/* ==UserStyle==
@name  Video Background Play Fix2
@namespace    https://greasyfork.org/en/users/xxoo110
@version      20250423
@description  Prevents YouTube and Vimeo from pausing videos when minimizing or switching tabs. Cross-browser port of https://addons.mozilla.org/en-US/firefox/addon/video-background-play-fix/
@author       xxoo110
@match        *://*.youtube.com/*
@match        *://*.vimeo.com/*
@grant        none
@run-at       document-start
@background
@license    MIT
@downloadURL https://update.greasyfork.icu/scripts/533727/Video%20Background%20Play%20Fix2.user.css
@updateURL https://update.greasyfork.icu/scripts/533727/Video%20Background%20Play%20Fix2.meta.css
==/UserStyle== */

(function () {
  'use strict';

  const IS_YOUTUBE = window.location.hostname.search(/(?:^|.+\.)youtube\.com/) > -1 ||
    window.location.hostname.search(/(?:^|.+\.)youtube-nocookie\.com/) > -1;
  const IS_MOBILE_YOUTUBE = window.location.hostname == 'm.youtube.com';
  const IS_DESKTOP_YOUTUBE = IS_YOUTUBE && !IS_MOBILE_YOUTUBE;
  const IS_VIMEO = window.location.hostname.search(/(?:^|.+\.)vimeo\.com/) > -1;

  const IS_ANDROID = window.navigator.userAgent.indexOf('Android') > -1;

  // Page Visibility API
  if (IS_ANDROID || !IS_DESKTOP_YOUTUBE) {
    Object.defineProperties(document,
      { 'hidden': { value: false }, 'visibilityState': { value: 'visible' } });
  }

  window.addEventListener(
    'visibilitychange', evt => evt.stopImmediatePropagation(), true);

  // Fullscreen API
  if (IS_VIMEO) {
    window.addEventListener(
      'fullscreenchange', evt => evt.stopImmediatePropagation(), true);
  }

  // User activity tracking
  if (IS_YOUTUBE) {
    loop(pressKey, 60 * 1000, 10 * 1000); // every minute +/- 10 seconds
  }

  function pressKey() {
    const key = 18;
    sendKeyEvent("keydown", key);
    sendKeyEvent("keyup", key);
  }

  function sendKeyEvent(aEvent, aKey) {
    document.dispatchEvent(new KeyboardEvent(aEvent, {
      bubbles: true,
      cancelable: true,
      keyCode: aKey,
      which: aKey,
    }));
  }

  function loop(aCallback, aDelay, aJitter) {
    let jitter = getRandomInt(-aJitter / 2, aJitter / 2);
    let delay = Math.max(aDelay + jitter, 0);

    window.setTimeout(() => {
      aCallback();
      loop(aCallback, aDelay, aJitter);
    }, delay);
  }

  function getRandomInt(aMin, aMax) {
    let min = Math.ceil(aMin);
    let max = Math.floor(aMax);
    return Math.floor(Math.random() * (max - min)) + min;
  }

})();