<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<link rel="help" src="https://www.w3.org/TR/scroll-animations-1/#named-range-animation-declaration">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/web-animations/testcommon.js"></script>
<script src="/web-animations/resources/keyframe-utils.js"></script>
<script src="support/testcommon.js"></script>
<script src="/scroll-animations/scroll-timelines/testcommon.js"></script>
<title>Programmatic API overrides animation-range-*</title>
</head>
<style type="text/css">
  #scroller {
    border:  10px solid lightgray;
    overflow-y: scroll;
    overflow-x: hidden;
    width: 300px;
    height: 200px;
  }
  @keyframes anim {
    from { margin-left: 0px; }
    to { margin-left: 100px; }
  }
  #target {
    margin: 800px 0px;
    width: 100px;
    height: 100px;
    z-index: -1;
    background-color: green;
  }
  .animate {
    animation:  anim auto linear;
    view-timeline:  --timeline;
    animation-timeline:  --timeline;
    animation-range-start:  entry 0%;
    animation-range-end:  entry 100%;
  }
</style>
<body>
  <div id=scroller>
    <div id=target></div>
  </div>
</body>
<script type="text/javascript">
  async function runTest() {
    function startAnimation(t) {
      target.classList.add('animate');
      t.add_cleanup(async () => {
        target.classList.remove('animate');
        await waitForNextFrame();
      });
      return target.getAnimations()[0];
    }

    promise_test(async t => {
      // Points of interest:
      // entry 0% @ 600
      // entry 100% / contain 0% @ 700
      // exit 0% / contain 100% @ 800
      // exit 100% @ 900
      const anim = startAnimation(t);
      await anim.ready;

      scroller.scrollTop = 650;
      await waitForNextFrame();

      // Timline time = (scroll pos - cover 0%) / (cover 100% - cover 0%) * 100%
      //              = (650 - 600)/(900 - 600) * 100% = 100/6%
      assert_percents_equal(anim.timeline.currentTime, 100/6,
                            'timeline\'s current time before style change');
      assert_percents_equal(anim.startTime, 0,
                            'animation\'s start time before style change');
      // Range start of entry 0% aligns with timeline start. Thus, animation's
      // and timeline's current time are equal.
      assert_percents_equal(anim.currentTime, 100/6,
                            'animation\'s current time before style change');
      // Iteration duration =
      //     (range end - range start) / (cover 100% - cover 0%) * 100%
      //   = (700 - 600) / (900 - 600) = 33.3333%
      assert_percents_equal(anim.effect.getComputedTiming().duration,
                            100/3,
                            'iteration duration before first style change');
      assert_equals(getComputedStyle(target).marginLeft, '50px',
                    'margin-left before style change');

      // Step 1: Set the range end programmatically and range start via CSS.
      // The start time will be respected since not previously set via the
      // animation API.
      await runAndWaitForFrameUpdate(() => {
        anim.rangeEnd = 'contain 100%';
        target.style.animationRangeStart = 'entry 50%';
      });

      // Animation range does not affect timeline's currentTime.
      assert_percents_equal(
          anim.timeline.currentTime, 100/6,
          'timeline\'s current time after first set of range updates');
      assert_percents_equal(
          anim.startTime, 100/6,
          'animation\'s start time after first set of range updates');
      // Scroll position aligns with range start.
      assert_percents_equal(
          anim.currentTime, 0,
          'animation\'s current time after first set of range updates');
      // Iteration duration =
      //     (range end - range start) / (cover 100% - cover 0%) * 100%
      //   = (800 - 650) / (900 - 600) = 50%
      assert_percents_equal(
          anim.effect.getComputedTiming().duration, 50,
          'iteration duration after first style change');
      assert_equals(getComputedStyle(target).marginLeft, '0px',
        'margin-left after first set of range updates');

      // Step 2: Programmatically set the range start.
      // Scroll position is current at entry 50%, thus the animation's current
      // time is negative.
      await runAndWaitForFrameUpdate(() => {
        anim.rangeStart = 'contain 0%';
      });
      // animation current time =
      //     (scroll pos - range start) / (cover 100% - cover 0%) * 100%
      //   = (650 - 700) / (900 - 600) * 100% = -100/6%
      assert_percents_equal(
        anim.currentTime, -100/6,
        'animation\'s current time after second set of range updates');
      // Iteration duration =
      //     (range end - range start) / (cover 100% - cover 0%) * 100%
      //   = (800 - 700) / (900 - 600) = 33.3333%
      assert_percents_equal(
          anim.effect.getComputedTiming().duration, 100/3,
          'iteration duration after second style change');
      assert_equals(getComputedStyle(target).marginLeft, '0px',
        'margin-left after second set of range updates');

      // Jump to contain / cover 50%
      scroller.scrollTop = 750;
      await waitForNextFrame();

      // animation current time =
      //     (scroll pos - range start) / (cover 100% - cover 0%) * 100%
      //   = (750 - 700) / (900 - 600) * 100% =  100/6%
      assert_percents_equal(
          anim.currentTime, 100/6,
          'animation\'s current time after bumping scroll position');
      assert_equals(getComputedStyle(target).marginLeft, '50px');

      // Step 3: Try to update the range start via CSS.  This change must be
      // ignored since previously set programmatically.
      await runAndWaitForFrameUpdate(() => {
        target.style.animationRangeStart = "entry 50%";
      });
      assert_percents_equal(
          anim.currentTime, 100/6,
          'Current time unchanged after change to ignored CSS property');
      assert_equals(
          getComputedStyle(target).marginLeft, '50px',
          'Margin-left unaffected by change to ignored CSS property');

    }, 'Animation API call rangeStart overrides animation-range-start');

    promise_test(async t => {
      const anim = startAnimation(t);
      await anim.ready;

      scroller.scrollTop = 650;
      await waitForNextFrame();

      // Step 1: Set the range start programmatically and range end via CSS.
      // The start time will be respected since not previously set via the
      // animation API.
      await runAndWaitForFrameUpdate(() => {
        anim.rangeStart = "entry 50%";
        target.style.animationRangeEnd = "contain 100%";
      });

      assert_percents_equal(
          anim.timeline.currentTime, 100/6,
          'timeline\'s current time after first set of range updates');
      assert_percents_equal(
          anim.startTime, 100/6,
          'animation\'s start time after first set of range updates');
      assert_percents_equal(
          anim.currentTime, 0,
          'animation\'s current time after first set of range updates');
      assert_percents_equal(
          anim.effect.getComputedTiming().duration, 50,
          'iteration duration after first style change');
      assert_equals(getComputedStyle(target).marginLeft, "0px",
        'margin-left after first set of range updates');

      // Step 2: Programmatically set the range.
      // Scroll position is current at entry 50%, thus the animation's current
      // time is negative.
      await runAndWaitForFrameUpdate(() => {
        anim.rangeStart = "contain 0%";
        anim.rangeEnd = "contain 100%";
      });

      assert_percents_equal(
        anim.currentTime, -100/6,
        'animation\'s current time after second set of range updates');
      assert_percents_equal(
          anim.effect.getComputedTiming().duration, 100/3,
          'iteration duration after second style change');
      assert_equals(getComputedStyle(target).marginLeft, "0px",
        'margin-left after second set of range updates');

      // Jump to contain / cover 50%
      scroller.scrollTop = 750;
      await waitForNextFrame();

      assert_percents_equal(
          anim.currentTime, 100/6,
          'animation\'s current time after bumping scroll position');
      assert_equals(getComputedStyle(target).marginLeft, "50px");

      // Step 3: Try to update the range end via CSS. This change must be
      // ignored since previously set programmatically.
      await runAndWaitForFrameUpdate(() => {
        target.style.animationRangeEnd = "cover 100%";
      });
      assert_percents_equal(
          anim.currentTime, 100/6,
          'Current time unchanged after change to ignored CSS property');
      assert_equals(
          getComputedStyle(target).marginLeft, '50px',
          'Margin-left unaffected by change to ignored CSS property');

    }, 'Animation API call rangeEnd overrides animation-range-end');
  }

  window.onload = runTest;
</script>
