<!doctype html>
<meta charset=utf-8>
<title>RTCPeerConnection.prototype.getStats</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="RTCPeerConnection-helper.js"></script>
<script src="dictionary-helper.js"></script>
<script src="RTCStats-helper.js"></script>
<script>
  'use strict';

  // Test is based on the following editor draft:
  // https://w3c.github.io/webrtc-pc/archives/20170605/webrtc.html
  // https://w3c.github.io/webrtc-stats/archives/20170614/webrtc-stats.html

  // The following helper function is called from RTCPeerConnection-helper.js
  //   getTrackFromUserMedia

  // The following helper function is called from RTCStats-helper.js
  //   validateStatsReport
  //   assert_stats_report_has_stats

  /*
    8.2.  RTCPeerConnection Interface Extensions
      partial interface RTCPeerConnection {
        Promise<RTCStatsReport> getStats(optional MediaStreamTrack? selector = null);
      };

    8.3.  RTCStatsReport Object
      interface RTCStatsReport {
        readonly maplike<DOMString, object>;
      };

    8.4.  RTCStats Dictionary
      dictionary RTCStats {
        DOMHighResTimeStamp timestamp;
        RTCStatsType        type;
        DOMString           id;
      };

      id
        Two RTCStats objects, extracted from two different RTCStatsReport objects, MUST
        have the same id if they were produced by inspecting the same underlying object.

    8.2.  getStats
      1.  Let selectorArg be the method's first argument.
      2.  Let connection be the RTCPeerConnection object on which the method was invoked.
      3.  If selectorArg is neither null nor a valid MediaStreamTrack, return a promise
          rejected with a newly created TypeError.
      5.  Let p be a new promise.
      6.  Run the following steps in parallel:
        1.  Gather the stats indicated by selector according to the stats selection algorithm.
        2.  Resolve p with the resulting RTCStatsReport object, containing the gathered stats.
   */

  promise_test(() => {
    const pc = new RTCPeerConnection();
    return pc.getStats();
  }, 'getStats() with no argument should succeed');

  promise_test(() => {
    const pc = new RTCPeerConnection();
    return pc.getStats(null);
  }, 'getStats(null) should succeed');

  /*
    8.2.  getStats
      4.  Let selector be a RTCRtpSender or RTCRtpReceiver on connection which track
          member matches selectorArg. If no such sender or receiver exists, return a promise
          rejected with a newly created InvalidAccessError.
   */
  promise_test(t => {
    const pc = new RTCPeerConnection();
    return getTrackFromUserMedia('audio')
    .then(([track, mediaStream]) => {
      return promise_rejects(t, 'InvalidAccessError', pc.getStats(track));
    });
  }, 'getStats() with track not added to connection should reject with InvalidAccessError');

  promise_test(t => {
    const pc = new RTCPeerConnection();
    return getTrackFromUserMedia('audio')
    .then(([track, mediaStream]) => {
      pc.addTrack(track, mediaStream);
      return pc.getStats(track);
    });
  }, 'getStats() with track added via addTrack should succeed');

  promise_test(t => {
    const pc = new RTCPeerConnection();
    const track = generateMediaStreamTrack();
    pc.addTransceiver(track);

    return pc.getStats(track);
  }, 'getStats() with track added via addTransceiver should succeed');

  /*
    8.2.  getStats
      4.  Let selector be a RTCRtpSender or RTCRtpReceiver on connection which track
          member matches selectorArg. If more than one sender or receiver fit this criteria,
          return a promise rejected with a newly created InvalidAccessError.
   */
  promise_test(t => {
    const pc = new RTCPeerConnection();
    return getTrackFromUserMedia('audio')
    .then(([track, mediaStream]) => {
      // addTransceiver allows adding same track multiple times
      const transceiver1 = pc.addTransceiver(track);
      const transceiver2 = pc.addTransceiver(track);

      assert_not_equals(transceiver1, transceiver2);
      assert_not_equals(transceiver1.sender, transceiver2.sender);
      assert_equals(transceiver1.sender.track, transceiver2.sender.track);

      return promise_rejects(t, 'InvalidAccessError', pc.getStats(track));
    });
  }, `getStats() with track associated with more than one sender should reject with InvalidAccessError`);

  promise_test(t => {
    const pc = new RTCPeerConnection();
    const transceiver1 = pc.addTransceiver('audio');

    // Create another transceiver that resends what
    // is being received, kind of like echo
    const transceiver2 = pc.addTransceiver(transceiver1.receiver.track);
    assert_equals(transceiver1.receiver.track, transceiver2.sender.track);

    return promise_rejects(t, 'InvalidAccessError', pc.getStats(transceiver1.receiver.track));
  }, 'getStats() with track associated with both sender and receiver should reject with InvalidAccessError');

  /*
    8.5.  The stats selection algorithm
      2.  If selector is null, gather stats for the whole connection, add them to result,
          return result, and abort these steps.
   */
  promise_test(t => {
    const pc = new RTCPeerConnection();
    return pc.getStats()
    .then(statsReport => {
      validateStatsReport(statsReport);
      assert_stats_report_has_stats(statsReport, ['peer-connection']);
    });
  }, 'getStats() with no argument should return stats report containing peer-connection stats');

  /*
    8.5.  The stats selection algorithm
      3.  If selector is an RTCRtpSender, gather stats for and add the following objects
          to result:
        - All RTCOutboundRTPStreamStats objects corresponding to selector.
        - All stats objects referenced directly or indirectly by the RTCOutboundRTPStreamStats
          objects added.
   */
  promise_test(() => {
    const pc = new RTCPeerConnection();
    return getTrackFromUserMedia('audio')
    .then(([track, mediaStream]) => {
      pc.addTrack(track, mediaStream);

      return pc.getStats(track)
      .then(statsReport => {
        validateStatsReport(statsReport);
        assert_stats_report_has_stats(statsReport, ['outbound-rtp']);
      });
    });
  }, `getStats() on track associated with RtpSender should return stats report containing outbound-rtp stats`);


  /*
    8.5.  The stats selection algorithm
      4.  If selector is an RTCRtpReceiver, gather stats for and add the following objects
          to result:
        - All RTCInboundRTPStreamStats objects corresponding to selector.
        - All stats objects referenced directly or indirectly by the RTCInboundRTPStreamStats
          added.
   */
  promise_test(() => {
    const pc = new RTCPeerConnection();
    const transceiver = pc.addTransceiver('audio');

    return pc.getStats(transceiver.receiver.track)
    .then(statsReport => {
      validateStatsReport(statsReport);
      assert_stats_report_has_stats(statsReport, ['inbound-rtp']);
    });
  }, `getStats() on track associated with RtpReceiver should return stats report containing inbound-rtp stats`);

</script>