background.js

(function () {
  var mutationIdx = 0;
  const MUTATION_UPDATE_STEP = 2;
  const cache = new Map();

  const ORIGINAL_TRANSLATIONS = [
    "original", // English
    "оригинал", // Russian
    "オリジナル", // Japanese
    "原始", // Chinese
    "원본", // Korean
    "origineel", // Dutch
    "original", // Spanish/Portuguese
    "originale", // Italian/French
    "original", // German
    "oryginał", // Polish
    "původní", // Czech
    "αρχικό", // Greek
    "orijinal", // Turkish
    "原創", // Traditional Chinese
    "gốc", // Vietnamese
    "asli", // Indonesian
    "מקורי", // Hebrew
    "أصلي", // Arabic
  ];

  function makeHttpObject() {
    try {
      return new XMLHttpRequest();
    } catch (error) {}
    try {
      return new ActiveXObject("Msxml2.XMLHTTP");
    } catch (error) {}
    try {
      return new ActiveXObject("Microsoft.XMLHTTP");
    } catch (error) {}

    throw new Error("Could not create HTTP request object.");
  }

  function makeLinksClickable(html) {
    return html.replace(
      /(https?:\/\/[^\s]+)/g,
      "<a rel='nofollow' target='_blank' dir='auto' class='yt-simple-endpoint style-scope yt-formatted-string' href='$1'>$1</a>"
    );
  }

  function get(url, callback) {
    if (cache.has(url)) {
      callback(cache.get(url));
      return;
    }
    var request = makeHttpObject();
    request.open("GET", url, true);
    request.send(null);
    request.onreadystatechange = function () {
      if (request.readyState == 4) {
        cache.set(url, request);
        callback(request);
      }
    };
  }

  function trimYoutube(title) {
    return title.replace(/ - YouTube$/, "");
  }

  function setTitleNode(text, afterNode) {
    if (document.getElementById("yt-anti-translate-fake-node")) {
      const node = document.getElementById("yt-anti-translate-fake-node");
      node.textContent = text;
      return;
    }

    const node = document.createElement("span");
    node.className = "style-scope ytd-video-primary-info-renderer";
    node.id = "yt-anti-translate-fake-node";
    node.textContent = text;
    afterNode.after(node);
  }

  function untranslateCurrentVideo() {
    let translatedTitleElement = document.querySelector(
      "#title > h1 > yt-formatted-string"
    );

    if (!translatedTitleElement || !translatedTitleElement.textContent) {
      translatedTitleElement = document.querySelector(
        "h1 > yt-formatted-string:not(.cbCustomTitle)"
      );
    }

    // that means we cannot find youtube title, so there is nothing we can do
    if (!translatedTitleElement || !translatedTitleElement.textContent) {
      return;
    }

    get(
      "https://www.youtube.com/oembed?url=" + document.location.href,
      function (response) {
        if (response.status !== 200) {
          return;
        }

        const realTitle = JSON.parse(response.responseText).title;

        if (!realTitle || !translatedTitleElement) {
          // Do nothing if video is not loaded yet
          return;
        }

        document.title = document.title.replace(
          translatedTitleElement.textContent,
          realTitle
        );

        if (realTitle === translatedTitleElement.textContent) {
          // Do not revert already original videos
          return;
        }

        // untranslate video by creating its copy
        translatedTitleElement.style.visibility = "hidden";
        translatedTitleElement.style.display = "none";

        console.log(
          `[YoutubeAntiTranslate] translated title to "${realTitle}"`
        );

        setTitleNode(realTitle, translatedTitleElement);

        // translatedTitleElement.textContent = realTitle;
        // translatedTitleElement.removeAttribute('is-empty');
        // translatedTitleElement.untranslatedByExtension = true;
      }
    );

    // disabled bugged description untranslation
    // const translatedDescriptions = [document.querySelector("#description .ytd-video-secondary-info-renderer"), document.getElementById('description-inline-expander')];

    // let realDescription = null;

    // // For description, try ytInitialPlayerResponse object Youtube creates whenever you open video page, if it is for this video
    // if (!window.ytInitialPlayerResponse) {
    //     return;
    // }

    // if (window.ytInitialPlayerResponse.videoDetails && window.ytInitialPlayerResponse.videoDetails.title === realTitle) {
    //     realDescription = window.ytInitialPlayerResponse.videoDetails.shortDescription;
    // } else {
    //     for (const translatedDescription of translatedDescriptions) {
    //         if (translatedDescription.firstChild.id === FIRST_CHILD_DESC_ID) {
    //             translatedDescription.removeChild(translatedDescription.firstChild);
    //         }
    //     }
    // }

    // console.log(realDescription, translatedDescriptions);

    // if (realDescription) {
    //     // for (const translatedDescription of translatedDescriptions) {
    //     //     const div = document.createElement('div');
    //     //     div.innerHTML = makeLinksClickable(realDescription) + "\n\n<b>TRANSLATED (added by <a class='yt-simple-endpoint style-scope yt-formatted-string' href='https://chrome.google.com/webstore/detail/youtube-anti-translate/ndpmhjnlfkgfalaieeneneenijondgag?hl=ru'>Youtube Anti Translate</a>):</b>\n";
    //     //     div.id = FIRST_CHILD_DESC_ID;
    //     //     translatedDescription.insertBefore(div, translatedDescription.firstChild);
    //     // }
    // }
  }

  function untranslateOtherVideos() {
    function untranslateArray(otherVideos) {
      for (let i = 0; i < otherVideos.length; i++) {
        let video = otherVideos[i];

        // video was deleted
        if (!video) {
          return;
        }

        let videoThumbnail = video.querySelector("a#thumbnail");

        // false positive result detected
        if (!videoThumbnail) {
          continue;
        }

        let videoId = videoThumbnail.href;

        if (
          !video.untranslatedByExtension ||
          video.untranslatedKey !== videoId
        ) {
          // do not request same video multiply times
          let href = video.querySelector("a");
          video.untranslatedByExtension = true;
          video.untranslatedKey = videoId;
          get(
            "https://www.youtube.com/oembed?url=" + href.href,
            function (response) {
              if (response.status !== 200) {
                return;
              }

              const title = JSON.parse(response.responseText).title;
              const titleElement = video.querySelector(
                "#video-title:not(.cbCustomTitle)"
              );
              if (title !== titleElement.innerText) {
                console.log(
                  `[YoutubeAntiTranslate] translated from "${titleElement.innerText}" to "${title}"`
                );
                if (titleElement) {
                  video.querySelector(
                    "#video-title:not(.cbCustomTitle)"
                  ).innerText = title;
                  video.querySelector(
                    "#video-title:not(.cbCustomTitle)"
                  ).title = title;
                  if (
                    video.querySelector(
                      "a#video-title-link:not(.cbCustomTitle)"
                    )
                  ) {
                    // home page
                    video.querySelector(
                      "a#video-title-link:not(.cbCustomTitle)"
                    ).title = title;
                  }
                }
              }
            }
          );
        }
      }
    }

    untranslateArray(document.querySelectorAll("ytd-video-renderer"));
    untranslateArray(document.querySelectorAll("ytd-rich-item-renderer"));
    untranslateArray(document.querySelectorAll("ytd-compact-video-renderer"));
    untranslateArray(document.querySelectorAll("ytd-grid-video-renderer"));
    untranslateArray(document.querySelectorAll("ytd-playlist-video-renderer"));
    untranslateArray(
      document.querySelectorAll("ytd-playlist-panel-video-renderer")
    );

    // let compactVideos = document.getElementsByTagName('ytd-compact-video-renderer');    // related videos
    // let normalVideos = document.getElementsByTagName('ytd-video-renderer');             // channel page videos
    // let gridVideos = document.getElementsByTagName('ytd-grid-video-renderer');          // grid page videos

    // untranslateArray(compactVideos);
    // untranslateArray(normalVideos);
    // untranslateArray(gridVideos);
  }

  function getOriginalTrack(tracks) {
    if (!tracks || !Array.isArray(tracks)) {
      return null;
    }

    // First find which field contains the name property
    let languageFieldName = null;
    for (const track of tracks) {
      if (!track || typeof track !== "object") continue;

      for (const [fieldName, field] of Object.entries(track)) {
        if (field && typeof field === "object" && field.name) {
          languageFieldName = fieldName;
          break;
        }
      }
      if (languageFieldName) break;
    }

    if (!languageFieldName) {
      return;
    }

    // Now find track with "original" in any language
    for (const track of tracks) {
      if (!track || !track[languageFieldName] || !track[languageFieldName].name)
        continue;

      const trackName = track[languageFieldName].name.toLowerCase();
      for (const originalWord of ORIGINAL_TRANSLATIONS) {
        if (trackName.includes(originalWord.toLowerCase())) {
          return track;
        }
      }
    }
  }

  function untranslateAudioTrack() {
    const player = document.querySelector("#movie_player");
    if (
      !player ||
      !player.getAvailableAudioTracks ||
      player.audioUntranslated
    ) {
      return;
    }

    const tracks = player.getAvailableAudioTracks();

    const originalTrack = getOriginalTrack(tracks);

    if (originalTrack) {
      player.setAudioTrack(originalTrack);
      player.audioUntranslated = true;
    }
  }

  function untranslate() {
    if (mutationIdx % MUTATION_UPDATE_STEP == 0) {
      untranslateCurrentVideo();
      untranslateOtherVideos();
    }
    mutationIdx++;
  }

  function run() {
    // Change current video title and description
    // Using MutationObserver as we can't exactly know the moment when YT js will load video title
    const target = document.body;
    const config = { childList: true, subtree: true };
    const observer = new MutationObserver(untranslate);
    observer.observe(target, config);
  }

  run();
})();