<!DOCTYPE html>
<link rel="help" href="https://drafts.csswg.org/css-ruby/#rubypos">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<body>

<p>
  <ruby id="a1">
    base
    <rtc><rt>annotation1</rt></rtc>
    <rtc><rt>annotation2</rt></rtc>
    <rtc><rt>annotation3</rt></rtc>
  </ruby>
</p>

<script>
for (const value of ['', 'alternate', 'alternate over', 'over alternate']) {
  test(() => {
    const a1 = document.querySelector('#a1');
    a1.style.rubyPosition = value;
    const [rt1, rt2, rt3] = a1.querySelectorAll('rt');
    assert_rt_is_over(rt1, a1);
    assert_rt_is_under(rt2, a1);
    assert_rt_is_over(rt3, a1);
    a1.style.rubyPosition = '';
  }, `ruby-position "${value}" alternate from over`);
}

for (const value of ['alternate under', 'under alternate']) {
  test(() => {
    const a1 = document.querySelector('#a1');
    a1.style.rubyPosition = value;
    const [rt1, rt2, rt3] = a1.querySelectorAll('rt');
    assert_rt_is_under(rt1, a1);
    assert_rt_is_over(rt2, a1);
    assert_rt_is_under(rt3, a1);
    a1.style.rubyPosition = '';
  }, `ruby-position "${value}" alternate from under`);
}

test(() => {
  const a1 = document.querySelector('#a1');
  const [rtc1, rtc2] = a1.querySelectorAll('rtc');
  const [rt1, rt2, rt3] = a1.querySelectorAll('rt');

  rtc1.style.rubyPosition = 'under';
  assert_rt_is_under(rt1, a1);
  assert_rt_is_over(rt2, a1);
  assert_rt_is_under(rt3, a1);

  rtc1.style.rubyPosition = 'over';
  assert_rt_is_over(rt1, a1);
  assert_rt_is_under(rt2, a1);
  assert_rt_is_over(rt3, a1);

  rtc1.style.rubyPosition = 'alternate';
  rtc2.style.rubyPosition = 'under';
  assert_rt_is_over(rt1, a1);
  assert_rt_is_under(rt2, a1);
  assert_rt_is_over(rt3, a1);

  rtc1.style.rubyPosition = '';
  rtc2.style.rubyPosition = '';
}, 'ruby-position alternate from previous ruby text container');

function assert_rt_is_over(rt, ruby) {
  assert_true(rt.getBoundingClientRect().top < ruby.getBoundingClientRect().top);
}

function assert_rt_is_under(rt, ruby) {
  assert_true(rt.getBoundingClientRect().bottom > ruby.getBoundingClientRect().bottom);
}

</script>
</body>