content.js

// content.js — 在 B 站视频页注入悬浮按钮与下载面板
(function () {
  if (window.__BILI_DL_INJECTED__) return;
  window.__BILI_DL_INJECTED__ = true;

  const log = (...a) => console.log('[BiliDL]', ...a);
  log('content script loaded at', location.href);

  const VIDEO_PAGE_RE = /^https?:\/\/www\.bilibili\.com\/(video\/|bangumi\/play\/|list\/)/;
  function isVideoPage() { return VIDEO_PAGE_RE.test(location.href); }

  // ---------- 从页面拿 __playinfo__ / __INITIAL_STATE__ ----------
  // content script 运行在 isolated world，拿不到 window 上的对象，需要注入脚本到 main world
  function readPlayInfoFromMainWorld() {
    return new Promise((resolve) => {
      const id = 'bili_dl_probe_' + Date.now();
      const handler = (e) => {
        if (e.source !== window || !e.data || e.data.__bili_dl_probe !== id) return;
        window.removeEventListener('message', handler);
        resolve(e.data.payload);
      };
      window.addEventListener('message', handler);

      const code = `(function(){
        try {
          var payload = {
            playinfo: window.__playinfo__ || null,
            initial: window.__INITIAL_STATE__ ? {
              videoData: window.__INITIAL_STATE__.videoData || null,
              epInfo: window.__INITIAL_STATE__.epInfo || null,
              mediaInfo: window.__INITIAL_STATE__.mediaInfo || null,
              h1Title: window.__INITIAL_STATE__.h1Title || null
            } : null,
            href: location.href,
            title: document.title
          };
          window.postMessage({ __bili_dl_probe: '${id}', payload: payload }, '*');
        } catch (e) {
          window.postMessage({ __bili_dl_probe: '${id}', payload: { error: String(e) } }, '*');
        }
      })();`;
      const s = document.createElement('script');
      s.textContent = code;
      (document.head || document.documentElement).appendChild(s);
      s.remove();

      setTimeout(() => {
        window.removeEventListener('message', handler);
        resolve(null);
      }, 1500);
    });
  }

  // 新版 B 站经常不再注入 window.__playinfo__，需要直接调 API
  // 同域 fetch 会自动带 SESSDATA cookie，登录用户能拿到高清晰度
  async function fetchPlayInfoViaApi() {
    try {
      // 1) 番剧 /bangumi/play/ep12345 或 ss12345
      const epMatch = location.pathname.match(/\/bangumi\/play\/ep(\d+)/);
      const ssMatch = location.pathname.match(/\/bangumi\/play\/ss(\d+)/);
      if (epMatch || ssMatch) {
        const q = epMatch ? `ep_id=${epMatch[1]}` : `season_id=${ssMatch[1]}`;
        const seasonRes = await fetch(`https://api.bilibili.com/pgc/view/web/season?${q}`, { credentials: 'include' }).then(r => r.json());
        const result = seasonRes && seasonRes.result;
        if (!result) return null;
        const episodes = result.episodes || [];
        const targetEpId = epMatch ? epMatch[1] : null;
        const ep = (targetEpId && episodes.find(e => String(e.ep_id) === targetEpId)) || episodes[0];
        if (!ep) return null;
        const playRes = await fetch(`https://api.bilibili.com/pgc/player/web/playurl?ep_id=${ep.ep_id}&cid=${ep.cid}&qn=120&fnval=4048&fourk=1`, { credentials: 'include' }).then(r => r.json());
        if (!playRes || !playRes.result) return null;
        return {
          playinfo: { data: playRes.result },
          initial: {
            videoData: { title: ep.long_title || ep.title || result.title, pic: ep.cover || result.cover },
            epInfo: ep,
            mediaInfo: { title: result.title }
          },
          href: location.href
        };
      }
      // 2) 普通视频 /video/BVxxxx
      const bvMatch = location.pathname.match(/\/video\/(BV[0-9A-Za-z]+)/);
      if (bvMatch) {
        const bvid = bvMatch[1];
        const pMatch = location.search.match(/[?&]p=(\d+)/);
        const pageIdx = pMatch ? Math.max(1, Number(pMatch[1])) - 1 : 0;
        const viewRes = await fetch(`https://api.bilibili.com/x/web-interface/view?bvid=${bvid}`, { credentials: 'include' }).then(r => r.json());
        const data = viewRes && viewRes.data;
        if (!data) return null;
        const page = (data.pages && data.pages[pageIdx]) || (data.pages && data.pages[0]);
        const cid = page ? page.cid : data.cid;
        if (!cid) return null;
        const playRes = await fetch(`https://api.bilibili.com/x/player/playurl?bvid=${bvid}&cid=${cid}&qn=120&fnval=4048&fourk=1`, { credentials: 'include' }).then(r => r.json());
        if (!playRes || !playRes.data) return null;
        return {
          playinfo: { data: playRes.data },
          initial: { videoData: { title: page && page.part ? `${data.title} - ${page.part}` : data.title, pic: data.pic } },
          href: location.href
        };
      }
    } catch (e) {
      console.error('[BiliDL] fetchPlayInfoViaApi failed', e);
    }
    return null;
  }

  function pickQualities(playinfo) {
    // dash
    if (playinfo && playinfo.data && playinfo.data.dash) {
      const dash = playinfo.data.dash;
      const accept = playinfo.data.accept_quality || [];
      const desc = playinfo.data.accept_description || [];
      const map = {};
      for (let i = 0; i < accept.length; i++) map[accept[i]] = desc[i];
      // 把每个清晰度的视频流挑出来（取 bandwidth 最高的同 id）
      const byQ = {};
      for (const v of (dash.video || [])) {
        if (!byQ[v.id] || v.bandwidth > byQ[v.id].bandwidth) byQ[v.id] = v;
      }
      // 音频流取最高码率
      let bestAudio = null;
      for (const a of (dash.audio || [])) {
        if (!bestAudio || a.bandwidth > bestAudio.bandwidth) bestAudio = a;
      }
      // 优先选 upos 主 CDN 的 URL（更稳），mcdn 边缘节点经常拒
      function pickStableUrl(s) {
        if (!s) return null;
        const candidates = [s.baseUrl || s.base_url, ...(s.backupUrl || s.backup_url || [])].filter(Boolean);
        const upos = candidates.find(u => /upos-[a-z]+-(mirror|estg)/.test(u));
        return upos || candidates[0] || null;
      }
      const list = Object.keys(byQ)
        .map(qid => ({
          quality: Number(qid),
          label: map[qid] || `清晰度${qid}`,
          videoUrl: pickStableUrl(byQ[qid]),
          audioUrl: pickStableUrl(bestAudio),
          container: 'dash'
        }))
        .sort((a, b) => b.quality - a.quality);
      return list;
    }
    // durl (mp4 / flv)
    if (playinfo && playinfo.data && playinfo.data.durl && playinfo.data.durl.length) {
      const format = playinfo.data.format || 'mp4';
      const qid = playinfo.data.quality;
      const accept = playinfo.data.accept_quality || [];
      const desc = playinfo.data.accept_description || [];
      const idx = accept.indexOf(qid);
      const label = idx >= 0 ? desc[idx] : `清晰度${qid}`;
      // durl 可能有多段（分P内部分片），这里只取第一段做演示，提示用户
      return [{
        quality: qid,
        label,
        videoUrl: playinfo.data.durl[0].url,
        audioUrl: null,
        container: format.includes('flv') ? 'flv' : 'mp4',
        multiSegment: playinfo.data.durl.length > 1
      }];
    }
    return [];
  }

  function extractMeta(probe) {
    let title = document.title.replace(/_哔哩哔哩.*$/, '').replace(/-哔哩哔哩.*$/, '').trim();
    let cover = '';
    if (probe && probe.initial) {
      const vd = probe.initial.videoData;
      if (vd) {
        title = vd.title || title;
        cover = vd.pic || cover;
      }
      const ep = probe.initial.epInfo;
      if (ep && ep.long_title) {
        title = (probe.initial.mediaInfo && probe.initial.mediaInfo.title ? probe.initial.mediaInfo.title + ' - ' : '') + (ep.long_title || ep.title || '');
        cover = ep.cover || cover;
      }
    }
    if (!cover) {
      const og = document.querySelector('meta[property="og:image"]');
      if (og) cover = og.content;
    }
    return { title, cover };
  }

  // ---------- UI ----------
  const root = document.createElement('div');
  root.id = 'bili-dl-root';
  root.innerHTML = `
    <button id="bili-dl-fab" title="打开视频下载">
      <svg viewBox="0 0 24 24" width="22" height="22" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
        <path d="M12 3v12"/>
        <path d="m7 10 5 5 5-5"/>
        <path d="M5 21h14"/>
      </svg>
      <span>下载</span>
    </button>
    <div id="bili-dl-panel" hidden>
      <div class="bdl-header">
        <button class="bdl-back" title="返回" hidden>
          <svg viewBox="0 0 24 24" width="18" height="18" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"><path d="m15 18-6-6 6-6"/></svg>
        </button>
        <div class="bdl-title">选择下载内容</div>
        <button class="bdl-close" title="关闭">✕</button>
      </div>

      <!-- 一级选择面板 -->
      <div class="bdl-view bdl-view-home">
        <div class="bdl-choice" data-choice="video">
          <div class="bdl-choice-icon">
            <svg viewBox="0 0 24 24" width="22" height="22" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M12 3v12"/><path d="m7 10 5 5 5-5"/><path d="M5 21h14"/></svg>
          </div>
          <div class="bdl-choice-text">
            <div class="bdl-choice-title">下载视频</div>
            <div class="bdl-choice-desc">下载当前视频为本地文件</div>
          </div>
          <div class="bdl-choice-arrow">
            <svg viewBox="0 0 24 24" width="18" height="18" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="m9 18 6-6-6-6"/></svg>
          </div>
        </div>
        <div class="bdl-choice" data-choice="transcript">
          <div class="bdl-choice-icon">
            <svg viewBox="0 0 24 24" width="22" height="22" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z"/><path d="M14 2v6h6"/><path d="M8 13h8"/><path d="M8 17h5"/></svg>
          </div>
          <div class="bdl-choice-text">
            <div class="bdl-choice-title">下载文稿</div>
            <div class="bdl-choice-desc">识别视频语音并导出文字稿</div>
          </div>
          <div class="bdl-choice-arrow">
            <svg viewBox="0 0 24 24" width="18" height="18" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="m9 18 6-6-6-6"/></svg>
          </div>
        </div>
      </div>

      <!-- 视频下载面板 -->
      <div class="bdl-view bdl-view-video" hidden>
        <div class="bdl-body">
          <div class="bdl-cover-wrap">
            <img class="bdl-cover" alt="封面"/>
          </div>
          <div class="bdl-meta">
            <div class="bdl-vtitle">加载中…</div>
            <div class="bdl-row">
              <label>清晰度</label>
              <select class="bdl-quality"></select>
            </div>
            <button class="bdl-go">开始下载</button>
            <div class="bdl-hint"></div>
          </div>
        </div>
        <div class="bdl-tasks">
          <div class="bdl-tasks-title">下载任务</div>
          <div class="bdl-tasks-list"></div>
        </div>
        <div class="bdl-footer">DASH 流在浏览器内自动合并为 mp4 · 切换页面不会中断</div>
      </div>

      <!-- 文稿生成面板 -->
      <div class="bdl-view bdl-view-transcript" hidden>
        <div class="bdl-body">
          <div class="bdl-cover-wrap">
            <img class="bdl-cover" alt="封面"/>
          </div>
          <div class="bdl-meta">
            <div class="bdl-vtitle">加载中…</div>
            <div class="bdl-row">
              <label>导出格式</label>
              <div class="bdl-fmt">
                <label class="bdl-fmt-opt"><input type="radio" name="bdl-ts-fmt" value="txt" checked><span>TXT</span></label>
                <label class="bdl-fmt-opt"><input type="radio" name="bdl-ts-fmt" value="md"><span>Markdown</span></label>
              </div>
            </div>
            <div class="bdl-row">
              <label>带时间戳</label>
              <label class="bdl-switch"><input type="checkbox" class="bdl-ts-time"><span class="bdl-switch-track"></span></label>
            </div>
            <button class="bdl-go-ts">开始生成文稿</button>
            <div class="bdl-hint"></div>
          </div>
        </div>
        <div class="bdl-footer">文稿来源为 B 站 AI 字幕 · 部分视频可能未提供字幕</div>
      </div>
    </div>
  `;
  document.documentElement.appendChild(root);

  function updateVisibility() {
    root.style.display = isVideoPage() ? '' : 'none';
  }
  updateVisibility();

  // 监听 B 站 SPA 路由变化，确保切到视频页时按钮重新出现
  let lastHref = location.href;
  const _push = history.pushState;
  const _replace = history.replaceState;
  history.pushState = function () { _push.apply(this, arguments); queueMicrotask(onUrlMaybeChanged); };
  history.replaceState = function () { _replace.apply(this, arguments); queueMicrotask(onUrlMaybeChanged); };
  window.addEventListener('popstate', onUrlMaybeChanged);
  setInterval(onUrlMaybeChanged, 1000);
  function onUrlMaybeChanged() {
    if (location.href === lastHref) return;
    lastHref = location.href;
    log('url changed →', lastHref);
    updateVisibility();
    closePanel();
  }

  const fab = root.querySelector('#bili-dl-fab');
  const panel = root.querySelector('#bili-dl-panel');
  const headerTitle = root.querySelector('.bdl-header .bdl-title');
  const backBtn = root.querySelector('.bdl-back');
  const closeBtn = root.querySelector('.bdl-close');

  const homeView = root.querySelector('.bdl-view-home');
  const videoView = root.querySelector('.bdl-view-video');
  const tsView = root.querySelector('.bdl-view-transcript');

  // 视频下载视图元素（作用域限定，避免与文稿视图同名 class 冲突）
  const coverImg = videoView.querySelector('.bdl-cover');
  const titleEl = videoView.querySelector('.bdl-vtitle');
  const qSel = videoView.querySelector('.bdl-quality');
  const goBtn = videoView.querySelector('.bdl-go');
  const hintEl = videoView.querySelector('.bdl-hint');
  const tasksList = videoView.querySelector('.bdl-tasks-list');

  // 文稿视图元素
  const tsCover = tsView.querySelector('.bdl-cover');
  const tsTitle = tsView.querySelector('.bdl-vtitle');
  const tsGoBtn = tsView.querySelector('.bdl-go-ts');
  const tsHint = tsView.querySelector('.bdl-hint');
  const tsTimeChk = tsView.querySelector('.bdl-ts-time');

  let currentMeta = null;
  let currentQualities = [];
  let currentView = 'home';

  const VIEW_TITLES = { home: '选择下载内容', video: '下载视频', transcript: '下载文稿' };
  function showView(name) {
    currentView = name;
    homeView.toggleAttribute('hidden', name !== 'home');
    videoView.toggleAttribute('hidden', name !== 'video');
    tsView.toggleAttribute('hidden', name !== 'transcript');
    backBtn.toggleAttribute('hidden', name === 'home');
    headerTitle.textContent = VIEW_TITLES[name] || 'B站下载助手';
  }

  function openPanel() {
    panel.removeAttribute('hidden');
    showView('home');
  }
  function closePanel() {
    panel.setAttribute('hidden', '');
    showView('home');
  }

  fab.addEventListener('click', () => {
    if (panel.hasAttribute('hidden')) openPanel();
    else closePanel();
  });
  closeBtn.addEventListener('click', closePanel);
  backBtn.addEventListener('click', () => showView('home'));

  // 一级选择面板：进入对应子视图并懒加载数据
  root.querySelectorAll('.bdl-choice').forEach(el => {
    el.addEventListener('click', async () => {
      const choice = el.getAttribute('data-choice');
      if (choice === 'video') {
        showView('video');
        await refreshVideoInfo();
        await refreshTasks();
      } else if (choice === 'transcript') {
        showView('transcript');
        await refreshTranscriptInfo();
      }
    });
  });

  async function refreshVideoInfo() {
    titleEl.textContent = '解析中…';
    qSel.innerHTML = '';
    hintEl.textContent = '';
    let probe = await readPlayInfoFromMainWorld();
    if (!probe || !probe.playinfo) {
      log('window.__playinfo__ 不存在，回退到 API 解析');
      probe = await fetchPlayInfoViaApi();
    }
    if (!probe || !probe.playinfo) {
      titleEl.textContent = '未能解析到视频源';
      hintEl.textContent = '可能是付费/会员视频，或需登录 B 站。请确认已登录后重试。';
      goBtn.disabled = true;
      return;
    }
    const meta = extractMeta(probe);
    const quals = pickQualities(probe.playinfo);
    currentMeta = meta;
    currentQualities = quals;
    titleEl.textContent = meta.title;
    if (meta.cover) coverImg.src = meta.cover.replace(/^http:/, 'https:');
    if (quals.length === 0) {
      hintEl.textContent = '当前页面没有可用下载源（可能是付费/会员/试看片段）。';
      goBtn.disabled = true;
      return;
    }
    for (const q of quals) {
      const opt = document.createElement('option');
      opt.value = String(q.quality);
      opt.textContent = `${q.label}（${q.container.toUpperCase()}${q.audioUrl ? ' + 音频' : ''}）`;
      qSel.appendChild(opt);
    }
    goBtn.disabled = false;
    const first = quals[0];
    if (first.container === 'dash') {
      hintEl.textContent = '该清晰度为 DASH，将自动用 ffmpeg.wasm 合并为单个 mp4。';
    } else if (first.multiSegment) {
      hintEl.textContent = '该视频有多个分段，当前仅下载第一段。';
    }
  }

  qSel.addEventListener('change', () => {
    const q = currentQualities.find(x => String(x.quality) === qSel.value);
    if (!q) return;
    if (q.container === 'dash') {
      hintEl.textContent = '该清晰度为 DASH，将自动用 ffmpeg.wasm 合并为单个 mp4。';
    } else if (q.multiSegment) {
      hintEl.textContent = '该视频有多个分段，当前仅下载第一段。';
    } else {
      hintEl.textContent = '';
    }
  });

  goBtn.addEventListener('click', async () => {
    const q = currentQualities.find(x => String(x.quality) === qSel.value);
    if (!q || !currentMeta) return;
    const taskId = 'tsk_' + Date.now() + '_' + Math.random().toString(36).slice(2, 7);
    const task = {
      id: taskId,
      title: currentMeta.title,
      cover: currentMeta.cover,
      quality: q.quality,
      qualityLabel: q.label,
      videoUrl: q.videoUrl,
      audioUrl: q.audioUrl,
      container: q.container,
      pageUrl: location.href
    };
    goBtn.disabled = true;
    goBtn.textContent = '已加入下载队列';
    setTimeout(() => { goBtn.disabled = false; goBtn.textContent = '开始下载'; }, 1500);
    await chrome.runtime.sendMessage({ type: 'CREATE_TASK', task });
    await refreshTasks();
  });

  async function refreshTasks() {
    const res = await chrome.runtime.sendMessage({ type: 'GET_TASKS' });
    if (!res || !res.ok) return;
    renderTasks(res.tasks);
  }

  function renderTasks(tasks) {
    const arr = Object.values(tasks).sort((a, b) => (b.createdAt || 0) - (a.createdAt || 0));
    if (arr.length === 0) {
      tasksList.innerHTML = '<div class="bdl-empty">暂无下载任务</div>';
      return;
    }
    tasksList.innerHTML = '';
    for (const t of arr) {
      const isDash = t.container === 'dash';
      let pct = 0, line = '';
      const phaseMap = { queued: '排队中', starting: '准备中', fetching: '拉取流', merging: '合并 mp4', saving: '保存中', done: '已完成', error: '失败' };
      const statusMap = { downloading: phaseMap[t.merge?.phase] || '下载中', done: '已完成', error: '失败', canceled: '已取消', interrupted: '已中断' };
      let statusLabel = statusMap[t.status] || t.status;

      if (isDash) {
        const m = t.merge || {};
        const vRecv = m.videoReceived || 0, vTot = m.videoTotal || 0;
        const aRecv = m.audioReceived || 0, aTot = m.audioTotal || 0;
        const fetchedBytes = vRecv + aRecv;
        const fetchTotal = (vTot || 0) + (aTot || 0);
        // 进度条：拉流占 0-70%，合并占 70-95%，保存 95-100%
        if (m.phase === 'merging') {
          pct = 70 + Math.floor((m.mergeProgress || 0) * 25);
        } else if (m.phase === 'saving') {
          pct = 96;
        } else if (m.phase === 'done') {
          pct = 100;
        } else if (m.phase === 'fetching' && fetchTotal > 0) {
          pct = Math.min(70, Math.floor(fetchedBytes / fetchTotal * 70));
        } else {
          pct = 2;
        }
        if (m.phase === 'fetching') {
          line = `${t.qualityLabel || ''} · 视频 ${formatBytes(vRecv)}/${vTot ? formatBytes(vTot) : '—'} · 音频 ${formatBytes(aRecv)}/${aTot ? formatBytes(aTot) : '—'}`;
        } else if (m.phase === 'merging') {
          line = `${t.qualityLabel || ''} · ffmpeg 合并中 ${Math.floor((m.mergeProgress || 0) * 100)}%`;
        } else if (m.phase === 'saving') {
          line = `${t.qualityLabel || ''} · 正在保存 mp4（${formatBytes(m.mp4Size || 0)}）`;
        } else if (m.phase === 'done') {
          line = `${t.qualityLabel || ''} · mp4 ${formatBytes(m.mp4Size || 0)}`;
        } else if (m.phase === 'error') {
          line = `${t.qualityLabel || ''} · ${t.error || '合并失败'}`;
        } else {
          line = t.qualityLabel || '';
        }
      } else {
        // 单文件 mp4/flv 路径
        const parts = Object.values(t.parts || {});
        const received = parts.reduce((s, p) => s + (p.bytesReceived || 0), 0);
        const total = parts.reduce((s, p) => s + (p.totalBytes || 0), 0);
        pct = total > 0 ? Math.min(100, Math.floor(received / total * 100)) : 0;
        line = `${t.qualityLabel || ''} · ${formatBytes(received)} / ${total ? formatBytes(total) : '—'}`;
      }

      const item = document.createElement('div');
      item.className = 'bdl-task ' + t.status;
      item.innerHTML = `
        <div class="bdl-t-row">
          <div class="bdl-t-title" title="${escapeHtml(t.title)}">${escapeHtml(t.title)}</div>
          <div class="bdl-t-status">${statusLabel}</div>
        </div>
        <div class="bdl-progress"><div class="bdl-progress-bar" style="width:${pct}%"></div></div>
        <div class="bdl-t-row bdl-t-sub">
          <span>${escapeHtml(line)}</span>
          <span class="bdl-t-actions">
            ${t.status === 'downloading' ? `<button data-act="cancel" data-id="${t.id}">取消</button>` : ''}
            <button data-act="remove" data-id="${t.id}">移除</button>
          </span>
        </div>
      `;
      tasksList.appendChild(item);
    }
    tasksList.querySelectorAll('button[data-act]').forEach(b => {
      b.addEventListener('click', async () => {
        const id = b.getAttribute('data-id');
        const act = b.getAttribute('data-act');
        if (act === 'cancel') await chrome.runtime.sendMessage({ type: 'CANCEL_TASK', taskId: id });
        if (act === 'remove') await chrome.runtime.sendMessage({ type: 'REMOVE_TASK', taskId: id });
        await refreshTasks();
      });
    });
  }

  // ---------- 文稿（B 站 AI 字幕） ----------
  async function refreshTranscriptInfo() {
    tsTitle.textContent = '解析中…';
    tsHint.textContent = '';
    tsGoBtn.disabled = true;
    // SPA 切视频后 window.__playinfo__ 经常不更新，需要 API 兜底，否则文件名会是旧视频的
    let probe = await readPlayInfoFromMainWorld();
    if (!probe || !probe.initial || !probe.initial.videoData) {
      log('[transcript] __playinfo__ 不可用，回落 API 取 meta');
      probe = await fetchPlayInfoViaApi();
    }
    const meta = extractMeta(probe);
    tsTitle.textContent = meta.title || '当前视频';
    if (meta.cover) tsCover.src = meta.cover.replace(/^http:/, 'https:');
    currentMeta = currentMeta || meta;
    tsView.__meta = meta;
    log('[transcript] meta', { title: meta.title, href: location.href });
    tsGoBtn.disabled = false;
  }

  // 向主世界脚本(mainworld.js)询问"当前正在播"的视频信息。
  // 自动连播/推荐换片后地址栏 BV 号会过期，主世界的 __INITIAL_STATE__.videoData 才是准的。
  function getCurrentVideoData(timeout = 1200) {
    return new Promise((resolve) => {
      const reqId = 'cv_' + Date.now() + '_' + Math.random().toString(36).slice(2);
      const handler = (e) => {
        if (e.source !== window || !e.data || e.data.__bili_dl_resp !== 'cur_video' || e.data.reqId !== reqId) return;
        window.removeEventListener('message', handler);
        resolve(e.data.payload || null);
      };
      window.addEventListener('message', handler);
      window.postMessage({ __bili_dl_req: 'cur_video', reqId }, '*');
      setTimeout(() => { window.removeEventListener('message', handler); resolve(null); }, timeout);
    });
  }

  // 拿到当前视频的 bvid + cid（番剧用 ep_id + cid）
  async function getVideoIds() {
    const epMatch = location.pathname.match(/\/bangumi\/play\/ep(\d+)/);
    const ssMatch = location.pathname.match(/\/bangumi\/play\/ss(\d+)/);
    if (epMatch || ssMatch) {
      const q = epMatch ? `ep_id=${epMatch[1]}` : `season_id=${ssMatch[1]}`;
      const seasonRes = await fetch(`https://api.bilibili.com/pgc/view/web/season?${q}`, { credentials: 'include' }).then(r => r.json());
      const result = seasonRes && seasonRes.result;
      if (!result) return null;
      const episodes = result.episodes || [];
      const targetEpId = epMatch ? epMatch[1] : null;
      const ep = (targetEpId && episodes.find(e => String(e.ep_id) === targetEpId)) || episodes[0];
      if (!ep) return null;
      return { bvid: ep.bvid || '', cid: ep.cid, epId: ep.ep_id, aid: ep.aid || null };
    }
    // 普通视频：从"播放器当前正在播"取 BV 号（回退地址栏），再用它向接口拿权威 cid。
    // 不直接信主世界的 cid——自动连播切换时 videoData 可能"标题已更新、cid 还残留旧视频"。
    const cur = await getCurrentVideoData();
    const bvMatch = location.pathname.match(/\/video\/(BV[0-9A-Za-z]+)/);
    const bvid = (cur && cur.bvid) || (bvMatch && bvMatch[1]);
    if (!bvid) return null;
    const pMatch = location.search.match(/[?&]p=(\d+)/);
    const pageIdx = pMatch ? Math.max(1, Number(pMatch[1])) - 1 : 0;
    const viewRes = await fetch(`https://api.bilibili.com/x/web-interface/view?bvid=${bvid}`, { credentials: 'include' }).then(r => r.json());
    const data = viewRes && viewRes.data;
    if (!data) return null;
    const pages = data.pages || [];
    // 仅当主世界给的 cid 确实属于这个 BV（出现在它的分 P 列表里）才采用，兼容多 P；
    // 否则一律用接口返回的本视频 cid，杜绝串台。
    let cid;
    if (cur && cur.cid && pages.some(p => String(p.cid) === String(cur.cid))) {
      cid = cur.cid;
    } else {
      const page = pages[pageIdx] || pages[0];
      cid = page ? page.cid : data.cid;
    }
    if (!cid) return null;
    log('[transcript] 解析视频', { bvid, cid, 主世界cid: cur && cur.cid, urlBvid: bvMatch && bvMatch[1] });
    return { bvid, cid, epId: null, aid: data.aid || null, resolvedTitle: data.title || '' };
  }

  // 调 x/player/v2 拿字幕列表（需登录 cookie 才有 AI 字幕）
  async function fetchSubtitleList(ids) {
    const params = ids.bvid ? `bvid=${ids.bvid}&cid=${ids.cid}` : `ep_id=${ids.epId}&cid=${ids.cid}`;
    try {
      // 必须用 wbi/v2：非 wbi 的 x/player/v2 会返回“串台”的旧字幕 URL（接口回显 cid 正确，
      // 但 subtitle_url 指向另一个视频的 AI 字幕文件）。wbi/v2 才返回与本视频匹配的字幕。
      const res = await fetch(`https://api.bilibili.com/x/player/wbi/v2?${params}`, { credentials: 'include' }).then(r => r.json());
      const data = res && res.data;
      // 关键诊断：B站接口会回显它实际为哪个视频应答。若与我们请求的 cid 不一致，
      // 说明拿到的是别的视频的字幕——这就是“内容对不上”的根因。
      log('[transcript] player/v2 回显', {
        请求cid: ids.cid, 回显cid: data && data.aid != null ? data.cid : '(无)',
        请求bvid: ids.bvid, 回显bvid: data && data.bvid,
        回显aid: data && data.aid
      });
      const subtitle = data && data.subtitle;
      const list = (subtitle && subtitle.subtitles) || [];
      const echoed = data ? { aid: data.aid, bvid: data.bvid, cid: data.cid } : null;
      return { list, echoed };
    } catch (e) {
      console.error('[BiliDL] fetchSubtitleList failed', e);
      return { list: [], echoed: null };
    }
  }

  function pickSubtitle(list) {
    if (!list.length) return null;
    // 优先级：人工中文字幕（质量高） > AI 中文字幕 > 第一条
    // B 站的 lan：人工中文 = 'zh-CN' / 'zh-Hans'；AI 中文 = 'ai-zh'
    const isAi = s => /^ai-/i.test(s.lan || '') || !!s.ai_type || !!s.ai_status;
    const manualZh = list.find(s => /zh/i.test(s.lan) && !isAi(s));
    if (manualZh) {
      log('[transcript] 选用人工中文字幕', manualZh.lan, manualZh.lan_doc);
      return manualZh;
    }
    const aiZh = list.find(s => /zh/i.test(s.lan));
    if (aiZh) {
      log('[transcript] 未找到人工中文，回落 AI 中文字幕', aiZh.lan);
      return aiZh;
    }
    return list[0];
  }

  async function fetchSubtitleBody(subtitleUrl) {
    const url = subtitleUrl.startsWith('//') ? 'https:' + subtitleUrl : subtitleUrl.replace(/^http:/, 'https:');
    const res = await fetch(url, { credentials: 'omit' });
    if (!res.ok) throw new Error(`字幕 HTTP ${res.status}`);
    const json = await res.json();
    return json.body || [];
  }

  function formatTimestamp(sec) {
    sec = Math.max(0, Math.floor(sec || 0));
    const h = Math.floor(sec / 3600);
    const m = Math.floor((sec % 3600) / 60);
    const s = sec % 60;
    const pad = n => String(n).padStart(2, '0');
    return h > 0 ? `${pad(h)}:${pad(m)}:${pad(s)}` : `${pad(m)}:${pad(s)}`;
  }

  function buildTranscript(body, title, format, withTime) {
    const lines = body.map(c => {
      const text = (c.content || '').trim();
      if (!text) return '';
      if (!withTime) return text;
      const ts = formatTimestamp(c.from);
      return format === 'md' ? `- **[${ts}]** ${text}` : `[${ts}] ${text}`;
    }).filter(Boolean);
    if (format === 'md') {
      const head = `# ${title || '视频文稿'}\n\n`;
      return head + (withTime ? lines.join('\n') : lines.join('\n\n')) + '\n';
    }
    return lines.join('\n') + '\n';
  }

  tsGoBtn.addEventListener('click', async () => {
    const format = (tsView.querySelector('input[name="bdl-ts-fmt"]:checked') || {}).value || 'txt';
    const withTime = !!(tsTimeChk && tsTimeChk.checked);
    const meta = tsView.__meta || extractMeta(null);
    tsGoBtn.disabled = true;
    const origText = tsGoBtn.textContent;
    tsGoBtn.textContent = '生成中…';
    tsHint.textContent = '正在解析视频信息…';
    try {
      const ids = await getVideoIds();
      log('[transcript] ids', ids, 'pageHref=', location.href);
      if (!ids) throw new Error('未能识别当前视频');
      // 文件名标题优先用"当前视频"的真实标题，避免面板缓存的旧标题
      const fileTitle = ids.resolvedTitle || meta.title || 'bilibili_video';
      tsHint.textContent = '正在获取字幕…';
      const { list, echoed } = await fetchSubtitleList(ids);
      // 关键诊断：对比“我们请求的 cid”与“B站接口实际应答的 cid”。
      const cidMatch = !echoed || echoed.cid == null || String(echoed.cid) === String(ids.cid);
      log('[transcript] player/v2 回显', { 请求cid: ids.cid, 回显cid: echoed && echoed.cid, 请求bvid: ids.bvid, 回显bvid: echoed && echoed.bvid, cidMatch });
      log('[transcript] subtitle list', list.map(s => ({ lan: s.lan, lan_doc: s.lan_doc, url: s.subtitle_url })));
      const sub = pickSubtitle(list);
      if (!sub || !sub.subtitle_url) {
        tsHint.textContent = '当前视频未提供 AI 字幕（UP 主未开启或视频无语音识别字幕），无法生成文稿。';
        return;
      }
      log('[transcript] picked', { lan: sub.lan, lan_doc: sub.lan_doc, url: sub.subtitle_url });
      const body = await fetchSubtitleBody(sub.subtitle_url);
      log('[transcript] body sample', {
        count: body.length,
        first3: body.slice(0, 3).map(c => c.content),
        savedTitle: meta.title
      });
      if (!body.length) {
        tsHint.textContent = '字幕内容为空，无法生成文稿。';
        return;
      }
      const text = buildTranscript(body, fileTitle, format, withTime);
      const ext = format === 'md' ? 'md' : 'txt';
      const res = await chrome.runtime.sendMessage({
        type: 'SAVE_TRANSCRIPT',
        title: fileTitle,
        ext,
        text
      });
      if (!res || !res.ok) throw new Error((res && res.error) || '保存失败');
      const firstLine = (body.find(c => (c.content || '').trim()) || {}).content || '';
      tsHint.textContent = `已导出（${body.length} 句，${ext.toUpperCase()}）\n视频：${(fileTitle || '').slice(0, 24)}\n首句：${firstLine.slice(0, 30)}`;
      tsHint.style.whiteSpace = 'pre-line';
    } catch (e) {
      console.error('[BiliDL] transcript failed', e);
      tsHint.textContent = '生成失败：' + String(e && e.message || e);
    } finally {
      tsGoBtn.disabled = false;
      tsGoBtn.textContent = origText;
    }
  });

  function sanitizeForCmd(s) {
    return String(s || 'output').replace(/["\\/:*?<>|]/g, '_').slice(0, 80);
  }
  function escapeHtml(s) {
    return String(s || '').replace(/[&<>"']/g, c => ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' }[c]));
  }
  function formatBytes(n) {
    if (!n) return '0 B';
    const u = ['B', 'KB', 'MB', 'GB'];
    let i = 0; let v = n;
    while (v >= 1024 && i < u.length - 1) { v /= 1024; i++; }
    return v.toFixed(v < 10 ? 2 : 1) + ' ' + u[i];
  }

  chrome.runtime.onMessage.addListener((msg) => {
    if (msg.type === 'TASK_UPDATED' || msg.type === 'TASK_REMOVED') {
      if (!panel.hasAttribute('hidden')) refreshTasks();
    }
    if (msg.type === 'TOGGLE_PANEL') {
      fab.click();
    }
  });
})();