<!DOCTYPE html>
<meta charset=utf-8>
<title>Playing an animation</title>
<link rel="help"
      href="https://drafts.csswg.org/web-animations/#playing-an-animation-section">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../../testcommon.js"></script>
<body>
<div id="log"></div>
<script>
'use strict';

test(t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  animation.currentTime = 1 * MS_PER_SEC;
  assert_time_equals_literal(animation.currentTime, 1 * MS_PER_SEC);
  animation.play();
  assert_time_equals_literal(animation.currentTime, 1 * MS_PER_SEC);
}, 'Playing a running animation leaves the current time unchanged');

test(t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  animation.finish();
  assert_time_equals_literal(animation.currentTime, 100 * MS_PER_SEC);
  animation.play();
  assert_time_equals_literal(animation.currentTime, 0);
}, 'Playing a finished animation seeks back to the start');

test(t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  animation.playbackRate = -1;
  animation.currentTime = 0;
  assert_time_equals_literal(animation.currentTime, 0);
  animation.play();
  assert_time_equals_literal(animation.currentTime, 100 * MS_PER_SEC);
}, 'Playing a finished and reversed animation seeks to end');

promise_test(async t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  animation.finish();

  // Initiate a pause then abort it
  animation.pause();
  animation.play();

  // Wait to return to running state
  await animation.ready;

  assert_true(animation.currentTime < 100 * 1000,
              'After aborting a pause when finished, the current time should'
              + ' jump back to the start of the animation');
}, 'Playing a pause-pending but previously finished animation seeks back to'
   + ' to the start');

promise_test(async t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  animation.finish();
  await animation.ready;

  animation.play();
  assert_equals(animation.startTime, null, 'start time is unresolved');
}, 'Playing a finished animation clears the start time');

test(t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  animation.cancel();
  const promise = animation.ready;
  animation.play();
  assert_not_equals(animation.ready, promise);
}, 'The ready promise should be replaced if the animation is not already'
   + ' pending');

promise_test(async t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  const promise = animation.ready;
  const promiseResult = await promise;
  assert_equals(promiseResult, animation);
  assert_equals(animation.ready, promise);
}, 'A pending ready promise should be resolved and not replaced when the'
   + ' animation enters the running state');

promise_test(async t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  animation.currentTime = 50 * MS_PER_SEC;
  await animation.ready;

  animation.pause();
  await animation.ready;

  const holdTime = animation.currentTime;

  animation.play();
  await animation.ready;

  assert_less_than_equal(
    animation.startTime,
    animation.timeline.currentTime - holdTime + TIME_PRECISION
  );
}, 'Resuming an animation from paused calculates start time from hold time');

promise_test(async t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  await animation.ready;

  // Go to pause-pending state
  animation.pause();
  assert_true(animation.pending, 'Animation is pending');
  const pauseReadyPromise = animation.ready;

  // Now play again immediately (abort the pause)
  animation.play();
  assert_true(animation.pending, 'Animation is still pending');
  assert_equals(animation.ready, pauseReadyPromise,
                'The pause Promise is re-used when playing while waiting'
                + ' to pause');

  // Sanity check: Animation proceeds to running state
  await animation.ready;
  assert_true(!animation.pending && animation.playState === 'running',
              'Animation is running after aborting a pause');
}, 'If a pause operation is interrupted, the ready promise is reused');

promise_test(async t => {
  // Seek animation beyond target end
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  animation.currentTime = -100 * MS_PER_SEC;
  await animation.ready;

  // Set pending playback rate to the opposite direction
  animation.updatePlaybackRate(-1);
  assert_true(animation.pending);
  assert_equals(animation.playbackRate, 1);

  // When we play, we should seek to the target end, NOT to zero (which
  // is where we would seek to if we used the playbackRate of 1.
  animation.play();
  assert_time_equals_literal(animation.currentTime, 100 * MS_PER_SEC);
}, 'A pending playback rate is used when determining auto-rewind behavior');

promise_test(async t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  animation.cancel();
  assert_equals(animation.startTime, null,
                'Start time should be unresolved');

  const playTime = animation.timeline.currentTime;
  animation.play();
  assert_true(animation.pending, 'Animation should be play-pending');

  await animation.ready;

  assert_false(animation.pending, 'animation should no longer be pending');
  assert_time_greater_than_equal(animation.startTime, playTime,
                      'The start time of the playing animation should be set');
}, 'Playing a canceled animation sets the start time');

promise_test(async t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  animation.playbackRate = -1;
  animation.cancel();
  assert_equals(animation.startTime, null,
                'Start time should be unresolved');

  const playTime = animation.timeline.currentTime;
  animation.play();
  assert_true(animation.pending, 'Animation should be play-pending');

  await animation.ready;

  assert_false(animation.pending, 'Animation should no longer be pending');
  assert_time_greater_than_equal(animation.startTime, playTime + 100 * MS_PER_SEC,
                      'The start time of the playing animation should be set');
}, 'Playing a canceled animation backwards sets the start time');

</script>
</body>
