RTCPeerConnection.prototype.addIceCandidate = function()

in monitoring-stack-cdk/resources/frontend/connect-rtc.js [4505:4587]
75 lines of code
27 McCabe index (conditional complexity)

      RTCPeerConnection.prototype.addIceCandidate = function(candidate) {
        var pc = this;
        var sections;
        if (candidate && !(candidate.sdpMLineIndex !== undefined ||
            candidate.sdpMid)) {
          return Promise.reject(new TypeError('sdpMLineIndex or sdpMid required'));
        }
    
        // TODO: needs to go into ops queue.
        return new Promise(function(resolve, reject) {
          if (!pc._remoteDescription) {
            return reject(makeError('InvalidStateError',
                'Can not add ICE candidate without a remote description'));
          } else if (!candidate || candidate.candidate === '') {
            for (var j = 0; j < pc.transceivers.length; j++) {
              if (pc.transceivers[j].rejected) {
                continue;
              }
              pc.transceivers[j].iceTransport.addRemoteCandidate({});
              sections = SDPUtils.getMediaSections(pc._remoteDescription.sdp);
              sections[j] += 'a=end-of-candidates\r\n';
              pc._remoteDescription.sdp =
                  SDPUtils.getDescription(pc._remoteDescription.sdp) +
                  sections.join('');
              if (pc.usingBundle) {
                break;
              }
            }
          } else {
            var sdpMLineIndex = candidate.sdpMLineIndex;
            if (candidate.sdpMid) {
              for (var i = 0; i < pc.transceivers.length; i++) {
                if (pc.transceivers[i].mid === candidate.sdpMid) {
                  sdpMLineIndex = i;
                  break;
                }
              }
            }
            var transceiver = pc.transceivers[sdpMLineIndex];
            if (transceiver) {
              if (transceiver.rejected) {
                return resolve();
              }
              var cand = Object.keys(candidate.candidate).length > 0 ?
                  SDPUtils.parseCandidate(candidate.candidate) : {};
              // Ignore Chrome's invalid candidates since Edge does not like them.
              if (cand.protocol === 'tcp' && (cand.port === 0 || cand.port === 9)) {
                return resolve();
              }
              // Ignore RTCP candidates, we assume RTCP-MUX.
              if (cand.component && cand.component !== 1) {
                return resolve();
              }
              // when using bundle, avoid adding candidates to the wrong
              // ice transport. And avoid adding candidates added in the SDP.
              if (sdpMLineIndex === 0 || (sdpMLineIndex > 0 &&
                  transceiver.iceTransport !== pc.transceivers[0].iceTransport)) {
                if (!maybeAddCandidate(transceiver.iceTransport, cand)) {
                  return reject(makeError('OperationError',
                      'Can not add ICE candidate'));
                }
              }
    
              // update the remoteDescription.
              var candidateString = candidate.candidate.trim();
              if (candidateString.indexOf('a=') === 0) {
                candidateString = candidateString.substr(2);
              }
              sections = SDPUtils.getMediaSections(pc._remoteDescription.sdp);
              sections[sdpMLineIndex] += 'a=' +
                  (cand.type ? candidateString : 'end-of-candidates')
                  + '\r\n';
              pc._remoteDescription.sdp =
                  SDPUtils.getDescription(pc._remoteDescription.sdp) +
                  sections.join('');
            } else {
              return reject(makeError('OperationError',
                  'Can not add ICE candidate'));
            }
          }
          resolve();
        });
      };