// ==UserScript==
// @name         网易云歌单 M4A 批量下载（自动播放拦截）
// @namespace    https://music.163.com/
// @version      2.7.6
// @description  歌单 m4a：media URL 来自 XHR/performance 拦截或 audio/video（任一先满足且未在 ignore 列表即采用）；行内解析歌名；GM_download 直链；任务列表与统计；暂停/继续。
// @author       getMusic
// @match        https://music.163.com/*
// @match        https://*.music.163.com/*
// @match        https://*.music.126.net/*
// @match        http://*.music.126.net/*
// @grant        GM_addStyle
// @grant        GM_xmlhttpRequest
// @grant        GM_download
// @grant        unsafeWindow
// @connect      *
// @run-at       document-start
// ==/UserScript==

(function () {
  'use strict';

  var SCRIPT_VERSION = '2.7.6';
  var MSG_DL_NAME = 'NETEASE_M4A_DL_NAME';
  var MSG_DL_DONE = 'NETEASE_M4A_DL_DONE';
  var POPUP_NAME_PREFIX = '__NETEASE_M4A_DL_NAME__:';

  function encodePopupFilename(name) {
    try {
      return POPUP_NAME_PREFIX + encodeURIComponent(String(name || 'audio.m4a'));
    } catch (e) {
      return POPUP_NAME_PREFIX + 'audio.m4a';
    }
  }

  function decodePopupFilename(raw) {
    if (!raw || typeof raw !== 'string') return '';
    if (raw.indexOf(POPUP_NAME_PREFIX) !== 0) return '';
    try {
      return decodeURIComponent(raw.slice(POPUP_NAME_PREFIX.length));
    } catch (e) {
      return raw.slice(POPUP_NAME_PREFIX.length);
    }
  }

  /** 与 Blob 同源下载时，使用 NFC 规范化，减少中文乱码 */
  function normalizeFilenameForDownload(name) {
    if (!name) return 'audio.m4a';
    try {
      return String(name).normalize('NFC');
    } catch (e) {
      return String(name);
    }
  }

  function triggerBlobDownload(blob, filename) {
    var fn = normalizeFilenameForDownload(filename);
    if (typeof GM_download === 'function') {
      var u = URL.createObjectURL(blob);
      try {
        GM_download({
          url: u,
          name: fn,
          saveAs: false,
          onload: function () {
            setTimeout(function () {
              try {
                URL.revokeObjectURL(u);
              } catch (e) {}
            }, 500);
          },
          onerror: function () {
            try {
              URL.revokeObjectURL(u);
            } catch (e2) {}
            triggerBlobDownloadAnchor(blob, fn);
          },
        });
        return;
      } catch (e) {
        try {
          URL.revokeObjectURL(u);
        } catch (e3) {}
        triggerBlobDownloadAnchor(blob, fn);
        return;
      }
    }
    triggerBlobDownloadAnchor(blob, fn);
  }

  function triggerBlobDownloadAnchor(blob, fn) {
    var u = URL.createObjectURL(blob);
    var a = document.createElement('a');
    a.href = u;
    a.download = fn;
    a.rel = 'noopener';
    a.style.display = 'none';
    var parent = document.body || document.documentElement;
    if (!parent) return;
    parent.appendChild(a);
    a.click();
    parent.removeChild(a);
    setTimeout(function () {
      try {
        URL.revokeObjectURL(u);
      } catch (e) {}
    }, 2500);
  }

  function gmFetchBlobAsBlob(url) {
    return new Promise(function (resolve, reject) {
      if (typeof GM_xmlhttpRequest === 'undefined') {
        reject(new Error('no-GM'));
        return;
      }
      GM_xmlhttpRequest({
        method: 'GET',
        url: url,
        responseType: 'arraybuffer',
        timeout: 180000,
        onload: function (r) {
          if (r.status >= 200 && r.status < 300) {
            resolve(new Blob([r.response], { type: 'audio/mp4' }));
          } else {
            reject(new Error('HTTP ' + r.status));
          }
        },
        onerror: function () {
          reject(new Error('net'));
        },
        ontimeout: function () {
          reject(new Error('timeout'));
        },
      });
    });
  }

  /**
   * CDN 预览页（新标签打开 m4a 直链时出现 <video>）：
   * 子页只负责静音并尽快解析出最终的媒体地址，再把地址回传给父页；
   * 真正的下载仍由父页执行，这样文件名始终以父页生成的「歌名-歌手」为准。
   */
  if (/\.music\.126\.net$/i.test(location.hostname)) {
    function runCdnPageHelper() {
      var filename = decodePopupFilename(window.name) || 'audio.m4a';
      var finished = false;
      var attempt = 0;
      function postToOpener(payload) {
        try {
          if (window.opener) window.opener.postMessage(payload, '*');
        } catch (e) {}
      }
      function bindMediaEvents() {
        try {
          var videos = document.querySelectorAll('video, audio');
          for (var i = 0; i < videos.length; i++) {
            var el = videos[i];
            if (el.__neteaseM4aBound) continue;
            el.__neteaseM4aBound = true;
            try {
              el.addEventListener('loadedmetadata', doDownload);
              el.addEventListener('loadeddata', doDownload);
              el.addEventListener('canplay', doDownload);
            } catch (e2) {}
          }
        } catch (e) {}
      }
      function syncMutedVideo() {
        try {
          var videos = document.querySelectorAll('video, audio');
          for (var i = 0; i < videos.length; i++) {
            try {
              videos[i].muted = true;
              videos[i].defaultMuted = true;
              videos[i].volume = 0;
              videos[i].setAttribute('muted', 'muted');
            } catch (e2) {}
          }
        } catch (e) {}
        bindMediaEvents();
      }
      function pickSrc() {
        var src = '';
        var video = document.querySelector('video');
        if (video) {
          try {
            video.muted = true;
            video.defaultMuted = true;
            video.volume = 0;
            video.setAttribute('muted', 'muted');
          } catch (e) {}
          var so = video.querySelector('source');
          if (so && so.src) src = so.src;
          else if (video.currentSrc) src = video.currentSrc;
          else if (video.src) src = video.src;
        }
        if (!src) {
          var h = location.href.split('#')[0];
          if (/\.m4a(\?|$)/i.test(h)) src = h;
        }
        return src;
      }
      function doDownload() {
        if (finished) return;
        var src = pickSrc();
        if (!src && attempt < 8) {
          attempt++;
          setTimeout(doDownload, 350);
          return;
        }
        finished = true;
        if (!src) {
          postToOpener({ type: MSG_DL_DONE, ok: false, reason: 'no-src', name: filename });
          setTimeout(function () {
            try {
              window.close();
            } catch (e2) {}
          }, 400);
          return;
        }
        function notifyDone(payload) {
          postToOpener(payload || { type: MSG_DL_DONE, ok: true, name: filename });
          setTimeout(function () {
            try {
              window.close();
            } catch (e2) {}
          }, 700);
        }
        if (window.opener) {
          notifyDone({ type: MSG_DL_DONE, ok: true, src: src, name: filename, via: 'video-popup' });
          return;
        }
        var normalizedName = normalizeFilenameForDownload(filename);
        if (typeof GM_download === 'function') {
          try {
            GM_download({
              url: src,
              name: normalizedName,
              saveAs: false,
              headers: {
                Referer: 'https://music.163.com/',
                Origin: 'https://music.163.com',
              },
            });
            notifyDone({ type: MSG_DL_DONE, ok: true, src: src, name: normalizedName, via: 'video-popup-self' });
            return;
          } catch (e3) {
            console.warn('[NetEaseDL] CDN 子页自下载异常，改用 <a download>:', e3);
          }
        }
        var a = document.createElement('a');
        a.href = src;
        a.setAttribute('download', normalizedName);
        a.rel = 'noopener';
        if (document.body) {
          document.body.appendChild(a);
          a.click();
          document.body.removeChild(a);
        } else {
          a.click();
        }
        notifyDone({ type: MSG_DL_DONE, ok: true, src: src, name: normalizedName, via: 'video-popup-self' });
      }
      window.addEventListener(
        'message',
        function (e) {
          if (e.data && e.data.type === MSG_DL_NAME && e.data.name) {
            filename = e.data.name;
            if (finished) return;
            attempt = 0;
            setTimeout(doDownload, 80);
          }
        },
        false
      );
      syncMutedVideo();
      var muteObs = null;
      try {
        muteObs = new MutationObserver(function () {
          syncMutedVideo();
          if (!finished) setTimeout(doDownload, 30);
        });
        muteObs.observe(document.documentElement || document, { childList: true, subtree: true, attributes: true });
      } catch (e4) {}
      setTimeout(function () {
        if (!finished) doDownload();
      }, 80);
    }
    if (document.readyState === 'loading') {
      document.addEventListener('DOMContentLoaded', runCdnPageHelper);
    } else {
      runCdnPageHelper();
    }
    return;
  }

  /** 每首下载完成后到下一首点击前的间隔，减轻 AbortError: play() interrupted by load */
  var BETWEEN_TRACK_MS = 3600;
  var URL_WAIT_MS = 50000;
  var META_RETRY_DELAY_MS = 400;
  /**
   * 点击 .ply 后稍候再监听「新」media URL：过短易把上一首缓冲/未切换前的地址当成新链；
   * 过长按体感像在等播放，一般 400～800ms 足够，可按网络调大。
   */
  var AFTER_PLAY_SETTLE_MS = 550;

  function delay(ms) {
    return new Promise(function (resolve) {
      setTimeout(resolve, ms);
    });
  }

  /**
   * 与 urls.text 一致的网易云 CDN media（m704/m804… + .m4a）
   * 部分请求 URL 可能不含 query 前的明显后缀，故同时认 jdyyaac 路径段
   */
  function isNeteaseMediaUrl(u) {
    if (!u || typeof u !== 'string') return false;
    if (!/^https:\/\//i.test(u)) return false;
    if (!/\.music\.126\.net\//i.test(u)) return false;
    if (!/^https:\/\/m\d+\.music\.126\.net\//i.test(u)) return false;
    if (/\.m4a(\?|#|$)/i.test(u)) return true;
    if (/jdyyaac\//i.test(u) && /\.m4a/i.test(u)) return true;
    return false;
  }

  var mediaUrlListeners = new Set();
  var recentMediaUrlEvents = [];
  var MAX_MEDIA_URL_EVENTS = 160;

  var lastNotifyUrl = '';
  var lastNotifyKey = '';
  var lastNotifyTs = 0;

  function getPerfNow() {
    try {
      if (typeof performance !== 'undefined' && performance && typeof performance.now === 'function') {
        return performance.now();
      }
    } catch (e) {}
    return 0;
  }

  /** 用于判断「是否同一首媒体文件」：忽略 query/fragment 差异（避免拦截到与上一首相同内容却字符串不同） */
  function normalizeNeteaseMediaUrlKey(u) {
    if (!u || typeof u !== 'string') return '';
    try {
      var x = new URL(u);
      return (x.origin + x.pathname).toLowerCase();
    } catch (e) {
      return String(u)
        .split('?')[0]
        .split('#')[0]
        .toLowerCase();
    }
  }

  function notifyMediaUrl(u, extra) {
    if (!isNeteaseMediaUrl(u)) return;
    var now = Date.now();
    var key = normalizeNeteaseMediaUrlKey(u);
    if (key === lastNotifyKey && now - lastNotifyTs < 800) return;
    var ev = {
      url: u,
      key: key,
      ts: now,
      perfNow:
        extra && typeof extra.perfNow === 'number'
          ? extra.perfNow
          : getPerfNow(),
      source: (extra && extra.source) || 'unknown',
    };
    lastNotifyUrl = u;
    lastNotifyKey = key;
    lastNotifyTs = now;
    recentMediaUrlEvents.push(ev);
    if (recentMediaUrlEvents.length > MAX_MEDIA_URL_EVENTS) {
      recentMediaUrlEvents.splice(0, recentMediaUrlEvents.length - MAX_MEDIA_URL_EVENTS);
    }
    mediaUrlListeners.forEach(function (fn) {
      try {
        fn(ev);
      } catch (e) {
        console.warn('[NetEaseDL] listener:', e);
      }
    });
  }

  function subscribeMediaUrl(fn) {
    mediaUrlListeners.add(fn);
    return function () {
      mediaUrlListeners.delete(fn);
    };
  }

  var PERF_POLL_MS = 450;
  var perfPollId = null;
  var lastPerfEntryCount = 0;

  function hookXHRAndFetchOnTarget(win, label) {
    if (!win || !win.XMLHttpRequest) return;
    try {
      if (!win.__neteaseM4aPatchedXHR) {
        win.__neteaseM4aPatchedXHR = true;
        var XO = win.XMLHttpRequest.prototype.open;
        win.XMLHttpRequest.prototype.open = function (method, url) {
          if (typeof url === 'string') notifyMediaUrl(url, { source: 'xhr' });
          return XO.apply(this, arguments);
        };
      }
    } catch (e) {
      console.warn('[NetEaseDL] XHR hook ' + (label || '') + ':', e);
    }
    try {
      if (!win.__neteaseM4aPatchedFetch) {
        var OF = win.fetch;
        if (typeof OF === 'function') {
          win.__neteaseM4aPatchedFetch = true;
          win.fetch = function (input, init) {
            try {
              var u = typeof input === 'string' ? input : input && input.url;
              if (u) notifyMediaUrl(u, { source: 'fetch' });
            } catch (e2) {}
            return OF.apply(this, arguments);
          };
        }
      }
    } catch (e) {
      console.warn('[NetEaseDL] fetch hook ' + (label || '') + ':', e);
    }
  }

  /** 沙箱 window + 页面真实 window（Tampermonkey 下二者可能不同） */
  function installMediaUrlHooks() {
    if (window.__neteaseM4aHookInstalled) return;
    window.__neteaseM4aHookInstalled = true;

    hookXHRAndFetchOnTarget(window, 'sandbox');
    try {
      var uw = typeof unsafeWindow !== 'undefined' ? unsafeWindow : window;
      hookXHRAndFetchOnTarget(uw, 'page');
    } catch (e) {
      console.warn('[NetEaseDL] unsafeWindow hook:', e);
    }

    if (perfPollId == null) {
      perfPollId = setInterval(function () {
        try {
          var perf = typeof performance !== 'undefined' ? performance : null;
          if (!perf || !perf.getEntriesByType) return;
          var entries = perf.getEntriesByType('resource');
          if (entries.length < lastPerfEntryCount) lastPerfEntryCount = 0;
          for (var i = lastPerfEntryCount; i < entries.length; i++) {
            var entry = entries[i];
            var n = entry && entry.name;
            if (n) {
              notifyMediaUrl(n, {
                source: 'performance',
                perfNow:
                  typeof entry.responseEnd === 'number' && entry.responseEnd > 0 ? entry.responseEnd : entry.startTime,
              });
            }
          }
          lastPerfEntryCount = entries.length;
        } catch (e3) {}
      }, PERF_POLL_MS);
    }
  }

  /** 注入到页面主世界，确保与播放器同一 JS 环境（通过 postMessage 回传） */
  var PAGE_MSG_TYPE = '__NetEaseM4aMediaUrl__';

  function installPageContextHook() {
    if (window.__neteaseM4aPageHookInjected) return;
    window.__neteaseM4aPageHookInjected = true;

    function inject() {
      if (!document || !document.documentElement) {
        setTimeout(inject, 10);
        return;
      }
      var id = 'netease-m4a-inline-hook';
      if (document.getElementById(id)) return;
      var s = document.createElement('script');
      s.id = id;
      s.setAttribute('type', 'text/javascript');
      var re =
        'function __neteaseM4aCheck(u){if(!u||typeof u!==\"string\")return false;if(!/^https:\\/\\//i.test(u))return false;if(!/\\.music\\.126\\.net\\//i.test(u))return false;if(!/^https:\\/\\/m\\d+\\.music\\.126\\.net\\//i.test(u))return false;if(/\\.m4a(\\?|#|$)/i.test(u))return true;if(/jdyyaac\\//i.test(u)&&/\\.m4a/i.test(u))return true;return false;}' +
        'function __neteaseM4aSend(u){if(!__neteaseM4aCheck(u))return;try{window.postMessage({t:\"' +
        PAGE_MSG_TYPE +
        '\",u:u},\"*\");}catch(e){}}' +
        'var XO=XMLHttpRequest.prototype.open;XMLHttpRequest.prototype.open=function(m,u){if(typeof u===\"string\")__neteaseM4aSend(u);return XO.apply(this,arguments);};' +
        'var OF=window.fetch;if(typeof OF===\"function\"){window.fetch=function(input,init){try{var u=typeof input===\"string\"?input:input&&input.url;if(u)__neteaseM4aSend(u);}catch(e){}return OF.apply(this,arguments);};}';
      s.textContent = re;
      (document.head || document.documentElement).appendChild(s);
      s.remove();
    }

    inject();

    function onPageMessage(ev) {
      try {
        var d = ev.data;
        if (!d || d.t !== PAGE_MSG_TYPE || !d.u) return;
        notifyMediaUrl(d.u, { source: 'page-message' });
      } catch (e) {}
    }
    try {
      var uwMsg = typeof unsafeWindow !== 'undefined' ? unsafeWindow : window;
      uwMsg.addEventListener('message', onPageMessage, true);
    } catch (e) {
      console.warn('[NetEaseDL] page message listener:', e);
      window.addEventListener('message', onPageMessage, true);
    }
  }

  /** 与 installPlayAbortSilencer 中注入代码一致，用于在 iframe 内再执行一次 */
  var PLAY_ABORT_PATCH_JS =
    '(function(){' +
    'if(window.__neteaseM4aPlayPatched)return;' +
    'window.__neteaseM4aPlayPatched=true;' +
    'var orig=HTMLMediaElement.prototype.play;' +
    'HTMLMediaElement.prototype.play=function(){' +
    'var ret=orig.apply(this,arguments);' +
    'if(ret&&typeof ret.then==="function"){' +
    'return ret.catch(function(err){' +
    'if(err&&err.name==="AbortError")return;' +
    'throw err;' +
    '});' +
    '}' +
    'return ret;' +
    '};' +
    '})();';

  /**
   * 在页面主世界为 HTMLMediaElement.play 的 Promise 接住 AbortError，
   * 避免网易云在快速切歌时出现 Uncaught (in promise) AbortError（见 https://goo.gl/LdLk22）。
   * 歌单若在 #g_iframe 内，播放器脚本是 iframe 的 realm，需对 iframe 文档同样注入。
   */
  function installPlayAbortSilencer() {
    if (window.__neteaseM4aPlaySilencerInstalled) return;
    window.__neteaseM4aPlaySilencerInstalled = true;

    function injectIntoDoc(doc) {
      if (!doc || !doc.documentElement) return;
      try {
        var id = 'netease-m4a-play-abort-patch';
        if (doc.getElementById(id)) return;
        var s = doc.createElement('script');
        s.id = id;
        s.setAttribute('type', 'text/javascript');
        s.textContent = PLAY_ABORT_PATCH_JS;
        (doc.head || doc.documentElement).appendChild(s);
        s.remove();
      } catch (e) {
        console.warn('[NetEaseDL] play AbortError 补丁注入失败:', e);
      }
    }

    function tryInjectFrames() {
      injectIntoDoc(document);
      try {
        var iframe = document.getElementById('g_iframe');
        if (iframe && iframe.contentDocument) injectIntoDoc(iframe.contentDocument);
      } catch (e) {}
      try {
        var list = document.querySelectorAll('iframe#contentFrame,iframe[src*="playlist"]');
        for (var i = 0; i < list.length; i++) {
          try {
            if (list[i].contentDocument) injectIntoDoc(list[i].contentDocument);
          } catch (e2) {}
        }
      } catch (e3) {}
    }

    function schedule() {
      if (!document || !document.documentElement) {
        setTimeout(schedule, 10);
        return;
      }
      tryInjectFrames();
    }
    schedule();
    if (document.readyState === 'loading') {
      document.addEventListener('DOMContentLoaded', tryInjectFrames);
    }
    window.addEventListener('load', tryInjectFrames);
    setTimeout(tryInjectFrames, 600);
    setTimeout(tryInjectFrames, 2200);
    try {
      var g = document.getElementById('g_iframe');
      if (g) g.addEventListener('load', tryInjectFrames);
    } catch (e) {}
  }

  installMediaUrlHooks();
  installPageContextHook();
  installPlayAbortSilencer();

  function scanAudioElementsForUrl(callback) {
    var docs = [];
    try {
      docs.push(document);
    } catch (e) {}
    try {
      if (window.top && window.top.document) docs.push(window.top.document);
    } catch (e) {}
    try {
      var ifr = document.querySelectorAll('iframe');
      for (var i = 0; i < ifr.length; i++) {
        if (ifr[i].contentDocument) docs.push(ifr[i].contentDocument);
      }
    } catch (e) {}
    for (var d = 0; d < docs.length; d++) {
      var doc = docs[d];
      if (!doc) continue;
      var nodes = doc.querySelectorAll('audio, video');
      for (var j = 0; j < nodes.length; j++) {
        var el = nodes[j];
        var u = el.currentSrc || el.src;
        if (u) callback(u);
      }
    }
  }

  function collectCurrentMediaUrls() {
    var urls = [];
    scanAudioElementsForUrl(function (u) {
      if (!isNeteaseMediaUrl(u)) return;
      if (urls.indexOf(u) >= 0) return;
      urls.push(u);
    });
    return urls;
  }

  function resetRecentMediaObservations() {
    recentMediaUrlEvents = [];
    lastNotifyUrl = '';
    lastNotifyKey = '';
    lastNotifyTs = 0;
    lastPerfEntryCount = 0;
    try {
      if (typeof performance !== 'undefined' && performance && typeof performance.clearResourceTimings === 'function') {
        performance.clearResourceTimings();
      }
    } catch (e) {}
  }

  function findPreferredCurrentMediaUrl(ignoreList) {
    var bestUrl = '';
    var bestScore = -1;
    var docs = [];
    try {
      docs.push(document);
    } catch (e) {}
    try {
      if (window.top && window.top.document && docs.indexOf(window.top.document) < 0) {
        docs.push(window.top.document);
      }
    } catch (e2) {}
    try {
      var ifr = document.querySelectorAll('iframe');
      for (var i = 0; i < ifr.length; i++) {
        try {
          if (ifr[i].contentDocument && docs.indexOf(ifr[i].contentDocument) < 0) {
            docs.push(ifr[i].contentDocument);
          }
        } catch (e3) {}
      }
    } catch (e4) {}
    for (var d = 0; d < docs.length; d++) {
      var doc = docs[d];
      if (!doc) continue;
      var nodes = doc.querySelectorAll('audio, video');
      for (var j = 0; j < nodes.length; j++) {
        var el = nodes[j];
        var u = el.currentSrc || el.src;
        if (!isNeteaseMediaUrl(u)) continue;
        if (isUrlIgnored(u, ignoreList)) continue;
        var score = 0;
        if (!el.paused) score += 100;
        if (!el.ended) score += 20;
        if ((el.currentTime || 0) > 0) score += 10;
        if ((el.readyState || 0) >= 2) score += 8;
        if ((el.networkState || 0) === 2) score += 4;
        if ((el.volume || 0) > 0) score += 1;
        if (score > bestScore) {
          bestScore = score;
          bestUrl = u;
        }
      }
    }
    return bestUrl;
  }

  /** 判断 u 是否与 ignore 列表中任一项指向同一媒体（按路径比较，避免 query 微差导致未忽略、反复下到第一首） */
  function isUrlIgnored(u, ignoreList) {
    if (!ignoreList || !ignoreList.length) return false;
    var uk = normalizeNeteaseMediaUrlKey(u);
    if (!uk) return false;
    for (var k = 0; k < ignoreList.length; k++) {
      var ign = ignoreList[k];
      if (!ign) continue;
      if (u === ign) return true;
      if (normalizeNeteaseMediaUrlKey(ign) === uk) return true;
    }
    return false;
  }

  /**
   * 等待新的 media URL。
   * 网易云部分环境下 audio 的 currentSrc 为 blob: 或不含直链，仅扫 DOM 会永远拿不到地址；
   * 因此同时采用：① XHR/performance/postMessage 拦截；② 轮询 audio/video。
   * 二者任一先得到「未在 ignore 列表」的 NetEase m4a URL 即 resolve（与 2.5.8 及以前一致）。
   */
  function findRecentMediaUrlCandidate(ignoreList, minTs, minPerfNow) {
    var i;
    for (i = recentMediaUrlEvents.length - 1; i >= 0; i--) {
      var ev = recentMediaUrlEvents[i];
      if (!ev || !ev.url) continue;
      var tsFresh = typeof minTs !== 'number' || ev.ts >= minTs;
      var perfFresh =
        typeof minPerfNow !== 'number' || (typeof ev.perfNow === 'number' && ev.perfNow >= minPerfNow);
      if (!tsFresh && !perfFresh) continue;
      if (isUrlIgnored(ev.url, ignoreList)) continue;
      return ev.url;
    }
    return '';
  }

  function waitForNewMediaUrl(ignoreList, timeoutMs, opts) {
    opts = opts || {};
    var minTs = typeof opts.minTs === 'number' ? opts.minTs : Date.now();
    var minPerfNow = typeof opts.minPerfNow === 'number' ? opts.minPerfNow : getPerfNow();
    return new Promise(function (resolve, reject) {
      var done = false;
      var warmCandidate = findRecentMediaUrlCandidate(ignoreList, minTs, minPerfNow);
      if (warmCandidate) {
        resolve(warmCandidate);
        return;
      }
      var unsub = subscribeMediaUrl(function (ev) {
        if (done) return;
        var u = ev && ev.url ? ev.url : ev;
        if (!isNeteaseMediaUrl(u)) return;
        var tsFresh = !ev || typeof ev.ts !== 'number' || ev.ts >= minTs;
        var perfFresh =
          !ev || typeof ev.perfNow !== 'number' || typeof minPerfNow !== 'number' || ev.perfNow >= minPerfNow;
        if (!tsFresh && !perfFresh) return;
        if (isUrlIgnored(u, ignoreList)) return;
        finish(u);
      });
      var pollId = setInterval(function () {
        if (done) return;
        var preferredUrl = findPreferredCurrentMediaUrl(ignoreList);
        if (preferredUrl) {
          finish(preferredUrl);
        }
      }, 280);
      var tid = setTimeout(function () {
        if (done) return;
        done = true;
        clearInterval(pollId);
        unsub();
        reject(new Error('等待 media URL 超时'));
      }, timeoutMs);
      function finish(u) {
        if (done) return;
        done = true;
        clearTimeout(tid);
        clearInterval(pollId);
        unsub();
        resolve(u);
      }
    });
  }

  /** 获取歌单所在 document（PC 版常在 iframe #g_iframe 内） */
  function getPlaylistDocument() {
    var iframe =
      document.getElementById('g_iframe') ||
      document.querySelector('iframe#contentFrame') ||
      document.querySelector('iframe[src*="playlist"]');
    try {
      if (iframe && iframe.contentDocument) return iframe.contentDocument;
    } catch (e) {
      console.warn('[NetEaseDL] 无法读取 iframe，使用顶层 document:', e);
    }
    return document;
  }

  /** 解码属性里的 &nbsp; 等实体（歌名常在 title / data-* 里） */
  function decodeHtmlEntities(s) {
    if (!s) return '';
    var ta = document.createElement('textarea');
    ta.innerHTML = String(s);
    return ta.value;
  }

  function normalizeMetaText(s) {
    if (!s) return '';
    return decodeHtmlEntities(String(s).trim())
      .replace(/\s+/g, ' ')
      .trim();
  }

  /** 去掉网易云反爬用的 .soil 节点后再取文本（仅作兜底） */
  function textContentSansSoil(el) {
    if (!el) return '';
    try {
      var clone = el.cloneNode(true);
      var soils = clone.querySelectorAll('.soil');
      var i;
      for (i = 0; i < soils.length; i++) {
        try {
          soils[i].parentNode.removeChild(soils[i]);
        } catch (e) {}
      }
      return normalizeMetaText(clone.textContent || '');
    } catch (e2) {
      return normalizeMetaText(el.textContent || '');
    }
  }

  /**
   * 从歌单行解析歌名、歌手。
   * PC 版列表在可见文字里混入 class="soil" 的假字，textContent 会乱码；
   * 优先用「分享」按钮上的 data-res-name / data-res-author，以及 b[title]、歌手列 div[title]。
   */
  function parseRowMeta(row) {
    if (!row) return null;
    var title = '';
    var artist = '';

    var share =
      row.querySelector('span[data-res-action="share"][data-res-name]') ||
      row.querySelector('[data-res-name][data-res-author]');
    if (share) {
      var dn = share.getAttribute('data-res-name');
      var da = share.getAttribute('data-res-author');
      if (dn) title = normalizeMetaText(dn);
      if (da) artist = normalizeMetaText(da);
    }

    if (!title) {
      var bTitle = row.querySelector('a[href*="/song?id="] b[title]') || row.querySelector('a[href*="/song"] b[title]');
      if (bTitle) {
        title = normalizeMetaText(bTitle.getAttribute('title') || '');
      }
    }
    if (!title) {
      var link = row.querySelector('a[href*="/song?id="]') || row.querySelector('a[href*="/song"]');
      if (link) {
        title = textContentSansSoil(link);
      }
    }

    if (!artist) {
      var artTd = row.querySelector('td:nth-child(4)') || row.querySelector('td.f-hide:nth-of-type(4)');
      if (artTd) {
        var divText = artTd.querySelector('div.text[title]');
        if (divText) {
          var dt = divText.getAttribute('title');
          if (dt) artist = normalizeMetaText(dt);
        }
        if (!artist) {
          var sp = artTd.querySelector('span[title]');
          if (sp) {
            var st = sp.getAttribute('title');
            if (st) artist = normalizeMetaText(st);
          }
        }
        if (!artist) {
          var artA = artTd.querySelector('a[href*="/artist"]');
          if (artA) artist = textContentSansSoil(artA);
        }
      }
    }

    return { title: title || '', artist: artist || '' };
  }

  /** 歌名、歌手是否均有（用于日志等） */
  function metaOk(meta) {
    return !!(meta && meta.title && meta.artist);
  }

  /** 序号左补零，宽度至少 3 且随歌单总首数变长 */
  function padPlaylistIndex(index1Based, total) {
    var w = Math.max(3, String(total).length);
    var s = String(index1Based);
    while (s.length < w) {
      s = '0' + s;
    }
    return s;
  }

  /**
   * 下载文件名：优先「歌名-歌手」；仅一侧则另一侧用未知；皆无则「歌单第NNN首」
   */
  function buildDownloadFilename(meta, index1Based, total) {
    var t = sanitizeFilePart(meta && meta.title);
    var a = sanitizeFilePart(meta && meta.artist);
    if (t && a) return t + '-' + a + '.m4a';
    if (t && !a) return t + '-未知歌手.m4a';
    if (!t && a) return '未知歌曲-' + a + '.m4a';
    return '歌单第' + padPlaylistIndex(index1Based, total) + '首.m4a';
  }

  /** 尽量等待 DOM 解析出歌名/歌手，超时仍返回当前能解析到的结果 */
  function waitForRowMetaBestEffort(row, timeoutMs) {
    var deadline = Date.now() + (timeoutMs || 6000);
    return new Promise(function (resolve) {
      function tick() {
        var m = parseRowMeta(row);
        if (!m) m = { title: '', artist: '' };
        if (metaOk(m) || Date.now() >= deadline) {
          resolve(m);
          return;
        }
        setTimeout(tick, META_RETRY_DELAY_MS);
      }
      tick();
    });
  }

  function collectSongRows() {
    var doc = getPlaylistDocument();
    var selectors = ['#song-list tbody tr', '.m-table tbody tr', 'table.m-table-1 tbody tr'];
    var rows = [];
    for (var s = 0; s < selectors.length; s++) {
      var found = doc.querySelectorAll(selectors[s]);
      if (found && found.length) {
        for (var i = 0; i < found.length; i++) rows.push(found[i]);
        break;
      }
    }
    return rows;
  }

  /** 点击行内播放按钮触发播放 */
  function playRow(row) {
    try {
      row.scrollIntoView({ block: 'center', behavior: 'instant' });
    } catch (e) {
      try {
        row.scrollIntoView(true);
      } catch (e2) {}
    }
    var ply =
      row.querySelector('span.ply[data-res-action="play"]') ||
      row.querySelector('span[data-res-action="play"].ply') ||
      row.querySelector('.ply');
    if (ply) {
      ply.click();
      return true;
    }
    try {
      row.dispatchEvent(new MouseEvent('dblclick', { bubbles: true, cancelable: true }));
      return true;
    } catch (e) {
      return false;
    }
  }

  function sanitizeFilePart(s) {
    if (!s) return '';
    return String(s)
      .replace(/[\\/:*?"<>|]/g, '_')
      .replace(/\s+/g, ' ')
      .trim();
  }

  function shouldPreferPopupHelper(url) {
    return isNeteaseMediaUrl(url);
  }

  function triggerDirectDownload(url, filename, onDone) {
    filename = filename || 'audio.m4a';
    onDone = onDone || function () {};
    var fn = normalizeFilenameForDownload(filename);
    function done() {
      try {
        onDone();
      } catch (e) {}
    }
    function anchorFallback(doneAfter) {
      var a = document.createElement('a');
      a.href = url;
      a.setAttribute('download', fn);
      a.rel = 'noopener noreferrer';
      a.style.display = 'none';
      document.body.appendChild(a);
      a.click();
      document.body.removeChild(a);
      setTimeout(function () {
        if (typeof doneAfter === 'function') doneAfter();
      }, 900);
    }
    function xhrThenFallback(doneAfter) {
      gmFetchBlobAsBlob(url)
        .then(function (blob) {
          triggerBlobDownload(blob, fn);
          if (typeof doneAfter === 'function') doneAfter();
        })
        .catch(function (e) {
          console.warn('[NetEaseDL] GM XHR 拉取失败，改用本页下载:', e);
          anchorFallback(doneAfter);
        });
    }
    if (typeof GM_download === 'function') {
      try {
        GM_download({
          url: url,
          name: fn,
          saveAs: false,
          headers: {
            Referer: 'https://music.163.com/',
            Origin: 'https://music.163.com',
          },
          onload: function () {
            console.log('[NetEaseDL] GM_download 直链任务已结束');
          },
          onerror: function () {
            console.warn('[NetEaseDL] GM_download 直链失败，改用 XHR 整包拉取（可能较慢）');
            xhrThenFallback();
          },
        });
        done();
        return;
      } catch (e) {
        console.warn('[NetEaseDL] GM_download 直链异常:', e);
      }
    }
    xhrThenFallback(done);
  }

  /**
   * 优先 GM_download 使用 CDN 直链：由扩展/浏览器后台拉取，脚本不必等整文件进内存即可进入下一首。
   * 若 GM_download 不可用或失败，再退回 GM_xmlhttpRequest+arraybuffer（会随文件大小卡住，易达数十秒）。
   */
  function triggerMediaDownload(url, filename, onDone) {
    filename = filename || 'audio.m4a';
    onDone = onDone || function () {};
    var fn = normalizeFilenameForDownload(filename);
    if (shouldPreferPopupHelper(url)) {
      var opened = triggerMediaDownloadFallback(url, fn, onDone, { allowAnchorFallback: false });
      if (opened) {
        console.log('[NetEaseDL] 已转交 CDN 子窗口辅助下载:', fn);
        return;
      }
      console.warn('[NetEaseDL] CDN 子窗口未能打开，退回直链/Blob 下载:', fn);
    }
    triggerDirectDownload(url, fn, onDone);
  }

  function triggerMediaDownloadFallback(url, filename, onDone, opts) {
    opts = opts || {};
    onDone = onDone || function () {};
    var w = null;
    try {
      w = window.open('', '_blank');
    } catch (e) {}
    if (!w) {
      if (opts.allowAnchorFallback === false) {
        return false;
      }
      console.warn('[NetEaseDL] 无法 window.open，改用本页 <a download>');
      var a = document.createElement('a');
      a.href = url;
      a.setAttribute('download', filename);
      a.rel = 'noopener noreferrer';
      a.style.display = 'none';
      document.body.appendChild(a);
      a.click();
      document.body.removeChild(a);
      setTimeout(onDone, 900);
      return true;
    }
    var finished = false;
    var mediaEl = null;
    function finish() {
      if (finished) return;
      finished = true;
      try {
        window.removeEventListener('message', onPopupMessage);
      } catch (e) {}
      try {
        clearInterval(poll);
      } catch (e2) {}
      try {
        clearTimeout(tmo);
      } catch (e3) {}
      try {
        if (mediaEl) {
          mediaEl.pause();
          mediaEl.removeAttribute('src');
          mediaEl.load();
        }
      } catch (e4) {}
      try {
        if (w && !w.closed) w.close();
      } catch (e5) {}
      onDone();
    }
    function tryStartDownload() {
      if (finished || !mediaEl) return;
      var resolvedUrl = '';
      try {
        resolvedUrl = mediaEl.currentSrc || mediaEl.src || '';
      } catch (e) {}
      if (!resolvedUrl || !isNeteaseMediaUrl(resolvedUrl)) return;
      console.log('[NetEaseDL] 子窗口 video 已就绪，父页开始下载:', filename);
      triggerDirectDownload(resolvedUrl, filename, finish);
    }
    function syncPopupMediaState() {
      if (!mediaEl) return;
      try {
        mediaEl.muted = true;
        mediaEl.defaultMuted = true;
        mediaEl.volume = 0;
        mediaEl.autoplay = true;
        mediaEl.controls = true;
        mediaEl.setAttribute('muted', 'muted');
        mediaEl.playsInline = true;
      } catch (e) {}
    }
    function onMediaError() {
      if (finished) return;
      console.warn('[NetEaseDL] 子窗口 video 加载失败，退回父页直接下载:', filename);
      triggerDirectDownload(url, filename, finish);
    }
    function onMediaReady() {
      tryStartDownload();
    }
    try {
      var doc = w.document;
      doc.open();
      doc.write(
        '<!doctype html><html><head><meta charset="utf-8"><title>' +
          normalizeFilenameForDownload(filename) +
          '</title><style>html,body{margin:0;background:#000;color:#fff;font-family:system-ui,sans-serif;height:100%;display:flex;align-items:center;justify-content:center}video,audio{max-width:100vw;max-height:100vh;background:#000}p{position:fixed;top:10px;left:12px;margin:0;font-size:12px;color:#aaa}</style></head><body><p>正在静音解析媒体...</p><video id="netease-m4a-popup-media" muted autoplay playsinline controls></video></body></html>'
      );
      doc.close();
      mediaEl = doc.getElementById('netease-m4a-popup-media');
      if (!mediaEl) throw new Error('popup-media-missing');
      syncPopupMediaState();
      mediaEl.addEventListener('loadedmetadata', onMediaReady);
      mediaEl.addEventListener('loadeddata', onMediaReady);
      mediaEl.addEventListener('canplay', onMediaReady);
      mediaEl.addEventListener('error', onMediaError);
      mediaEl.src = url;
      try {
        mediaEl.load();
      } catch (e6) {}
      try {
        var playPromise = mediaEl.play();
        if (playPromise && typeof playPromise.catch === 'function') {
          playPromise.catch(function () {});
        }
      } catch (e7) {}
    } catch (e8) {
      try {
        if (w && !w.closed) w.close();
      } catch (e9) {}
      if (opts.allowAnchorFallback === false) {
        return false;
      }
      console.warn('[NetEaseDL] 子窗口辅助页初始化失败，改用本页下载:', e8);
      triggerDirectDownload(url, filename, onDone);
      return true;
    }
    function onPopupMessage(e) {
      if (e.data && e.data.type === MSG_DL_DONE) {
        if (e.data.src) {
          triggerDirectDownload(e.data.src, filename, finish);
          return;
        }
        finish();
      }
    }
    window.addEventListener('message', onPopupMessage, false);
    var poll = setInterval(function () {
      try {
        syncPopupMediaState();
        tryStartDownload();
        if (w.closed) finish();
      } catch (e) {
        finish();
      }
    }, 450);
    var tmo = setTimeout(function () {
      if (finished) return;
      console.warn('[NetEaseDL] 子窗口解析超时，退回父页直接下载:', filename);
      triggerDirectDownload(url, filename, finish);
    }, 12000);
    return true;
  }

  function confirmSkipOrAbort(reason) {
    var msg =
      reason + '\n\n是否跳过当前曲目并继续下一首？\n「确定」= 跳过\n「取消」= 结束全部任务';
    return window.confirm(msg);
  }

  /**
   * 自动模式：逐首播放 → 等新 URL → 元数据 OK → 下载 OK → 再下一首
   */
  function runAutoPlaylistDownload(opts) {
    opts = opts || {};
    var emitProgress = function (ev) {
      if (typeof opts.onProgress === 'function') {
        try {
          opts.onProgress(ev);
        } catch (e) {
          console.warn('[NetEaseDL] onProgress:', e);
        }
      }
    };
    var waitBetweenTracks =
      typeof opts.waitBetweenTracks === 'function'
        ? opts.waitBetweenTracks
        : function () {
            return Promise.resolve();
          };
    var shouldCancel = opts.isCancelled || function () {
      return false;
    };
    var perTrackAttempts = typeof opts.perTrackAttempts === 'number' ? opts.perTrackAttempts : 1;
    var betweenMs = typeof opts.betweenMs === 'number' ? opts.betweenMs : BETWEEN_TRACK_MS;
    var afterPlayMs = typeof opts.afterPlaySettleMs === 'number' ? opts.afterPlaySettleMs : AFTER_PLAY_SETTLE_MS;

    var rows = collectSongRows();
    if (!rows.length) {
      window.alert('未找到歌单列表行，请在歌单页使用（列表需已加载）。');
      return Promise.reject(new Error('无歌单行'));
    }

    var n = rows.length;
    var startIndex = typeof opts.startIndex === 'number' ? opts.startIndex : 0;
    if (startIndex < 0) startIndex = 0;
    if (startIndex >= n) {
      window.alert('起始曲目超出歌单范围。');
      return Promise.reject(new Error('起始曲目超范围'));
    }
    var lastDownloadedUrl = null;
    emitProgress({ phase: 'start', total: n - startIndex, startIndex: startIndex + 1 });

    function runTrack(index) {
      if (shouldCancel()) {
        emitProgress({ phase: 'done' });
        return Promise.resolve();
      }
      if (index >= n) {
        emitProgress({ phase: 'done' });
        console.log('[NetEaseDL] 自动队列全部完成。');
        return Promise.resolve();
      }

      var row = rows[index];
      var idxLabel = index + 1 + '/' + n;
      var attempt = 0;

      function tryOnce() {
        if (shouldCancel()) {
          emitProgress({ phase: 'done' });
          return Promise.resolve();
        }
        attempt++;
        var preClickUrls = collectCurrentMediaUrls();
        resetRecentMediaObservations();
        var startedAtTs = Date.now();
        var startedAtPerf = getPerfNow();
        if (!playRow(row)) {
          return Promise.reject(new Error('无法触发播放（未找到 .ply）'));
        }
        var ignoreUrls = [];
        if (lastDownloadedUrl) ignoreUrls.push(lastDownloadedUrl);
        if (preClickUrls.length) ignoreUrls = ignoreUrls.concat(preClickUrls);
        return delay(afterPlayMs)
          .then(function () {
            return waitForNewMediaUrl(ignoreUrls, URL_WAIT_MS, {
              minTs: startedAtTs,
              minPerfNow: startedAtPerf,
            });
          })
          .then(function (mediaUrl) {
            if (!isNeteaseMediaUrl(mediaUrl)) {
              throw new Error('拦截到的地址格式非预期 m4a CDN');
            }
            if (
              lastDownloadedUrl &&
              normalizeNeteaseMediaUrlKey(mediaUrl) === normalizeNeteaseMediaUrlKey(lastDownloadedUrl)
            ) {
              throw new Error('拦截到的仍是上一首的媒体地址（与 lastDownloaded 同资源），将重试');
            }
            var meta = parseRowMeta(row) || { title: '', artist: '' };
            console.log(
              '[NetEaseDL]',
              idxLabel,
              metaOk(meta) ? meta.title + ' - ' + meta.artist : '（将用歌单序号命名）',
              '\n',
              mediaUrl
            );
            var name = buildDownloadFilename(meta, index + 1, n);
            lastDownloadedUrl = mediaUrl;
            emitProgress({
              phase: 'track',
              index: index + 1,
              total: n,
              title: meta.title || '—',
              artist: meta.artist || '—',
              status: '进行中',
            });
            return new Promise(function (r) {
              triggerMediaDownload(mediaUrl, name, function () {
                console.log('[NetEaseDL] 本首下载流程结束:', name);
                emitProgress({
                  phase: 'track',
                  index: index + 1,
                  total: n,
                  title: meta.title || '—',
                  artist: meta.artist || '—',
                  status: '成功',
                });
                setTimeout(function () {
                  waitBetweenTracks().then(function () {
                    if (shouldCancel()) {
                      emitProgress({ phase: 'done' });
                      r();
                      return;
                    }
                    r(runTrack(index + 1));
                  });
                }, betweenMs);
              });
            });
          })
          .catch(function (err) {
            console.error('[NetEaseDL] 第 ' + idxLabel + ' 首尝试 ' + attempt + ' 失败:', err);
            if (attempt >= perTrackAttempts) {
              var mmFail = parseRowMeta(row) || { title: '', artist: '' };
              emitProgress({
                phase: 'track',
                index: index + 1,
                total: n,
                title: mmFail.title || '—',
                artist: mmFail.artist || '—',
                status: '失败',
                detail: (err && err.message) || String(err),
              });
            }
            if (attempt < perTrackAttempts) {
              return new Promise(function (r) {
                setTimeout(function () {
                  if (shouldCancel()) {
                    emitProgress({ phase: 'done' });
                    r(Promise.resolve());
                    return;
                  }
                  r(tryOnce());
                }, 1500);
              });
            }
            console.warn(
              '[NetEaseDL] 第 ' + idxLabel + ' 首多次重试仍失败，将自动跳过:',
              (err && err.message) || String(err)
            );
            return new Promise(function (r) {
              setTimeout(function () {
                if (shouldCancel()) {
                  emitProgress({ phase: 'done' });
                  r();
                  return;
                }
                r(runTrack(index + 1));
              }, betweenMs);
            });
          });
      }

      return tryOnce();
    }

    return runTrack(startIndex);
  }

  /**
   * 粘贴 URL 模式：与自动模式相同的进度事件与 GM Blob / GM_download 保存
   */
  function runDownload(urls, opts) {
    opts = opts || {};
    var delayMs = typeof opts.delayMs === 'number' ? opts.delayMs : 800;
    var waitBetweenTracks =
      typeof opts.waitBetweenTracks === 'function'
        ? opts.waitBetweenTracks
        : function () {
            return Promise.resolve();
          };
    var shouldCancel = opts.isCancelled || function () {
      return false;
    };
    function emitProgress(ev) {
      if (typeof opts.onProgress === 'function') {
        try {
          opts.onProgress(ev);
        } catch (e) {
          console.warn('[NetEaseDL] onProgress:', e);
        }
      }
    }
    var rows = collectSongRows();
    if (!rows.length) {
      window.alert('未找到歌单列表行，请确认在「网页版歌单」页面且列表已加载（若在 iframe 内需同域）。');
      return Promise.reject(new Error('无歌单行'));
    }
    if (!urls.length) {
      window.alert('URL 列表为空。');
      return Promise.reject(new Error('无 URL'));
    }
    var n = Math.min(urls.length, rows.length);
    if (urls.length !== rows.length) {
      console.warn(
        '[NetEaseDL] URL 行数(' + urls.length + ')与列表行数(' + rows.length + ')不一致，将只处理前 ' + n + ' 条。'
      );
    }
    var startIndex = typeof opts.startIndex === 'number' ? opts.startIndex : 0;
    if (startIndex < 0) startIndex = 0;
    if (startIndex >= n) {
      window.alert('起始曲目超出可处理范围。');
      return Promise.reject(new Error('起始曲目超范围'));
    }

    emitProgress({ phase: 'start', total: n - startIndex, startIndex: startIndex + 1 });

    function runTrack(i) {
      if (shouldCancel()) {
        emitProgress({ phase: 'done' });
        return Promise.resolve();
      }
      if (i >= n) {
        emitProgress({ phase: 'done' });
        console.log('[NetEaseDL] 全部队列处理完毕。');
        return Promise.resolve();
      }
      var url = urls[i].trim();
      var row = rows[i];
      var meta = parseRowMeta(row) || { title: '', artist: '' };
      var idxLabel = i + 1 + '/' + n;
      emitProgress({
        phase: 'track',
        index: i + 1,
        total: n,
        title: meta.title || '—',
        artist: meta.artist || '—',
        status: '进行中',
      });
      if (!metaOk(meta)) {
        console.warn('[NetEaseDL] 第 ' + idxLabel + ' 首：歌名/歌手不完整，将用歌单序号命名');
      } else {
        console.log('[NetEaseDL] 第 ' + idxLabel + ' 首 — 歌名:', meta.title, '歌手:', meta.artist);
      }

      if (!url || url.indexOf('http') !== 0) {
        console.error('[NetEaseDL] 无效 URL:', url);
        emitProgress({
          phase: 'track',
          index: i + 1,
          total: n,
          title: meta.title || '—',
          artist: meta.artist || '—',
          status: '失败',
          detail: '无效 URL',
        });
        console.warn('[NetEaseDL] 第 ' + idxLabel + ' 首 URL 无效，将自动跳过。');
        return delay(delayMs)
          .then(function () {
            return waitBetweenTracks();
          })
          .then(function () {
            return runTrack(i + 1);
          });
      }

      var name = buildDownloadFilename(meta, i + 1, n);
      return new Promise(function (resolve) {
        try {
          triggerMediaDownload(url, name, function () {
            console.log('[NetEaseDL] 粘贴模式本首结束:', name);
            emitProgress({
              phase: 'track',
              index: i + 1,
              total: n,
              title: meta.title || '—',
              artist: meta.artist || '—',
              status: '成功',
            });
            setTimeout(function () {
              waitBetweenTracks().then(function () {
                resolve(runTrack(i + 1));
              });
            }, delayMs);
          });
        } catch (err) {
          console.error('[NetEaseDL] 触发下载失败:', err);
          emitProgress({
            phase: 'track',
            index: i + 1,
            total: n,
            title: meta.title || '—',
            artist: meta.artist || '—',
            status: '失败',
            detail: (err && err.message) || String(err),
          });
          console.warn(
            '[NetEaseDL] 第 ' + idxLabel + ' 首触发下载异常，将自动跳过:',
            (err && err.message) || String(err)
          );
          delay(delayMs)
            .then(function () {
              return waitBetweenTracks();
            })
            .then(function () {
              resolve(runTrack(i + 1));
            });
        }
      });
    }

    return runTrack(startIndex);
  }

  function parseUrlsText(text) {
    return String(text)
      .split(/\r?\n/)
      .map(function (l) {
        return l.trim();
      })
      .filter(function (l) {
        return /^https?:\/\//i.test(l);
      });
  }

  function normalizeStartIndexInput(rawValue, maxTotal) {
    var n = parseInt(rawValue, 10);
    if (isNaN(n) || n < 1) n = 1;
    if (typeof maxTotal === 'number' && maxTotal > 0 && n > maxTotal) n = maxTotal;
    return n;
  }

  function mountUi() {
    if (document.getElementById('netease-m4a-dl-root')) return;

    GM_addStyle(
      [
        '#netease-m4a-dl-root{font-family:system-ui,-apple-system,sans-serif;z-index:2147483646;}',
        '#netease-m4a-dl-toggle{position:fixed;right:16px;bottom:16px;z-index:2147483647;padding:10px 14px;border:none;border-radius:20px;background:#ec4141;color:#fff;font-size:13px;cursor:pointer;box-shadow:0 2px 10px rgba(0,0,0,.2);}',
        '#netease-m4a-dl-toggle:hover{filter:brightness(1.05);}',
        '#netease-m4a-dl-panel{position:fixed;right:16px;bottom:56px;z-index:2147483647;width:min(440px,calc(100vw - 32px));max-height:78vh;display:none;flex-direction:column;min-height:0;background:#1e1e1e;color:#e8e8e8;border-radius:10px;box-shadow:0 8px 32px rgba(0,0,0,.35);overflow:hidden;}',
        '#netease-m4a-dl-panel.netease-m4a-dl-open{display:flex;}',
        '#netease-m4a-dl-head{display:flex;align-items:center;justify-content:space-between;padding:12px 14px;background:#2a2a2a;border-bottom:1px solid #333;}',
        '#netease-m4a-dl-head h2{margin:0;font-size:15px;font-weight:600;}',
        '#netease-m4a-dl-ver{font-size:11px;color:#999;margin-left:8px;}',
        '#netease-m4a-dl-close{background:transparent;border:none;color:#aaa;font-size:18px;line-height:1;cursor:pointer;padding:4px 8px;}',
        '#netease-m4a-dl-close:hover{color:#fff;}',
        '#netease-m4a-dl-body{flex:1;min-height:0;padding:12px 14px;display:flex;flex-direction:column;gap:10px;overflow:hidden;}',
        '#netease-m4a-dl-hint{margin:0;font-size:12px;color:#aaa;line-height:1.5;}',
        '#netease-m4a-dl-ta{width:100%;min-height:72px;box-sizing:border-box;padding:10px;border:1px solid #444;border-radius:6px;background:#111;color:#eee;font-size:11px;line-height:1.35;resize:vertical;}',
        '#netease-m4a-dl-row{display:flex;align-items:center;gap:8px;flex-wrap:wrap;}',
        '#netease-m4a-dl-delay,#netease-m4a-dl-start-index{width:72px;padding:6px 8px;border:1px solid #444;border-radius:6px;background:#111;color:#eee;font-size:12px;}',
        '#netease-m4a-dl-start,#netease-m4a-dl-auto{flex:1;min-width:88px;padding:10px 12px;border:none;border-radius:8px;background:#ec4141;color:#fff;font-size:13px;font-weight:600;cursor:pointer;}',
        '#netease-m4a-dl-stop,#netease-m4a-dl-pause{padding:10px 12px;border:none;border-radius:8px;background:#555;color:#eee;font-size:13px;cursor:pointer;}',
        '#netease-m4a-dl-resume{padding:10px 12px;border:none;border-radius:8px;background:#2d5a2d;color:#eee;font-size:13px;cursor:pointer;}',
        '#netease-m4a-dl-start:disabled,#netease-m4a-dl-auto:disabled,.netease-m4a-dl-muted{opacity:.55;cursor:not-allowed;}',
        '#netease-m4a-dl-status{margin:0;font-size:12px;color:#7cb342;min-height:1.2em;}',
        '#netease-m4a-dl-stat{margin:0;font-size:12px;color:#ccc;line-height:1.6;}',
        '#netease-m4a-dl-stat span{font-weight:600;color:#fff;}',
        '#netease-m4a-dl-list-wrap{flex:1;min-height:120px;max-height:36vh;overflow:auto;border:1px solid #333;border-radius:6px;background:#111;}',
        '#netease-m4a-dl-list{margin:0;padding:0;list-style:none;font-size:12px;}',
        '#netease-m4a-dl-list li{padding:8px 10px;border-bottom:1px solid #2a2a2a;line-height:1.45;}',
        '#netease-m4a-dl-list li:last-child{border-bottom:none;}',
        '.netease-m4a-dl-st-ok{color:#7cb342;}',
        '.netease-m4a-dl-st-fail{color:#e57373;}',
        '.netease-m4a-dl-st-run{color:#ffb74d;}',
        '.netease-m4a-dl-st-wait{color:#888;}',
      ].join('')
    );

    var root = document.createElement('div');
    root.id = 'netease-m4a-dl-root';
    root.innerHTML =
      '<button type="button" id="netease-m4a-dl-toggle" title="网易云歌单 M4A">M4A 下载</button>' +
      '<div id="netease-m4a-dl-panel">' +
      '<div id="netease-m4a-dl-head">' +
      '<div style="display:flex;align-items:baseline;gap:8px"><h2>歌单 M4A</h2><span id="netease-m4a-dl-ver">v' +
      SCRIPT_VERSION +
      '</span></div>' +
      '<button type="button" id="netease-m4a-dl-close" aria-label="关闭">×</button>' +
      '</div>' +
      '<div id="netease-m4a-dl-body">' +
      '<p id="netease-m4a-dl-hint">当前脚本版本 v' +
      SCRIPT_VERSION +
      '。下载优先使用 GM 拉取音频后保存（中文文件名）；失败时可能打开 CDN 子页或本页直链，请允许弹窗。</p>' +
      '<div class="netease-m4a-dl-row">' +
      '<label for="netease-m4a-dl-start-index">从第几首</label>' +
      '<input id="netease-m4a-dl-start-index" type="number" min="1" step="1" value="1" />' +
      '</div>' +
      '<div class="netease-m4a-dl-row">' +
      '<button type="button" id="netease-m4a-dl-auto">自动播放并下载</button>' +
      '<button type="button" id="netease-m4a-dl-pause" style="display:none">暂停</button>' +
      '<button type="button" id="netease-m4a-dl-resume" style="display:none" disabled>继续</button>' +
      '<button type="button" id="netease-m4a-dl-stop" style="display:none">停止</button>' +
      '</div>' +
      '<p style="margin:0;font-size:12px;color:#888">备用：粘贴 URL 与歌单行配对下载</p>' +
      '<textarea id="netease-m4a-dl-ta" placeholder="（可选）粘贴 urls.text…" spellcheck="false"></textarea>' +
      '<div class="netease-m4a-dl-row">' +
      '<label for="netease-m4a-dl-delay">间隔(ms)</label>' +
      '<input id="netease-m4a-dl-delay" type="number" min="0" max="60000" step="100" value="800" />' +
      '<button type="button" id="netease-m4a-dl-start">粘贴 URL 下载</button>' +
      '</div>' +
      '<p id="netease-m4a-dl-stat">下载总数 <span id="netease-m4a-dl-stat-total">0</span>　剩余 <span id="netease-m4a-dl-stat-rem">0</span>　成功 <span id="netease-m4a-dl-stat-ok">0</span>　失败 <span id="netease-m4a-dl-stat-fail">0</span></p>' +
      '<div id="netease-m4a-dl-list-wrap"><ul id="netease-m4a-dl-list"></ul></div>' +
      '<p id="netease-m4a-dl-status"></p>' +
      '</div></div>';

    document.body.appendChild(root);

    var panel = document.getElementById('netease-m4a-dl-panel');
    var toggle = document.getElementById('netease-m4a-dl-toggle');
    var closeBtn = document.getElementById('netease-m4a-dl-close');
    var ta = document.getElementById('netease-m4a-dl-ta');
    var delayInput = document.getElementById('netease-m4a-dl-delay');
    var startIndexInput = document.getElementById('netease-m4a-dl-start-index');
    var startBtn = document.getElementById('netease-m4a-dl-start');
    var autoBtn = document.getElementById('netease-m4a-dl-auto');
    var stopBtn = document.getElementById('netease-m4a-dl-stop');
    var pauseBtn = document.getElementById('netease-m4a-dl-pause');
    var resumeBtn = document.getElementById('netease-m4a-dl-resume');
    var statusEl = document.getElementById('netease-m4a-dl-status');
    var statTotalEl = document.getElementById('netease-m4a-dl-stat-total');
    var statRemEl = document.getElementById('netease-m4a-dl-stat-rem');
    var statOkEl = document.getElementById('netease-m4a-dl-stat-ok');
    var statFailEl = document.getElementById('netease-m4a-dl-stat-fail');
    var listEl = document.getElementById('netease-m4a-dl-list');

    var taskCancelled = false;
    var queuePaused = false;
    var resumeWait = null;
    var dlTotal = 0;
    var dlStartIndex = 1;
    var dlEndIndex = 0;
    var dlSuccess = 0;
    var dlFail = 0;
    var terminalByIndex = {};
    var trackByIndex = {};

    function renderStats() {
      var rem = dlTotal - dlSuccess - dlFail;
      if (rem < 0) rem = 0;
      statTotalEl.textContent = String(dlTotal);
      statRemEl.textContent = String(rem);
      statOkEl.textContent = String(dlSuccess);
      statFailEl.textContent = String(dlFail);
    }

    function statusClass(st) {
      if (st === '成功') return 'netease-m4a-dl-st-ok';
      if (st === '失败') return 'netease-m4a-dl-st-fail';
      if (st === '进行中') return 'netease-m4a-dl-st-run';
      return 'netease-m4a-dl-st-wait';
    }

    function renderList() {
      var html = '';
      var i;
      var start = dlStartIndex;
      var end = dlEndIndex >= dlStartIndex ? dlEndIndex : dlStartIndex + dlTotal - 1;
      for (i = start; i <= end; i++) {
        var tr = trackByIndex[i];
        var title = tr && tr.title ? tr.title : '—';
        var artist = tr && tr.artist ? tr.artist : '—';
        var st = (tr && tr.status) || '等待中';
        html +=
          '<li>' +
          title +
          ' - ' +
          artist +
          ' - <span class="' +
          statusClass(st) +
          '">' +
          st +
          '</span></li>';
      }
      listEl.innerHTML = html;
    }

    function resetTaskPanel() {
      dlTotal = 0;
      dlSuccess = 0;
      dlFail = 0;
      terminalByIndex = {};
      trackByIndex = {};
      renderStats();
      listEl.innerHTML = '';
    }

    function handleDownloadProgress(ev) {
      if (!ev) return;
      if (ev.phase === 'start') {
        dlTotal = typeof ev.total === 'number' ? ev.total : 0;
        dlStartIndex = typeof ev.startIndex === 'number' ? ev.startIndex : 1;
        dlEndIndex = dlTotal > 0 ? dlStartIndex + dlTotal - 1 : 0;
        dlSuccess = 0;
        dlFail = 0;
        terminalByIndex = {};
        trackByIndex = {};
        renderStats();
        renderList();
        return;
      }
      if (ev.phase === 'done') {
        queuePaused = false;
        resumeWait = null;
        pauseBtn.style.display = 'none';
        resumeBtn.style.display = 'none';
        resumeBtn.disabled = true;
        return;
      }
      if (ev.phase === 'track') {
        var idx = ev.index;
        trackByIndex[idx] = {
          title: ev.title || '—',
          artist: ev.artist || '—',
          status: ev.status || '—',
        };
        var st = ev.status;
        if (st === '成功') {
          if (terminalByIndex[idx] !== '成功') {
            if (terminalByIndex[idx] === '失败') dlFail--;
            terminalByIndex[idx] = '成功';
            dlSuccess++;
          }
        } else if (st === '失败') {
          if (terminalByIndex[idx] !== '失败') {
            if (terminalByIndex[idx] === '成功') dlSuccess--;
            terminalByIndex[idx] = '失败';
            dlFail++;
          }
        }
        renderStats();
        renderList();
      }
    }

    function waitBetweenTracks() {
      return new Promise(function (resolve) {
        if (!queuePaused) {
          resolve();
          return;
        }
        resumeWait = resolve;
      });
    }

    function flushResume() {
      if (resumeWait) {
        var r = resumeWait;
        resumeWait = null;
        r();
      }
    }

    function setOpen(open) {
      if (open) panel.classList.add('netease-m4a-dl-open');
      else panel.classList.remove('netease-m4a-dl-open');
    }

    toggle.addEventListener('click', function () {
      setOpen(!panel.classList.contains('netease-m4a-dl-open'));
    });
    closeBtn.addEventListener('click', function () {
      setOpen(false);
    });

    function setBusy(isBusy) {
      startBtn.disabled = isBusy;
      autoBtn.disabled = isBusy;
      startIndexInput.disabled = isBusy;
      stopBtn.style.display = isBusy ? 'inline-block' : 'none';
      pauseBtn.style.display = isBusy ? 'inline-block' : 'none';
      if (!isBusy) {
        pauseBtn.style.display = 'none';
        resumeBtn.style.display = 'none';
        resumeBtn.disabled = true;
        queuePaused = false;
        flushResume();
      } else {
        syncPauseUi();
      }
    }

    function syncPauseUi() {
      pauseBtn.disabled = queuePaused;
      resumeBtn.style.display = queuePaused ? 'inline-block' : 'none';
      resumeBtn.disabled = !queuePaused;
    }

    pauseBtn.addEventListener('click', function () {
      if (!queuePaused) {
        queuePaused = true;
        if (statusEl) {
          statusEl.style.color = '#ffb74d';
          statusEl.textContent = '已暂停：当前曲目完成后，将在进入下一首前等待。';
        }
        syncPauseUi();
      }
    });

    resumeBtn.addEventListener('click', function () {
      queuePaused = false;
      if (statusEl) {
        statusEl.style.color = '#7cb342';
        statusEl.textContent = '已继续。';
      }
      syncPauseUi();
      flushResume();
    });

    stopBtn.addEventListener('click', function () {
      taskCancelled = true;
      queuePaused = false;
      flushResume();
      if (statusEl) {
        statusEl.style.color = '#ffb74d';
        statusEl.textContent = '已请求停止：本首若仍在进行会尽量完成，完成后不再继续下一首。';
      }
      syncPauseUi();
    });

    autoBtn.addEventListener('click', function () {
      var totalRows = collectSongRows().length;
      var startTrackNo = normalizeStartIndexInput(startIndexInput.value, totalRows);
      startIndexInput.value = String(startTrackNo);
      if (!window.confirm('将从第 ' + startTrackNo + ' 首开始自动播放并下载，请保持页面未静音且网络稳定。是否继续？')) return;
      taskCancelled = false;
      queuePaused = false;
      resetTaskPanel();
      setBusy(true);
      if (statusEl) {
        statusEl.style.color = '#7cb342';
        statusEl.textContent = '自动模式运行中…';
      }
      setTimeout(function () {
        runAutoPlaylistDownload({
          startIndex: startTrackNo - 1,
          betweenMs: BETWEEN_TRACK_MS,
          afterPlaySettleMs: AFTER_PLAY_SETTLE_MS,
          onProgress: handleDownloadProgress,
          waitBetweenTracks: waitBetweenTracks,
          isCancelled: function () {
            return taskCancelled;
          },
        })
          .then(function () {
            if (statusEl) {
              statusEl.style.color = '#7cb342';
              statusEl.textContent = taskCancelled ? '已停止。' : '自动任务已结束。';
            }
          })
          .catch(function (e) {
            if (statusEl) {
              statusEl.style.color = '#e57373';
              statusEl.textContent = '已停止：' + ((e && e.message) || String(e));
            }
          })
          .finally(function () {
            setBusy(false);
            handleDownloadProgress({ phase: 'done' });
          });
      }, 0);
    });

    startBtn.addEventListener('click', function () {
      var urls = parseUrlsText(ta.value);
      var delayMs = parseInt(delayInput.value, 10);
      var startTrackNo = normalizeStartIndexInput(startIndexInput.value, urls.length);
      startIndexInput.value = String(startTrackNo);
      if (statusEl) statusEl.textContent = '';
      if (!urls.length) {
        window.alert('请先粘贴至少一行以 http 开头的 media URL。');
        return;
      }
      taskCancelled = false;
      queuePaused = false;
      resetTaskPanel();
      setBusy(true);
      if (statusEl) {
        statusEl.style.color = '#7cb342';
        statusEl.textContent = '粘贴模式：准备下载 ' + urls.length + ' 条…';
      }
      setTimeout(function () {
        runDownload(urls, {
          startIndex: startTrackNo - 1,
          delayMs: isNaN(delayMs) ? 800 : delayMs,
          onProgress: handleDownloadProgress,
          waitBetweenTracks: waitBetweenTracks,
          isCancelled: function () {
            return taskCancelled;
          },
        })
          .then(function () {
            if (statusEl) {
              statusEl.style.color = '#7cb342';
              statusEl.textContent = taskCancelled ? '已停止。' : '队列已结束。';
            }
          })
          .catch(function (e) {
            if (statusEl) {
              statusEl.style.color = '#e57373';
              statusEl.textContent = '已停止：' + ((e && e.message) || String(e));
            }
          })
          .finally(function () {
            setBusy(false);
            handleDownloadProgress({ phase: 'done' });
          });
      }, 0);
    });
  }

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