window.renderAdminHeader = async function renderAdminHeader() {
  const mount = document.getElementById('admin-header');
  if (!mount || mount.children.length) return;
  const scriptVersion = (() => {
    try {
      const script = document.querySelector('script[src*="/static/js/admin-header.js"]');
      if (!script) return 'v1';
      return new URL(script.src, window.location.href).searchParams.get('v') || 'v1';
    } catch {
      return 'v1';
    }
  })();
  const HEADER_HTML_CACHE_KEY = `grok2api.admin_header_html.${scriptVersion}`;
  const META_VERSION_CACHE_KEY = `grok2api.meta_version.${scriptVersion}`;
  let appVersion = '';
  let updateInfo = null;
  let updateStatus = 'idle';
  let updatePromise = null;

  const readSessionCache = (key) => {
    try {
      return sessionStorage.getItem(key) || '';
    } catch {
      return '';
    }
  };

  const writeSessionCache = (key, value) => {
    if (!value) return;
    try {
      sessionStorage.setItem(key, value);
    } catch {}
  };

  const languageCodes = {
    zh: 'CN',
    en: 'EN',
    ja: 'JA',
    es: 'ES',
    de: 'DE',
    fr: 'FR',
  };

  const initLanguageMenu = () => {
    const menu = mount.querySelector('#hd-lang-menu');
    const trigger = mount.querySelector('#hd-lang-trigger');
    const code = mount.querySelector('#hd-lang-code');
    const options = Array.from(mount.querySelectorAll('.admin-lang-option'));
    if (!menu || !trigger || !code || !options.length) return;

    const close = () => {
      menu.classList.remove('open');
      trigger.setAttribute('aria-expanded', 'false');
    };

    const sync = () => {
      const current = window.I18n?.getLang?.() || localStorage.getItem('grok2api_lang') || 'zh';
      code.textContent = languageCodes[current] || current.toUpperCase();
      options.forEach((option) => {
        option.classList.toggle('active', option.dataset.lang === current);
      });
    };

    trigger.addEventListener('click', (event) => {
      event.stopPropagation();
      const open = !menu.classList.contains('open');
      menu.classList.toggle('open', open);
      trigger.setAttribute('aria-expanded', open ? 'true' : 'false');
    });

    options.forEach((option) => {
      option.addEventListener('click', () => {
        const lang = option.dataset.lang;
        if (!lang) return;
        close();
        if (window.I18n?.setLang) {
          I18n.setLang(lang);
        } else {
          localStorage.setItem('grok2api_lang', lang);
          location.reload();
        }
      });
    });

    document.addEventListener('click', (event) => {
      const target = event.target;
      if (!(target instanceof Node) || !menu.contains(target)) close();
    });
    document.addEventListener('keydown', (event) => {
      if (event.key === 'Escape') close();
    });

    sync();
    return sync;
  };

  const applyHeaderI18n = () => {
    if (window.I18n?.apply) I18n.apply(mount);
    const trigger = mount.querySelector('#hd-lang-trigger');
    if (trigger) {
      const label = window.t ? t('header.languageLabel') : 'Language';
      trigger.title = label;
      trigger.setAttribute('aria-label', label);
    }
    const logout = mount.querySelector('#hd-logout');
    if (logout) {
      const label = window.t ? t('header.logout') : 'Logout';
      logout.title = label;
      logout.setAttribute('aria-label', label);
    }
  };

  const loadVersion = async () => {
    const cachedVersion = window.__grok2apiMetaVersion || readSessionCache(META_VERSION_CACHE_KEY);
    if (cachedVersion) {
      appVersion = String(cachedVersion).trim();
      window.__grok2apiMetaVersion = appVersion;
      return;
    }
    try {
      const res = await fetch('/meta');
      if (!res.ok) throw new Error('meta unavailable');
      const data = await res.json();
      appVersion = String(data?.version || '').trim();
      window.__grok2apiMetaVersion = appVersion;
      writeSessionCache(META_VERSION_CACHE_KEY, appVersion);
    } catch {
      appVersion = '';
    }
  };

  const refreshUpdate = async (force = false) => {
    if (updatePromise) return updatePromise;
    if (force) updateInfo = null;
    updateStatus = 'loading';
    updatePromise = (async () => {
      try {
        const path = force ? '/meta/update?force=true' : '/meta/update';
        const res = await fetch(path, { cache: 'no-store' });
        if (!res.ok) throw new Error('update unavailable');
        const data = await res.json();
        updateInfo = data && typeof data === 'object' ? data : null;
        updateStatus = 'ready';
      } catch {
        updateInfo = null;
        updateStatus = 'error';
      }
    })().finally(() => {
      updatePromise = null;
    });
    return updatePromise;
  };

  const text = (key, fallback, params) => {
    if (typeof window.t !== 'function') return fallback;
    const value = t(key, params);
    return value === key ? fallback : value;
  };

  const formatDateTime = (value) => {
    if (!value) return '-';
    const date = new Date(value);
    if (Number.isNaN(date.getTime())) return String(value);
    return date.toLocaleString();
  };

  const escapeHtml = (value) => String(value)
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&#39;');

  const sanitizeUrl = (value) => {
    try {
      const url = new URL(value, window.location.origin);
      return ['http:', 'https:', 'mailto:'].includes(url.protocol) ? url.href : '';
    } catch {
      return '';
    }
  };

  const sanitizeRenderedHtml = (html) => {
    const template = document.createElement('template');
    template.innerHTML = html;
    const blockedTags = new Set(['script', 'style', 'iframe', 'object', 'embed', 'link', 'meta']);

    const walk = (node) => {
      if (node.nodeType !== Node.ELEMENT_NODE) return;
      const el = node;
      const tag = el.tagName.toLowerCase();

      if (blockedTags.has(tag)) {
        el.remove();
        return;
      }

      Array.from(el.attributes).forEach((attr) => {
        const name = attr.name.toLowerCase();
        const value = attr.value || '';
        if (name.startsWith('on')) {
          el.removeAttribute(attr.name);
          return;
        }
        if ((name === 'href' || name === 'src') && !sanitizeUrl(value)) {
          el.removeAttribute(attr.name);
          return;
        }
        if (name === 'target') {
          el.setAttribute('target', '_blank');
        }
      });

      Array.from(el.children).forEach((child) => walk(child));
    };

    Array.from(template.content.children).forEach((child) => walk(child));
    return template.innerHTML;
  };

  const renderInlineMarkdown = (source) => {
    let html = escapeHtml(source);
    html = html.replace(/`([^`]+)`/g, (_, code) => `<code>${code}</code>`);
    html = html.replace(/\[([^\]]+)\]\(([^)]+)\)/g, (_, label, href) => {
      const safeHref = sanitizeUrl(href.trim());
      const safeLabel = escapeHtml(label.trim() || href.trim());
      return safeHref
        ? `<a href="${escapeHtml(safeHref)}" target="_blank" rel="noreferrer">${safeLabel}</a>`
        : safeLabel;
    });
    html = html.replace(/(^|[\s(>])((https?:\/\/|mailto:)[^\s<]+)/g, (_, prefix, rawUrl) => {
      const safeHref = sanitizeUrl(rawUrl.trim());
      if (!safeHref) return `${prefix}${rawUrl}`;
      return `${prefix}<a href="${escapeHtml(safeHref)}" target="_blank" rel="noreferrer">${escapeHtml(rawUrl)}</a>`;
    });
    html = html.replace(/\*\*([^*]+)\*\*/g, '<strong>$1</strong>');
    html = html.replace(/(^|[^\*])\*([^*]+)\*/g, '$1<em>$2</em>');
    return html;
  };

  const renderMarkdown = (source) => {
    const lines = String(source || '').replace(/\r\n?/g, '\n').split('\n');
    const html = [];
    const paragraph = [];
    let listType = '';
    let listItems = [];
    let inCodeBlock = false;
    let codeLines = [];
    let quoteLines = [];

    const flushParagraph = () => {
      if (!paragraph.length) return;
      html.push(`<p>${renderInlineMarkdown(paragraph.map((line) => line.trim()).join(' '))}</p>`);
      paragraph.length = 0;
    };

    const flushList = () => {
      if (!listItems.length) return;
      html.push(`<${listType}>${listItems.map((item) => `<li>${renderInlineMarkdown(item)}</li>`).join('')}</${listType}>`);
      listItems = [];
      listType = '';
    };

    const flushCodeBlock = () => {
      if (!inCodeBlock) return;
      html.push(`<pre><code>${escapeHtml(codeLines.join('\n'))}</code></pre>`);
      inCodeBlock = false;
      codeLines = [];
    };

    const flushQuote = () => {
      if (!quoteLines.length) return;
      html.push(`<blockquote>${renderInlineMarkdown(quoteLines.map((line) => line.trim()).join(' '))}</blockquote>`);
      quoteLines = [];
    };

    for (const line of lines) {
      if (line.startsWith('```')) {
        flushParagraph();
        flushList();
        flushQuote();
        if (inCodeBlock) {
          flushCodeBlock();
        } else {
          inCodeBlock = true;
          codeLines = [];
        }
        continue;
      }

      if (inCodeBlock) {
        codeLines.push(line);
        continue;
      }

      const trimmed = line.trim();
      const headingMatch = trimmed.match(/^(#{1,6})\s+(.*)$/);
      const unorderedMatch = trimmed.match(/^[-*+]\s+(.*)$/);
      const orderedMatch = trimmed.match(/^\d+\.\s+(.*)$/);
      const quoteMatch = trimmed.match(/^>\s?(.*)$/);

      if (!trimmed) {
        flushParagraph();
        flushList();
        flushQuote();
        continue;
      }

      if (headingMatch) {
        flushParagraph();
        flushList();
        flushQuote();
        const level = headingMatch[1].length;
        html.push(`<h${level}>${renderInlineMarkdown(headingMatch[2])}</h${level}>`);
        continue;
      }

      if (unorderedMatch || orderedMatch) {
        flushParagraph();
        flushQuote();
        const nextType = unorderedMatch ? 'ul' : 'ol';
        const itemText = unorderedMatch ? unorderedMatch[1] : orderedMatch[1];
        if (listType && listType !== nextType) flushList();
        listType = nextType;
        listItems.push(itemText);
        continue;
      }

      flushList();

      if (quoteMatch) {
        flushParagraph();
        quoteLines.push(quoteMatch[1]);
        continue;
      }

      flushQuote();

      if (/^(-{3,}|\*{3,}|_{3,})$/.test(trimmed)) {
        flushParagraph();
        flushQuote();
        html.push('<hr>');
        continue;
      }

      paragraph.push(line);
    }

    flushParagraph();
    flushList();
    flushQuote();
    flushCodeBlock();
    return html.join('') || '<p></p>';
  };

  const renderReleaseNotes = (source) => {
    if (!source.trim()) return `<p>${escapeHtml(text('header.versionNotesEmpty', 'No release notes available.'))}</p>`;
    if (window.marked && typeof window.marked.parse === 'function') {
      return sanitizeRenderedHtml(window.marked.parse(source, {
        async: false,
        breaks: false,
        gfm: true,
      }));
    }
    return renderMarkdown(source);
  };

  const ensureVersionModal = () => {
    let overlay = document.getElementById('admin-version-modal');
    if (overlay) return overlay;

    overlay = document.createElement('div');
    overlay.id = 'admin-version-modal';
    overlay.className = 'modal-overlay';
    overlay.innerHTML = `
      <div class="modal admin-version-modal" role="dialog" aria-modal="true" aria-labelledby="admin-version-modal-title">
        <div class="admin-version-modal-head">
          <div class="modal-title" id="admin-version-modal-title"></div>
          <div class="admin-version-modal-badge" id="admin-version-modal-badge" hidden></div>
        </div>
        <div class="admin-version-modal-meta">
          <div class="admin-version-modal-status" id="admin-version-modal-status"></div>
          <div class="admin-version-modal-row">
            <span class="admin-version-modal-label" id="admin-version-modal-current-label"></span>
            <span class="admin-version-modal-value" id="admin-version-modal-current"></span>
          </div>
          <div class="admin-version-modal-row">
            <span class="admin-version-modal-label" id="admin-version-modal-latest-label"></span>
            <span class="admin-version-modal-value" id="admin-version-modal-latest"></span>
          </div>
          <div class="admin-version-modal-row">
            <span class="admin-version-modal-label" id="admin-version-modal-published-label"></span>
            <span class="admin-version-modal-value" id="admin-version-modal-published"></span>
          </div>
        </div>
        <div class="admin-version-modal-notes" id="admin-version-modal-notes"></div>
        <div class="modal-footer">
          <button id="admin-version-modal-refresh" type="button" class="btn btn-ghost"></button>
          <a id="admin-version-modal-link" class="btn btn-ghost admin-version-modal-link" href="#" target="_blank" rel="noopener"></a>
          <button id="admin-version-modal-close" type="button" class="btn btn-primary"></button>
        </div>
      </div>
    `;
    document.body.appendChild(overlay);

    const close = () => {
      overlay.classList.remove('open');
      overlay.setAttribute('aria-hidden', 'true');
    };

    overlay.addEventListener('click', (event) => {
      if (event.target === overlay) close();
    });

    overlay.querySelector('#admin-version-modal-close')?.addEventListener('click', close);
    document.addEventListener('keydown', (event) => {
      if (event.key === 'Escape' && overlay.classList.contains('open')) close();
    });

    return overlay;
  };

  const renderVersionModal = (overlay = ensureVersionModal()) => {
    const title = overlay.querySelector('#admin-version-modal-title');
    const badge = overlay.querySelector('#admin-version-modal-badge');
    const status = overlay.querySelector('#admin-version-modal-status');
    const currentLabel = overlay.querySelector('#admin-version-modal-current-label');
    const currentValue = overlay.querySelector('#admin-version-modal-current');
    const latestLabel = overlay.querySelector('#admin-version-modal-latest-label');
    const latestValue = overlay.querySelector('#admin-version-modal-latest');
    const publishedLabel = overlay.querySelector('#admin-version-modal-published-label');
    const publishedValue = overlay.querySelector('#admin-version-modal-published');
    const notes = overlay.querySelector('#admin-version-modal-notes');
    const link = overlay.querySelector('#admin-version-modal-link');
    const refresh = overlay.querySelector('#admin-version-modal-refresh');
    const close = overlay.querySelector('#admin-version-modal-close');
    const latestVersion = String(updateInfo?.latest_version || appVersion || '').trim();
    const currentVersion = String(appVersion || updateInfo?.current_version || '').trim();
    const releaseUrl = String(updateInfo?.release_url || '').trim();
    const releaseNotes = String(updateInfo?.release_notes || '').trim();

    if (title) title.textContent = text('header.versionDialogTitle', 'Version');
    if (currentLabel) currentLabel.textContent = `${text('header.versionCurrent', 'Current')}:`;
    if (currentValue) currentValue.textContent = currentVersion ? `v${currentVersion}` : '-';
    if (latestLabel) latestLabel.textContent = `${text('header.versionLatest', 'Latest')}:`;
    if (latestValue) latestValue.textContent = latestVersion ? `v${latestVersion}` : '-';
    if (publishedLabel) publishedLabel.textContent = `${text('header.versionPublishedAt', 'Published')}:`;
    if (publishedValue) publishedValue.textContent = formatDateTime(updateInfo?.published_at);

    if (badge) {
      badge.hidden = true;
      badge.textContent = '';
      badge.className = 'admin-version-modal-badge';
    }

    if (status) {
      status.textContent = '';
      status.className = 'admin-version-modal-status is-hidden';
    }

    if (badge) {
      if (updateStatus === 'loading') {
        badge.hidden = false;
        badge.textContent = text('header.versionChecking', 'Checking for updates...');
        badge.className = 'admin-version-modal-badge is-muted';
      } else if (updateStatus === 'error' || !updateInfo || updateInfo.status === 'error') {
        badge.hidden = false;
        badge.textContent = text('header.versionUnavailable', 'Unable to check for updates right now.');
        badge.className = 'admin-version-modal-badge is-muted';
      } else if (updateInfo.update_available) {
        badge.hidden = false;
        badge.textContent = text('header.versionUpdateAvailable', 'A new version is available.');
        badge.className = 'admin-version-modal-badge is-update';
      } else {
        badge.hidden = false;
        badge.textContent = text('header.versionUpToDate', 'You are already on the latest version.');
        badge.className = 'admin-version-modal-badge is-current';
      }
    }

    if (notes) {
      if (updateStatus === 'loading' || updateStatus === 'error' || !updateInfo || updateInfo.status === 'error') {
        notes.hidden = true;
        notes.innerHTML = '';
      } else {
        notes.hidden = false;
        notes.innerHTML = renderReleaseNotes(releaseNotes);
      }
    }

    if (link instanceof HTMLAnchorElement) {
      if (releaseUrl) {
        link.hidden = false;
        link.style.display = 'inline-flex';
        link.href = releaseUrl;
        link.textContent = text('header.versionOpenRelease', 'Open Release');
      } else {
        link.hidden = true;
        link.style.display = 'none';
        link.removeAttribute('href');
        link.textContent = '';
      }
    }

    if (refresh instanceof HTMLButtonElement) {
      refresh.textContent = text('header.versionRefresh', 'Check Now');
      refresh.disabled = updateStatus === 'loading';
    }

    if (close instanceof HTMLButtonElement) {
      close.textContent = text('header.versionClose', 'Close');
    }

    overlay.classList.add('open');
    overlay.setAttribute('aria-hidden', 'false');
  };

  const openVersionModal = async () => {
    const overlay = ensureVersionModal();
    updateStatus = 'loading';
    renderVersionModal(overlay);
    try {
      await refreshUpdate(false);
    } finally {
      applyVersion();
      if (overlay.classList.contains('open')) {
        renderVersionModal(overlay);
      }
    }
  };

  const applyVersion = () => {
    const right = mount.querySelector('.admin-header-right');
    if (!right) return;
    let node = mount.querySelector('#hd-version');
    if (!appVersion) {
      node?.remove();
      return;
    }
    if (!node) {
      node = document.createElement('span');
      node.id = 'hd-version';
      node.className = 'admin-header-version';
      right.insertBefore(node, right.firstChild);
    }
    const value = `v${appVersion}`;
    node.textContent = value;
    node.title = value;
    node.classList.toggle('has-update', Boolean(updateInfo?.update_available));
    node.setAttribute('role', 'button');
    node.setAttribute('tabindex', '0');
    node.onclick = () => {
      void openVersionModal();
    };
    node.onkeydown = (event) => {
      if (event.key === 'Enter' || event.key === ' ') {
        event.preventDefault();
        void openVersionModal();
      }
    };
  };

  await loadVersion();

  try {
    const cachedHtml = window.__grok2apiAdminHeaderHtml || readSessionCache(HEADER_HTML_CACHE_KEY);
    if (cachedHtml) {
      mount.innerHTML = cachedHtml;
    } else {
      const res = await fetch('/static/admin/header.html');
      if (!res.ok) throw new Error('header unavailable');
      const html = await res.text();
      mount.innerHTML = html;
      window.__grok2apiAdminHeaderHtml = html;
      writeSessionCache(HEADER_HTML_CACHE_KEY, html);
    }
  } catch {
    mount.innerHTML = `
      <header class="admin-header">
        <div class="admin-header-inner">
          <div class="admin-brand-wrap">
            <a href="https://github.com/chenyme/grok2api" target="_blank" rel="noopener" class="admin-brand-link">
              <span class="admin-brand">Grok2API</span>
            </a>
            <a href="https://blog.cheny.me/" target="_blank" rel="noopener" class="admin-username" id="hd-user">@Chenyme</a>
          </div>
          <nav class="admin-nav">
            <a href="/admin/account" class="admin-nav-link" data-nav="/admin/account" data-i18n="header.account">账户管理</a>
            <a href="/admin/config" class="admin-nav-link" data-nav="/admin/config" data-i18n="header.config">配置管理</a>
            <a href="/admin/cache" class="admin-nav-link" data-nav="/admin/cache" data-i18n="header.cache">缓存管理</a>
          </nav>
          <div class="admin-header-right">
            <div class="admin-lang-menu" id="hd-lang-menu">
              <button type="button" class="btn admin-header-control admin-lang-trigger" id="hd-lang-trigger" aria-label="Language" aria-haspopup="menu" aria-expanded="false">
                <span class="admin-lang-trigger-code" id="hd-lang-code">CN</span>
                <svg viewBox="0 0 24 24" aria-hidden="true">
                  <path d="m7 10 5 5 5-5"/>
                </svg>
              </button>
              <div class="admin-lang-popover" id="hd-lang-popover" role="menu" aria-labelledby="hd-lang-trigger">
                <button type="button" class="admin-lang-option" data-lang="zh" role="menuitem">
                  <span class="admin-lang-option-code">CN</span>
                  <span class="admin-lang-option-name">简体中文</span>
                </button>
                <button type="button" class="admin-lang-option" data-lang="en" role="menuitem">
                  <span class="admin-lang-option-code">EN</span>
                  <span class="admin-lang-option-name">English</span>
                </button>
                <button type="button" class="admin-lang-option" data-lang="ja" role="menuitem">
                  <span class="admin-lang-option-code">JA</span>
                  <span class="admin-lang-option-name">日本語</span>
                </button>
                <button type="button" class="admin-lang-option" data-lang="es" role="menuitem">
                  <span class="admin-lang-option-code">ES</span>
                  <span class="admin-lang-option-name">Español</span>
                </button>
                <button type="button" class="admin-lang-option" data-lang="de" role="menuitem">
                  <span class="admin-lang-option-code">DE</span>
                  <span class="admin-lang-option-name">Deutsch</span>
                </button>
                <button type="button" class="admin-lang-option" data-lang="fr" role="menuitem">
                  <span class="admin-lang-option-code">FR</span>
                  <span class="admin-lang-option-name">Français</span>
                </button>
              </div>
            </div>
            <button onclick="adminLogout()" class="btn admin-header-control admin-header-icon-btn" id="hd-logout" aria-label="Logout" title="Logout">
              <svg viewBox="0 0 24 24" aria-hidden="true">
                <path d="M9 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h4"/>
                <path d="M16 17l5-5-5-5"/>
                <path d="M21 12H9"/>
              </svg>
            </button>
          </div>
        </div>
      </header>`;
  }

  const active = mount.dataset.active || location.pathname;
  mount.querySelectorAll('[data-nav]').forEach((link) => {
    link.classList.toggle('active', link.dataset.nav === active);
  });

  const syncLanguageMenu = initLanguageMenu();
  applyHeaderI18n();
  applyVersion();
  syncLanguageMenu?.();

  const versionModal = ensureVersionModal();
  versionModal.querySelector('#admin-version-modal-refresh')?.addEventListener('click', async () => {
    renderVersionModal(versionModal);
    try {
      await refreshUpdate(true);
    } finally {
      applyVersion();
      if (versionModal.classList.contains('open')) {
        renderVersionModal(versionModal);
      }
    }
  });
};