// ==UserScript==
// @name 资料宝库·文档下载器
// @namespace http://tampermonkey.net/
// @version 3.3
// @description 替换网页预览区为完整全文渲染（支持文字文档和PPT图片文档），解除试读限制，支持直接选择/复制/下载
// @author you
// @match *://web.cpsad.cn/*
// @icon https://web.cpsad.cn/favicon.ico
// @grant GM_xmlhttpRequest
// @grant GM_addStyle
// @grant GM_log
// @connect gyy.kuduoke.net
// @connect web.cpsad.cn
// @run-at document-start
// @license MIT
// ==/UserScript==

(function () {
  'use strict';

  const TAG = '[cpsad_dl]';
  const log = (...a) => {
    const msg = a.map(x => (typeof x === 'string' ? x : JSON.stringify(x))).join(' ');
    try { GM_log(TAG + ' ' + msg); } catch (e) {}
    try { console.log(TAG, ...a); } catch (e) {}
  };

  log('脚本启动 v3.3, URL =', location.href);

  // ===== 样式 =====
  GM_addStyle(`
    /* 全文渲染容器 — 替换原 iframe 预览区 */
    .cpsad-fullview {
      width: 100% !important; min-height: 60vh !important;
      padding: 32px 48px !important; box-sizing: border-box !important;
      background: #fff !important; position: relative !important;
      font-family: "仿宋_GB2312","仿宋",FangSong,STFangsong,serif !important;
      font-size: 16pt !important; line-height: 1.9 !important; color: #333 !important;
      overflow: visible !important;
      -webkit-user-select: text !important; user-select: text !important;
      -webkit-touch-callout: default !important;
    }
    .cpsad-fullview * {
      box-sizing: border-box !important;
      -webkit-user-select: text !important; user-select: text !important;
    }
    .cpsad-fullview p {
      margin: 0 0 4pt 0 !important; text-indent: 2em !important; text-align: justify !important;
    }
    .cpsad-fullview h1 {
      font-family: SimHei,"黑体" !important; font-size: 16pt !important; font-weight: normal !important;
      text-indent: 2em !important; margin: 12pt 0 4pt 0 !important;
    }
    .cpsad-fullview h2 {
      font-family: KaiTi,"楷体" !important; font-size: 16pt !important; font-weight: normal !important;
      text-indent: 2em !important; margin: 12pt 0 4pt 0 !important;
    }
    .cpsad-fullview h3 {
      font-size: 16pt !important; font-weight: bold !important;
      text-indent: 2em !important; margin: 12pt 0 4pt 0 !important;
    }
    .cpsad-fullview h4 {
      font-size: 16pt !important; font-weight: normal !important;
      text-indent: 2em !important; margin: 8pt 0 4pt 0 !important;
    }
    .cpsad-fullview table { border-collapse: collapse !important; width: 100% !important; margin: 8pt 0 !important; }
    .cpsad-fullview table td, .cpsad-fullview table th {
      border: 1px solid #999 !important; padding: 6px 10px !important; font-size: 14pt !important;
    }
    .cpsad-fullview img { max-width: 100% !important; height: auto !important; }
    .cpsad-fullview .gw-title {
      font-family: "方正小标宋简体","小标宋体","华文中宋",SimSun,serif !important;
      font-size: 22pt !important; text-align: center !important; text-indent: 0 !important;
      font-weight: normal !important; margin: 0 0 28pt 0 !important; line-height: 1.5 !important;
    }

    /* PPT 图片容器 */
    .cpsad-pptview {
      width: 100% !important; display: flex !important; flex-direction: column !important;
      align-items: center !important; gap: 16px !important; padding: 24px 0 !important;
    }
    .cpsad-pptview .ppt-slide {
      width: 100% !important; max-width: 888px !important; position: relative !important;
      border-radius: 8px !important; overflow: hidden !important;
      box-shadow: 0 2px 12px rgba(0,0,0,0.12) !important; background: #f8f9fa !important;
    }
    .cpsad-pptview .ppt-slide img {
      display: block !important; width: 100% !important; height: auto !important;
      object-fit: contain !important;
    }
    .cpsad-pptview .ppt-page-num {
      position: absolute !important; top: 8px !important; right: 12px !important;
      background: rgba(0,0,0,0.5) !important; color: #fff !important;
      padding: 2px 10px !important; border-radius: 12px !important; font-size: 12px !important;
      font-family: -apple-system, BlinkMacSystemFont, sans-serif !important; z-index: 1 !important;
    }
    @media (min-width: 768px) {
      .cpsad-pptview.ppt-multiple { flex-direction: row !important; flex-wrap: wrap !important; justify-content: center !important; }
      .cpsad-pptview.ppt-multiple .ppt-slide { width: calc(50% - 8px) !important; max-width: 444px !important; }
    }

    /* 顶部工具条 */
    .cpsad-actionbar {
      display: flex !important; align-items: center !important; gap: 10px !important;
      padding: 12px 24px !important; background: #f8f8f8 !important;
      border-bottom: 1px solid #e8e8e8 !important; border-radius: 8px 8px 0 0 !important;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif !important;
      position: sticky !important; top: 0 !important; z-index: 100 !important;
    }
    .cpsad-actionbar .cpsad-title-display {
      flex: 1 !important; font-size: 15px !important; font-weight: 600 !important; color: #333 !important;
      overflow: hidden !important; text-overflow: ellipsis !important; white-space: nowrap !important;
    }
    .cpsad-actionbar button {
      border: none !important; border-radius: 6px !important; padding: 8px 16px !important;
      font-size: 13px !important; cursor: pointer !important; font-weight: 500 !important;
      transition: all .15s !important; white-space: nowrap !important;
    }
    .cpsad-actionbar .btn-copy { background: #8e44ad !important; color: #fff !important; }
    .cpsad-actionbar .btn-copy:hover { background: #7d3c9d !important; }
    .cpsad-actionbar .btn-copy:disabled { background: #bbb !important; cursor: not-allowed !important; }
    .cpsad-actionbar .btn-download { background: #07c160 !important; color: #fff !important; }
    .cpsad-actionbar .btn-download:hover { background: #06ad56 !important; }
    .cpsad-actionbar .btn-download:disabled { background: #bbb !important; cursor: not-allowed !important; }
    .cpsad-actionbar .btn-restore { background: #f0f0f0 !important; color: #666 !important; }
    .cpsad-actionbar .btn-restore:hover { background: #e0e0e0 !important; }

    /* 占位 */
    .cpsad-placeholder {
      padding: 60px 24px !important; text-align: center !important;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif !important;
      font-size: 15px !important; color: #999 !important;
    }
    .cpsad-placeholder.error { color: #e64340 !important; }

    /* Toast */
    .cpsad-toast {
      position: fixed !important; top: 50% !important; left: 50% !important;
      transform: translate(-50%, -50%) !important; z-index: 2147483647 !important;
      background: rgba(0,0,0,.8) !important; color: #fff !important;
      padding: 12px 28px !important; border-radius: 8px !important; font-size: 15px !important;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif !important;
      animation: cpsad-toast-in .2s ease !important;
    }
    @keyframes cpsad-toast-in { from { opacity: 0; transform: translate(-50%, -45%); } to { opacity: 1; transform: translate(-50%, -50%); } }
  `);

  // ===== 全局拦截：阻止原网页 JS 禁用复制/选择/右键 =====
  const rawAddEventListener = EventTarget.prototype.addEventListener;
  const blockedEvents = ['contextmenu', 'selectstart', 'dragstart', 'copy'];
  EventTarget.prototype.addEventListener = function (type, listener, options) {
    if (blockedEvents.includes(type)) { return; }
    return rawAddEventListener.call(this, type, listener, options);
  };

  ['oncontextmenu', 'onselectstart', 'oncopy', 'ondragstart'].forEach(prop => {
    try {
      Object.defineProperty(document, prop, { get: () => null, set: () => {}, configurable: true });
    } catch (e) {}
  });

  ['contextmenu', 'selectstart', 'copy', 'dragstart'].forEach(evtName => {
    document.addEventListener(evtName, e => {
      e.stopImmediatePropagation();
      if (e.cancelable) e.returnValue = true;
    }, true);
  });

  const styleUnlock = document.createElement('style');
  styleUnlock.textContent = `
    body, * { -webkit-user-select: text !important; user-select: text !important; -webkit-touch-callout: default !important; }
  `;
  (document.head || document.documentElement).appendChild(styleUnlock);

  // ===== 查找预览 iframe 及 URL =====
  function findPreviewIframe() {
    const ifr = document.querySelector('iframe[src*="gyy.kuduoke.net"], iframe[src*="kuduoke"]');
    if (ifr) return { iframe: ifr, url: ifr.src };
    const html = document.documentElement.outerHTML;
    const m = html.match(/https?:\/\/gyy\.kuduoke\.net[^\s"'<>\\]+/i)
          || html.match(/https?:\/\/[\w.-]*kuduoke\.net[^\s"'<>\\]+/i);
    if (m) {
      const anyIfr = document.querySelector('iframe');
      return { iframe: anyIfr, url: m[0] };
    }
    return null;
  }

  // ===== 缓存 =====
  let cachedDoc = null;

  // ===== 抓取预览页完整正文 =====
  function fetchPreviewContent(previewUrl, callback) {
    GM_xmlhttpRequest({
      method: 'GET',
      url: previewUrl,
      headers: { 'Referer': location.href },
      timeout: 15000,
      onload: function (resp) {
        const html = resp.responseText || '';
        log('预览返回 状态:', resp.status, '长度:', html.length);

        const bodyMatch = html.match(/<body[^>]*>([\s\S]*?)<\/body>/i);
        if (!bodyMatch) {
          callback({ error: 'parse', msg: '未匹配到 <body>' });
          return;
        }

        const rawBody = bodyMatch[1];
        const previewOrigin = previewUrl.match(/^(https?:\/\/[^/]+)/i)[1];
        const docIdMatch = previewUrl.match(/\/html\/([\w]+)\.html/i);
        const docId = docIdMatch ? docIdMatch[1] : '';

        // ===== 检测 PPT/图片类型 =====
        const hasGallery = rawBody.includes('galleryContainer') || rawBody.includes('img-container');

        if (hasGallery) {
          log('检测到 PPT/图片类型文档');
          const images = [];
          const imgRegex = /data-src=["']([^"']+)["']/gi;
          let m;
          while ((m = imgRegex.exec(rawBody)) !== null) {
            let src = m[1];
            if (src.startsWith('/')) src = previewOrigin + src;
            else if (!src.startsWith('http')) src = previewOrigin + '/html/' + docId + '/' + src;
            images.push(src);
          }
          if (images.length === 0) {
            const srcRegex = /<img[^>]*\ssrc=["'](?!data:)([^"']+)["']/gi;
            while ((m = srcRegex.exec(rawBody)) !== null) {
              let src = m[1];
              if (src.startsWith('/')) src = previewOrigin + src;
              else if (!src.startsWith('http')) src = previewOrigin + '/html/' + docId + '/' + src;
              images.push(src);
            }
          }
          if (images.length === 0) {
            callback({ error: 'parse', msg: 'PPT文档但未找到图片' });
            return;
          }
          log('PPT图片总数:', images.length);

          let title = '';
          const h1 = document.querySelector('h1');
          if (h1) title = h1.textContent.trim();
          if (!title) title = document.title;
          title = title.replace(/试读.*$/, '').replace(/[\\/:*?"<>|]/g, '_').trim();
          if (!title) title = 'cpsad_doc';

          cachedDoc = { title, body: '', type: 'ppt', images };
          callback({ ok: true, title, body: '', type: 'ppt', images });
          return;
        }

        // ===== 文字类型文档 =====
        const textLen = html.replace(/<[^>]+>/g, '').trim().length;
        if (textLen < 200) {
          callback({ error: 'skip', msg: '仅PPT/图片，无可提取文本' });
          return;
        }

        let body = rawBody;
        body = body.replace(/<div\s+class="watermark"[^>]*>[\s\S]*?<\/div>/gi, '');
        body = body.replace(/<div\s+id="trialEndNotice"[^>]*>[\s\S]*?<\/div>/gi, '');
        body = body.replace(/<script[^>]*>[\s\S]*?<\/script>/gi, '');
        body = body.replace(/<style[^>]*>[\s\S]*?<\/style>/gi, '');
        body = body.replace(/<\/?span[^>]*>/g, '');
        body = body.replace(/<\/?font[^>]*>/g, '');
        body = body.replace(/\s(?:style|class|bgcolor|color|face|align)\s*=\s*("[^"]*"|'[^']*')/gi, '');
        body = body.replace(/<p[^>]*>(?:\s|&nbsp;|<br\s*\/?>)*<\/p>/gi, '');

        let title = '';
        const h1 = document.querySelector('h1');
        if (h1) title = h1.textContent.trim();
        if (!title) {
          const t = body.match(/<h1[^>]*>(.*?)<\/h1>/i);
          if (t) title = t[1].replace(/<[^>]+>/g, '').trim();
        }
        if (!title) title = document.title;
        title = title.replace(/试读.*$/, '').replace(/[\\/:*?"<>|]/g, '_').trim();
        if (!title) title = 'cpsad_doc';
        body = body.replace(/<h1[^>]*>[\s\S]*?<\/h1>/i, '');

        cachedDoc = { title, body, type: 'text' };
        callback({ ok: true, title, body, type: 'text' });
      },
      onerror: function () { callback({ error: 'network', msg: '网络错误' }); },
      ontimeout: function () { callback({ error: 'timeout', msg: '请求超时' }); }
    });
  }

  // ===== 生成 .doc（文字文档）=====
  function downloadDoc(title, body) {
    const docHtml = `<!DOCTYPE html>
<html xmlns:o='urn:schemas-microsoft-com:office:office'
 xmlns:w='urn:schemas-microsoft-com:office:word'
 xmlns='http://www.w3.org/TR/REC-html40'>
<head>
<meta charset="utf-8">
<title>${title}</title>
<!--[if gte mso 9]><xml><w:WordDocument><w:View>Print</w:View><w:Zoom>100</w:Zoom></w:WordDocument></xml><![endif]-->
<style>
@page WordSection1 {
 size: 595.3pt 841.9pt;
 margin: 37.0mm 26.0mm 35.0mm 28.0mm;
 mso-header-margin: 28.0mm; mso-footer-margin: 20.0mm; mso-footer: f1; mso-paper-source: 0;
}
div.WordSection1 { page: WordSection1; }
body { font-family: "仿宋_GB2312","仿宋",FangSong,STFangsong,serif; font-size: 16.0pt; }
.WordSection1, .WordSection1 p, .WordSection1 div, .WordSection1 li {
 font-family: "仿宋_GB2312","仿宋",FangSong,STFangsong,serif;
 font-size: 16.0pt; line-height: 28.8pt; mso-line-height-rule: exactly; mso-pagination: widow-orphan;
}
.WordSection1 p { margin: 0; text-align: justify; text-indent: 32.0pt; mso-char-indent-count: 2.0; }
.WordSection1 p.gw-title {
 font-family: "方正小标宋简体","小标宋体","华文中宋",SimSun,serif;
 font-size: 22.0pt; font-weight: normal; text-align: center;
 text-indent: 0; line-height: normal; margin: 0 0 28.0pt 0;
}
.WordSection1 h1, .WordSection1 h2, .WordSection1 h3, .WordSection1 h4 {
 font-size: 16.0pt; line-height: 28.8pt; mso-line-height-rule: exactly;
 text-indent: 32.0pt; mso-char-indent-count: 2.0; margin: 0; text-align: justify;
}
.WordSection1 h1 { font-family: SimHei,"黑体"; font-weight: normal; }
.WordSection1 h2 { font-family: KaiTi,KaiTi_GB2312,"楷体_GB2312","楷体",STKaiti; font-weight: normal; }
.WordSection1 h3 { font-family: "仿宋_GB2312","仿宋",FangSong,serif; font-weight: bold; }
.WordSection1 h4 { font-family: "仿宋_GB2312","仿宋",FangSong,serif; font-weight: normal; }
.WordSection1 table td, .WordSection1 table th {
 font-family: "仿宋_GB2312","仿宋",FangSong,serif; font-size: 16.0pt;
}
p.MsoFooter { font-family: SimSun,"宋体"; font-size: 14.0pt; text-align: center; margin: 0; }
</style>
</head>
<body>
<div class="WordSection1">
<p class="gw-title">${title}</p>
${body}
</div>
<div style='mso-element:footer' id='f1'>
<p class='MsoFooter'>—&nbsp;<span style='mso-element:field-begin'></span> PAGE <span style='mso-element:field-end'></span>&nbsp;—</p>
</div>
</body>
</html>`;

    const blob = new Blob([docHtml], { type: 'application/msword' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url; a.download = title + '.doc';
    document.body.appendChild(a); a.click(); document.body.removeChild(a);
    URL.revokeObjectURL(url);
    log('下载完成:', title + '.doc');
  }

  // ===== 下载 PPT 图片（打包为 HTML）=====
  function downloadPptHtml(title, images) {
    const imgsHtml = images.map((src, i) =>
      `<div style="text-align:center;margin-bottom:20px;"><p style="font-size:14px;color:#999;margin:5px 0;">第 ${i + 1} 页 / 共 ${images.length} 页</p><img src="${src}" style="max-width:100%;height:auto;border:1px solid #eee;" /></div>`
    ).join('\n');
    const html = `<!DOCTYPE html><html><head><meta charset="utf-8"><title>${title}</title>
<style>body{font-family:sans-serif;max-width:900px;margin:0 auto;padding:20px;}
h1{text-align:center;font-size:22px;margin-bottom:30px;}</style></head>
<body><h1>${title}</h1>${imgsHtml}</body></html>`;
    const blob = new Blob([html], { type: 'text/html' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url; a.download = title + '.html';
    document.body.appendChild(a); a.click(); document.body.removeChild(a);
    URL.revokeObjectURL(url);
    log('PPT下载完成:', title + '.html');
  }

  // ===== Toast =====
  function showToast(msg, duration = 2000) {
    const old = document.querySelector('.cpsad-toast');
    if (old) old.remove();
    const toast = document.createElement('div');
    toast.className = 'cpsad-toast';
    toast.textContent = msg;
    document.body.appendChild(toast);
    setTimeout(() => toast.remove(), duration);
  }

  // ===== 复制（文字文档）=====
  function copyToClipboard(title, body, btn) {
    let plainText = title + '\n\n';
    const temp = document.createElement('div');
    temp.innerHTML = body;
    temp.querySelectorAll('p, h1, h2, h3, h4, div').forEach(el => {
      el.insertAdjacentText('beforebegin', '\n');
      el.insertAdjacentText('afterend', '\n');
    });
    temp.querySelectorAll('br').forEach(el => { el.insertAdjacentText('beforebegin', '\n'); });
    temp.querySelectorAll('tr').forEach(el => { el.insertAdjacentText('afterend', '\n'); });
    temp.querySelectorAll('td, th').forEach(el => { el.insertAdjacentText('afterend', '\t'); });
    plainText += temp.textContent.replace(/\n{3,}/g, '\n\n').trim();

    const done = () => {
      btn.textContent = '✅ 已复制';
      showToast('✅ 已复制全文到剪贴板');
      setTimeout(() => { btn.textContent = '📋 复制全文'; btn.disabled = false; }, 2500);
    };
    btn.disabled = true;
    if (navigator.clipboard && navigator.clipboard.writeText) {
      navigator.clipboard.writeText(plainText).then(done).catch(() => fallbackCopy(plainText, btn, done));
    } else {
      fallbackCopy(plainText, btn, done);
    }
  }

  function fallbackCopy(text, btn, done) {
    const ta = document.createElement('textarea');
    ta.value = text;
    ta.style.cssText = 'position:fixed;left:-9999px;top:-9999px;opacity:0;';
    document.body.appendChild(ta); ta.select();
    try { document.execCommand('copy'); done(); }
    catch (e) { showToast('❌ 复制失败，请手动选择文本'); btn.disabled = false; }
    document.body.removeChild(ta);
  }

  // ===== 替换预览区 =====
  function replacePreviewWithFullView(targetEl, previewUrl) {
    const originalEl = targetEl;
    const parentNode = originalEl.parentNode;

    const wrapper = document.createElement('div');
    wrapper.className = 'cpsad-fullview-wrapper';
    wrapper.setAttribute('data-cpsad-original', '1');

    const actionbar = document.createElement('div');
    actionbar.className = 'cpsad-actionbar';

    const titleDisplay = document.createElement('div');
    titleDisplay.className = 'cpsad-title-display';
    titleDisplay.textContent = '📄 加载中...';

    const btnCopy = document.createElement('button');
    btnCopy.className = 'btn-copy';
    btnCopy.textContent = '📋 复制全文';
    btnCopy.disabled = true;

    const btnDownload = document.createElement('button');
    btnDownload.className = 'btn-download';
    btnDownload.textContent = '📄 下载文档';
    btnDownload.disabled = true;

    const btnRestore = document.createElement('button');
    btnRestore.className = 'btn-restore';
    btnRestore.textContent = '↩ 恢复原预览';
    btnRestore.onclick = function () { wrapper.replaceWith(originalEl); };

    actionbar.appendChild(titleDisplay);
    actionbar.appendChild(btnCopy);
    actionbar.appendChild(btnDownload);
    actionbar.appendChild(btnRestore);

    const content = document.createElement('div');
    content.innerHTML = '<div class="cpsad-placeholder">⏳ 正在获取完整正文...</div>';

    wrapper.appendChild(actionbar);
    wrapper.appendChild(content);
    parentNode.replaceChild(wrapper, originalEl);
    log('已替换预览区，开始抓取完整正文');

    function load(callback) {
      if (cachedDoc) { callback({ ok: true, ...cachedDoc }); return; }
      fetchPreviewContent(previewUrl, callback);
    }

    load(function (res) {
      if (res.ok) {
        if (res.type === 'ppt') {
          // ===== 渲染 PPT 图片 =====
          content.className = 'cpsad-pptview' + (res.images.length > 1 ? ' ppt-multiple' : '');
          content.innerHTML = '';
          res.images.forEach((src, i) => {
            const slide = document.createElement('div');
            slide.className = 'ppt-slide';
            const num = document.createElement('div');
            num.className = 'ppt-page-num';
            num.textContent = (i + 1) + ' / ' + res.images.length;
            const img = document.createElement('img');
            img.src = src;
            img.alt = '第' + (i + 1) + '页';
            img.loading = 'lazy';
            slide.appendChild(num);
            slide.appendChild(img);
            content.appendChild(slide);
          });

          titleDisplay.textContent = res.title + '（PPT · ' + res.images.length + '页）';
          titleDisplay.title = res.title;

          btnCopy.disabled = true;
          btnCopy.textContent = '📋 PPT不支持复制';
          btnCopy.title = '图片类型文档无法复制文字';

          btnDownload.disabled = false;
          btnDownload.textContent = '📄 下载PPT';
          btnDownload.onclick = function () {
            downloadPptHtml(res.title, res.images);
            const orig = btnDownload.textContent;
            btnDownload.textContent = '✅ 已下载';
            setTimeout(() => { btnDownload.textContent = orig; }, 2500);
          };

          log('PPT渲染完成:', res.title, res.images.length + '张图片');
        } else {
          // ===== 渲染文字文档 =====
          content.className = 'cpsad-fullview';
          content.innerHTML = '';
          const titleP = document.createElement('p');
          titleP.className = 'gw-title';
          titleP.textContent = res.title;
          content.appendChild(titleP);
          content.innerHTML += res.body;

          titleDisplay.textContent = res.title;
          titleDisplay.title = res.title;

          btnCopy.disabled = false;
          btnCopy.onclick = function () { copyToClipboard(res.title, res.body, btnCopy); };

          btnDownload.disabled = false;
          btnDownload.onclick = function () {
            downloadDoc(res.title, res.body);
            const orig = btnDownload.textContent;
            btnDownload.textContent = '✅ 已下载';
            setTimeout(() => { btnDownload.textContent = orig; }, 2500);
          };

          log('全文渲染完成:', res.title);
        }
      } else if (res.error === 'skip') {
        content.innerHTML = `<div class="cpsad-placeholder">⚠️ ${res.msg}</div>`;
        titleDisplay.textContent = '⚠️ ' + res.msg;
      } else {
        content.innerHTML = `<div class="cpsad-placeholder error">❌ ${res.msg}</div>`;
        titleDisplay.textContent = '❌ 加载失败';
      }
    });
  }

  // ===== 轮询等待预览 iframe =====
  let pollTimer = null;
  function waitForPreview() {
    if (pollTimer) { clearInterval(pollTimer); pollTimer = null; }
    let tries = 0;
    const maxTries = 30;
    pollTimer = setInterval(() => {
      tries++;
      const result = findPreviewIframe();
      if (result && result.iframe) {
        clearInterval(pollTimer); pollTimer = null;
        log('找到预览 iframe（第' + tries + '次）:', result.url);
        if (document.querySelector('.cpsad-fullview-wrapper[data-cpsad-original]')) {
          log('已存在替换容器，跳过');
          return;
        }
        replacePreviewWithFullView(result.iframe, result.url);
      } else if (tries >= maxTries) {
        clearInterval(pollTimer); pollTimer = null;
        log('超时仍未找到预览 iframe');
      }
    }, 600);
  }

  function onReady(callback) {
    if (document.readyState === 'loading') {
      document.addEventListener('DOMContentLoaded', callback);
    } else {
      callback();
    }
  }

  onReady(() => {
    log('DOM ready, 开始检测预览 iframe');
    waitForPreview();
  });

  // ===== SPA 路由监听 =====
  ['pushState', 'replaceState'].forEach(fn => {
    const raw = history[fn];
    history[fn] = function () {
      const r = raw.apply(this, arguments);
      window.dispatchEvent(new Event('cpsad:locationchange'));
      return r;
    };
  });
  window.addEventListener('popstate', () => window.dispatchEvent(new Event('cpsad:locationchange')));

  let lastHref = location.href;
  window.addEventListener('cpsad:locationchange', () => {
    if (location.href === lastHref) return;
    lastHref = location.href;
    log('检测到路由变化:', location.href);
    setTimeout(() => {
      cachedDoc = null;
      const oldWrapper = document.querySelector('.cpsad-fullview-wrapper[data-cpsad-original]');
      if (oldWrapper) oldWrapper.remove();
      waitForPreview();
    }, 300);
  });
})();