<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8" />
  <title>CSS Test (Selectors): :focus behavior with shadow hosts & delegatesFocus </title>
  <link rel="author" title="Rakina Zata Amni" href="rakina@chromium.org" />
  <link rel="help" href="https://html.spec.whatwg.org/multipage/semantics-other.html#selector-focus" />
  <script src="/resources/testharness.js"></script>
  <script src="/resources/testharnessreport.js"></script>
  <script src="resources/shadow-utils.js"></script>
</head>

<body>
<input>

<script>
function createFocusableDiv() {
  const div = document.createElement("div");
  div.innerText = "foo";
  div.tabIndex = 0;
  return div;
}

function createShadowHost(delegatesFocus, container) {
  const host = document.createElement("div");
  host.attachShadow({ mode: "open", delegatesFocus: delegatesFocus });
  container.appendChild(host);
  return host;
}

const delegatesFocusValues = [true, false];

for (const delegatesFocus of delegatesFocusValues) {
  test(() => {
    resetFocus();
    const host = createShadowHost(delegatesFocus, document.body);
    const shadowChild = createFocusableDiv();
    host.shadowRoot.appendChild(shadowChild);

    shadowChild.focus();
    assert_true(shadowChild.matches(":focus"), "element in shadow tree matches :focus");
    assert_true(host.matches(":focus"), "host matches :focus");
  }, `:focus applies to host with delegatesFocus=${delegatesFocus} when the shadow root's descendant has focus`);

  test(() => {
    resetFocus();
    const host = createShadowHost(delegatesFocus, document.body);
    const slotted = createFocusableDiv();
    host.shadowRoot.appendChild(document.createElement("slot"));
    host.appendChild(slotted);

    slotted.focus();
    assert_true(slotted.matches(":focus"), "slotted element matches :focus");
    assert_false(host.matches(":focus"), "host matches :focus");
  }, `:focus does not apply to host with delegatesFocus=${delegatesFocus} when slotted element has focus`);

  for (const nestedDelegatesFocus of delegatesFocusValues) {
    test(() => {
      resetFocus();
      const host = createShadowHost(delegatesFocus, document.body);
      const nestedHost = createShadowHost(nestedDelegatesFocus, host.shadowRoot);
      const nestedShadowChild = createFocusableDiv();
      nestedHost.shadowRoot.appendChild(nestedShadowChild);
      nestedShadowChild.focus();
      assert_true(nestedShadowChild.matches(":focus"), "element in nested shadow tree matches :focus");
      assert_true(nestedHost.matches(":focus"), "host of nested shadow tree matches focus");
      assert_true(host.matches(":focus"), "topmost host matches focus");
    }, `:focus applies to host with delegatesFocus=${delegatesFocus} when an element in a nested shadow tree with delegatesFocus=${nestedDelegatesFocus} is focused`);

    test(() => {
      resetFocus();
      const host = createShadowHost(delegatesFocus, document.body);
      const nestedHost = createShadowHost(nestedDelegatesFocus, host.shadowRoot);
      const nestedShadowChild = createFocusableDiv();
      nestedHost.shadowRoot.appendChild(nestedShadowChild);
      // All nested shadow hosts should has :focus applied
      nestedShadowChild.focus();

      const elementOutsideOfShadowDOM = document.querySelector("input");
      // Move the focus to an element which is outside of the nested
      // shadow DOM trees
      elementOutsideOfShadowDOM.focus();

      assert_false(nestedShadowChild.matches(":focus"), "element in nested shadow tree doesn't matche :focus");
      assert_false(nestedHost.matches(":focus"), "host of nested shadow tree doesn't match focus");
      assert_false(host.matches(":focus"), "topmost host matches focus");
      assert_true(elementOutsideOfShadowDOM.matches(":focus"), "The element outside of shadow dom matches :focus");
    }, `:focus should be removed from hosts with delegatesFocus=${delegatesFocus} when none of the elements in a nested shadow tree with delegatesFocus=${nestedDelegatesFocus} is focused`);
  }
}
</script>
</body>
