(function () {
  'use strict';
  if (window.YianQuestionBankExporter) return;
  const core = window.QuestionBankCore;
  const store = window.YianBankStore;
  const matcher = window.YianAnswerMatcher;
  const config = { autoAnswer: false, allowCopy: true, autoExport: true, role: '', course: '' };
  let snapshot = { records: [], counts: {}, total: 0, revision: '', storage: 'origin' };
  let loading = true, disposed = false, page = null, previous = null;
  let searchQuery = '', runKey = '', debounceTimer;
  const exported = new Set();
  const settleMs = 1200;
  const copy = window.YianCopyController.create();
  const emptyMetrics = () => ({ selected: 0, pending: 0, missing: 0, conflict: 0, locked: 0, failed: 0, unsupported: 0, total: 0 });
  let metrics = emptyMetrics();

  function routeInfo() {
    const original = location.protocol === 'file:' ? core.savedSourceURL(document) : '';
    const url = new URL(original || location.href);
    let params = url.searchParams;
    if (url.hash.startsWith('#/')) params = new URL(url.hash.slice(1), url.origin).searchParams;
    const root = document.querySelector('app-examtest, .pc_examtest');
    const mode = (params.get('flag') || '').toLowerCase();
    const marker = root && Array.from(root.querySelectorAll('.pc_examtest_commit'))
      .some(node => node.textContent.trim() === '重新练习' && !node.classList.contains('hidden'));
    const identity = new URL(location.href);
    identity.searchParams.delete('t');
    return { root, practice: !!root && (mode ? mode === 'exercise' : !!marker),
      local: location.protocol === 'file:', sourceUrl: url.href, key: identity.href,
      expectedTitle: mode === 'exercise' ? params.get('title') || '' : '', mode };
  }

  function structureSignature(bank) {
    return JSON.stringify([bank.title, bank.expectedTotal, bank.questions.map(q =>
      [q.number, q.type, q.question, q.options.map(option => [option.label, option.text, option.images])])]);
  }

  // 点击前现读上下文，阻断轮询尚未发现的路由、岗位、题目变化。
  function getContext() {
    const route = routeInfo();
    const bank = route.root ? core.extract(document, route.sourceUrl) : { title: '', questions: [] };
    const signature = route.root ? structureSignature(bank) : '';
    return { ready: !!page && page.ready && !loading && page.key === route.key
      && page.root === route.root && page.signature === signature,
      practice: route.practice, local: route.local, role: config.role, course: bank.title,
      sourceUrl: route.sourceUrl, routeKey: route.key, root: route.root,
      pageSignature: signature, revision: snapshot.revision, snapshot };
  }

  const runner = window.YianAnswerRunner.create({ getContext,
    match: (question, context) => matcher.match(question, context, snapshot),
    onProgress: progress => { metrics = progress; panel.setState({ metrics }); },
    onState: (state, reason) => {
      if (disposed) return;
      if (state === 'paused') { config.autoAnswer = false; runKey = ''; panel.setState({ autoAnswer: false }); }
      if (reason && (state === 'paused' || state === 'complete')) panel.setNotice(reason, state === 'paused' ? 'warning' : 'success');
    }
  });
  function courses() {
    return Array.from(new Set(snapshot.records.filter(record => record.role === config.role).map(record => record.course))).sort();
  }
  function refreshPanel(extra) {
    panel.setState(Object.assign({ autoAnswer: config.autoAnswer, allowCopy: config.allowCopy,
      autoExport: config.autoExport, role: config.role, course: config.course, courses: courses(),
      bankTotal: snapshot.total, roleCounts: snapshot.counts, storageMode: snapshot.storage, loading, metrics }, extra || {}));
  }
  function performSearch(query = searchQuery, options = {}) {
    searchQuery = String(query || '');
    const offset = options.offset || 0;
    const result = searchQuery.trim() ? matcher.search(searchQuery,
      { role: config.role, course: config.course, limit: 20, offset }, snapshot) : { items: [], total: 0 };
    panel.renderSearch(Object.assign({}, result, { offset }));
    if (!config.role && !options.quiet) panel.setNotice('请先选择主操、班长或副操。', 'warning');
    return result;
  }
  async function saveSetting(key, value) {
    try { await store.setSetting(key, value); }
    catch (error) { panel.setNotice('设置保存失败：' + error.message, 'error'); }
  }
  async function setRole(role) {
    if (!store.roles.includes(role)) throw new Error('请选择主操、班长或副操');
    runner.stop('岗位已切换'); config.role = role; config.course = ''; runKey = ''; metrics = emptyMetrics();
    refreshPanel(); performSearch(); tick(); await saveSetting('role', role); return role;
  }
  function setAutoAnswer(enabled) {
    const context = getContext();
    if (enabled && (!context.ready || !context.practice || context.local || !config.role || !snapshot.counts[config.role])) {
      panel.setNotice('请先导入所选岗位题库，并进入已加载完成的兼容练习页面。', 'warning'); refreshPanel(); return false;
    }
    config.autoAnswer = !!enabled; runKey = '';
    if (!enabled) runner.stop('自动选择已关闭，已生效的选择保留。');
    refreshPanel(); tick(); return config.autoAnswer;
  }
  function setCopy(enabled) {
    config.allowCopy = !!enabled; copy.setEnabled(config.allowCopy); refreshPanel(); saveSetting('allowCopy', config.allowCopy);
  }
  async function importFiles(files) {
    runner.stop('正在更新题库'); loading = true; runKey = ''; refreshPanel(); panel.setNotice('正在解析题库，请稍候…');
    try {
      snapshot = await store.importFiles(Array.from(files || []), { role: config.role });
      metrics = emptyMetrics(); config.course = '';
      panel.setNotice('题库导入成功：' + snapshot.total + ' 条记录。请选择岗位后搜索或自动选择。', 'success');
      return snapshot;
    } catch (error) {
      panel.setNotice('导入失败：' + error.message + '。原有题库保留。', 'error'); throw error;
    } finally { loading = false; refreshPanel(); performSearch(searchQuery, { quiet: true }); tick(); }
  }
  function exportCurrent(format = 'csv') {
    const route = routeInfo();
    if (!route.practice) throw new Error('请先进入支持的练习页面');
    const bank = core.extract(document, route.sourceUrl);
    if (!bank.total) throw new Error('页面题目尚未加载');
    core.download(bank, format);
    panel.setNotice((bank.complete ? '已发起下载：' : '已发起不完整题库下载：') + bank.title
      + '，' + bank.total + ' 题、' + bank.answered + ' 个答案。若没有文件，请点击导出按钮。', bank.complete ? 'success' : 'warning');
    return bank;
  }
  const panel = window.YianAssistantPanel.create({
    onAutoChange: setAutoAnswer, onCopyChange: setCopy,
    onRoleChange: role => { setRole(role).catch(error => panel.setNotice(error.message, 'error')); },
    onCourseChange: course => { config.course = course; performSearch(); },
    onImport: files => { importFiles(files).catch(() => {}); }, onSearch: performSearch,
    onSelectionSearch: text => performSearch(text),
    onExport: format => { try { exportCurrent(format); } catch (error) { panel.setNotice(error.message, 'error'); } },
    onAutoExportChange: enabled => { config.autoExport = !!enabled; saveSetting('autoExport', config.autoExport); tick(); }
  });

  function tick() {
    if (disposed) return;
    const route = routeInfo();
    if (!route.root) {
      if (runner.running) runner.stop('当前页面未识别到练习题目');
      if (page) previous = page;
      page = null;
      refreshPanel({ canAnswer: false, canExport: false, pageStatus: '当前网页可搜索题库和复制文字；未识别到支持的练习题目。' }); return;
    }
    const bank = core.extract(document, route.sourceUrl), signature = structureSignature(bank), now = Date.now();
    if (!page || page.key !== route.key || page.root !== route.root) {
      if (runner.running) runner.stop('页面已切换，旧任务已停止');
      const last = page || previous;
      page = { key: route.key, root: route.root, signature, since: now, ready: false,
        waiting: !!last && last.key !== route.key && last.root === route.root && last.signature === signature };
      runKey = ''; metrics = emptyMetrics(); refreshPanel({ expanded: true });
    }
    if (page.signature !== signature) {
      if (runner.running) runner.stop('题目内容已更新');
      page.signature = signature; page.since = now; page.waiting = false; runKey = ''; metrics = emptyMetrics();
    }
    const countComplete = bank.expectedTotal === null || bank.expectedTotal === bank.total;
    const titleReady = !route.expectedTitle || route.expectedTitle.trim() === bank.title.trim();
    page.ready = !!bank.total && countComplete && titleReady && !page.waiting && now - page.since >= settleMs;
    let status;
    if (!route.practice) status = '已识别题目，但未确认练习模式；自动选择和导出暂停。';
    else if (page.waiting || !titleReady) status = '等待本次练习的题目加载…';
    else if (!bank.total || now - page.since < settleMs) status = '正在读取题目与隐藏答案…';
    else if (!countComplete) status = '已读取 ' + bank.total + ' / ' + bank.expectedTotal + ' 题，等待全部加载。';
    else status = bank.title + '：' + bank.total + ' 题，' + (bank.missingAnswers.length
      ? '缺少 ' + bank.missingAnswers.length + ' 个网页答案；可用导入题库选择。' : '网页答案齐全。')
      + (route.local ? ' 保存网页支持搜索与导出；自动选择需要在线练习页面。' : '');
    refreshPanel({ pageStatus: status, canExport: route.practice && !!bank.total,
      canAnswer: route.practice && !route.local && page.ready && !loading && !!config.role && !!snapshot.counts[config.role] });
    if (!route.practice || !page.ready || loading) { if (runner.running) runner.stop('等待兼容练习页面准备完成'); return; }
    if (config.autoExport && bank.complete) {
      const key = route.key + '|' + signature;
      if (!exported.has(key)) {
        try { exportCurrent('csv'); exported.add(key); }
        catch (error) { config.autoExport = false; refreshPanel(); panel.setNotice('自动下载失败：' + error.message, 'error'); }
      }
    }
    const nextRunKey = route.key + '|' + signature + '|' + config.role + '|' + snapshot.revision;
    if (config.autoAnswer && config.role && snapshot.counts[config.role] && runKey !== nextRunKey && !runner.running) {
      runKey = nextRunKey;
      runner.start().catch(error => { config.autoAnswer = false; refreshPanel(); panel.setNotice('自动选择失败：' + error.message, 'error'); });
    }
  }
  const observer = new MutationObserver(records => {
    if (records.every(record => record.target === panel.host || panel.host.contains(record.target))) return;
    clearTimeout(debounceTimer); debounceTimer = setTimeout(tick, 200);
  });
  observer.observe(document.body, { childList: true, subtree: true, characterData: true, attributes: true, attributeFilter: ['class'] });
  const timer = setInterval(tick, 600);
  const onNavigation = () => { runner.stop('页面地址已变化'); runKey = ''; tick(); };
  window.addEventListener('popstate', onNavigation); window.addEventListener('hashchange', onNavigation);
  function dispose() {
    disposed = true; observer.disconnect(); clearInterval(timer); clearTimeout(debounceTimer);
    window.removeEventListener('popstate', onNavigation); window.removeEventListener('hashchange', onNavigation);
    runner.destroy(); copy.destroy(); panel.destroy();
  }
  const ready = (async () => {
    try {
      const values = await Promise.all([store.load(), store.getSetting('role', ''), store.getSetting('allowCopy', true), store.getSetting('autoExport', true)]);
      snapshot = values[0]; config.role = store.roles.includes(values[1]) ? values[1] : '';
      config.allowCopy = values[2] !== false; config.autoExport = values[3] !== false;
    } catch (error) { panel.setNotice('题库读取失败：' + error.message + '。可重新导入题库。', 'error'); }
    loading = false; copy.setEnabled(config.allowCopy); refreshPanel(); tick(); return snapshot;
  })();
  const api = Object.freeze({ ready, importFiles, setRole, setAutoAnswer, setCopy, search: performSearch, getContext,
    getSnapshot: () => snapshot, getState: () => ({ ...config, metrics, pageReady: !!page && page.ready }),
    exportCurrent, collectCurrent: () => core.extract(document, routeInfo().sourceUrl), stop: dispose });
  window.YianAssistant = api; window.YianQuestionBankExporter = api;
  refreshPanel(); tick();
})();