// ==UserScript==
// @name         hipda-avatar
// @namespace    https://github.com/maltoze/tampermonkey-scripts
// @version      0.1.4
// @description  在帖子列表显示头像
// @author       maltoze
// @match        https://www.hi-pda.com/forum/forumdisplay.php?fid=*
// @match        https://www.hi-pda.com/forum/search.php?*
// @match        https://www.4d4y.com/forum/forumdisplay.php?fid=*
// @match        https://www.4d4y.com/forum/search.php?*
// @require      https://cdn.jsdelivr.net/npm/lozad@1.16.0/dist/lozad.min.js
// @license      MIT
// @downloadURL none
// ==/UserScript==

(function () {
  'use strict';

  const AVATAR_BASE = '000000000';
  const FORUM_SERVER_SSL = 'https://www.4d4y.com';
  const BASE_URL = FORUM_SERVER_SSL + '/forum/';
  const SIZE = 24;
  const DEFAULT_AVATAR_PREFIX = `https://ui-avatars.com/api/?background=9287AE&color=fff&size=${SIZE}`;
  const READ_PATTERN = 'folder_common.gif';

  async function getAvatarUrl(uid) {
    const avatarBaseUrl = BASE_URL + 'uc_server/data/avatar/';
    const fullUid =
      new Array(AVATAR_BASE.length - uid.toString().length + 1).join('0') + uid;
    const str = [
      fullUid.substring(0, 3),
      fullUid.substring(3, 5),
      fullUid.substring(5, 7),
      fullUid.substring(7, 9),
    ].join('/');
    const avatarUrl = avatarBaseUrl + str + '_avatar_small.jpg';
    try {
      const resp = await fetch(avatarUrl, { method: 'HEAD' });
      if (resp.ok) {
        return avatarUrl;
      }
    } catch (error) {
      return null;
    }
  }

  async function renderAvatar(imgNode, uid, name) {
    const avatarUrl = await getAvatarUrl(uid);
    if (avatarUrl) {
      imgNode.setAttribute('data-src', avatarUrl);
    } else {
      imgNode.setAttribute(
        'data-src',
        `${DEFAULT_AVATAR_PREFIX}&name=${encodeURIComponent(name)}`,
      );
    }
  }

  async function main() {
    const tbodyNodes = document.getElementsByTagName('tbody');
    const promises = [];

    for (const tbodyNode of tbodyNodes) {
      const imgNode = tbodyNode.querySelector('tr > td.folder > a > img');
      const authorNode = tbodyNode.querySelector('tr > td.author > cite > a');
      if (!authorNode || !imgNode) continue;

      const subjectNode = tbodyNode.querySelector('tr > th.subject a');
      if (subjectNode) {
        // 通过改变标题颜色来标记已读
        if (imgNode.src.match(READ_PATTERN)) {
          subjectNode.style.color = '#5a5a5a';
        }
        // 默认新标签打开
        subjectNode.setAttribute('target', '_blank');
      }

      const imgAnchorNode = tbodyNode.querySelector('tr > td.folder > a');
      imgAnchorNode.removeAttribute('title');
      // 点击头像打开个人主页
      imgAnchorNode.setAttribute('href', authorNode.getAttribute('href'));

      imgNode.classList.add('lozad');

      const uidMatch = authorNode.href.match(/uid=(\d+)/);
      if (uidMatch) {
        promises.push(renderAvatar(imgNode, uidMatch[1], authorNode.text));
      }
    }

    promises.length > 0 && (await Promise.all(promises));
    // eslint-disable-next-line no-undef
    const observer = lozad('.lozad', {
      load: function (el) {
        el.src = el.getAttribute('data-src');
        el.width = SIZE;
        el.style.borderRadius = '0.25rem';
      },
    });
    observer.observe();
  }

  main();
})();