const axios = require('axios');

class ToolExecutor {
  static async execute(toolName, args, context = []) {
    const startTime = Date.now();
    console.log(`[ToolExecutor] Executing: ${toolName}`, args);

    const handlers = {
      query_weather: this.queryWeather,
      query_order: this.queryOrder,
      search_knowledge: this.searchKnowledge,
      get_current_time: this.getCurrentTime,
      calculate: this.calculate,
    };

    const handler = handlers[toolName];
    if (!handler) {
      console.warn(`[ToolExecutor] Unknown tool: ${toolName}`);
      return { error: `未知的工具: ${toolName}` };
    }

    try {
      const result = await handler.call(this, args, context);
      const ms = Date.now() - startTime;
      console.log(`[ToolExecutor] ${toolName} completed in ${ms}ms:`, JSON.stringify(result).substring(0, 200));
      return result;
    } catch (error) {
      console.error(`[ToolExecutor] ${toolName} error:`, error);
      return { error: `工具执行失败: ${error.message}` };
    }
  }

  static async queryWeather({ city }) {
    const mockData = {
      '北京': { temp: '22°C', weather: '晴', humidity: '45%', wind: '北风3级', aqi: 65, tips: '空气质量良好，适合户外活动' },
      '上海': { temp: '26°C', weather: '多云', humidity: '72%', wind: '东南风2级', aqi: 78, tips: '注意防晒' },
      '广州': { temp: '30°C', weather: '阵雨', humidity: '85%', wind: '南风1级', aqi: 55, tips: '记得带伞' },
      '深圳': { temp: '29°C', weather: '多云', humidity: '80%', wind: '东风2级', aqi: 60, tips: '较为闷热，注意防暑' },
      '杭州': { temp: '24°C', weather: '晴', humidity: '55%', wind: '西北风2级', aqi: 50, tips: '天气宜人' },
      '成都': { temp: '20°C', weather: '阴', humidity: '70%', wind: '微风', aqi: 85, tips: '天气阴沉，适合室内活动' },
      '武汉': { temp: '25°C', weather: '晴', humidity: '60%', wind: '东风3级', aqi: 72, tips: '适合出行' },
      '南京': { temp: '23°C', weather: '多云', humidity: '58%', wind: '东北风2级', aqi: 68, tips: '温度适宜' },
      '西安': { temp: '18°C', weather: '晴', humidity: '35%', wind: '西北风3级', aqi: 90, tips: '天气干燥，注意补水' },
      '重庆': { temp: '27°C', weather: '阴转多云', humidity: '75%', wind: '微风', aqi: 80, tips: '注意防潮' },
    };

    const data = mockData[city];
    if (data) {
      return { city, date: new Date().toLocaleDateString('zh-CN'), ...data };
    }
    // 对未知城市生成随机数据
    const weathers = ['晴', '多云', '阴', '小雨', '大风'];
    return {
      city,
      date: new Date().toLocaleDateString('zh-CN'),
      temp: `${Math.floor(Math.random() * 20 + 10)}°C`,
      weather: weathers[Math.floor(Math.random() * weathers.length)],
      humidity: `${Math.floor(Math.random() * 50 + 30)}%`,
      wind: '微风',
      aqi: Math.floor(Math.random() * 100 + 30),
      tips: '数据仅供参考',
    };
  }

  static async queryOrder({ order_id }) {
    const statuses = ['待支付', '已支付', '拣货中', '已发货', '运输中', '已签收'];
    const hash = order_id.split('').reduce((a, c) => a + c.charCodeAt(0), 0);
    const statusIdx = hash % statuses.length;

    return {
      order_id,
      status: statuses[statusIdx],
      estimated_delivery: '2026-03-01',
      tracking_number: 'SF' + order_id.replace(/\D/g, '').padEnd(10, '0').substring(0, 10),
      items: [
        { name: '智能音箱 Pro', quantity: 1, price: '¥299' },
      ],
      create_time: '2026-02-20 14:30:00',
    };
  }

  static async searchKnowledge({ query } = {}, context = []) {
    const startTime = Date.now();
    query = query || '';
    console.log(`[ToolExecutor] searchKnowledge called with query="${query}"`);
    
    const kbIds = process.env.VOLC_ARK_KNOWLEDGE_BASE_IDS;
    if (kbIds && kbIds !== 'your_knowledge_base_dataset_id') {
      try {
        console.log('[ToolExecutor] Trying Ark Knowledge Search...');
        const result = await this.searchArkKnowledge(query, context);
        console.log(`[ToolExecutor] Ark KB search succeeded in ${Date.now() - startTime}ms`);
        return result;
      } catch (error) {
        console.warn('[ToolExecutor] Ark Knowledge Search failed:', error.message);
        console.log('[ToolExecutor] Falling back to local Knowledge Base');
      }
    }

    
    console.log('[ToolExecutor] Using local Knowledge Base (voice fast path)');
    const result = this.searchLocalKnowledge(query);
    console.log(`[ToolExecutor] Local KB search completed in ${Date.now() - startTime}ms`);
    return result;
  }

  /**
   * 通过方舟 Chat Completions API + knowledge_base metadata 进行知识检索
   * 使用独立的 LLM 调用，专门用于知识库检索场景（如语音通话的工具回调）
   */
  static async searchArkKnowledge(query, context = []) {
    const endpointId = process.env.VOLC_ARK_ENDPOINT_ID;
    const authKey = process.env.VOLC_ARK_API_KEY || process.env.VOLC_ACCESS_KEY_ID;
    const kbIds = process.env.VOLC_ARK_KNOWLEDGE_BASE_IDS;

    const datasetIds = kbIds.split(',').map(id => id.trim()).filter(Boolean);
    const topK = parseInt(process.env.VOLC_ARK_KNOWLEDGE_TOP_K) || 3;
    const threshold = parseFloat(process.env.VOLC_ARK_KNOWLEDGE_THRESHOLD) || 0.5;

    // 当 query 为空时（FC 流式 chunks 乱序无法解析），使用简短的默认查询
    const effectiveQuery = (query && query.trim()) ? query : '请介绍你们的产品和服务';
    if (!query || !query.trim()) {
      console.log('[ToolExecutor] Empty query, using default: "' + effectiveQuery + '"');
    }

    // 提取最近 3 轮对话作为上下文（最多 6 条 user/assistant 消息）
    const recentContext = context
      .filter(m => m.role === 'user' || m.role === 'assistant')
      .slice(-6);

    const messages = [
      {
        role: 'system',
        content: '你是一个知识库检索助手。请根据知识库中的内容回答用户问题。如果知识库中没有相关内容，请如实说明。回答时请引用知识库来源。',
      },
      ...recentContext,
      {
        role: 'user',
        content: effectiveQuery,
      },
    ];

    if (recentContext.length > 0) {
      console.log(`[ToolExecutor] Ark KB search with ${recentContext.length} context messages`);
    }

    const body = {
      model: endpointId,
      messages,
      metadata: {
        knowledge_base: {
          dataset_ids: datasetIds,
          top_k: topK,
          threshold: threshold,
        },
      },
      stream: false,
    };

    const response = await axios.post(
      'https://ark.cn-beijing.volces.com/api/v3/chat/completions',
      body,
      {
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${authKey}`,
        },
        timeout: 15000, // 方舟知识库超时 15s（减少等待，防止 LLM 重试风暴）
      }
    );

    const choice = response.data.choices?.[0];
    const content = choice?.message?.content || '未找到相关信息';

    return {
      query,
      results: [{
        title: '方舟知识库检索结果',
        content: content,
      }],
      total: 1,
      source: 'ark_knowledge',
    };
  }

  /**
   * 通过 Coze v3 Chat API 进行知识库检索
   * 需要在 Coze 平台创建 Bot 并挂载知识库插件
   */
  static async searchCozeKnowledge(query) {
    const apiToken = process.env.COZE_API_TOKEN;
    const botId = process.env.COZE_BOT_ID;
    const baseUrl = 'https://api.coze.cn/v3';
    const headers = {
      'Content-Type': 'application/json',
      'Authorization': `Bearer ${apiToken}`,
    };

    // 1. 创建对话
    const chatRes = await axios.post(`${baseUrl}/chat`, {
      bot_id: botId,
      user_id: 'kb_search_user',
      additional_messages: [
        {
          role: 'user',
          content: query,
          content_type: 'text',
        },
      ],
      stream: true,
      auto_save_history: false,
    }, { headers, timeout: 15000 });

    const chatData = chatRes.data?.data;
    if (!chatData?.id || !chatData?.conversation_id) {
      throw new Error('Coze chat creation failed: ' + JSON.stringify(chatRes.data));
    }

    const chatId = chatData.id;
    const conversationId = chatData.conversation_id;

    // 2. 轮询等待完成（最多 30 秒）
    const maxAttempts = 15;
    for (let i = 0; i < maxAttempts; i++) {
      await new Promise(r => setTimeout(r, 2000));

      const statusRes = await axios.get(
        `${baseUrl}/chat/retrieve?chat_id=${chatId}&conversation_id=${conversationId}`,
        { headers, timeout: 10000 }
      );

      const status = statusRes.data?.data?.status;
      if (status === 'completed') break;
      if (status === 'failed' || status === 'requires_action') {
        throw new Error(`Coze chat ended with status: ${status}`);
      }
    }

    // 3. 获取消息列表
    const msgRes = await axios.get(
      `${baseUrl}/chat/message/list?chat_id=${chatId}&conversation_id=${conversationId}`,
      { headers, timeout: 10000 }
    );

    const messages = msgRes.data?.data || [];
    const answerMsg = messages.find(m => m.role === 'assistant' && m.type === 'answer');
    const content = answerMsg?.content || '未找到相关信息';

    return {
      query,
      results: [{
        title: 'Coze 知识库检索结果',
        content: content,
      }],
      total: 1,
      source: 'coze',
    };
  }

  static async searchLocalKnowledge(query) {
    const knowledgeBase = {
      '退货': {
        title: '退货政策',
        content: '自签收之日起7天内可无理由退货，15天内可换货。请保持商品及包装完好。退货运费由买家承担（质量问题除外）。',
      },
      '退款': {
        title: '退款流程',
        content: '退货审核通过后，退款将在3-5个工作日内原路返回。如超过时间未到账，请联系客服。',
      },
      '配送': {
        title: '配送说明',
        content: '默认顺丰快递，普通订单1-3天送达，偏远地区3-7天。满99元免运费。',
      },
      '保修': {
        title: '保修政策',
        content: '电子产品保修期1年，自购买之日起计算。人为损坏不在保修范围内。',
      },
      '会员': {
        title: '会员权益',
        content: '会员享受9折优惠、免运费、专属客服、生日礼券等权益。年费128元。',
      },
    };

    const results = [];
    const q = query || '';
    for (const [key, value] of Object.entries(knowledgeBase)) {
      if (q.includes(key) || key.includes(q)) {
        results.push(value);
      }
    }

    if (results.length === 0) {
      results.push({
        title: '搜索结果',
        content: `未找到与"${query}"直接相关的知识库文档。建议联系人工客服获取更详细的帮助。`,
      });
    }

    return { query, results, total: results.length, source: 'local' };
  }

  static async getCurrentTime() {
    const now = new Date();
    return {
      datetime: now.toLocaleString('zh-CN', { timeZone: 'Asia/Shanghai' }),
      timestamp: now.getTime(),
      timezone: 'Asia/Shanghai',
      weekday: ['周日', '周一', '周二', '周三', '周四', '周五', '周六'][now.getDay()],
    };
  }

  static async calculate({ expression }) {
    try {
      // 仅允许数字和基本运算符，防止注入
      const sanitized = expression.replace(/[^0-9+\-*/().% ]/g, '');
      if (!sanitized || sanitized !== expression.replace(/\s/g, '')) {
        return { error: '表达式包含不支持的字符', expression };
      }
      const result = Function('"use strict"; return (' + sanitized + ')')();
      return { expression, result: Number(result), formatted: String(result) };
    } catch (e) {
      return { error: '计算失败: ' + e.message, expression };
    }
  }
}

module.exports = ToolExecutor;