    this._reconnecting = false;
    this._currentSessionState = null;
  }

  joinAudio({ isListenOnly, extension, inputDeviceId }, managerCallback) {
    return new Promise((resolve, reject) => {
      const callExtension = extension ? `${extension}${this.userData.voiceBridge}` : this.userData.voiceBridge;

      const callback = (message) => {
        // There will sometimes we erroneous errors put out like timeouts and improper shutdowns,
        // but only the first error ever matters
        if (this.alreadyErrored) {
          logger.info({
            logCode: 'sip_js_absorbing_callback_message',
            extraInfo: { message },
          }, 'Absorbing a redundant callback message.');
          return;
        }

        if (message.status === this.baseCallStates.failed) {
          this.alreadyErrored = true;
        }

        managerCallback(message).then(resolve);
      };

      this.callback = callback;

      // If there's an extension passed it means that we're joining the echo test first
      this.inEchoTest = !!extension;

      return this.doCall({ callExtension, isListenOnly, inputDeviceId })
        .catch((reason) => {
          reject(reason);
        });
    });
  }

  async getIceServers(sessionToken) {
    try {
      const iceServers = await fetchWebRTCMappedStunTurnServers(sessionToken);
      return iceServers;
    } catch (error) {
      logger.error({
        logCode: 'sip_js_fetchstunturninfo_error',
        extraInfo: {
          errorCode: error.code,
          errorMessage: error.message,
          callerIdName: this.user.callerIdName,
        },
      }, 'Full audio bridge failed to fetch STUN/TURN info');
      return getMappedFallbackStun();
    }
  }

  doCall(options) {
    const {
      isListenOnly,
      inputDeviceId,
    } = options;

    this.inputDeviceId = inputDeviceId;

    const {
      userId,
      name,
      sessionToken,
    } = this.user;

    const callerIdName = [
      `${userId}_${getAudioSessionNumber()}`,
      'bbbID',
      isListenOnly ? `LISTENONLY-${name}` : name,
    ].join('-').replace(/"/g, "'");

    this.user.callerIdName = callerIdName;
    this.callOptions = options;

    return this.getIceServers(sessionToken)
      .then(this.createUserAgent.bind(this))
      .then(this.inviteUserAgent.bind(this));
  }

  transferCall(onTransferSuccess) {
    return new Promise((resolve, reject) => {
      this.inEchoTest = false;

      let trackerControl = null;

      const timeout = setTimeout(() => {
        trackerControl.stop();
        logger.error({ logCode: 'sip_js_transfer_timed_out' }, 'Timeout on transferring from echo test to conference');
        this.callback({
          status: this.baseCallStates.failed,
          error: 1008,
          bridgeError: 'Timeout on call transfer',
        });

        this.exitAudio();

        reject(this.baseErrorCodes.REQUEST_TIMEOUT);
      }, CALL_TRANSFER_TIMEOUT);

      // This is is the call transfer code ask @chadpilkey
      if (this.sessionSupportRTPPayloadDtmf(this.currentSession)) {
        this.currentSession.sessionDescriptionHandler.sendDtmf(1);
      } else {
        // RFC4733 not supported , sending DTMF through INFO
        logger.debug({
          logCode: 'sip_js_rtp_payload_dtmf_not_supported',
          extraInfo: {
            callerIdName: this.user.callerIdName,
          },
        }, 'Browser do not support payload dtmf, using INFO instead');
        this.sendDtmf(1);
      }

      Tracker.autorun((c) => {
        trackerControl = c;
        const selector = { meetingId: Auth.meetingID, userId: Auth.userID };
        const query = VoiceCallStates.find(selector);

        query.observeChanges({
          changed: (id, fields) => {
            if (fields.callState === CallStateOptions.IN_CONFERENCE) {
              clearTimeout(timeout);
              onTransferSuccess();

              c.stop();
              resolve();
            }
          },
        });
      });
    });
  }

  /**
    *
    * sessionSupportRTPPayloadDtmf
    * tells if browser support RFC4733 DTMF.
    * Safari 13 doens't support it yet
    */
  sessionSupportRTPPayloadDtmf(session) {
    try {
      const sessionDescriptionHandler = session
        ? session.sessionDescriptionHandler
        : this.currentSession.sessionDescriptionHandler;

      const senders = sessionDescriptionHandler.peerConnection.getSenders();
      return !!(senders[0].dtmf);
    } catch (error) {
      return false;
    }
  }

  /**
    * sendDtmf - send DTMF Tones using INFO message
    *
    * same as SimpleUser's dtmf
    */
  sendDtmf(tone) {
    const dtmf = tone;
    const duration = 2000;
    const body = {
      contentDisposition: 'render',
      contentType: 'application/dtmf-relay',
      content: `Signal=${dtmf}\r\nDuration=${duration}`,
    };
    const requestOptions = { body };
    return this.currentSession.info({ requestOptions });
  }

  exitAudio() {
    return new Promise((resolve, reject) => {
      let hangupRetries = 0;
      this._hangupFlag = false;

      this.userRequestedHangup = true;

      const tryHangup = () => {
        if (this._hangupFlag) {
          resolve();
        }

        if ((this.currentSession
          && (this.currentSession.state === SIP.SessionState.Terminated))
          || (this.userAgent && (!this.userAgent.isConnected()))) {
          this._hangupFlag = true;
          return resolve();
        }

        if (this.currentSession
          && ((this.currentSession.state === SIP.SessionState.Establishing))) {
          this.currentSession.cancel().then(() => {
            this._hangupFlag = true;
            return resolve();
          });
        }

        if (this.currentSession
          && ((this.currentSession.state === SIP.SessionState.Established))) {
          this.currentSession.bye().then(() => {
            this._hangupFlag = true;
            return resolve();
          });
        }

        if (this.userAgent && this.userAgent.isConnected()) {
          this.userAgent.stop();
          window.removeEventListener('beforeunload', this.onBeforeUnload);
        }


        hangupRetries += 1;

        setTimeout(() => {
          if (hangupRetries > CALL_HANGUP_MAX_RETRIES) {
            this.callback({
              status: this.baseCallStates.failed,
              error: 1006,
              bridgeError: 'Timeout on call hangup',
            });
            return reject(this.baseErrorCodes.REQUEST_TIMEOUT);
          }

          if (!this._hangupFlag) return tryHangup();
          return resolve();
        }, CALL_HANGUP_TIMEOUT);
      };

      return tryHangup();
    });
  }

  stopUserAgent() {
    if (this.userAgent && (typeof this.userAgent.stop === 'function')) {
      return this.userAgent.stop();
    }
    return Promise.resolve();
  }

  onBeforeUnload() {
    this.userRequestedHangup = true;
    return this.stopUserAgent();
  }

  createUserAgent(iceServers) {
    return new Promise((resolve, reject) => {
      if (this.userRequestedHangup === true) reject();

      const {
        hostname,
        protocol,
      } = this;

      const {
        callerIdName,
        sessionToken,
      } = this.user;

      logger.debug({ logCode: 'sip_js_creating_user_agent', extraInfo: { callerIdName } }, 'Creating the user agent');

      if (this.userAgent && this.userAgent.isConnected()) {
        if (this.userAgent.configuration.hostPortParams === this.hostname) {
          logger.debug({ logCode: 'sip_js_reusing_user_agent', extraInfo: { callerIdName } }, 'Reusing the user agent');
          resolve(this.userAgent);
          return;
        }
        logger.debug({ logCode: 'sip_js_different_host_name', extraInfo: { callerIdName } }, 'Different host name. need to kill');
      }

      const localSdpCallback = (sdp) => {
        // For now we just need to call the utils function to parse and log the different pieces.
        // In the future we're going to want to be tracking whether there were TURN candidates
        // and IPv4 candidates to make informed decisions about what to do on fallbacks/reconnects.
        analyzeSdp(sdp);
      };

      const remoteSdpCallback = (sdp) => {
        // We have have to find the candidate that FS sends back to us to determine if the client
        // is connecting with IPv4 or IPv6
        const sdpInfo = analyzeSdp(sdp, false);
        this.protocolIsIpv6 = sdpInfo.v6Info.found;
      };

      let userAgentConnected = false;
      const token = `sessionToken=${sessionToken}`;

      this.userAgent = new SIP.UserAgent({
        uri: SIP.UserAgent.makeURI(`sip:${encodeURIComponent(callerIdName)}@${hostname}`),
        transportOptions: {
          server: `${(protocol === 'https:' ? 'wss://' : 'ws://')}${hostname}/ws?${token}`,
          connectionTimeout: USER_AGENT_CONNECTION_TIMEOUT_MS,
        },
        sessionDescriptionHandlerFactoryOptions: {
          peerConnectionConfiguration: {
            iceServers,
          },
        },
        displayName: callerIdName,
        register: false,
        userAgentString: 'BigBlueButton',
      });

      const handleUserAgentConnection = () => {
        if (!userAgentConnected) {
          userAgentConnected = true;
          resolve(this.userAgent);
        }
      };

      const handleUserAgentDisconnection = () => {
        if (this.userAgent) {
          if (this.userRequestedHangup) {
            userAgentConnected = false;
            return;
          }

          let error;
          let bridgeError;

          if (!this._reconnecting) {

            logger.info({
              logCode: 'sip_js_session_ua_disconnected',
              extraInfo: {
                callerIdName: this.user.callerIdName,
              },
            }, 'User agent disconnected: trying to reconnect...'
              + ` (userHangup = ${!!this.userRequestedHangup})`);

            logger.info({
              logCode: 'sip_js_session_ua_reconnecting',
              extraInfo: {
                callerIdName: this.user.callerIdName,
              },
            }, 'User agent disconnected, reconnecting');

            this.reconnect().then(() => {
              logger.info({
                logCode: 'sip_js_session_ua_reconnected',
                extraInfo: {
                  callerIdName: this.user.callerIdName,
                },
              }, 'User agent succesfully reconnected');
            }).catch(() => {
              if (userAgentConnected) {
                error = 1001;
                bridgeError = 'Websocket disconnected';
              } else {
                error = 1002;
                bridgeError = 'Websocket failed to connect';
              }

              this.stopUserAgent();

              this.callback({
                status: this.baseCallStates.failed,
                error,
                bridgeError,
              });
              reject(this.baseErrorCodes.CONNECTION_ERROR);
            });
          }
        }
      };

      this.userAgent.transport.onConnect = handleUserAgentConnection;
      this.userAgent.transport.onDisconnect = handleUserAgentDisconnection;

      const preturn = this.userAgent.start().then(() => {
        logger.info({
          logCode: 'sip_js_session_ua_connected',
          extraInfo: {
            callerIdName: this.user.callerIdName,
          },
        }, 'User agent succesfully connected');

        window.addEventListener('beforeunload', this.onBeforeUnload.bind(this));

        resolve();
      }).catch((error) => {
        logger.info({
          logCode: 'sip_js_session_ua_reconnecting',
          extraInfo: {
            callerIdName: this.user.callerIdName,
          },
        }, 'User agent failed to connect, reconnecting');

        const code = getErrorCode(error);


        if (code === 1006) {
          this.stopUserAgent();

          this.callback({
            status: this.baseCallStates.failed,
            error: 1006,
            bridgeError: 'Websocket failed to connect',
          });
          return reject({
            type: this.baseErrorCodes.CONNECTION_ERROR,
          });
        }

        this.reconnect().then(() => {
          logger.info({
            logCode: 'sip_js_session_ua_reconnected',
            extraInfo: {
              callerIdName: this.user.callerIdName,
            },
          }, 'User agent succesfully reconnected');

          resolve();
        }).catch(() => {
          this.stopUserAgent();

          logger.info({
            logCode: 'sip_js_session_ua_disconnected',
            extraInfo: {
              callerIdName: this.user.callerIdName,
            },
          }, 'User agent failed to reconnect after'
            + ` ${USER_AGENT_RECONNECTION_ATTEMPTS} attemps`);

          this.callback({
            status: this.baseCallStates.failed,
            error: 1002,
            bridgeError: 'Websocket failed to connect',
          });

          reject({
            type: this.baseErrorCodes.CONNECTION_ERROR,
          });
        });
      });

      return preturn;
    });
  }

  reconnect(attempts = 1) {
    return new Promise((resolve, reject) => {
      if (this._reconnecting) {
        return resolve();
      }

      if (attempts > USER_AGENT_RECONNECTION_ATTEMPTS) {
        return reject({
          type: this.baseErrorCodes.CONNECTION_ERROR,
        });
      }

      this._reconnecting = true;

      logger.info({
        logCode: 'sip_js_session_ua_reconnection_attempt',
        extraInfo: {
          callerIdName: this.user.callerIdName,
        },
      }, `User agent reconnection attempt ${attempts}`);

      setTimeout(() => {
        this.userAgent.reconnect().then(() => {
          this._reconnecting = false;
          resolve();
        }).catch(() => {
          this._reconnecting = false;
          this.reconnect(++attempts).then(() => {
            resolve();
          }).catch((error) => {
            reject(error);
          });
        });
      }, USER_AGENT_RECONNECTION_DELAY_MS);
    });
  }

  inviteUserAgent(userAgent) {
    return new Promise((resolve, reject) => {
      if (this.userRequestedHangup === true) reject();
      const {
        hostname,
      } = this;

      const {
        callExtension,
        isListenOnly,
      } = this.callOptions;


      const target = SIP.UserAgent.makeURI(`sip:${callExtension}@${hostname}`);

      const audioDeviceConstraint = this.inputDeviceId
        ? { deviceId: { exact: this.inputDeviceId } }
        : true;

      const inviterOptions = {
        sessionDescriptionHandlerOptions: {
          constraints: {
            audio: isListenOnly
              ? false
              : audioDeviceConstraint,
            video: false,
          },
          iceGatheringTimeout: ICE_GATHERING_TIMEOUT,
        },
        sessionDescriptionHandlerModifiersPostICEGathering:
          [stripMDnsCandidates],
      };


      if (isListenOnly) {
        inviterOptions.sessionDescriptionHandlerOptions.offerOptions = {
          offerToReceiveAudio: true,
        };
      }

      const inviter = new SIP.Inviter(userAgent, target, inviterOptions);
      this.currentSession = inviter;

      this.setupEventHandlers(inviter).then(() => {
        inviter.invite().then(() => {
          resolve();
        }).catch(e => reject(e));
      });
    });
  }

  setupEventHandlers(currentSession) {
    return new Promise((resolve, reject) => {
      if (this.userRequestedHangup === true) reject();

      let iceCompleted = false;
      let fsReady = false;

      const setupRemoteMedia = () => {
        const mediaElement = document.querySelector(MEDIA_TAG);

        this.remoteStream = new MediaStream();

        this.currentSession.sessionDescriptionHandler
          .peerConnection.getReceivers().forEach((receiver) => {
            if (receiver.track) {
              this.remoteStream.addTrack(receiver.track);
            }
          });

        logger.info({
          logCode: 'sip_js_session_playing_remote_media',
          extraInfo: {
            callerIdName: this.user.callerIdName,
          },
        }, 'Audio call - playing remote media');

        mediaElement.srcObject = this.remoteStream;
        mediaElement.play();
      };

      const checkIfCallReady = () => {
        if (this.userRequestedHangup === true) {
          this.exitAudio();
          resolve();
        }

        logger.info({
          logCode: 'sip_js_session_check_if_call_ready',
          extraInfo: {
            iceCompleted,
            fsReady,
          },
        }, 'Audio call - check if ICE is finished and FreeSWITCH is ready');
        if (iceCompleted && fsReady) {
          this.webrtcConnected = true;
          setupRemoteMedia();

          const { sdp } = this.currentSession.sessionDescriptionHandler
            .peerConnection.remoteDescription;

          logger.info({
            logCode: 'sip_js_session_setup_remote_media',
            extraInfo: {
              callerIdName: this.user.callerIdName,
              sdp,
            },
          }, 'Audio call - setup remote media');

          this.callback({ status: this.baseCallStates.started });
          resolve();
        }
      };

      // Sometimes FreeSWITCH just won't respond with anything and hangs. This timeout is to
      // avoid that issue
      const callTimeout = setTimeout(() => {
        this.callback({
          status: this.baseCallStates.failed,
          error: 1006,
          bridgeError: `Call timed out on start after ${CALL_CONNECT_TIMEOUT / 1000}s`,
        });

        this.exitAudio();
      }, CALL_CONNECT_TIMEOUT);

      let iceNegotiationTimeout;

      const handleSessionAccepted = () => {
        logger.info({ logCode: 'sip_js_session_accepted', extraInfo: { callerIdName: this.user.callerIdName } }, 'Audio call session accepted');
        clearTimeout(callTimeout);

        // If ICE isn't connected yet then start timeout waiting for ICE to finish
        if (!iceCompleted) {
          iceNegotiationTimeout = setTimeout(() => {
            this.callback({
              status: this.baseCallStates.failed,
              error: 1010,
              bridgeError: 'ICE negotiation timeout after '
                + `${ICE_NEGOTIATION_TIMEOUT / 1000}s`,
            });

            this.exitAudio();

            reject({
              type: this.baseErrorCodes.CONNECTION_ERROR,
            });
          }, ICE_NEGOTIATION_TIMEOUT);
        }
        checkIfCallReady();
      };

      const handleIceNegotiationFailed = (peer) => {
        if (iceCompleted) {
          logger.error({
            logCode: 'sipjs_ice_failed_after',
            extraInfo: {
              callerIdName: this.user.callerIdName,
            },
          }, 'ICE connection failed after success');
        } else {
          logger.error({
            logCode: 'sipjs_ice_failed_before',
            extraInfo: {
              callerIdName: this.user.callerIdName,
            },
          }, 'ICE connection failed before success');
        }
        clearTimeout(callTimeout);
        clearTimeout(iceNegotiationTimeout);
        this.callback({
          status: this.baseCallStates.failed,
          error: 1007,
          bridgeError: 'ICE negotiation failed. Current state '
            + `- ${peer.iceConnectionState}`,
        });
      };

      const handleIceConnectionTerminated = (peer) => {
        if (!this.userRequestedHangup) {
          logger.error({
            logCode: 'sipjs_ice_closed',
            extraInfo: {
              callerIdName: this.user.callerIdName,
            },
          }, 'ICE connection closed');
        }

        this.callback({
          status: this.baseCallStates.failed,
          error: 1012,
          bridgeError: 'ICE connection closed. Current state -'
            + `${peer.iceConnectionState}`,
        });
      };

      const handleSessionProgress = (update) => {
        logger.info({
          logCode: 'sip_js_session_progress',
          extraInfo: {
            callerIdName: this.user.callerIdName,
            update,
          },
        }, 'Audio call session progress update');

        this.currentSession.sessionDescriptionHandler.peerConnectionDelegate = {
          onconnectionstatechange: (event) => {
            const peer = event.target;

            switch (peer.connectionState) {
              case 'connected':
                if (iceCompleted) {
                  logger.info({
                    logCode: 'sip_js_ice_connection_success_after_success',
                    extraInfo: {
                      currentState: peer.connectionState,
                      callerIdName: this.user.callerIdName,
                    },
                  }, 'ICE connection success, but user is already connected'
                      + 'ignoring it...'
                      + `${peer.iceConnectionState}`);

                  return;
                }

                logger.info({
                  logCode: 'sip_js_ice_connection_success',
                  extraInfo: {
                    currentState: peer.connectionState,
                    callerIdName: this.user.callerIdName,
                  },
                }, 'ICE connection success. Current state - '
                    + `${peer.iceConnectionState}`);

                clearTimeout(callTimeout);
                clearTimeout(iceNegotiationTimeout);

                iceCompleted = true;

                logSelectedCandidate(peer, this.protocolIsIpv6);

                checkIfCallReady();
                break;
              case 'failed':
                handleIceNegotiationFailed(peer);
                break;

              case 'closed':
                handleIceConnectionTerminated(peer);
                break;
              default:
                break;
            }
          },
        };
      };

      const handleSessionTerminated = (message) => {
        clearTimeout(callTimeout);
        clearTimeout(iceNegotiationTimeout);

        if (!message && !!this.userRequestedHangup) {
          return this.callback({
            status: this.baseCallStates.ended,
          });
        }

        // if session hasn't even started, we let audio-modal to handle
        // any possile errors
        if (!this._currentSessionState) return false;


        let mappedCause;
        let cause;
        if (!iceCompleted) {
          mappedCause = '1004';
          cause = 'ICE error';
        } else {
          cause = 'Audio Conference Error';
          mappedCause = '1005';
        }

        logger.error({
          logCode: 'sip_js_call_terminated',
          extraInfo: { cause, callerIdName: this.user.callerIdName },
        }, `Audio call terminated. cause=${cause}`);

        return this.callback({
          status: this.baseCallStates.failed,
          error: mappedCause,
          bridgeError: cause,
        });
      };

      currentSession.stateChange.addListener((state) => {
        switch (state) {
          case SIP.SessionState.Initial:
            break;
          case SIP.SessionState.Establishing:
            handleSessionProgress();
            break;
          case SIP.SessionState.Established:
            handleSessionAccepted();
            break;
          case SIP.SessionState.Terminating:
            break;
          case SIP.SessionState.Terminated:
            handleSessionTerminated();
            break;
          default:
            logger.error({
              logCode: 'sipjs_ice_session_unknown_state',
              extraInfo: {
                callerIdName: this.user.callerIdName,
              },
            }, 'SIP.js unknown session state');
            break;
        }
        this._currentSessionState = state;
      });

      Tracker.autorun((c) => {
        const selector = { meetingId: Auth.meetingID, userId: Auth.userID };
        const query = VoiceCallStates.find(selector);

        query.observeChanges({
          changed: (id, fields) => {
            if ((this.inEchoTest && fields.callState === CallStateOptions.IN_ECHO_TEST)
              || (!this.inEchoTest && fields.callState === CallStateOptions.IN_CONFERENCE)) {
              fsReady = true;
              checkIfCallReady();

              c.stop();
            }
          },
        });
      });

      resolve();
    });
  }
}

export default class SIPBridge extends BaseAudioBridge {
  constructor(userData) {
    super(userData);

    const {
      userId,
      username,
      sessionToken,
    } = userData;

    this.user = {
      userId,
      sessionToken,
      name: username,
    };

    this.media = {
      inputDevice: {},
    };

    this.protocol = window.document.location.protocol;
    this.hostname = window.document.location.hostname;

    // SDP conversion utilitary methods to be used inside SIP.js
    window.isUnifiedPlan = isUnifiedPlan;
    window.toUnifiedPlan = toUnifiedPlan;
    window.toPlanB = toPlanB;
    window.stripMDnsCandidates = stripMDnsCandidates;

    // No easy way to expose the client logger to sip.js code so we need to attach it globally
    window.clientLogger = logger;
  }

  get inputDeviceId () {
    return this.media.inputDevice ? this.media.inputDevice.inputDeviceId : null;
  }

  joinAudio({ isListenOnly, extension }, managerCallback) {
    const hasFallbackDomain = typeof IPV4_FALLBACK_DOMAIN === 'string' && IPV4_FALLBACK_DOMAIN !== '';

    return new Promise((resolve, reject) => {
      let { hostname } = this;

      this.activeSession = new SIPSession(this.user, this.userData, this.protocol,
        hostname, this.baseCallStates, this.baseErrorCodes, false);

      const callback = (message) => {
        if (message.status === this.baseCallStates.failed) {
          let shouldTryReconnect = false;

          // Try and get the call to clean up and end on an error
          this.activeSession.exitAudio().catch(() => {});

          if (this.activeSession.webrtcConnected) {
            // webrtc was able to connect so just try again
            message.silenceNotifications = true;
            callback({ status: this.baseCallStates.reconnecting });
            shouldTryReconnect = true;
          } else if (hasFallbackDomain === true && hostname !== IPV4_FALLBACK_DOMAIN) {
            message.silenceNotifications = true;
            logger.info({ logCode: 'sip_js_attempt_ipv4_fallback', extraInfo: { callerIdName: this.user.callerIdName } }, 'Attempting to fallback to IPv4 domain for audio');
            hostname = IPV4_FALLBACK_DOMAIN;
            shouldTryReconnect = true;
          }

          if (shouldTryReconnect) {
            const fallbackExtension = this.activeSession.inEchoTest ? extension : undefined;
            this.activeSession = new SIPSession(this.user, this.userData, this.protocol,
              hostname, this.baseCallStates, this.baseErrorCodes, true);
            const { inputDeviceId } = this.media.inputDevice;
            this.activeSession.joinAudio({
              isListenOnly,
              extension: fallbackExtension,
              inputDeviceId,
            }, callback)
              .then((value) => {
                resolve(value);
              }).catch((reason) => {
                reject(reason);
              });
          }
        }

        return managerCallback(message);
      };

      const { inputDeviceId } = this.media.inputDevice;
      this.activeSession.joinAudio({
        isListenOnly,
        extension,
        inputDeviceId,
      }, callback)
        .then((value) => {
          resolve(value);
        }).catch((reason) => {
          reject(reason);
        });
    });
  }

  transferCall(onTransferSuccess) {
    return this.activeSession.transferCall(onTransferSuccess);
  }

  getPeerConnection() {
    const { currentSession } = this.activeSession;
    if (currentSession && currentSession.sessionDescriptionHandler) {
      return currentSession.sessionDescriptionHandler.peerConnection;
    }
    return null;
  }

  exitAudio() {
    return this.activeSession.exitAudio();
  }

  setDefaultInputDevice() {
    this.media.inputDevice.inputDeviceId = DEFAULT_INPUT_DEVICE_ID;
  }

  async changeInputDeviceId(inputDeviceId) {
    if (!inputDeviceId) {
      throw new Error();
    }

    this.media.inputDevice.inputDeviceId = inputDeviceId;
    return inputDeviceId;
  }

  async changeOutputDevice(value) {
    const audioContext = document.querySelector(MEDIA_TAG);

    if (audioContext.setSinkId) {
      try {
        audioContext.srcObject = null;
        await audioContext.setSinkId(value);
        this.media.outputDeviceId = value;
      } catch (err) {
        logger.error({
          logCode: 'audio_sip_changeoutputdevice_error',
          extraInfo: { error: err, callerIdName: this.user.callerIdName },
        }, 'Change Output Device error');
        throw new Error(this.baseErrorCodes.MEDIA_ERROR);
      }
    }

    return this.media.outputDeviceId || value;
  }
}