return-youtube-dislike/Extensions/firefox/return-youtube-dislike.background.js

const apiUrl = "https://return-youtube-dislike-api.azurewebsites.net";

browser.runtime.onMessage.addListener((request, sender, sendResponse) => {
  if (request.message === "get_auth_token") {
    // chrome.identity.getAuthToken({ interactive: true }, function (token) {
    //   console.log(token);
    //   chrome.identity.getProfileUserInfo(function (userInfo) {
    //     console.log(JSON.stringify(userInfo));
    //   });
    // });
  } else if (request.message === "log_off") {
    // console.log("logging off");
    // chrome.identity.clearAllCachedAuthTokens(() => console.log("logged off"));
  } else if (request.message == "set_state") {
    console.log(request);
    // chrome.identity.getAuthToken({ interactive: true }, function (token) {
    let token = "";
    fetch(`${apiUrl}/votes?videoId=${request.videoId}`, {
      method: "GET",
      headers: {
        Accept: "application/json",
        Authorization: "Bearer " + token,
      },
    })
      .then((response) => response.json())
      .then((response) => {
        console.log(response);
        sendResponse(response);
      })
      .catch();
    //});
    return true;
  } else if (request.message == "send_links") {
    toSend = toSend.concat(request.videoIds.filter((x) => !sentIds.has(x)));
    if (toSend.length >= 20) {
      fetch(`${apiUrl}/votes`, {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify(toSend),
      });
      for (const toSendUrl of toSend) {
        sentIds.add(toSendUrl);
      }
      toSend = [];
    }
  } else if (request.message == "fetch_from_youtube") {
    fetch(`https://www.youtube.com/watch?v=${request.videoId}`, {
      method: "GET",
    })
      .then((response) => response.text())
      .then((text) => {
        let result = getDislikesFromYoutubeResponse(text);
        sendResponse(result);
        try {
          sendUserSubmittedStatisticsToApi({
            ...result,
            videoId: request.videoId,
          });
        } catch {}
      });
    return true;
  }
});

const sentIds = new Set();
let toSend = [];
let lastCalled = new Date();

browser.tabs.onUpdated.addListener(async (tabId, changeInfo, tab) => {
  if (changeInfo.status == "complete" && new Date() - lastCalled > 100) {
    lastCalled = new Date();
    console.log("Tab update complete");

    if (tab.url && tab.url.indexOf("youtube.") < 0) return;
    browser.tabs.get(tabId, (tab) => {
      browser.tabs.executeScript(tab.id, {
        file: "return-youtube-dislike.script.js",
      });
    });
  }
});

function getDislikesFromYoutubeResponse(htmlResponse) {
  let start =
    htmlResponse.indexOf('"videoDetails":') + '"videoDetails":'.length;
  let end =
    htmlResponse.indexOf('"isLiveContent":false}', start) +
    '"isLiveContent":false}'.length;
  if (end < start) {
    end =
      htmlResponse.indexOf('"isLiveContent":true}', start) +
      '"isLiveContent":true}'.length;
  }
  let jsonStr = htmlResponse.substring(start, end);
  let jsonResult = JSON.parse(jsonStr);
  let rating = jsonResult.averageRating;

  start = htmlResponse.indexOf('"topLevelButtons":[', end);
  start =
    htmlResponse.indexOf('"accessibilityData":', start) +
    '"accessibilityData":'.length;
  end = htmlResponse.indexOf("}", start);
  let likes = +htmlResponse.substring(start, end).replace(/\D/g, "");
  let dislikes = (likes * (5 - rating)) / (rating - 1);
  let result = {
    likes,
    dislikes: Math.round(dislikes),
    rating,
    viewCount: +jsonResult.viewCount,
  };
  return result;
}

function sendUserSubmittedStatisticsToApi(statistics) {
  fetch(`${apiUrl}/votes/user-submitted`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
    },
    body: JSON.stringify(statistics),
  });
}