<!DOCTYPE html>
<html>
<title>MediaSource-in-Worker buffering test case with media element detachment at various places</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="mediasource-message-util.js"></script>
<body>
<script>

const AFTER_SETTING_SRCOBJECT = "after setting srcObject";
const AFTER_STARTED_BUFFERING = "after receiving Started Buffering message from worker";
const AFTER_FINISHED_BUFFERING = "after receiving Finished Buffering message from worker";

[ AFTER_SETTING_SRCOBJECT, AFTER_STARTED_BUFFERING, AFTER_FINISHED_BUFFERING ].forEach(when => {
  for (let timeouts = 0; timeouts < 5; ++timeouts) {
    async_test(test => { startWorkerAndDetachElement(test, when, timeouts); },
        "Test element detachment from worker MediaSource after at least " + timeouts +
          " main thread setTimeouts, starting counting " + when);
  }
});

function detachElementAfterMultipleSetTimeouts(test, element, timeouts_remaining) {
  if (timeouts_remaining <= 0) {
    // While not the best way to detach, this triggers interoperable logic that
    // includes detachment.
    element.srcObject = null;
    test.step_timeout(() => { test.done(); }, 10);
  } else {
    test.step_timeout(() => {
      detachElementAfterMultipleSetTimeouts(test, element, --timeouts_remaining);
    }, 0);
  }
}

function startWorkerAndDetachElement(test, when_to_start_timeouts, timeouts_to_await) {
  // Fail fast if MSE-in-Workers is not supported.
  assert_true(MediaSource.hasOwnProperty("canConstructInDedicatedWorker"), "MediaSource hasOwnProperty 'canConstructInDedicatedWorker'");
  assert_true(MediaSource.canConstructInDedicatedWorker, "MediaSource.canConstructInDedicatedWorker");

  const worker = new Worker("mediasource-worker-detach-element.js");
  worker.onerror = test.unreached_func("worker error");

  const video = document.createElement("video");
  document.body.appendChild(video);

  worker.onmessage = test.step_func(e => {
    let subject = e.data.subject;
    assert_true(subject != undefined, "message must have a subject field");
    switch (subject) {
      case messageSubject.ERROR:
        assert_unreached("Worker error: " + e.data.info);
        break;
      case messageSubject.HANDLE:
        const handle = e.data.info;
        video.srcObject = handle;
        if (when_to_start_timeouts == AFTER_SETTING_SRCOBJECT) {
          detachElementAfterMultipleSetTimeouts(test, video, timeouts_to_await);
        }
        break;
      case messageSubject.STARTED_BUFFERING:
        if (when_to_start_timeouts == AFTER_STARTED_BUFFERING)
          detachElementAfterMultipleSetTimeouts(test, video, timeouts_to_await);
        break;
      case messageSubject.FINISHED_BUFFERING:
        if (when_to_start_timeouts == AFTER_FINISHED_BUFFERING)
          detachElementAfterMultipleSetTimeouts(test, video, timeouts_to_await);
        break;
      default:
        assert_unreached("Unrecognized message subject: " + subject);
    }
  });
}
</script>
</body>
</html>
