// ==UserScript==
// @name         抖音账号视频批量下载器
// @namespace    https://github.com/jsk789456
// @version      0.4.1
// @description  抖音账号视频批量下载：①可锁定“电脑任意盘任意文件夹”(Chrome/Edge选目录，FSA直写)；②统计作品年份+按年份筛选；③设置一次性最多下载N个；④开始/暂停/停止下载可控；⑤自动模式无人值守。仅个人学习备份，勿二次分发或商用。
// @author       爱国者 / 姜老师可视化课堂
// @match        https://www.douyin.com/user/*
// @grant        GM_download
// @grant        GM_setValue
// @grant        GM_getValue
// @connect      douyin.com
// @connect      *.douyinvod.com
// @connect      *.tiktokcdn.com
// @run-at       document-start
// @license All Rights Reserved
// ==/UserScript==

(function () {
  'use strict';

  /* =========================================================
   * 说明（v0.4）：
   * v0.3 基础上新增/增强：
   * 1)【保存位置·绝对路径】：Tampermonkey 的 GM_download 只能落到“浏览器默认下载目录”
   *    下的相对子路径，无法指定 D:\xxx 这种绝对盘符路径。
   *    因此新增「📁 选择保存文件夹」按钮：用 File System Access API 让用户亲自授权
   *    一个绝对目录（如 D:\教学素材\徐老师），脚本之后用 fetch+blob 直接写入该绝对路径，
   *    并记到 IndexedDB 跨会话记忆。
   *    ⚠️ 限制：仅 Chrome/Edge 支持；且部分抖音视频 CDN 跨域，fetch 会被拦 → 此时自动
   *    回退到 GM_download（落到浏览器下载目录）。若想 100% 落绝对盘，请在浏览器设置里把
   *    “默认下载目录”改成目标盘根，本脚本“保存位置(子路径)”填子文件夹名即可。
   * 2)【作品年份】：解析接口里的 create_time，统计年份分布，可按年份筛选下载。
   * 3)【一次性下载多少个】：设“最多下载 N 个”(0=不限)，超限不再发起新下载。
   * 4)【开始/停止下载】：新增 ⏸暂停/继续、⏹停止下载 控制；🚀自动开始 即“开始”。
   *
   * 抖音接口字段/路径会随版本漂移，首次运行请按浏览器实测微调下方 CFG。
   * ========================================================= */

  // ---------- 配置 ----------
  const CFG = {
    listApiRegex: /aweme\/post|user\/post|aweme\/v1\/web\/aweme\/post/i,
    noWatermark: true,
    autoScrollMax: 60,
    scrollIntervalMs: 1300,
    noNewStop: 9,
    maxConcurrent: 3,
    downloadGapMs: 600,
    fileNameMax: 40,
    saveFolder: GM_getValue('jb_save_folder', '抖音视频'),   // 相对子路径（GM_download 回退用）
    maxDownloadN: GM_getValue('jb_max_n', 0)                  // 0=不限；>0 一次性最多下载N个
  };

  // ---------- 数据 ----------
  const collected = new Map();
  const downloaded = new Set(GM_getValue('jb_downloaded', []));
  let fileSeq = GM_getValue('jb_file_seq', 0);
  let dlCount = 0;                 // 本次运行已发起下载数（受 maxDownloadN 约束）
  const yearCount = {};            // 年份 -> 数量
  let selectedYear = 'all';        // 年份筛选

  // 下载控制
  let dlPaused = false;
  let dlStopped = false;

  // 绝对目录句柄（FSA）
  let saveDirHandle = null;

  // ---------- 工具 ----------
  function cleanName(s) {
    return (s || '无标题').replace(/[\\/:*?"<>|]/g, '_').replace(/\s+/g, ' ').slice(0, CFG.fileNameMax);
  }
  function cleanFolder(s) {
    return (s || '抖音视频')
      .replace(/[\\:*?"<>|]/g, '/')
      .replace(/\/{2,}/g, '/')
      .replace(/^\/|\/$/g, '')
      .trim() || '抖音视频';
  }
  function setFolder(v) { CFG.saveFolder = cleanFolder(v); GM_setValue('jb_save_folder', CFG.saveFolder); updateSaveHint(); }
  function markDownloaded(id) { downloaded.add(id); GM_setValue('jb_downloaded', Array.from(downloaded)); }
  function finalFname(it) { return String(it.seq).padStart(3, '0') + '_' + it.desc + '_' + it.awemeId + '.mp4'; }

  // ---------- IndexedDB 存取目录句柄 ----------
  const FS_DB = 'jb-dy-fs', FS_STORE = 'handles';
  function idbOpen() {
    return new Promise(function (res, rej) {
      const r = indexedDB.open(FS_DB, 1);
      r.onupgradeneeded = function () { r.result.createObjectStore(FS_STORE); };
      r.onsuccess = function () { res(r.result); };
      r.onerror = function () { rej(r.error); };
    });
  }
  async function saveHandle(h) {
    const db = await idbOpen();
    return new Promise(function (res) {
      const tx = db.transaction(FS_STORE, 'readwrite');
      tx.objectStore(FS_STORE).put(h, 'dir');
      tx.oncomplete = res; tx.onerror = function () { res(); };
    });
  }
  async function loadHandle() {
    try {
      const db = await idbOpen();
      return await new Promise(function (res) {
        const tx = db.transaction(FS_STORE, 'readonly');
        const rq = tx.objectStore(FS_STORE).get('dir');
        rq.onsuccess = function () { res(rq.result || null); };
        rq.onerror = function () { res(null); };
      });
    } catch (e) { return null; }
  }
  async function chooseFolder() {
    if (!window.showDirectoryPicker) {
      setStatus('当前浏览器不支持“直接选文件夹”(请用 Chrome/Edge)。可改用：浏览器设置→下载→默认下载目录设为目标盘，本脚本“保存位置”填子文件夹名。');
      return;
    }
    try {
      const h = await window.showDirectoryPicker();
      const opt = { mode: 'readwrite' };
      let perm = 'granted';
      try { perm = (await h.queryPermission(opt)); } catch (e) {}
      if (perm !== 'granted') { try { perm = (await h.requestPermission(opt)); } catch (e) {} }
      if (perm !== 'granted') { setStatus('未授权写入，已取消。'); return; }
      saveDirHandle = h; await saveHandle(h);
      updateAbsLabel();
      setStatus('✅ 已锁定绝对保存目录，下载将直接写入该路径（跨域视频会自动回退浏览器下载目录）。');
    } catch (e) { setStatus('选择取消/失败：' + (e && e.message ? e.message : e)); }
  }
  function updateAbsLabel() {
    const el = panel && panel.querySelector('#jb-dy-absdir');
    if (el) el.textContent = saveDirHandle ? ('绝对目录：' + (saveDirHandle.name || '已授权') + '（直接写入）') : '绝对目录：未设置（用下方“保存位置”子路径→浏览器下载目录）';
  }

  // ---------- 解析作品列表 ----------
  function parseAwemeList(txt, autoEnqueue) {
    let data;
    try { data = JSON.parse(txt); } catch (e) { return; }
    const list =
      data.aweme_list ||
      (data.data && data.data.aweme_list) ||
      (Array.isArray(data.aweme_list) ? data.aweme_list : null);
    if (!Array.isArray(list)) return;
    let added = 0;
    for (const aw of list) {
      if (!aw || !aw.aweme_id || !aw.video) continue;
      const playAddr = aw.video.play_addr && aw.video.play_addr.url_list;
      const dlAddr = aw.video.download_addr && aw.video.download_addr.url_list;
      let url = (playAddr && playAddr[0]) || (dlAddr && dlAddr[0]);
      if (!url) continue;
      if (CFG.noWatermark) url = url.replace(/playwm/g, 'play');
      const key = String(aw.aweme_id);
      if (!collected.has(key)) {
        const ct = aw.create_time;
        const year = (ct && !isNaN(ct)) ? new Date(ct * 1000).getFullYear() : '未知';
        const item = { desc: cleanName(aw.desc), url, awemeId: key, year: year };
        collected.set(key, item);
        added++;
        yearCount[year] = (yearCount[year] || 0) + 1;
        refreshYearOptions();
        if (autoEnqueue && !downloaded.has(key)) enqueueDownload(item);
      }
    }
    if (added > 0) { updatePanel(); updateYearStat(); }
  }

  // ---------- 拦截 fetch ----------
  const origFetch = window.fetch;
  window.fetch = function (input, init) {
    const url = typeof input === 'string' ? input : (input && input.url) || '';
    return origFetch.apply(this, arguments).then(function (resp) {
      if (CFG.listApiRegex.test(url)) {
        try { resp.clone().text().then(function (t) { parseAwemeList(t, autoMode); }).catch(function () {}); } catch (e) {}
      }
      return resp;
    });
  };
  const origOpen = XMLHttpRequest.prototype.open;
  const origSend = XMLHttpRequest.prototype.send;
  XMLHttpRequest.prototype.open = function (method, url) { this.__url = url; return origOpen.apply(this, arguments); };
  XMLHttpRequest.prototype.send = function () {
    const self = this, url = self.__url || '';
    if (CFG.listApiRegex.test(url)) {
      self.addEventListener('readystatechange', function () {
        if (self.readyState === 4 && self.status === 200) { try { parseAwemeList(self.responseText, autoMode); } catch (e) {} }
      });
    }
    return origSend.apply(self, arguments);
  };

  // ---------- 自动点击“作品/视频”标签 ----------
  function autoClickWorksTab() {
    try {
      const tabs = document.querySelectorAll('div[class*="tab"], li[class*="tab"], [role="tab"], a[class*="tab"]');
      for (const t of tabs) {
        const txt = (t.textContent || '').trim();
        if (/作品|视频/.test(txt) && !/喜欢|收藏|推荐|直播/.test(txt)) {
          if (!t.__jbClicked) { t.__jbClicked = true; t.click(); }
          break;
        }
      }
    } catch (e) {}
  }

  // ---------- 下载队列（并发 + 暂停/停止） ----------
  const downloadQueue = [];
  let activeDownloads = 0;

  function enqueueDownload(it) {
    if (selectedYear !== 'all' && String(it.year) !== String(selectedYear)) return;
    if (CFG.maxDownloadN > 0 && dlCount >= CFG.maxDownloadN) return;
    dlCount++;
    it.seq = ++fileSeq;
    GM_setValue('jb_file_seq', fileSeq);
    downloadQueue.push(it);
    pump();
  }
  function pump() {
    while (!dlPaused && !dlStopped && activeDownloads < CFG.maxConcurrent && downloadQueue.length) {
      const it = downloadQueue.shift();
      activeDownloads++;
      if (saveDirHandle) downloadViaFSA(it); else downloadViaGM(it);
    }
  }
  function finishOne(it) {
    activeDownloads--;
    markDownloaded(it.awemeId);
    updatePanel();
    pump();
    checkAutoDone();
  }
  function downloadViaGM(it) {
    GM_download({
      url: it.url, name: CFG.saveFolder + '/' + finalFname(it), saveAs: false,
      headers: { Referer: 'https://www.douyin.com/' },
      onload: function () { finishOne(it); },
      onerror: function (e) { finishOne(it); setStatus('⚠️ 下载失败 ' + it.awemeId + '：' + ((e && e.error) || '未知')); }
    });
  }
  async function downloadViaFSA(it) {
    const fname = finalFname(it);
    try {
      const resp = await fetch(it.url, { mode: 'cors', headers: { Referer: 'https://www.douyin.com/' } });
      if (!resp.ok) throw new Error('HTTP ' + resp.status);
      const blob = await resp.blob();
      const fh = await saveDirHandle.getFileHandle(fname, { create: true });
      const w = await fh.createWritable();
      await w.write(blob); await w.close();
      finishOne(it);
    } catch (e) {
      // 跨域或权限失败 → 回退 GM_download
      GM_download({
        url: it.url, name: CFG.saveFolder + '/' + fname, saveAs: false,
        headers: { Referer: 'https://www.douyin.com/' },
        onload: function () { finishOne(it); },
        onerror: function () { finishOne(it); }
      });
      setStatus('⚠️ 直接写失败(' + (e && e.message ? e.message : e) + ')，已回退到浏览器下载目录');
    }
  }
  function waitQueueDrain(cb) {
    const t = setInterval(function () {
      if (downloadQueue.length === 0 && activeDownloads === 0) { clearInterval(t); cb(); }
    }, 500);
  }

  // ---------- 手动：滚动收集 ----------
  let scrolling = false, stopFlag = false;
  function autoCollect() {
    if (scrolling) return;
    scrolling = true; stopFlag = false;
    let i = 0; autoClickWorksTab();
    setStatus('正在滚动收集链接…（可点“停止滚动”）');
    const timer = setInterval(function () {
      window.scrollTo(0, document.body.scrollHeight); autoClickWorksTab(); i++;
      if (i >= CFG.autoScrollMax || stopFlag) {
        clearInterval(timer); scrolling = false;
        const pending = collected.size - downloaded.size;
        setStatus('收集完成，共 ' + collected.size + ' 条，待下载 ' + pending + ' 条。点🚀或②下载。');
      }
    }, CFG.scrollIntervalMs);
  }

  // ---------- 手动：一键下载 ----------
  function startDownload() {
    dlCount = 0; dlStopped = false; dlPaused = false;
    const pending = Array.from(collected.values()).filter(function (it) { return !downloaded.has(it.awemeId); });
    if (!pending.length) { setStatus('没有待下载视频（已全部下载或尚未收集）。'); return; }
    setStatus('开始下载 ' + pending.length + ' 条 → ' + (saveDirHandle ? '绝对目录' : (CFG.saveFolder + '/')));
    pending.forEach(function (it, idx) { setTimeout(function () { enqueueDownload(it); }, idx * CFG.downloadGapMs); });
  }

  // ---------- 自动模式 ----------
  let autoMode = GM_getValue('jb_auto', false);
  let autoRunning = false, autoTimer = null, autoScrollMaxGuard = 0;
  function autoRun() {
    if (autoRunning) return;
    autoRunning = true; dlCount = 0; dlStopped = false; dlPaused = false;
    let lastSize = collected.size, noNew = 0; autoScrollMaxGuard = 0;
    setStatus('⚙️ 自动模式：自动收集并下载到「' + (saveDirHandle ? '绝对目录' : CFG.saveFolder) + '」…');
    autoClickWorksTab();
    autoTimer = setInterval(function () {
      window.scrollTo(0, document.body.scrollHeight); autoClickWorksTab();
      if (collected.size === lastSize) noNew++; else { noNew = 0; lastSize = collected.size; }
      if (noNew >= CFG.noNewStop || autoScrollMaxGuard++ >= CFG.autoScrollMax) {
        clearInterval(autoTimer);
        waitQueueDrain(function () {
          autoRunning = false;
          setStatus('✅ 自动完成：共 ' + collected.size + ' 条，已下载 ' + downloaded.size + ' 条 → ' + (saveDirHandle ? '绝对目录' : (CFG.saveFolder + '/')));
        });
      }
    }, CFG.scrollIntervalMs);
  }
  function checkAutoDone() {}

  // ---------- 暂停 / 停止 下载 ----------
  function togglePause() {
    if (dlStopped) { setStatus('已停止，点🚀/②可重新开始。'); return; }
    dlPaused = !dlPaused;
    if (dlPaused) { setStatus('⏸ 已暂停下载（已发起的继续完成）。点“暂停/继续”恢复。'); }
    else { setStatus('▶ 继续下载。'); pump(); }
    const btn = panel && panel.querySelector('#jb-dy-pause');
    if (btn) btn.textContent = dlPaused ? '▶ 继续下载' : '⏸ 暂停下载';
  }
  function stopDownload() {
    dlStopped = true; dlPaused = false;
    downloadQueue.length = 0;
    const btn = panel && panel.querySelector('#jb-dy-pause');
    if (btn) btn.textContent = '⏸ 暂停下载';
    setStatus('⏹ 已停止下载（已发起的将继续完成，已下载的不重复）。');
  }

  // ---------- 面板 UI ----------
  let panel, statusEl, countEl, doneEl, saveHintEl, yearSelEl, yearStatEl;
  let yearOptionsBuilt = false;
  function ensurePanel() {
    if (panel) return;
    const s = document.createElement('style');
    s.textContent = `
      #jb-dy-panel{position:fixed;right:16px;bottom:16px;z-index:99999;width:330px;
        background:rgba(20,33,61,0.78);backdrop-filter:blur(12px);border:1px solid rgba(255,255,255,0.18);
        border-radius:16px;padding:16px;color:#fff;font:14px/1.5 "Microsoft YaHei",sans-serif;
        box-shadow:0 8px 32px rgba(0,0,0,0.4)}
      #jb-dy-panel h4{margin:0 0 10px;font-size:15px;
        background:linear-gradient(90deg,#FFB347,#FF8C42);-webkit-background-clip:text;background-clip:text;color:transparent}
      #jb-dy-panel button{width:100%;margin:6px 0;padding:9px;border:none;border-radius:10px;cursor:pointer;
        font-weight:700;color:#14213d;background:linear-gradient(90deg,#FFB347,#FF8C42)}
      #jb-dy-panel .mini{background:rgba(255,255,255,0.15);color:#fff}
      #jb-dy-panel .auto{background:linear-gradient(90deg,#4ade80,#22c55e);color:#06301a}
      #jb-dy-panel .row{display:flex;align-items:center;gap:8px;margin:8px 0;font-size:13px}
      #jb-dy-panel .cnt{color:#FFB347;font-weight:700}
      #jb-dy-panel input[type=text],#jb-dy-panel select{flex:1;padding:6px 8px;border-radius:8px;
        border:1px solid rgba(255,255,255,0.3);background:rgba(255,255,255,0.1);color:#fff;font-size:13px}
      #jb-dy-status{font-size:12px;opacity:.85;margin-top:6px;min-height:16px}
      #jb-dy-savehint,#jb-dy-absdir,#jb-dy-yearstat{font-size:11px;opacity:.7;margin-top:2px;word-break:break-all}
      #jb-dy-tip{font-size:11px;opacity:.6;margin-top:6px;line-height:1.4}
    `;
    document.head.appendChild(s);

    panel = document.createElement('div');
    panel.id = 'jb-dy-panel';
    panel.innerHTML = `
      <h4>抖音批量下载 · 姜老师助手</h4>
      <div class="row">已收集：<span class="cnt" id="jb-dy-count">0</span> 条　已下载：<span class="cnt" id="jb-dy-done">0</span> 条</div>
      <div class="row"><label><input type="checkbox" id="jb-dy-nwm" ${CFG.noWatermark ? 'checked' : ''}> 无水印</label>
        <label><input type="checkbox" id="jb-dy-auto" ${autoMode ? 'checked' : ''}> 自动模式</label></div>
      <div class="row">保存位置(子路径)：<input type="text" id="jb-dy-folder" value="${CFG.saveFolder}"></div>
      <div id="jb-dy-savehint"></div>
      <button id="jb-dy-choose">📁 选择绝对保存文件夹(电脑任意盘)</button>
      <div id="jb-dy-absdir"></div>
      <div class="row">按年份筛选：<select id="jb-dy-year"><option value="all">全部年份</option></select></div>
      <div id="jb-dy-yearstat"></div>
      <div class="row">一次性最多下载：<input type="text" id="jb-dy-maxn" value="${CFG.maxDownloadN}" style="max-width:80px"> 个(0=不限)</div>
      <button id="jb-dy-auto-run" class="auto">🚀 自动开始（收集+下载）</button>
      <button id="jb-dy-start">① 手动收集链接</button>
      <button id="jb-dy-dl">② 手动下载已获取</button>
      <button id="jb-dy-pause" class="mini">⏸ 暂停下载</button>
      <button id="jb-dy-stop" class="mini">⏹ 停止下载</button>
      <button id="jb-dy-stopscroll" class="mini">停止滚动</button>
      <button id="jb-dy-copy" class="mini">复制全部链接</button>
      <div id="jb-dy-status">先设好保存位置/选文件夹，再点 🚀 自动开始。首次请手动切到“作品/视频”标签。</div>
      <div id="jb-dy-tip">① 想要落到“D盘某文件夹”：Chrome/Edge 点「选择绝对保存文件夹」授权即可；若提示直接写失败(跨域)，请把浏览器“默认下载目录”设成目标盘，本脚本“保存位置”填子文件夹。<br>② 若下载仍逐个弹窗，请关闭浏览器“每次询问保存位置”。</div>
    `;
    document.body.appendChild(panel);

    countEl = panel.querySelector('#jb-dy-count');
    doneEl = panel.querySelector('#jb-dy-done');
    statusEl = panel.querySelector('#jb-dy-status');
    saveHintEl = panel.querySelector('#jb-dy-savehint');
    yearSelEl = panel.querySelector('#jb-dy-year');
    yearStatEl = panel.querySelector('#jb-dy-yearstat');

    panel.querySelector('#jb-dy-nwm').addEventListener('change', function (e) { CFG.noWatermark = e.target.checked; });
    panel.querySelector('#jb-dy-auto').addEventListener('change', function (e) {
      autoMode = e.target.checked; GM_setValue('jb_auto', autoMode);
      setStatus(autoMode ? '自动模式已开启：下次进抖音用户主页自动运行。当前页可点🚀。' : '自动模式已关闭。');
    });
    panel.querySelector('#jb-dy-folder').addEventListener('change', function (e) { setFolder(e.target.value); });
    panel.querySelector('#jb-dy-choose').addEventListener('click', chooseFolder);
    panel.querySelector('#jb-dy-year').addEventListener('change', function (e) { selectedYear = e.target.value; setStatus('已按年份筛选：' + (selectedYear === 'all' ? '全部' : selectedYear)); });
    panel.querySelector('#jb-dy-maxn').addEventListener('change', function (e) {
      const v = parseInt(e.target.value, 10); CFG.maxDownloadN = isNaN(v) || v < 0 ? 0 : v; GM_setValue('jb_max_n', CFG.maxDownloadN);
    });
    panel.querySelector('#jb-dy-auto-run').addEventListener('click', autoRun);
    panel.querySelector('#jb-dy-start').addEventListener('click', autoCollect);
    panel.querySelector('#jb-dy-dl').addEventListener('click', startDownload);
    panel.querySelector('#jb-dy-pause').addEventListener('click', togglePause);
    panel.querySelector('#jb-dy-stop').addEventListener('click', stopDownload);
    panel.querySelector('#jb-dy-stopscroll').addEventListener('click', function () { stopFlag = true; });
    panel.querySelector('#jb-dy-copy').addEventListener('click', function () {
      const links = Array.from(collected.values()).map(v => v.url).join('\n');
      navigator.clipboard.writeText(links).then(function () { setStatus('已复制 ' + collected.size + ' 条链接'); });
    });

    updatePanel(); updateSaveHint(); updateAbsLabel();
    loadHandle().then(function (h) { if (h) { saveDirHandle = h; updateAbsLabel(); } });
  }

  function refreshYearOptions() {
    if (!yearSelEl) return;
    const years = Object.keys(yearCount).sort();
    for (const y of years) {
      if (!yearOptionsBuilt || !yearSelEl.querySelector('option[value="' + y + '"]')) {
        const o = document.createElement('option'); o.value = y; o.textContent = y + '年'; yearSelEl.appendChild(o);
      }
    }
    yearOptionsBuilt = true;
  }
  function updateYearStat() {
    if (yearStatEl) {
      const parts = Object.keys(yearCount).sort().map(function (y) { return y + '年:' + yearCount[y]; });
      yearStatEl.textContent = '年份统计：' + (parts.length ? parts.join('  ') : '暂无');
    }
  }
  function updatePanel() { if (countEl) countEl.textContent = collected.size; if (doneEl) doneEl.textContent = downloaded.size; }
  function updateSaveHint() { if (saveHintEl) saveHintEl.textContent = '子路径落点：浏览器下载目录 / ' + CFG.saveFolder + ' /'; }
  function setStatus(t) { if (statusEl) statusEl.textContent = t; }

  // ---------- 初始化 ----------
  function init() {
    ensurePanel();
    if (autoMode) setTimeout(function () { autoRun(); }, 1500);
  }
  if (document.body) init();
  else document.addEventListener('DOMContentLoaded', init);
  window.addEventListener('load', function () { setTimeout(ensurePanel, 800); });

})();