(function (root, factory) {
  if (typeof module === 'object' && module.exports) {
    module.exports = factory(root);
    return;
  }

  root.HelpPages = factory(root);
  if (root.document) {
    root.document.addEventListener('DOMContentLoaded', function () {
      root.HelpPages.init();
    });
  }
})(typeof globalThis !== 'undefined' ? globalThis : window, function (root) {
  'use strict';

  function escapeHtml(value) {
    return String(value === undefined || value === null ? '' : value)
      .replace(/&/g, '&')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;')
      .replace(/"/g, '&quot;')
      .replace(/'/g, '&#39;');
  }

  function normalizeId(value) {
    var text;

    if (typeof value === 'number' && !Number.isSafeInteger(value)) return '';
    if (value === undefined || value === null) return '';
    text = String(value).trim();
    return /^[1-9][0-9]*$/.test(text) ? text : '';
  }

  function normalizeCount(value) {
    var text;

    if (value === undefined || value === null || value === '') return '0';
    if (typeof value === 'number' && (!Number.isSafeInteger(value) || value < 0)) return '';
    text = String(value).trim();
    return /^(?:0|[1-9][0-9]*)$/.test(text) ? text : '';
  }

  function text(value) {
    return value === undefined || value === null ? '' : String(value).trim();
  }

  function normalizeHelpArticle(item) {
    var source = item || {};
    var helpId = normalizeId(source.helpId);
    var helpTitle = text(source.helpTitle);
    var helpContent = text(source.helpContent);
    var viewCount = normalizeCount(source.viewCount);

    if (!helpId || !helpTitle || !helpContent || !viewCount || String(source.status) !== '0') {
      return null;
    }
    return {
      helpId: helpId,
      helpCategory: text(source.helpCategory),
      helpTitle: helpTitle,
      helpContent: helpContent,
      viewCount: viewCount
    };
  }

  function normalizeHelpArticleList(data) {
    var items;

    if (!Array.isArray(data)) return [];
    items = data.map(normalizeHelpArticle);
    return items.some(function (item) { return !item; }) ? [] : items;
  }

  function renderHelpArticleList(data) {
    var items = normalizeHelpArticleList(data);

    if (!items.length) return '<div class="api-empty">当前暂无帮助文章</div>';
    return items.map(function (item) {
      var meta = [item.helpCategory, '浏览 ' + item.viewCount + ' 次'].filter(Boolean).join(' · ');

      return '<details class="tilt-card" data-help-article-id="' + escapeHtml(item.helpId) + '">' +
        '<summary>' + escapeHtml(item.helpTitle) + '</summary>' +
        '<p>' + escapeHtml(meta) + '</p>' +
        '<div class="help-detail" data-help-detail-panel="' + escapeHtml(item.helpId) + '">' +
        '<button class="btn ghost" type="button" data-help-detail-id="' +
        escapeHtml(item.helpId) + '">查看完整解答</button></div></details>';
    }).join('');
  }

  function renderHelpArticleDetail(item) {
    var article = normalizeHelpArticle(item);
    var meta;

    if (!article) return '<div class="api-empty">帮助文章不存在或已停用</div>';
    meta = [article.helpCategory, '浏览 ' + article.viewCount + ' 次'].filter(Boolean).join(' · ');
    return '<div class="help-detail-content"><p class="module-meta">' + escapeHtml(meta) +
      '</p><p>' + escapeHtml(article.helpContent).replace(/\r?\n/g, '<br />') + '</p></div>';
  }

  async function loadHelpArticleDetail(api, helpId) {
    var targetId = normalizeId(helpId);
    var article;

    if (!api || typeof api.helpArticleDetail !== 'function') throw new Error('帮助文章接口不可用');
    if (!targetId) throw new Error('帮助文章编号无效');
    article = normalizeHelpArticle(await api.helpArticleDetail(targetId));
    if (!article) throw new Error('帮助文章详情响应无效');
    if (article.helpId !== targetId) throw new Error('详情响应与请求编号不一致');
    return article;
  }

  async function loadHelpArticles(api) {
    var data;
    var items;

    if (!api || typeof api.helpArticles !== 'function') throw new Error('帮助文章接口不可用');
    data = await api.helpArticles();
    items = normalizeHelpArticleList(data);
    if (!Array.isArray(data) || items.length !== data.length) throw new Error('帮助文章列表响应无效');
    return items;
  }

  function shouldRedirectToLogin(api, error) {
    var status = error && (error.status || error.code);

    return !api || !api.getToken || !api.getToken() || Number(status) === 401;
  }

  function redirectToLogin(api) {
    if (api && api.clearToken) api.clearToken();
    if (!root.location) return;
    if (typeof root.location.replace === 'function') root.location.replace('login.html');
    else root.location.href = 'login.html';
  }

  async function init() {
    var list = root.document && root.document.querySelector('[data-help-list]');
    var status = root.document && root.document.querySelector('[data-help-status]');
    var refresh = root.document && root.document.querySelector('[data-help-refresh]');
    var api = root.GenealogyApi && root.GenealogyApi.defaultClient;

    if (!list) return;
    if (shouldRedirectToLogin(api)) {
      redirectToLogin(api);
      return;
    }

    function setStatus(message) {
      if (status) status.textContent = message || '';
    }

    async function refreshList() {
      try {
        list.classList.add('is-loading');
        setStatus('正在读取帮助文章…');
        list.innerHTML = renderHelpArticleList(await loadHelpArticles(api));
        setStatus('');
      } catch (error) {
        if (shouldRedirectToLogin(api, error)) {
          redirectToLogin(api);
          return;
        }
        list.innerHTML = '<div class="api-empty">帮助文章读取失败，请稍后重试</div>';
        setStatus(error.message || '帮助文章读取失败');
      } finally {
        list.classList.remove('is-loading');
      }
    }

    list.addEventListener('click', async function (event) {
      var button = event.target.closest('[data-help-detail-id]');
      var helpId;
      var panel;

      if (!button || button.disabled) return;
      helpId = button.getAttribute('data-help-detail-id');
      panel = list.querySelector('[data-help-detail-panel="' + helpId + '"]');
      if (!panel) return;
      button.disabled = true;
      panel.textContent = '正在读取完整解答…';
      try {
        panel.innerHTML = renderHelpArticleDetail(await loadHelpArticleDetail(api, helpId));
      } catch (error) {
        if (shouldRedirectToLogin(api, error)) {
          redirectToLogin(api);
          return;
        }
        panel.textContent = error.message || '帮助文章详情读取失败';
      }
    });

    if (refresh) refresh.addEventListener('click', refreshList);
    await refreshList();
  }

  return {
    normalizeHelpArticle: normalizeHelpArticle,
    normalizeHelpArticleList: normalizeHelpArticleList,
    renderHelpArticleList: renderHelpArticleList,
    renderHelpArticleDetail: renderHelpArticleDetail,
    loadHelpArticleDetail: loadHelpArticleDetail,
    loadHelpArticles: loadHelpArticles,
    shouldRedirectToLogin: shouldRedirectToLogin,
    init: init
  };
});