var counter = 0;
var interacted;
var timestamps = []
const MAX_CLICKS = 50;
// Entries for one hard navigation + 50 soft navigations.
const MAX_PAINT_ENTRIES = 51;
const URL = "foobar.html";
const readValue = (value, defaultValue) => {
  return value !== undefined ? value : defaultValue;
}
const testSoftNavigation =
    options => {
      const addContent = options.addContent;
      const link = options.link;
      const pushState = readValue(options.pushState,
        url=>{history.pushState({}, '', url)});
      const clicks = readValue(options.clicks, 1);
      const extraValidations = readValue(options.extraValidations,
                                                   () => {});
      const testName = options.testName;
      const pushUrl = readValue(options.pushUrl, true);
      const eventType = readValue(options.eventType, "click");
      const interactionFunc = options.interactionFunc;
      const eventPrepWork = options.eventPrepWork;
      promise_test(async t => {
        await waitInitialLCP();
        const preClickLcp = await getLcpEntries();
        setEvent(t, link, pushState, addContent, pushUrl, eventType,
                 eventPrepWork);
        let first_navigation_id;
        for (let i = 0; i < clicks; ++i) {
          const firstClick = (i === 0);
          let paint_entries_promise =
              waitOnPaintEntriesPromise(firstClick);
          interacted = false;
          interact(link, interactionFunc);

          const navigation_id = await waitOnSoftNav();
          if (!first_navigation_id) {
            first_navigation_id = navigation_id;
          }
          // Ensure paint timing entries are fired before moving on to the next
          // click.
          await paint_entries_promise;
        }
        assert_equals(
            document.softNavigations, clicks,
            'Soft Navigations detected are the same as the number of clicks');
        await validateSoftNavigationEntry(
            clicks, extraValidations, pushUrl);

        await runEntryValidations(preClickLcp, first_navigation_id, clicks + 1, options.validate);
      }, testName);
    };

const testNavigationApi = (testName, navigateEventHandler, link) => {
  promise_test(async t => {
    navigation.addEventListener('navigate', navigateEventHandler);
    const navigated = new Promise(resolve => {
      navigation.addEventListener('navigatesuccess', resolve);
      navigation.addEventListener('navigateerror', resolve);
    });
    await waitInitialLCP();
    const preClickLcp = await getLcpEntries();
    let paint_entries_promise = waitOnPaintEntriesPromise();
    interact(link);
    const first_navigation_id = await waitOnSoftNav();
    await navigated;
    await paint_entries_promise;
    assert_equals(document.softNavigations, 1, 'Soft Navigation detected');
    await validateSoftNavigationEntry(1, () => {}, 'foobar.html');

    await runEntryValidations(preClickLcp, first_navigation_id);
  }, testName);
};

const testSoftNavigationNotDetected = options => {
    promise_test(async t => {
      const preClickLcp = await getLcpEntries();
      options.eventTarget.addEventListener(options.eventName, options.eventHandler);
      interact(options.link);
      await new Promise((resolve, reject) => {
        (new PerformanceObserver(() =>
            reject("Soft navigation should not be triggered"))).observe({
          type: 'soft-navigation',
          buffered: true
        });
        t.step_timeout(resolve, 1000);
      });
      if (document.softNavigations) {
        assert_equals(
          document.softNavigations, 0, 'Soft Navigation not detected');
      }
      const postClickLcp = await getLcpEntries();
      assert_equals(
          preClickLcp.length, postClickLcp.length, 'No LCP entries accumulated');
    }, options.testName);
  };

const runEntryValidations =
    async (preClickLcp, first_navigation_id, entries_expected_number = 2,
           validate = null) => {
  await validatePaintEntries('first-contentful-paint', entries_expected_number,
                             first_navigation_id);
  await validatePaintEntries('first-paint', entries_expected_number,
                             first_navigation_id);
  const postClickLcp = await getLcpEntries();
  const postClickLcpWithoutSoftNavs = await getLcpEntriesWithoutSoftNavs();
  assert_greater_than(
      postClickLcp.length, preClickLcp.length,
      'Soft navigation should have triggered at least an LCP entry');

  if (validate) {
    await validate();
  }
  assert_equals(
      postClickLcpWithoutSoftNavs.length, preClickLcp.length,
      'Soft navigation should not have triggered an LCP entry when the ' +
      'observer did not opt in');
  assert_not_equals(
      postClickLcp[postClickLcp.length - 1].size,
      preClickLcp[preClickLcp.length - 1].size,
      'Soft navigation LCP element should not have identical size to the hard ' +
          'navigation LCP element');
  assert_equals(
      postClickLcp[preClickLcp.length].navigationId,
      first_navigation_id, 'Soft navigation LCP should have the same navigation ' +
      'ID as the last soft nav entry')
};

const interact =
    (link, interactionFunc = undefined) => {
      if (test_driver) {
        if (interactionFunc) {
          interactionFunc();
        } else {
          test_driver.click(link);
        }
        timestamps[counter] = {"syncPostInteraction": performance.now()};
      }
    }

const setEvent = (t, button, pushState, addContent, pushUrl, eventType, prepWork) => {
  const eventObject =
      (eventType == 'click' || eventType.startsWith("key")) ? button : window;
  eventObject.addEventListener(eventType, async e => {
    let prepWorkFailed = false;
    if (prepWork &&!prepWork(t)) {
      prepWorkFailed = true;
    }
    // This is the end of the event's sync processing.
    if (!timestamps[counter]["eventEnd"]) {
      timestamps[counter]["eventEnd"] = performance.now();
    }
    if (prepWorkFailed) {
      return;
    }
    // Jump through a task, to ensure task tracking is working properly.
    await new Promise(r => t.step_timeout(r, 0));

    const url = URL + "?" + counter;
    if (pushState) {
      // Change the URL
      if (pushUrl) {
        pushState(url);
      } else {
        pushState();
      }
    }

    // Wait 10 ms to make sure the timestamps are correct.
    await new Promise(r => t.step_timeout(r, 10));

    await addContent(url);

    interacted = true;
    ++counter;
  });
};

const validateSoftNavigationEntry = async (clicks, extraValidations,
                                              pushUrl) => {
  const [entries, options] = await new Promise(resolve => {
    (new PerformanceObserver((list, obs, options) => resolve(
      [list.getEntries(), options]))).observe(
      {type: 'soft-navigation', buffered: true});
    });
  const expectedClicks = Math.min(clicks, MAX_CLICKS);

  assert_equals(entries.length, expectedClicks,
                "Performance observer got an entry");
  for (let i = 0; i < entries.length; ++i) {
    const entry = entries[i];
    assert_true(entry.name.includes(pushUrl ? URL : document.location.href),
                "The soft navigation name is properly set");
    const entryTimestamp = entry.startTime;
    assert_less_than_equal(timestamps[i]["syncPostInteraction"], entryTimestamp,
                "Entry timestamp is lower than the post interaction one");
    assert_greater_than_equal(
        entryTimestamp, timestamps[i]['eventEnd'],
        'Event start timestamp matches');
    assert_not_equals(entry.navigationId,
                      performance.getEntriesByType("navigation")[0].navigationId,
      "The navigation ID was re-generated and different from the initial one.");
    if (i > 0) {
      assert_not_equals(entry.navigationId,
                        entries[i-1].navigationId,
        "The navigation ID was re-generated between clicks");
    }
  }
  assert_equals(performance.getEntriesByType("soft-navigation").length,
                expectedClicks, "Performance timeline got an entry");
  await extraValidations(entries, options);

};

const validatePaintEntries = async (type, entries_number, first_navigation_id) => {
  if (!performance.softNavPaintMetricsSupported) {
    return;
  }
  const expected_entries_number = Math.min(entries_number, MAX_PAINT_ENTRIES);
  const entries = await new Promise(resolve => {
    const entries = [];
    (new PerformanceObserver(list => {
      entries.push(...list.getEntriesByName(type));
      if (entries.length >= expected_entries_number) {
        resolve(entries);
      }
    })).observe(
      {type: 'paint', buffered: true, includeSoftNavigationObservations: true});
    });
  const entries_without_softnavs = await new Promise(resolve => {
    (new PerformanceObserver(list => resolve(
      list.getEntriesByName(type)))).observe(
      {type: 'paint', buffered: true});
    });
  assert_equals(entries.length, expected_entries_number,
    `There are ${entries_number} entries for ${type}`);
  assert_equals(entries_without_softnavs.length, 1,
    `There is one non-softnav entry for ${type}`);
  if (entries_number > 1) {
    assert_not_equals(entries[0].startTime, entries[1].startTime,
      "Entries have different timestamps for " + type);
  }
  if (expected_entries_number > entries_without_softnavs.length) {
    assert_equals(entries[entries_without_softnavs.length].navigationId,
      first_navigation_id,
      "First paint entry should have the same navigation ID as the last soft " +
      "navigation entry");
  }
};

const waitInitialLCP = () => {
  return new Promise(resolve => {
      new PerformanceObserver(list => resolve()).observe({
        type: 'largest-contentful-paint',
        buffered: true
      });
  });
}

const waitOnSoftNav = () => {
  return new Promise(resolve => {
    (new PerformanceObserver(list => {
       const entries = list.getEntries();
       assert_equals(entries.length, 1,
                     "Only one soft navigation entry");
       resolve(entries[0].navigationId);
    })).observe({
      type: 'soft-navigation'
    });
  });
};

const getLcpEntries = async () => {
  const entries = await new Promise(resolve => {
    (new PerformanceObserver(list => resolve(
      list.getEntries()))).observe(
      {type: 'largest-contentful-paint', buffered: true,
       includeSoftNavigationObservations: true});
    });
  return entries;
};

const getLcpEntriesWithoutSoftNavs = async () => {
  const entries = await new Promise(resolve => {
    (new PerformanceObserver(list => resolve(
      list.getEntries()))).observe(
      {type: 'largest-contentful-paint', buffered: true});
    });
  return entries;
};

const addImage = async (element, url="blue.png", id = "imagelcp") => {
  const img = new Image();
  img.src = '/images/'+ url + "?" + Math.random();
  img.id=id
  img.setAttribute("elementtiming", id);
  await img.decode();
  element.appendChild(img);
};
const addImageToMain = async (url="blue.png", id = "imagelcp") => {
  await addImage(document.getElementById('main'), url, id);
};

const addTextParagraphToMain = (text, element_timing = "") => {
  const main = document.getElementById("main");
  const p = document.createElement("p");
  const textNode = document.createTextNode(text);
  p.appendChild(textNode);
  if (element_timing) {
    p.setAttribute("elementtiming", element_timing);
  }
  p.style = "font-size: 3em";
  main.appendChild(p);
  return p;
};
const addTextToDivOnMain = () => {
  const main = document.getElementById("main");
  const prevDiv = document.getElementsByTagName("div")[0];
  if (prevDiv) {
    main.removeChild(prevDiv);
  }
  const div = document.createElement("div");
  const text = document.createTextNode("Lorem Ipsum");
  div.appendChild(text);
  div.style = "font-size: 3em";
  main.appendChild(div);
}

const waitOnPaintEntriesPromise = (expectLCP = true) => {
  return new Promise((resolve, reject) => {
    if (performance.softNavPaintMetricsSupported) {
      const paint_entries = []
      new PerformanceObserver(list => {
        paint_entries.push(...list.getEntries());
        if (paint_entries.length == 2) {
          resolve();
        } else if (paint_entries.length > 2) {
          reject();
        }
      }).observe({type: 'paint', includeSoftNavigationObservations: true});
    } else if (expectLCP) {
        new PerformanceObserver(list => {
          resolve();
        }).observe({
          type: 'largest-contentful-paint',
          includeSoftNavigationObservations: true
        });
    } else {
        step_timeout(
            () => requestAnimationFrame(() => requestAnimationFrame(resolve)),
            100);
    }
  });
};