// ==UserScript==
// @name         Manhuagui - Recover Blocked Manga
// @namespace    https://www.manhuagui.com/
// @version      0.2
// @description  Recover blocked manga on www.manhuagui.com | 添加对 checkAdult 按钮的检测；localStorage的key添加ID用以区分不同的漫画作品
// @author       DD1969
// @match        https://www.manhuagui.com/comic/*/
// @match        https://www.manhuagui.com/comic/*/*.html
// @require      https://unpkg.com/axios@0.27.2/dist/axios.min.js
// @require      https://unpkg.com/vanilla-lazyload@17.8.2/dist/lazyload.min.js
// @icon         https://www.google.com/s2/favicons?sz=64&domain=manhuagui.com
// @grant        none
// @downloadURL none
// ==/UserScript==

(async function(axios, LazyLoad) {
  'use strict';

  try {
    // check if current comic/chapter is blocked
    const isBlocked = await axios.get(window.location.href).then(res => res.data.match(/erroraudit_show/) !== null && res.data.match(/checkAdult/) === null);
    if (!isBlocked) {
      console.log('No need to recover.');
      return;s
    }

    window.location.href.includes('.html') ? loadImages() : loadCatalog();
  } catch (error) {
    console.log(error);
  }

  async function loadCatalog() {
    // setup container
    const container = await getContainer();
    container.classList.add('chapter-list');
    container.innerHTML = '<ul style="display: block;" id="recover-list"></ul>';
    const list = document.getElementById('recover-list');

    // get comic id and latest chapter id
    const latestChapterURL = document.querySelector('.detail-list .status a.blue').href;
    const latestChapterData = await getChapterData(latestChapterURL);
    const comicID = latestChapterData.bid;
    let currentTargetID = latestChapterData.cid;

    // store all collected chapter data
    let chapterData = [];

    // if there is data stored in localStorage before, get them and process
    const storedChapterDataString = window.localStorage.getItem(`recovered-chapter-data-${comicID}`);
    if (storedChapterDataString) {
      const storedChapterData = JSON.parse(storedChapterDataString);
      chapterData = [].concat(storedChapterData);
      chapterData.forEach(data => {
        const listItem = getListItem(data.url, data.title, data.pageAmount);
        list.appendChild(listItem);
      });

      currentTargetID = chapterData[chapterData.length - 1].prevID;
    }

    // get chapter data with interval
    const timer = setInterval(async () => {
      if (currentTargetID === 0) {
        clearInterval(timer);
        console.log('All chapters are recovered.');
      } else {
        const currentChapterURL = `https://www.manhuagui.com/comic/${comicID}/${currentTargetID}.html`;
        const { cname, len, prevId } = await getChapterData(currentChapterURL);

        const listItem = getListItem(currentChapterURL, cname, len);
        list.appendChild(listItem);

        // update localStorage
        chapterData.push({
          url: currentChapterURL,
          title: cname,
          pageAmount: len,
          prevID: prevId
        });
        window.localStorage.setItem(`recovered-chapter-data-${comicID}`, JSON.stringify(chapterData));

        currentTargetID = prevId;
      }
    }, 10 * 1000); // 10 seconds per chapter
  }

  async function loadImages() {
    // generate image urls
    const imageURLs = await getChapterData(window.location.href).then(({ files, path, sl }) => {
      const origin = 'https://us.hamreus.com';
      return files.map(fileName => `${origin}${path}${fileName}?e=${sl.e}&m=${sl.m}`)
    });

    // load images
    const container = await getContainer();
    container.innerHTML = `${imageURLs.reduce((acc, cur) => {
      return acc + `<img class="lazy" data-src="${cur}" style="display:block; min-height: 400px; max-width: 80vw;" />`;
    }, '')}`;

    // setup image lazyload
    new LazyLoad({ threshold: 900 });
  }

  // wait for the div element whose id is 'erroraudit_show' appear
  async function getContainer() {
    const container = await new Promise(resolve => {
      const timer = setInterval(() => {
        const errorAudit = document.getElementById('erroraudit_show');
        if (errorAudit) {
          clearInterval(timer);
          resolve(errorAudit);
        }
      }, 100);
    });

    container.classList.remove('warning-bar');
    container.id = 'recover-container';

    return container;
  }

  // generate list item
  function getListItem(href, title, pageAmount) {
    const li = document.createElement('li');
    li.innerHTML = `
      <a href="${href}" title="${title}" class="status0" target="_blank" rel="noopener noreferrer">
        <span style="display: flex; justify-content: center; align-items: center;">
          <span style="max-width: 75%; border: none; overflow: hidden; white-space: nowrap; text-overflow: ellipsis;">${title}</span>
          <i>${pageAmount}p</i>
        </span>
      </a>
    `;
    return li;
  }

  // get episode data from <script> tag of the html
  async function getChapterData(url) {
    return await axios
      .get(url)
      .then(res => {
        const script = res.data.match(/window\["\\x65\\x76\\x61\\x6c"\].*\{\}\)\)/gm)[0];
        const func = script.replace(`window["\\x65\\x76\\x61\\x6c"]`, 'episodeDataString = ');
        window.eval(func);
        return JSON.parse(episodeDataString.replace('SMH.imgData(', '').replace(').preInit();', ''));
      });
  }

})(axios, LazyLoad);