function waitForRender() {
  return new Promise(resolve => requestAnimationFrame(() => requestAnimationFrame(resolve)));
}

function waitForTick() {
  return new Promise(resolve => step_timeout(resolve, 0));
}

async function clickOn(element) {
  const actions = new test_driver.Actions();
  await waitForRender();
  await actions.pointerMove(0, 0, {origin: element})
      .pointerDown({button: actions.ButtonType.LEFT})
      .pointerUp({button: actions.ButtonType.LEFT})
      .send();
  await waitForRender();
}
async function sendTab() {
  await waitForRender();
  const kTab = '\uE004';
  await new test_driver.send_keys(document.documentElement,kTab);
  await waitForRender();
}
// Waiting for crbug.com/893480:
// async function sendShiftTab() {
//   await waitForRender();
//   const kShift = '\uE008';
//   const kTab = '\uE004';
//   await new test_driver.Actions()
//     .keyDown(kShift)
//     .keyDown(kTab)
//     .keyUp(kTab)
//     .keyUp(kShift)
//     .send();
//   await waitForRender();
// }
async function sendEscape() {
  await waitForRender();
  await new test_driver.send_keys(document.documentElement,'\uE00C'); // Escape
  await waitForRender();
}
async function sendEnter() {
  await waitForRender();
  await new test_driver.send_keys(document.documentElement,'\uE007'); // Enter
  await waitForRender();
}
function isElementVisible(el) {
  return !!(el.offsetWidth || el.offsetHeight || el.getClientRects().length);
}
function isTopLayer(el) {
  // A bit of a hack. Just test a few properties of the ::backdrop pseudo
  // element that change when in the top layer.
  const properties = ['right','background'];
  const testEl = document.createElement('div');
  document.body.appendChild(testEl);
  const computedStyle = getComputedStyle(testEl, '::backdrop');
  const nonTopLayerValues = properties.map(p => computedStyle[p]);
  testEl.remove();
  for(let i=0;i<properties.length;++i) {
    if (getComputedStyle(el,'::backdrop')[properties[i]] !== nonTopLayerValues[i]) {
      return true;
    }
  }
  return false;
}
async function finishAnimations(popover) {
  popover.getAnimations({subtree: true}).forEach(animation => animation.finish());
  await waitForRender();
}
let mousemoveInfo;
function mouseOver(element) {
  mousemoveInfo?.controller?.abort();
  const controller = new AbortController();
  mousemoveInfo = {element, controller, moved: false, started: performance.now()};
  return (new test_driver.Actions())
    .pointerMove(0, 0, {origin: element})
    .send()
    .then(() => {
      document.addEventListener("mousemove", (e) => {mousemoveInfo.moved = true;}, {signal: controller.signal});
    })
}
function msSinceMouseOver() {
  return performance.now() - mousemoveInfo.started;
}
function assertMouseStillOver(element) {
  assert_equals(mousemoveInfo.element, element, 'Broken test harness');
  assert_false(mousemoveInfo.moved,'Broken test harness');
}
async function waitForHoverTime(hoverWaitTimeMs) {
  await new Promise(resolve => step_timeout(resolve,hoverWaitTimeMs));
  await waitForRender();
};
async function mouseHover(element,hoverWaitTimeMs) {
  await mouseOver(element);
  await waitForHoverTime(hoverWaitTimeMs);
  assertMouseStillOver(element);
}

async function blessTopLayer(visibleElement) {
  // The normal "bless" function doesn't work well when there are top layer
  // elements blocking clicks. Additionally, since the normal test_driver.bless
  // function just adds a button to the main document and clicks it, we can't
  // call that in the presence of open popovers, since that click will close them.
  const button = document.createElement('button');
  button.innerHTML = "Click me to activate";
  visibleElement.appendChild(button);
  let wait_click = new Promise(resolve => button.addEventListener("click", resolve, {once: true}));
  await test_driver.click(button);
  await wait_click;
  button.remove();
}
// This is a "polyfill" of sorts for the `defaultopen` attribute.
// It can be called before window.load is complete, and it will
// show defaultopen popovers according to the rules previously part
// of the popover API: any popover=manual popover can be shown this
// way, and only the first popover=auto popover.
function showDefaultopenPopoversOnLoad() {
  function show() {
    const popovers = Array.from(document.querySelectorAll('[popover][defaultopen]'));
    popovers.forEach((p) => {
        // The showPopover calls below aren't guarded by a check on the popover
        // open/closed status. If they throw exceptions, this function was
        // probably called at a bad time. However, a check is made for open
        // <dialog open> elements.
        if (p instanceof HTMLDialogElement && p.hasAttribute('open'))
          return;
        switch (p.popover) {
          case 'auto':
            if (!document.querySelector('[popover]:popover-open'))
              p.showPopover();
            return;
          case 'manual':
            p.showPopover();
            return;
          default:
            assert_unreached(`Unknown popover type ${p.popover}`);
        }
      });
  }
  if (document.readyState === 'complete') {
    show();
  } else {
    window.addEventListener('load',show,{once:true});
  }
}
function popoverHintSupported() {
  // TODO(crbug.com/1416284): This function should be removed, and
  // any calls replaced with `true`, once popover=hint ships.
  const testElement = document.createElement('div');
  testElement.popover = 'hint';
  return testElement.popover === 'hint';
}

function assertPopoverVisibility(popover, isPopover, expectedVisibility, message) {
  const isVisible = isElementVisible(popover);
  assert_equals(isVisible, expectedVisibility,`${message}: Expected this element to be ${expectedVisibility ? "visible" : "not visible"}`);
  // Check other things related to being visible or not:
  if (isVisible) {
    assert_not_equals(window.getComputedStyle(popover).display,'none');
    assert_equals(popover.matches(':popover-open'),isPopover,`${message}: Visible popovers should match :popover-open`);
  } else {
    assert_equals(window.getComputedStyle(popover).display,'none',`${message}: Non-showing popovers should have display:none`);
    assert_false(popover.matches(':popover-open'),`${message}: Non-showing popovers should *not* match :popover-open`);
  }
}

function assertIsFunctionalPopover(popover, checkVisibility) {
  assertPopoverVisibility(popover, /*isPopover*/true, /*expectedVisibility*/false, 'A popover should start out hidden');
  popover.showPopover();
  if (checkVisibility) assertPopoverVisibility(popover, /*isPopover*/true, /*expectedVisibility*/true, 'After showPopover(), a popover should be visible');
  popover.showPopover(); // Calling showPopover on a showing popover should not throw.
  popover.hidePopover();
  if (checkVisibility) assertPopoverVisibility(popover, /*isPopover*/true, /*expectedVisibility*/false, 'After hidePopover(), a popover should be hidden');
  popover.hidePopover(); // Calling hidePopover on a hidden popover should not throw.
  popover.togglePopover();
  if (checkVisibility) assertPopoverVisibility(popover, /*isPopover*/true, /*expectedVisibility*/true, 'After togglePopover() on hidden popover, it should be visible');
  popover.togglePopover();
  if (checkVisibility) assertPopoverVisibility(popover, /*isPopover*/true, /*expectedVisibility*/false, 'After togglePopover() on visible popover, it should be hidden');
  popover.togglePopover(/*force=*/true);
  if (checkVisibility) assertPopoverVisibility(popover, /*isPopover*/true, /*expectedVisibility*/true, 'After togglePopover(true) on hidden popover, it should be visible');
  popover.togglePopover(/*force=*/true);
  if (checkVisibility) assertPopoverVisibility(popover, /*isPopover*/true, /*expectedVisibility*/true, 'After togglePopover(true) on visible popover, it should be visible');
  popover.togglePopover(/*force=*/false);
  if (checkVisibility) assertPopoverVisibility(popover, /*isPopover*/true, /*expectedVisibility*/false, 'After togglePopover(false) on visible popover, it should be hidden');
  popover.togglePopover(/*force=*/false);
  if (checkVisibility) assertPopoverVisibility(popover, /*isPopover*/true, /*expectedVisibility*/false, 'After togglePopover(false) on hidden popover, it should be hidden');
  const parent = popover.parentElement;
  popover.remove();
  assert_throws_dom("InvalidStateError",() => popover.showPopover(),'Calling showPopover on a disconnected popover should throw InvalidStateError');
  popover.hidePopover(); // Calling hidePopover on a disconnected popover should not throw.
  assert_throws_dom("InvalidStateError",() => popover.togglePopover(),'Calling hidePopover on a disconnected popover should throw InvalidStateError');
  parent.appendChild(popover);
}

function assertNotAPopover(nonPopover) {
  // If the non-popover element nonetheless has a 'popover' attribute, it should
  // be invisible. Otherwise, it should be visible.
  const expectVisible = !nonPopover.hasAttribute('popover');
  assertPopoverVisibility(nonPopover, /*isPopover*/false, expectVisible, 'A non-popover should start out visible');
  assert_throws_dom("NotSupportedError",() => nonPopover.showPopover(),'Calling showPopover on a non-popover should throw NotSupported');
  assertPopoverVisibility(nonPopover, /*isPopover*/false, expectVisible, 'Calling showPopover on a non-popover should leave it visible');
  assert_throws_dom("NotSupportedError",() => nonPopover.hidePopover(),'Calling hidePopover on a non-popover should throw NotSupported');
  assertPopoverVisibility(nonPopover, /*isPopover*/false, expectVisible, 'Calling hidePopover on a non-popover should leave it visible');
  assert_throws_dom("NotSupportedError",() => nonPopover.togglePopover(),'Calling togglePopover on a non-popover should throw NotSupported');
  assertPopoverVisibility(nonPopover, /*isPopover*/false, expectVisible, 'Calling togglePopover on a non-popover should leave it visible');
}