private connectWithPromises()

in src/audiovideocontroller/DefaultAudioVideoController.ts [367:438]
54 lines of code
2 McCabe index (conditional complexity)

  private connectWithPromises(needsToWaitForAttendeePresence: boolean): Task {
    const context = this.meetingSessionContext;

    // Syntactic sugar.
    const timeout = (timeoutMs: number, task: Task): TimeoutTask => {
      return new TimeoutTask(this.logger, task, timeoutMs);
    };

    // First layer.
    this.monitorTask = new MonitorTask(
      context,
      this.configuration.connectionHealthPolicyConfiguration,
      this.connectionHealthData
    );
    const monitor = this.monitorTask.once();

    // Second layer.
    const receiveAudioInput = new ReceiveAudioInputTask(context).once();
    this.receiveIndexTask = new ReceiveVideoStreamIndexTask(context);
    // See declaration (unpaused in actionFinishConnecting)
    this.monitorTask.pauseResubscribeCheck();
    this.receiveIndexTask.pauseIngestion();
    const signaling = new SerialGroupTask(this.logger, 'Signaling', [
      // If pre-connecting, this will be an existing task that has already been run.
      this.createOrReuseSignalingTask(),
      new ListenForVolumeIndicatorsTask(context),
      new SendAndReceiveDataMessagesTask(context),
      new JoinAndReceiveIndexTask(context),
      this.receiveIndexTask,
    ]).once();

    // Third layer.
    const createPeerConnection = new CreatePeerConnectionTask(context).once(signaling);
    const attachMediaInput = new AttachMediaInputTask(context).once(
      createPeerConnection,
      receiveAudioInput
    );

    // Mostly serial section -- kept as promises to allow for finer-grained breakdown.
    const createSDP = new CreateSDPTask(context).once(attachMediaInput);
    const setLocalDescription = new SetLocalDescriptionTask(context).once(createSDP);
    const ice = new FinishGatheringICECandidatesTask(context).once(setLocalDescription);
    const subscribeAck = new SubscribeAndReceiveSubscribeAckTask(context).once(ice);

    this.receiveRemotePauseResumeTask = new ReceiveRemoteVideoPauseResume(context);
    this.receiveRemotePauseResumeTask.once(subscribeAck);

    // The ending is a delicate time: we need the connection as a whole to have a timeout,
    // and for the attendee presence timer to not start ticking until after the subscribe/ack.
    return new SerialGroupTask(this.logger, this.wrapTaskName('AudioVideoStart'), [
      monitor,
      timeout(
        this.configuration.connectionTimeoutMs,
        new SerialGroupTask(this.logger, 'Peer', [
          // The order of these two matters. If canceled, the first one that's still running
          // will contribute any special rejection, and we don't want that to be "attendee not found"!
          subscribeAck,
          this.receiveRemotePauseResumeTask,
          needsToWaitForAttendeePresence
            ? new TimeoutTask(
                this.logger,
                new ParallelGroupTask(this.logger, 'FinalizeConnection', [
                  new WaitForAttendeePresenceTask(context),
                  new SetRemoteDescriptionTask(context),
                ]),
                this.meetingSessionContext.meetingSessionConfiguration.attendeePresenceTimeoutMs
              )
            : /* istanbul ignore next */ new SetRemoteDescriptionTask(context),
        ])
      ),
    ]);
  }