// ==UserScript==
// @name YouTubeで自動翻訳字幕（日本語）を常にオン
// @description B:再度試みる　N.:次の動画　P,:前の動画
// @version      0.3
// @run-at document-idle
// @match *://www.youtube.com/*
// @grant none
// @namespace https://greasyfork.org/users/181558
// @downloadURL none
// ==/UserScript==

(function() {

  const WAIT_PAGEOPEN = 600; // ミリ秒
  const WAIT_EACHACTION = 600; // ミリ秒
  const ENABLE_EVENJAPANESE = 0; // 日本語タイトルの動画でも実行
  const ENABLE_EVENEMBED = 1; // 埋め込みでも実行

  document.addEventListener('keydown', function(e) {
    if (/input|textarea/i.test(e.target.tagName) == false) {
      var key = (e.shiftKey ? "Shift+" : "") + (e.altKey ? "Alt+" : "") + (e.ctrlKey ? "Ctrl+" : "") + e.key;
      if (key == "b") {
        toJP();
        e.preventDefault();
        return false;
      }
      if (key == "n" || key == ".") {
        elecli('//a[@class="ytp-next-button ytp-button" and @aria-label="次へ（SHIFT+n）"]|//a[@class="ytp-next-button ytp-button cleaned" and @role="button" and @aria-label="次へ（SHIFT+n）"]');
        e.preventDefault();
        return false;
      }
      if (key == "p" || key == ",") {
        elecli('//a[@class="ytp-prev-button ytp-button" and @aria-label="前へ（SHIFT+p）"]|//a[@class="ytp-prev-button ytp-button cleaned" and @role="button" and  @aria-label="前へ（SHIFT+p）"]');
        e.preventDefault();
        return false;
      }
    }
  }, false);

  var href = location.href;
  var observer = new MutationObserver(function(mutations) {
    if (href !== location.href) {
      href = location.href;
      run(WAIT_PAGEOPEN * 3);
    }
  });
  observer.observe(document, { childList: true, subtree: true });

  if (window == parent) run(WAIT_PAGEOPEN);

  for (let ele of elegeta('//div[@id="player"]/div/div/button[@aria-label="再生"]')) {
    ele.addEventListener('click', () => { setTimeout(run, WAIT_PAGEOPEN) });
  }

  return;

  function run(delay = 500) {
    setTimeout(function() {
      //      console.log("run");
      var title = eleget0('//h1/yt-formatted-string');
      if (!(location.href.match(/\/embed/)) && !title) { setTimeout(() => { run(); }, 100); return; }
      if (!ENABLE_EVENJAPANESE && title && title.innerText.match(/[\u30a0-\u30ff\u3040-\u309f\u3005-\u3006\u30e0-\u9fcf]+/)) return; // タイトルに日本語あるならやめる
      toJP();
    }, delay);
  }

  function toJP() {
    if (!(location.href.match(ENABLE_EVENEMBED ? /:\/\/www\.youtube\.com\/watch\?|:\/\/www\.youtube\.com\/embed/ : /:\/\/www\.youtube\.com\/watch\?/))) return;
    if (eleget0('//button[@class="ytp-subtitles-button ytp-button" and @aria-label="字幕（c）"]')) { // 字幕ボタン
      elecli('//button[@class="ytp-subtitles-button ytp-button" and @aria-label="字幕（c）" and @aria-pressed="false"]', 1); // 字幕ボタン
      elecli('//div[@class="ytp-right-controls"]/button[@aria-label="設定"]', 2); // 設定ボタン
      elecli('//div[@class="ytp-menuitem-label"]/div/span[text()="字幕"]', 3, "close", "smooth");
      elecli('//div[@class="ytp-menuitem-label" and text()="自動翻訳"]', 4, "close", "instant");
      elecli('//div[@class="ytp-menuitem-label" and text()="日本語"]', 5, "close");
      elecli('//div[last()]/button[@data-tooltip-target-id="ytp-settings-button" and @aria-expanded="true"]', 7, "blur");
    }
  }

  function elecli(xpath, delay = 0, command = false, beha = null) {
    setTimeout(() => {
      var ele = eleget0(xpath);
      //      console.log(xpath, (elegeta(xpath).length));
      if (ele) {
        var ele = elegeta(xpath);
        ele = ele[ele.length - 1]; // 複数ある時は最後の１つ
        if (command == "focus") ele.focus();
        else {
          ele.click();
          if (window != parent && beha) {
            let foc = eleget0('//div[@id="movie_player"]|//div[@id="player"]');
            if (foc) foc.scrollIntoView({ behavior: beha, block: "center", inline: "center" });
          }
        }
      } else {
        if (command == "close") {
          elecli('//div[last()]/button[@data-tooltip-target-id="ytp-settings-button" and @aria-expanded="true"]');
        } //elecli('//div[@id="movie_player"]|//div[@id="player"]/div/div/video', 0, "focus"); }
      }
      if (command == "blur") elecli('//div[@id="movie_player"]|//div[@id="player"]/div/div/video', 0, "focus");
    }, delay * WAIT_EACHACTION)
  }

  function eleget0(xpath, node = document) {
    if (!xpath) return null;
    try {
      var ele = document.evaluate(xpath, node, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);
      return ele.snapshotLength > 0 ? ele.snapshotItem(0) : "";
    } catch (e) { return null; }
  }

  function elegeta(xpath, node = document) {
    var ele = document.evaluate("." + xpath, node, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);
    var array = [];
    for (var i = 0; i < ele.snapshotLength; i++) array[i] = ele.snapshotItem(i);
    return array;
  }
})()