// ==UserScript==
// @name         Twitch - Disable automatic video downscale
// @namespace    CommanderRoot
// @copyright    CommanderRoot
// @license      Unlicense
// @version      1.2.2
// @description  Disables the automatic downscaling of Twitch streams while tabbed away
// @author       https://twitter.com/CommanderRoot
// @match        https://www.twitch.tv/*
// @match        https://m.twitch.tv/*
// @match        https://player.twitch.tv/*
// @grant        none
// @run-at       document-start
// @downloadURL none
// ==/UserScript==
"use strict";

// Try to trick the site into thinking it's never hidden
Object.defineProperty(document, 'hidden', { value: false, writable: false });
Object.defineProperty(document, 'mozHidden', { value: false, writable: false });
Object.defineProperty(document, 'webkitHidden', { value: false, writable: false });
Object.defineProperty(document, 'visibilityState', { value: 'visible', writable: false });
Object.defineProperty(document, 'webkitVisibilityState', { value: 'visible', writable: false });
document.hasFocus = function () { return true; };
document.dispatchEvent(new Event('visibilitychange'));
let lastVideoPlaying = null;

// visibilitychange events are captured and stopped
document.addEventListener('visibilitychange', function (e) {
  e.stopImmediatePropagation();
  // Try to play the video on Chrome
  if (typeof chrome !== 'undefined') {
    playVideo();
  }
}, true);

function setQualitySettings() {
  // Set the player quality to "Source"
  try {
    window.localStorage.setItem('s-qs-ts', Math.floor(Date.now()));
    window.localStorage.setItem('video-quality', '{"default":"chunked"}');
  } catch (e) {
    console.log(e);
  }
}

function playVideo() {
  const videos = document.getElementsByTagName('video');
  if (videos.length > 0) {
    const lastStatus = lastVideoPlaying;
    lastVideoPlaying = !videos[0].paused && !videos[0].ended;
    if (lastStatus === true && !videos[0].ended) {
      videos[0].play();
    }
  } else {
    lastStatus = null;
  }
}

setQualitySettings();

// Add event handler for when we switch between pages
// This is useful when we switch for example from a Clip
// without "Source" to a livestream
window.addEventListener('popstate', () => {
  setQualitySettings();
});