// ==UserScript==
// @name         网页媒体抓取器 · 图片/视频批量下载
// @namespace    https://workbuddy.local/web-media-grabber
// @version      1.0.0
// @description  自动扫描网页里的图片与视频（含懒加载属性、srcset、背景图、video/source、媒体直链），悬浮面板里筛选、预览、批量下载，支持自动下载模式。
// @author       WorkBuddy
// @match        *://*/*
// @grant        GM_download
// @grant        GM_xmlhttpRequest
// @grant        GM_setValue
// @grant        GM_getValue
// @grant        GM_registerMenuCommand
// @grant        GM_addStyle
// @connect      *
// @run-at       document-idle
// @noframes
// @license MIT
// ==/UserScript==

(function () {
  'use strict';

  /* ======================================================================
   * 0. 常量与设置
   * ==================================================================== */
  const NS = 'wmg';
  const IMG_EXT = /\.(jpe?g|jfif|png|gif|webp|avif|bmp|svg|tiff?|ico)(?=$|[?#])/i;
  const VID_EXT = /\.(mp4|m4v|webm|mov|mkv|avi|flv|wmv|ts)(?=$|[?#])/i;
  const AUD_EXT = /\.(mp3|m4a|aac|flac|ogg|oga|wav|opus)(?=$|[?#])/i;
  const STREAM_EXT = /\.(m3u8|mpd)(?=$|[?#])/i;
  const LAZY_ATTRS = ['data-src', 'data-original', 'data-lazy', 'data-lazy-src',
    'data-echo', 'data-url', 'data-image', 'data-img', 'data-actualsrc',
    'data-srcset', 'data-origin', 'data-hi-res-src', 'data-large', 'data-full'];

  const DEFAULTS = {
    auto: false,          // 自动下载
    autoKind: 'image',    // 自动下载类型
    minW: 300,            // 最小宽度（图片）
    minH: 0,
    delay: 700,           // 每个文件之间的间隔(ms)
    scanBg: true,         // 扫描背景图
    scanLinks: true,      // 扫描 <a> 直链
    nameRule: 'url',      // url | index
    prefixTitle: false,   // 文件名前缀加页面标题
    theme: 'auto'         // auto | light | dark
  };
  const S = Object.assign({}, DEFAULTS);
  const store = {
    get(k, d) { try { const v = GM_getValue(NS + '_' + k); return v === undefined ? d : v; } catch (e) { return d; } },
    set(k, v) { try { GM_setValue(NS + '_' + k, v); } catch (e) { /* ignore */ } }
  };
  Object.keys(DEFAULTS).forEach(k => { S[k] = store.get(k, DEFAULTS[k]); });
  const saveCfg = () => Object.keys(DEFAULTS).forEach(k => store.set(k, S[k]));

  /* ======================================================================
   * 1. 工具函数
   * ==================================================================== */
  const $ = (sel, root) => (root || document).querySelector(sel);

  function absUrl(u, base) {
    if (!u) return '';
    u = String(u).trim().replace(/^['"]|['"]$/g, '');
    if (!u || /^(data|blob|javascript|about):/i.test(u)) return '';
    try { return new URL(u, base || location.href).href; } catch (e) { return ''; }
  }

  function kindOf(url) {
    if (!url) return null;
    if (STREAM_EXT.test(url)) return 'stream';
    if (IMG_EXT.test(url)) return 'image';
    if (VID_EXT.test(url)) return 'video';
    if (AUD_EXT.test(url)) return 'audio';
    return null;
  }

  function extOf(url, kind) {
    const m = String(url).split(/[?#]/)[0].match(/\.([a-z0-9]{2,5})$/i);
    if (m) return m[1].toLowerCase();
    return kind === 'video' ? 'mp4' : kind === 'audio' ? 'mp3' : 'jpg';
  }

  const sanitize = s => String(s || '').replace(/[\\/:*?"<>|\u0000-\u001f]/g, '_').replace(/\s+/g, ' ').trim();

  function fileName(item, idx) {
    let base;
    if (S.nameRule === 'index') {
      base = String(idx + 1).padStart(4, '0');
    } else {
      try {
        const p = new URL(item.url).pathname;
        base = decodeURIComponent(p.split('/').filter(Boolean).pop() || '');
      } catch (e) { base = ''; }
      base = base.replace(/\.[a-z0-9]{2,5}$/i, '');
      base = sanitize(base).slice(0, 60);
      if (!base) base = item.alt ? sanitize(item.alt).slice(0, 60) : 'media';
    }
    if (S.prefixTitle && document.title) {
      base = sanitize(document.title).slice(0, 30) + '_' + base;
    }
    return base + '.' + extOf(item.url, item.kind);
  }

  function fmtSize(n) {
    if (!n && n !== 0) return '';
    if (n < 1024) return n + ' B';
    if (n < 1048576) return (n / 1024).toFixed(1) + ' KB';
    return (n / 1048576).toFixed(1) + ' MB';
  }

  function parseSrcset(v) {
    if (!v) return [];
    return String(v).split(',').map(part => {
      const bits = part.trim().split(/\s+/);
      if (!bits[0]) return null;
      const d = bits[1] || '';
      let w = 0;
      if (/^\d+w$/i.test(d)) w = parseInt(d, 10);
      else if (/^\d+(\.\d+)?x$/i.test(d)) w = parseFloat(d) * 1000;
      return { url: bits[0], w: w || 1 };
    }).filter(Boolean);
  }

  /* ======================================================================
   * 2. 采集页面媒体
   * ==================================================================== */
  function makeItem(url, kind, extra) {
    return Object.assign({
      url: url, kind: kind, w: 0, h: 0, alt: '', size: 0, from: ''
    }, extra || {});
  }

  function scan() {
    const map = new Map();
    const put = (rawUrl, kind, extra, base) => {
      const u = absUrl(rawUrl, base);
      if (!u) return;
      const k = kindOf(u);
      if (!k) return;                       // 无法判断类型则忽略
      const key = u;
      const prev = map.get(key);
      const it = makeItem(u, k === 'stream' ? 'video' : k, extra);
      it.stream = (k === 'stream');
      if (prev) {
        prev.w = Math.max(prev.w, it.w || 0);
        prev.h = Math.max(prev.h, it.h || 0);
        if (!prev.alt && it.alt) prev.alt = it.alt;
        return;
      }
      map.set(key, it);
    };

    const roots = [document];
    // 同源 iframe 也扫一遍
    document.querySelectorAll('iframe').forEach(fr => {
      try { if (fr.contentDocument) roots.push(fr.contentDocument); } catch (e) { /* 跨域跳过 */ }
    });

    roots.forEach(root => {
      // ---- <img> ----
      root.querySelectorAll('img').forEach(img => {
        const alt = img.getAttribute('alt') || '';
        const w = img.naturalWidth || 0, h = img.naturalHeight || 0;
        const cands = [img.currentSrc, img.getAttribute('src')];
        LAZY_ATTRS.forEach(a => { const v = img.getAttribute(a); if (v && !/set$/i.test(a)) cands.push(v); });
        cands.forEach(c => put(c, 'image', { w: w, h: h, alt: alt, from: 'img' }));
        // srcset：取最大
        [img.getAttribute('srcset'), img.getAttribute('data-srcset')].forEach(ss => {
          const list = parseSrcset(ss);
          if (list.length) {
            list.sort((a, b) => b.w - a.w);
            put(list[0].url, 'image', { w: w, h: h, alt: alt, from: 'srcset' });
          }
        });
      });

      // ---- <picture><source> ----
      root.querySelectorAll('picture source').forEach(sc => {
        parseSrcset(sc.getAttribute('srcset')).sort((a, b) => b.w - a.w)
          .forEach((x, i) => { if (i === 0) put(x.url, 'image', { from: 'picture' }); });
      });

      // ---- <video> / <audio> / <source> ----
      root.querySelectorAll('video, audio').forEach(v => {
        const kind = v.tagName === 'VIDEO' ? 'video' : 'audio';
        const poster = v.getAttribute('poster');
        if (poster) put(poster, 'image', { from: 'poster' });
        [v.getAttribute('src'), v.currentSrc].forEach(c => put(c, kind, { from: v.tagName.toLowerCase() }));
        v.querySelectorAll('source').forEach(s => {
          put(s.getAttribute('src'), kindOf(s.getAttribute('src')) || kind, { from: 'source' });
        });
      });

      // ---- <a> 直链 ----
      if (S.scanLinks) {
        root.querySelectorAll('a[href]').forEach(a => {
          const href = a.getAttribute('href');
          if (!href || href.startsWith('#')) return;
          const k = kindOf(absUrl(href));
          if (k) put(href, k === 'stream' ? 'video' : k, { from: 'link', alt: a.getAttribute('title') || '' });
        });
      }

      // ---- 背景图 ----
      if (S.scanBg) {
        const els = root.querySelectorAll('*');
        const cap = Math.min(els.length, 4000);   // 大页面限制扫描量
        for (let i = 0; i < cap; i++) {
          const el = els[i];
          const tag = el.tagName;
          if (tag === 'SCRIPT' || tag === 'STYLE' || tag === 'NOSCRIPT') continue;
          let bg = '';
          try { bg = getComputedStyle(el).backgroundImage; } catch (e) { continue; }
          if (!bg || bg === 'none') continue;
          const m = bg.match(/url\((['"]?)(.*?)\1\)/g) || [];
          m.forEach(one => {
            const u = one.replace(/^url\((['"]?)/, '').replace(/(['"]?)\)$/, '');
            put(u, 'image', { from: 'background' });
          });
        }
      }

      // ---- meta og ----
      root.querySelectorAll('meta[property="og:image"],meta[property="og:video"],meta[name="twitter:image"]').forEach(mt => {
        put(mt.getAttribute('content'), kindOf(mt.getAttribute('content')) || 'image', { from: 'meta' });
      });
    });

    return Array.from(map.values()).sort((a, b) => (b.w * b.h) - (a.w * a.h));
  }

  /* ======================================================================
   * 3. 下载
   * ==================================================================== */
  let stopFlag = false;

  function downloadOne(item, idx) {
    return new Promise(resolve => {
      const name = fileName(item, idx);
      const done = ok => resolve({ ok: ok, name: name, url: item.url });

      if (typeof GM_download === 'function') {
        try {
          GM_download({
            url: item.url, name: name, saveAs: false,
            onload: () => done(true),
            onerror: () => blobFallback(item, name).then(done),
            ontimeout: () => done(false)
          });
          return;
        } catch (e) { /* 落到兜底 */ }
      }
      blobFallback(item, name).then(done);
    });
  }

  function blobFallback(item, name) {
    return new Promise(resolve => {
      const tryFetch = () => {
        try {
          return fetch(item.url, { credentials: 'omit', referrerPolicy: 'no-referrer' })
            .then(r => { if (!r.ok) throw new Error(r.status); return r.blob(); })
            .then(b => { saveBlob(b, name); resolve(true); })
            .catch(() => resolve(false));
        } catch (e) { resolve(false); }
      };
      if (typeof GM_xmlhttpRequest === 'function') {
        GM_xmlhttpRequest({
          method: 'GET', url: item.url, responseType: 'blob', timeout: 60000,
          onload: res => {
            if (res.status >= 200 && res.status < 300 && res.response) {
              saveBlob(res.response, name); resolve(true);
            } else { tryFetch(); }
          },
          onerror: () => tryFetch(),
          ontimeout: () => resolve(false)
        });
      } else { tryFetch(); }
    });
  }

  function saveBlob(blob, name) {
    const a = document.createElement('a');
    a.href = URL.createObjectURL(blob);
    a.download = name;
    document.body.appendChild(a);
    a.click();
    setTimeout(() => { URL.revokeObjectURL(a.href); a.remove(); }, 4000);
  }

  async function runQueue(items) {
    if (!items.length) { toast('没有需要下载的项目'); return; }
    stopFlag = false;
    UI.setBusy(true);
    let ok = 0, bad = 0;
    for (let i = 0; i < items.length; i++) {
      if (stopFlag) break;
      UI.progress(i, items.length);
      UI.status(`下载中 ${i + 1}/${items.length} …`);
      const r = await downloadOne(items[i], i);
      r.ok ? ok++ : bad++;
      if (bad && bad <= 3) console.warn('[媒体抓取] 失败:', r.url);
      await sleep(S.delay);
    }
    UI.progress(items.length, items.length);
    UI.setBusy(false);
    UI.status(`完成：成功 ${ok} / 失败 ${bad} / 共 ${items.length}`);
    toast(`下载完成 ✅ 成功 ${ok}${bad ? '，失败 ' + bad : ''}`);
    if (bad) console.warn('[媒体抓取] 有失败项。若为跨域受限，可在脚本管理器里允许该域名的 @connect。');
  }

  const sleep = ms => new Promise(r => setTimeout(r, ms));

  /* ======================================================================
   * 4. 样式
   * ==================================================================== */
  const CSS = `
.wmg-btn{position:fixed;right:18px;bottom:18px;z-index:2147483600;width:46px;height:46px;border-radius:50%;
  border:none;cursor:pointer;background:#2d8cf0;color:#fff;font-size:20px;line-height:46px;text-align:center;
  box-shadow:0 3px 12px rgba(0,0,0,.28);transition:transform .15s;}
.wmg-btn:hover{transform:scale(1.08);}
.wmg-panel{position:fixed;right:18px;bottom:74px;z-index:2147483601;width:430px;max-height:72vh;display:flex;
  flex-direction:column;background:#fff;color:#222;border-radius:10px;overflow:hidden;
  box-shadow:0 8px 32px rgba(0,0,0,.30);font:13px/1.5 -apple-system,"Segoe UI",Roboto,"Microsoft YaHei",sans-serif;}
.wmg-panel.wmg-dark{background:#22262b;color:#e6e6e6;}
.wmg-hd{display:flex;align-items:center;gap:8px;padding:9px 12px;background:#2d8cf0;color:#fff;font-weight:600;}
.wmg-hd .wmg-cnt{font-weight:400;opacity:.9;font-size:12px;}
.wmg-hd button{margin-left:auto;background:transparent;border:none;color:#fff;font-size:16px;cursor:pointer;}
.wmg-cfg{padding:8px 12px;border-bottom:1px solid #eee;display:flex;flex-wrap:wrap;gap:6px;align-items:center;}
.wmg-panel.wmg-dark .wmg-cfg{border-color:#3a3f46;}
.wmg-cfg select,.wmg-cfg input[type=number],.wmg-cfg input[type=text]{padding:4px 6px;border:1px solid #ccc;
  border-radius:5px;background:#fff;color:#222;font-size:12px;}
.wmg-panel.wmg-dark .wmg-cfg select,.wmg-panel.wmg-dark .wmg-cfg input{background:#2b3037;color:#eee;border-color:#4a5058;}
.wmg-cfg label{display:flex;align-items:center;gap:4px;font-size:12px;}
.wmg-list{overflow:auto;flex:1;padding:6px;}
.wmg-item{display:flex;align-items:center;gap:8px;padding:5px 6px;border-radius:6px;cursor:pointer;}
.wmg-item:hover{background:#f2f6ff;}
.wmg-panel.wmg-dark .wmg-item:hover{background:#2c3138;}
.wmg-item.sel{background:#e6f0ff;}
.wmg-panel.wmg-dark .wmg-item.sel{background:#2a3a52;}
.wmg-thumb{width:56px;height:42px;object-fit:cover;border-radius:4px;background:#f0f0f0;flex:none;}
.wmg-meta{flex:1;min-width:0;}
.wmg-name{font-size:12px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}
.wmg-sub{font-size:11px;color:#888;}
.wmg-tag{font-size:10px;padding:1px 5px;border-radius:3px;background:#eef2f7;color:#556;flex:none;}
.wmg-tag.video{background:#ffe8e8;color:#c33;}
.wmg-panel.wmg-dark .wmg-tag{background:#333a44;color:#bbc;}
.wmg-ft{padding:8px 12px;border-top:1px solid #eee;display:flex;flex-wrap:wrap;gap:6px;}
.wmg-panel.wmg-dark .wmg-ft{border-color:#3a3f46;}
.wmg-ft button,.wmg-cfg button{padding:5px 10px;border:1px solid #2d8cf0;background:#2d8cf0;color:#fff;
  border-radius:6px;cursor:pointer;font-size:12px;}
.wmg-ft button.ghost{background:transparent;color:#2d8cf0;}
.wmg-panel.wmg-dark .wmg-ft button.ghost{color:#6db3ff;border-color:#6db3ff;}
.wmg-ft button:disabled{opacity:.5;cursor:default;}
.wmg-bar{height:4px;background:#eee;border-radius:2px;overflow:hidden;width:100%;margin-top:6px;display:none;}
.wmg-bar>i{display:block;height:100%;width:0;background:#2d8cf0;transition:width .2s;}
.wmg-status{font-size:11px;color:#888;margin-top:4px;width:100%;}
.wmg-toast{position:fixed;right:18px;bottom:74px;z-index:2147483602;background:rgba(0,0,0,.82);color:#fff;
  padding:8px 14px;border-radius:8px;font:13px/1.4 -apple-system,"Segoe UI",sans-serif;opacity:0;
  transition:opacity .25s;pointer-events:none;}
.wmg-toast.on{opacity:1;}
.wmg-empty{padding:22px;text-align:center;color:#999;font-size:12px;}
`;

  /* ======================================================================
   * 5. UI
   * ==================================================================== */
  const UI = {
    panel: null, listEl: null, statusEl: null, cntEl: null, barEl: null,
    items: [], view: [], selected: new Set(), busy: false,

    init() {
      const dark = S.theme === 'dark' || (S.theme === 'auto' && matchMedia('(prefers-color-scheme: dark)').matches);
      const btn = document.createElement('button');
      btn.className = 'wmg-btn';
      btn.textContent = '⤓';
      btn.title = '网页媒体抓取器（Alt+S 开关）';
      btn.onclick = () => this.toggle();
      document.documentElement.appendChild(btn);
      this.btn = btn;
      this._buildPanel(dark);
    },

    _buildPanel(dark) {
      const p = document.createElement('div');
      p.className = 'wmg-panel' + (dark ? ' wmg-dark' : '');
      p.style.display = 'none';
      p.innerHTML = `
        <div class="wmg-hd">
          <span>媒体抓取</span><span class="wmg-cnt" id="wmg-cnt">0</span>
          <button id="wmg-close" title="关闭">✕</button>
        </div>
        <div class="wmg-cfg">
          <select id="wmg-kind">
            <option value="all">全部</option><option value="image">仅图片</option>
            <option value="video">仅视频</option><option value="audio">仅音频</option>
          </select>
          <label>≧宽<input id="wmg-minw" type="number" style="width:56px" min="0" step="50"></label>
          <input id="wmg-kw" type="text" placeholder="关键词(URL/alt)" style="flex:1;min-width:90px">
          <label><input id="wmg-bg" type="checkbox">背景图</label>
          <button id="wmg-scan" class="ghost">重新扫描</button>
          <button id="wmg-roll" class="ghost">滚动加载</button>
        </div>
        <div class="wmg-list" id="wmg-list"></div>
        <div class="wmg-ft">
          <button id="wmg-all">全选</button>
          <button id="wmg-none" class="ghost">清空</button>
          <button id="wmg-inv" class="ghost">反选</button>
          <button id="wmg-dlsel">下载选中</button>
          <button id="wmg-dlall" class="ghost">下载全部</button>
          <button id="wmg-copy" class="ghost">复制链接</button>
          <button id="wmg-stop" class="ghost" disabled>停止</button>
          <div class="wmg-bar" id="wmg-bar"><i></i></div>
          <div class="wmg-status" id="wmg-status">就绪</div>
        </div>`;
      document.documentElement.appendChild(p);
      this.panel = p;
      this.listEl = p.querySelector('#wmg-list');
      this.statusEl = p.querySelector('#wmg-status');
      this.cntEl = p.querySelector('#wmg-cnt');
      this.barEl = p.querySelector('#wmg-bar');

      p.querySelector('#wmg-close').onclick = () => this.toggle(false);
      p.querySelector('#wmg-scan').onclick = () => this.rescan();
      p.querySelector('#wmg-roll').onclick = () => this.autoScroll();
      p.querySelector('#wmg-all').onclick = () => { this.view.forEach(i => this.selected.add(i.url)); this.renderList(); };
      p.querySelector('#wmg-none').onclick = () => { this.selected.clear(); this.renderList(); };
      p.querySelector('#wmg-inv').onclick = () => {
        this.view.forEach(i => this.selected.has(i.url) ? this.selected.delete(i.url) : this.selected.add(i.url));
        this.renderList();
      };
      p.querySelector('#wmg-dlsel').onclick = () => this.downloadSelected();
      p.querySelector('#wmg-dlall').onclick = () => runQueue(this.view.slice());
      p.querySelector('#wmg-stop').onclick = () => { stopFlag = true; this.status('正在停止…'); };
      p.querySelector('#wmg-copy').onclick = () => {
        const t = this.view.map(i => i.url).join('\n');
        (navigator.clipboard ? navigator.clipboard.writeText(t) : Promise.reject())
          .then(() => toast('已复制 ' + this.view.length + ' 条链接'))
          .catch(() => toast('复制失败，请手动选择'));
      };

      const kindSel = p.querySelector('#wmg-kind');
      kindSel.value = 'all';
      kindSel.onchange = () => this.applyFilter();
      const minw = p.querySelector('#wmg-minw');
      minw.value = S.minW;
      minw.onchange = () => { S.minW = +minw.value || 0; saveCfg(); this.applyFilter(); };
      const kw = p.querySelector('#wmg-kw');
      let kwt = null;
      kw.oninput = () => { clearTimeout(kwt); kwt = setTimeout(() => this.applyFilter(), 220); };
      const bg = p.querySelector('#wmg-bg');
      bg.checked = !!S.scanBg;
      bg.onchange = () => { S.scanBg = bg.checked; saveCfg(); this.rescan(); };
    },

    toggle(force) {
      const show = force === undefined ? this.panel.style.display === 'none' : force;
      this.panel.style.display = show ? 'flex' : 'none';
      if (show && !this.items.length) this.rescan();
    },

    rescan() {
      this.status('扫描中…');
      setTimeout(() => {
        this.items = scan();
        this.selected.clear();
        this.applyFilter();
        this.status(`扫描完成，共 ${this.items.length} 个媒体`);
      }, 30);
    },

    applyFilter() {
      const p = this.panel;
      const kind = p.querySelector('#wmg-kind').value;
      const minw = +p.querySelector('#wmg-minw').value || 0;
      const kw = p.querySelector('#wmg-kw').value.trim().toLowerCase();
      this.view = this.items.filter(it => {
        if (kind !== 'all' && it.kind !== kind) return false;
        if (minw && it.kind === 'image') {
          const w = it.w || 0;
          if (w && w < minw) return false;
        }
        if (kw) {
          const hay = (it.url + ' ' + (it.alt || '')).toLowerCase();
          if (!hay.includes(kw)) return false;
        }
        return true;
      });
      this.renderList();
    },

    renderList() {
      const L = this.listEl;
      L.innerHTML = '';
      this.cntEl.textContent = `${this.view.length}/${this.items.length} 已选 ${this.selected.size}`;
      if (!this.view.length) {
        L.innerHTML = '<div class="wmg-empty">没有匹配的媒体。<br>试试「滚动加载」后重新扫描，或放宽筛选条件。</div>';
        return;
      }
      const frag = document.createDocumentFragment();
      this.view.forEach(it => {
        const row = document.createElement('div');
        row.className = 'wmg-item' + (this.selected.has(it.url) ? ' sel' : '');
        const res = it.w ? `${it.w}×${it.h}` : '';
        const tagCls = it.kind === 'video' ? 'wmg-tag video' : 'wmg-tag';
        const tagTxt = { image: '图', video: '视', audio: '音' }[it.kind] || it.kind;
        row.innerHTML = `
          <input type="checkbox" ${this.selected.has(it.url) ? 'checked' : ''}>
          <img class="wmg-thumb" loading="lazy" referrerpolicy="no-referrer">
          <div class="wmg-meta">
            <div class="wmg-name"></div>
            <div class="wmg-sub"></div>
          </div>
          <span class="${tagCls}">${tagTxt}</span>`;
        const th = row.querySelector('.wmg-thumb');
        if (it.kind === 'image') th.src = it.url; else th.style.visibility = 'hidden';
        row.querySelector('.wmg-name').textContent = decodeURIComponent(
          (it.url.split('/').pop() || it.url).split('?')[0]).slice(0, 70) || it.url;
        row.querySelector('.wmg-sub').textContent =
          [res, it.from, it.stream ? '流媒体(m3u8/mpd)' : ''].filter(Boolean).join(' · ');
        const cb = row.querySelector('input');
        const toggle = () => {
          if (this.selected.has(it.url)) { this.selected.delete(it.url); row.classList.remove('sel'); cb.checked = false; }
          else { this.selected.add(it.url); row.classList.add('sel'); cb.checked = true; }
          this.cntEl.textContent = `${this.view.length}/${this.items.length} 已选 ${this.selected.size}`;
        };
        cb.onclick = e => { e.stopPropagation(); toggle(); };
        row.onclick = toggle;
        frag.appendChild(row);
      });
      L.appendChild(frag);
    },

    downloadSelected() {
      const items = this.view.filter(i => this.selected.has(i.url));
      const stream = items.filter(i => i.stream);
      if (stream.length) toast(`${stream.length} 个是 m3u8/mpd 流，浏览器无法直接保存，建议用 N_m3u8DL-RE 等工具`);
      runQueue(items.filter(i => !i.stream));
    },

    async autoScroll() {
      this.status('自动滚动加载中…');
      const step = Math.round(innerHeight * 0.85);
      let last = 0;
      for (let i = 0; i < 25; i++) {
        scrollBy(0, step);
        await sleep(500);
        const y = scrollY + innerHeight;
        if (y >= document.body.scrollHeight - 4 && y === last) break;
        last = y;
      }
      scrollTo(0, 0);
      this.rescan();
    },

    setBusy(b) {
      this.busy = b;
      this.panel.querySelector('#wmg-stop').disabled = !b;
      ['#wmg-dlsel', '#wmg-dlall', '#wmg-scan', '#wmg-roll'].forEach(s => {
        const el = this.panel.querySelector(s); if (el) el.disabled = b;
      });
    },
    progress(cur, total) {
      this.barEl.style.display = 'block';
      this.barEl.firstChild.style.width = (total ? (cur / total * 100) : 0) + '%';
    },
    status(t) { this.statusEl.textContent = t; }
  };

  function toast(msg) {
    let t = document.querySelector('.wmg-toast');
    if (!t) { t = document.createElement('div'); t.className = 'wmg-toast'; document.documentElement.appendChild(t); }
    t.textContent = msg;
    t.classList.add('on');
    clearTimeout(t._tm);
    t._tm = setTimeout(() => t.classList.remove('on'), 2600);
  }

  /* ======================================================================
   * 6. 自动下载
   * ==================================================================== */
  async function autoRun() {
    await sleep(1200);
    const items = scan().filter(it =>
      it.kind === S.autoKind && !it.stream &&
      (!S.minW || it.kind !== 'image' || !it.w || it.w >= S.minW));
    if (!items.length) { console.info('[媒体抓取] 自动模式：没有匹配的媒体'); return; }
    console.info('[媒体抓取] 自动模式开始，共', items.length);
    UI.toggle(true);
    UI.items = items; UI.view = items; UI.renderList();
    runQueue(items);
  }

  /* ======================================================================
   * 7. 启动
   * ==================================================================== */
  (typeof GM_addStyle === 'function' ? GM_addStyle(CSS) : (() => {
    const st = document.createElement('style'); st.textContent = CSS; document.documentElement.appendChild(st);
  })());

  UI.init();

  document.addEventListener('keydown', e => {
    if (e.altKey && (e.key === 's' || e.key === 'S')) { e.preventDefault(); UI.toggle(); }
  });

  if (typeof GM_registerMenuCommand === 'function') {
    GM_registerMenuCommand('打开/关闭 面板 (Alt+S)', () => UI.toggle());
    GM_registerMenuCommand('立即扫描并列出媒体', () => { UI.toggle(true); UI.rescan(); });
    GM_registerMenuCommand(`自动下载模式：${S.auto ? '已开启' : '已关闭'}（点击切换）`, () => {
      S.auto = !S.auto; saveCfg();
      toast('自动下载已' + (S.auto ? '开启（刷新后生效）' : '关闭'));
    });
    GM_registerMenuCommand(`自动下载类型：${S.autoKind === 'image' ? '图片' : '视频'}（点击切换）`, () => {
      S.autoKind = S.autoKind === 'image' ? 'video' : 'image'; saveCfg();
      toast('自动下载类型：' + (S.autoKind === 'image' ? '图片' : '视频'));
    });
  }

  if (S.auto) autoRun();

  console.info('[网页媒体抓取器] 已加载 · Alt+S 打开面板');
})();