<!DOCTYPE HTML>
<title>Test VisibleStateEntry</title>
<link rel="author" title="Noam Rosenthal"  href="mailto:noam@chromium.org">
<link rel="help" href="https://html.spec.whatwg.org/multipage/interaction.html#page-visibility">
<meta name="timeout" content="long">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="resources/window_state_context.js"></script>
<script>

setup(() => {
    assert_implements(window.VisibilityStateEntry, 'VisibilityStateEntry is not supported.');
});

promise_test(async t => {
    const {minimize, restore} = window_state_context(t);
    let entries = performance.getEntriesByType("visibility-state");
    assert_equals(entries.length, 1);
    assert_equals(entries[0].name, "visible");
    assert_equals(entries[0].startTime, 0);
    assert_equals(entries[0].duration, 0);
    await minimize();
    entries = performance.getEntriesByType("visibility-state");
    assert_equals(entries.length, 2);
    assert_equals(entries[1].name, "hidden");
    assert_equals(entries[1].duration, 0);
    await restore();
    assert_equals(entries.length, 3);
    assert_equals(entries[2].name, "visible");
    assert_equals(entries[2].duration, 0);
}, "Hiding/showing the page should create visibility-state entries");

promise_test(async t => {
    const {minimize, restore} = window_state_context(t);
    await minimize();
    const popup = window.open("resources/blank_page_green.html");
    t.add_cleanup(() => popup.close());
    await restore();
    let entries = popup.performance.getEntriesByType("visibility-state");
    assert_equals(entries.length, 2);
    assert_equals(entries[0].name, "hidden");
    assert_equals(entries[0].startTime, 0);
    assert_equals(entries[1].name, "visible");
    assert_greater_than(entries[1].startTime, 0);

}, "If a page starts as hidden, the first visibility-state entry should be hidden");

promise_test(async t => {
    const {minimize, restore} = window_state_context(t);
    await minimize();
    const observed = new Promise(resolve => new PerformanceObserver(list => {
        const entries = list.getEntries();
        assert_equals(entries.length, 1);
        assert_equals(entries[0].name, "visible");
        assert_greater_than(entries[0].startTime, 0);
        assert_equals(entries[0].duration, 0);
        resolve();
    }).observe({entryTypes: ['visibility-state'], buffered: true}));
    await restore();
    await observed;
}, "Visibility state entries should be queued to performance observers");

promise_test(async t => {
    const {minimize, restore} = window_state_context(t);
    await minimize();
    await restore();
    await new Promise(resolve => new PerformanceObserver(list => {
        const entries = list.getEntries();
        assert_equals(entries.length, 3);
        assert_equals(entries[0].name, "visible");
        assert_equals(entries[0].startTime, 0);
        assert_equals(entries[0].duration, 0);
        assert_equals(entries[1].name, "hidden");
        assert_equals(entries[1].duration, 0);
        assert_equals(entries[2].name, "visible");
        assert_equals(entries[2].duration, 0);
        resolve();
    }).observe({entryTypes: ['visibility-state'], buffered: true}));
}, "Visibility state entries should respect the buffered flag");
</script>