/**
 * history.js — 历史记录页(检索历史 + 对话历史)
 */
const HistoryPage = {
  state: {
    tab: 'chat',  // 'chat' 或 'search'
    chatPage: 1,
    chatPageSize: 20,
    chatData: null,
    searchPage: 1,
    searchPageSize: 20,
    searchData: null,
    loading: false,
    error: null,
    detailChat: null,  // 查看详情的对话
  },

  render() {
    const tab = this.state.tab;
    return `
      <div class="p-4 md:p-6 max-w-4xl mx-auto">
        <h2 class="text-lg font-semibold mb-4">历史记录</h2>

        <!-- Tab 切换 -->
        <div class="flex gap-2 mb-4">
          <button onclick="HistoryPage.setTab('chat')"
            class="px-4 py-2 text-sm rounded-lg ${tab === 'chat' ? 'bg-gray-900 text-white' : 'bg-white border border-gray-200 text-gray-600 hover:bg-gray-50'}">
            对话历史
          </button>
          <button onclick="HistoryPage.setTab('search')"
            class="px-4 py-2 text-sm rounded-lg ${tab === 'search' ? 'bg-gray-900 text-white' : 'bg-white border border-gray-200 text-gray-600 hover:bg-gray-50'}">
            检索历史
          </button>
          <div class="flex-1"></div>
          <button onclick="HistoryPage.clearAll()"
            class="px-3 py-2 text-xs text-rose-500 hover:bg-rose-50 rounded-lg">
            清空${tab === 'chat' ? '对话' : '检索'}历史
          </button>
        </div>

        <!-- 内容区 -->
        <div id="history-content">
          ${this._renderLoading()}
        </div>
      </div>
    `;
  },

  init() {
    this.loadList();
  },

  _renderLoading() {
    return `<div class="flex items-center justify-center py-16 gap-3 text-gray-400">${UI.spinner(20)}<span class="text-sm">加载中...</span></div>`;
  },

  setTab(tab) {
    this.state.tab = tab;
    this.state.error = null;
    this.state.detailChat = null;
    const content = document.getElementById('content');
    content.innerHTML = this.render();
    this.loadList();
  },

  async loadList() {
    this.state.loading = true;
    this.state.error = null;
    const el = document.getElementById('history-content');
    if (el) el.innerHTML = this._renderLoading();

    try {
      if (this.state.tab === 'chat') {
        const resp = await API.get(`/api/history/chat?page=${this.state.chatPage}&page_size=${this.state.chatPageSize}`);
        this.state.chatData = resp.data;
      } else {
        const resp = await API.get(`/api/history/search?page=${this.state.searchPage}&page_size=${this.state.searchPageSize}`);
        this.state.searchData = resp.data;
      }
      this.state.loading = false;
      this.renderList();
    } catch (e) {
      this.state.loading = false;
      this.state.error = e.message;
      this.renderList();
    }
  },

  renderList() {
    const el = document.getElementById('history-content');
    if (!el) return;

    if (this.state.error) {
      el.innerHTML = UI.errorState(this.state.error, 'HistoryPage.loadList()');
      return;
    }

    if (this.state.tab === 'chat') {
      el.innerHTML = this._renderChatList();
    } else {
      el.innerHTML = this._renderSearchList();
    }
  },

  _renderChatList() {
    const data = this.state.chatData;
    if (!data || !data.items || data.items.length === 0) {
      return UI.emptyState('暂无对话历史', '在智能问答页提问后会自动记录');
    }

    const items = data.items.map(item => {
      const tplLabel = { simple: '通俗解释', professional: '专业分析', compare: '对比条文' }[item.template] || item.template;
      const statusBadge = item.status === 'error'
        ? '<span class="text-xs text-rose-500">错误</span>'
        : item.status === 'streaming'
          ? '<span class="text-xs text-amber-500">生成中</span>'
          : '';
      const answerPreview = item.answer
        ? item.answer.substring(0, 120).replace(/\n/g, ' ') + (item.answer.length > 120 ? '...' : '')
        : '<span class="text-gray-400 italic">无答案</span>';
      const citationCount = item.citations ? item.citations.length : 0;

      return `
        <div class="bg-white rounded-xl border border-gray-200 p-4 mb-3 hover:border-gray-300 transition">
          <div class="flex items-start justify-between gap-3">
            <div class="flex-1 min-w-0">
              <div class="flex items-center gap-2 mb-1.5 flex-wrap">
                <span class="text-xs text-gray-400">${item.created_at}</span>
                <span class="px-1.5 py-0.5 text-xs rounded bg-gray-100 text-gray-600">${tplLabel}</span>
                ${item.thinking_enabled ? '<span class="px-1.5 py-0.5 text-xs rounded bg-indigo-50 text-indigo-600">Thinking</span>' : ''}
                ${statusBadge}
                ${citationCount ? `<span class="text-xs text-gray-400">引用 ${citationCount} 条</span>` : ''}
              </div>
              <div class="text-sm font-medium text-gray-900 mb-1">${this._escapeHtml(item.question)}</div>
              <div class="text-xs text-gray-500 leading-relaxed">${this._escapeHtml(answerPreview)}</div>
            </div>
            <div class="flex flex-col gap-1 shrink-0">
              <button onclick="HistoryPage.viewChat(${item.id})"
                class="px-2 py-1 text-xs text-gray-500 hover:text-gray-900 hover:bg-gray-100 rounded">查看</button>
              <button onclick="HistoryPage.deleteChat(${item.id})"
                class="px-2 py-1 text-xs text-rose-400 hover:text-rose-600 hover:bg-rose-50 rounded">删除</button>
            </div>
          </div>
        </div>
      `;
    }).join('');

    const pagination = UI.pagination(
      data.page, data.page_size, data.total,
      'HistoryPage.changeChatPage'
    );

    return items + pagination;
  },

  _renderSearchList() {
    const data = this.state.searchData;
    if (!data || !data.items || data.items.length === 0) {
      return UI.emptyState('暂无检索历史', '在语义检索页查询后会自动记录');
    }

    const items = data.items.map(item => {
      const filters = [];
      if (item.category) filters.push(UI.categoryBadge(item.category));
      if (item.province) filters.push(`<span class="text-xs text-gray-400">[${item.province}]</span>`);
      return `
        <div class="bg-white rounded-xl border border-gray-200 p-3 mb-2 hover:border-gray-300 transition">
          <div class="flex items-center justify-between gap-3">
            <div class="flex-1 min-w-0">
              <div class="flex items-center gap-2 mb-1 flex-wrap">
                <span class="text-xs text-gray-400">${item.created_at}</span>
                ${filters.join('')}
                <span class="text-xs text-gray-400">${item.result_count} 条结果</span>
              </div>
              <div class="text-sm text-gray-900 truncate">${this._escapeHtml(item.query)}</div>
            </div>
            <div class="flex gap-1 shrink-0">
              <button onclick="HistoryPage.replaySearch(${JSON.stringify(item).replace(/"/g, '&quot;')})"
                class="px-2 py-1 text-xs text-gray-500 hover:text-gray-900 hover:bg-gray-100 rounded">重查</button>
              <button onclick="HistoryPage.deleteSearch(${item.id})"
                class="px-2 py-1 text-xs text-rose-400 hover:text-rose-600 hover:bg-rose-50 rounded">删除</button>
            </div>
          </div>
        </div>
      `;
    }).join('');

    const pagination = UI.pagination(
      data.page, data.page_size, data.total,
      'HistoryPage.changeSearchPage'
    );

    return items + pagination;
  },

  changeChatPage(page) {
    this.state.chatPage = page;
    this.loadList();
  },

  changeSearchPage(page) {
    this.state.searchPage = page;
    this.loadList();
  },

  async viewChat(id) {
    try {
      const resp = await API.get(`/api/history/chat/${id}`);
      this.state.detailChat = resp.data;
      this._renderChatDetail();
    } catch (e) {
      this.state.error = e.message;
      this.renderList();
    }
  },

  _renderChatDetail() {
    const chat = this.state.detailChat;
    if (!chat) return;

    const tplLabel = { simple: '通俗解释', professional: '专业分析', compare: '对比条文' }[chat.template] || chat.template;
    const thinkingHtml = chat.thinking
      ? `<details class="mb-4 group">
          <summary class="cursor-pointer flex items-center gap-2 text-xs text-gray-400 hover:text-gray-600 py-2">
            <svg class="w-3 h-3 transition-transform group-open:rotate-90" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="9 18 15 12 9 6"/></svg>
            <span>Thinking 思考过程</span>
            <span class="text-gray-300">${chat.thinking.length} 字</span>
          </summary>
          <div class="mt-2 p-3 bg-gray-50 rounded-lg border border-gray-100 max-h-96 overflow-y-auto scroll-thin">
            <pre class="text-xs text-gray-500 whitespace-pre-wrap font-mono leading-relaxed">${this._escapeHtml(chat.thinking)}</pre>
          </div>
        </details>`
      : '';
    const answerHtml = chat.answer
      ? `<div class="md-content text-sm leading-relaxed">${marked.parse(chat.answer)}</div>`
      : '<div class="text-sm text-gray-400 italic">无答案</div>';
    const citationsHtml = chat.citations && chat.citations.length
      ? `<div class="mt-6 pt-4 border-t border-gray-200"><div class="text-xs font-semibold text-gray-500 mb-3">引用条文(${chat.citations.length})</div>${chat.citations.map(c => UI.clauseCard(c)).join('')}</div>`
      : '';

    const el = document.getElementById('history-content');
    el.innerHTML = `
      <div class="mb-4">
        <button onclick="HistoryPage.closeDetail()"
          class="flex items-center gap-1.5 text-sm text-gray-500 hover:text-gray-900">
          <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="15 18 9 12 15 6"/></svg>
          返回列表
        </button>
      </div>
      <div class="bg-white rounded-xl border border-gray-200 p-4">
        <div class="flex items-center gap-2 mb-3 flex-wrap">
          <span class="text-xs text-gray-400">${chat.created_at}</span>
          <span class="px-1.5 py-0.5 text-xs rounded bg-gray-100 text-gray-600">${tplLabel}</span>
          ${chat.thinking_enabled ? '<span class="px-1.5 py-0.5 text-xs rounded bg-indigo-50 text-indigo-600">Thinking</span>' : ''}
        </div>
        <div class="text-sm font-semibold text-gray-900 mb-3 pb-3 border-b border-gray-100">${this._escapeHtml(chat.question)}</div>
        <div class="text-xs font-semibold text-gray-500 mb-3">AI 回答</div>
        ${thinkingHtml}
        ${answerHtml}
        ${citationsHtml}
      </div>
    `;
  },

  closeDetail() {
    this.state.detailChat = null;
    this.renderList();
  },

  async deleteChat(id) {
    if (!confirm('确认删除这条对话历史?')) return;
    try {
      await fetch(`/api/history/chat/${id}`, { method: 'DELETE' });
      this.loadList();
    } catch (e) {
      alert('删除失败: ' + e.message);
    }
  },

  async deleteSearch(id) {
    if (!confirm('确认删除这条检索历史?')) return;
    try {
      await fetch(`/api/history/search/${id}`, { method: 'DELETE' });
      this.loadList();
    } catch (e) {
      alert('删除失败: ' + e.message);
    }
  },

  async clearAll() {
    const type = this.state.tab === 'chat' ? '对话' : '检索';
    if (!confirm(`确认清空全部${type}历史?此操作不可恢复。`)) return;
    try {
      const url = this.state.tab === 'chat' ? '/api/history/chat' : '/api/history/search';
      await fetch(url, { method: 'DELETE' });
      this.loadList();
    } catch (e) {
      alert('清空失败: ' + e.message);
    }
  },

  replaySearch(item) {
    // 跳转到检索页并填充查询条件
    navigate('search');
    setTimeout(() => {
      const input = document.getElementById('search-input');
      if (input) input.value = item.query;
      if (SearchPage.state) {
        SearchPage.state.query = item.query;
        SearchPage.state.category = item.category || '';
        SearchPage.state.province = item.province || '';
        if (item.category) {
          const sel = document.getElementById('search-category');
          if (sel) sel.value = item.category;
        }
        if (item.province) {
          const sel = document.getElementById('search-province');
          if (sel) sel.value = item.province;
        }
      }
      // 自动触发检索
      if (SearchPage.submit) SearchPage.submit();
    }, 100);
  },

  _escapeHtml(text) {
    if (!text) return '';
    const div = document.createElement('div');
    div.textContent = text;
    return div.innerHTML;
  },
};