// ==UserScript==
// @name         Acfun-hls
// @name:zh-CN   Acfun视频下载器
// @namespace    https://greasyfork.org/zh-CN/users/135090
// @version      3.1.2
// @description  Acfun parse hls url,streams download mpegts file.
// @description:zh-CN  Acfun解析各清晰度M3U8地址，可直接下载,也可复制链接给其他工具
// @author       zwb83925462
// @match        https://www.acfun.cn/v/ac*
// @match        https://www.acfun.cn/player/*
// @grant        unsafeWindow
// @run-at       document-end
// @license      CC0
// @noframes
// ==/UserScript==

(() => {
  const W = (typeof unsafeWindow !== 'undefined') ? unsafeWindow : window;
  const $ = (t, s) => Object.assign(document.createElement(t), { style: s });

  // 解析缓存：引用没变就不重复 parse
  let lastRaw = null, cachedReps = null;
  function getReps(force) {
    const raw = W.videoInfo?.currentVideoInfo?.ksPlayJson;
    if (!raw) return null;
    if (!force && raw === lastRaw) return cachedReps;
    try {
      const obj = (typeof raw === 'string') ? JSON.parse(raw) : raw;
      cachedReps = obj?.adaptationSet?.[0]?.representation || null;
    } catch { cachedReps = null; }
    lastRaw = raw;
    return cachedReps;
  }

  // 流式下载：Chrome/Edge 写盘，其它降级 Blob
  async function download(url, name, onProg) {
    const text = await (await fetch(url)).text();
    const ts = text.split('\n').map(s => s.trim())
      .filter(s => s && !s.startsWith('#'))
      .map(s => s.startsWith('http') ? s : new URL(s, url).href);
    if (!ts.length) throw new Error('m3u8 无 ts 分片');

    if (window.showSaveFilePicker) {
      const w = (await window.showSaveFilePicker({
        suggestedName: name,
        types: [{ description: 'MPEG-TS', accept: { 'video/mp2t': ['.ts'] } }]
      })).createWritable();
      for (let i = 0; i < ts.length; i++) {
        const r = (await fetch(ts[i])).body.getReader();
        for (;;) { const { done, value } = await r.read(); if (done) break; await w.write(value); }
        onProg?.(`下载中 ${i + 1}/${ts.length}`);
      }
      await w.close();
      return { mode: 'stream', count: ts.length };
    }

    if (ts.length > 300) throw new Error('该浏览器不支持流式写入且分片过多，请用 Chrome/Edge');
    const buf = [];
    for (let i = 0; i < ts.length; i++) { buf.push(await (await fetch(ts[i])).arrayBuffer()); onProg?.(`下载中 ${i + 1}/${ts.length}`); }
    const blob = new Blob(buf, { type: 'video/mp2t' });
    const a = $('a'); a.href = URL.createObjectURL(blob); a.download = name; a.click();
    setTimeout(() => URL.revokeObjectURL(a.href), 5000);
    return { mode: 'blob', count: ts.length };
  }

  // 面板
  function buildPanel(reps, acvid) {
    document.getElementById('acfun-hls-panel')?.remove();
    const box = $('div', 'position:fixed;top:80px;right:12px;z-index:2147483647;background:rgba(20,20,20,.92);color:#eee;padding:10px 12px;border-radius:8px;font:13px/1.6 sans-serif;min-width:200px;box-shadow:0 2px 12px rgba(0,0,0,.4)');
    box.id = 'acfun-hls-panel';

    const head = $('div', 'display:flex;justify-content:space-between;margin-bottom:6px');
    head.innerHTML = `<span style="color:#ff69b4">${acvid}</span>`;
    const x = $('span', 'cursor:pointer;color:#999;padding:0 4px'); x.textContent = '×'; x.onclick = () => box.remove();
    head.appendChild(x); box.appendChild(head);

    const st = $('div', 'color:#8fc;font-size:12px;min-height:16px;margin-bottom:4px'); box.appendChild(st);

    reps.forEach((r, i) => {
      if (!r?.url) return;
      const row = $('div', 'display:flex;align-items:center;gap:8px;margin:4px 0');
      const a = $('a', 'color:#11AA11;text-decoration:underline;min-width:70px');
      a.href = r.url; a.target = '_blank'; a.textContent = r.qualityLabel || ('档' + i);
      const b = $('button', 'background:#4CAF50;color:#fff;border:0;padding:3px 10px;border-radius:4px;cursor:pointer;font-size:12px');
      b.textContent = '下载';
      b.onclick = async () => {
        b.disabled = true; b.textContent = '…';
        try { const res = await download(r.url, `acfun_${r.qualityLabel || i}.ts`, m => st.textContent = m);
              st.textContent = `完成：${res.count} 分片（${res.mode}）`; }
        catch (e) { st.textContent = '失败：' + (e?.message || e); console.error('[acfun-hls]', e); }
        finally { b.disabled = false; b.textContent = '下载'; }
      };
      row.append(a, b); box.appendChild(row);
    });
    document.body.appendChild(box);
  }

  // 扫描：先做零成本判断，有变化才建面板
  let lastKey = '';
  function scan(force) {
    const reps = getReps(force);
    if (!reps?.length) return false;
    const key = location.pathname + '|' + reps.map(r => r.qualityLabel).join(',');
    if (!force && key === lastKey && document.getElementById('acfun-hls-panel')) return true;
    lastKey = key;
    buildPanel(reps, location.pathname.split('/').pop());
    return true;
  }

  // 防抖调度：DOM/路由抖动时合并触发
  let tid = 0;
  const schedule = (force) => { clearTimeout(tid); tid = setTimeout(() => scan(force), 300); };

  // 事件驱动：SPA 切集
  const onNav = () => { lastKey = ''; schedule(true); };
  const _push = history.pushState.bind(history), _replace = history.replaceState.bind(history);
  history.pushState = function (...a) { _push(...a); onNav(); };
  history.replaceState = function (...a) { _replace(...a); onNav(); };
  addEventListener('popstate', onNav);

  // 事件驱动：播放器/数据挂载（回调极轻，引用没变直接返回）
  new MutationObserver(() => schedule()).observe(document.body, { childList: true, subtree: true });

  // 兜底：5 秒一次，且因缓存命中几乎不消耗
  setInterval(() => scan(), 5000);

  // 手动兜底按钮（强制重新解析）
  const fab = $('button', 'position:fixed;bottom:20px;right:12px;z-index:2147483647;background:#ff69b4;color:#fff;border:0;padding:6px 12px;border-radius:16px;cursor:pointer');
  fab.textContent = 'AC 提取';
  fab.onclick = () => { lastRaw = null; lastKey = ''; scan(true) || alert('没读到 videoInfo.ksPlayJson，可能播放器还没初始化'); };
  document.body.appendChild(fab);

  schedule(true);
})();