// src/routes/v1/services/queryEngine.ts
import pool from '../../../db';

type QueryContext = {
  current_tenant_id?: string;
  operator_role?: string;
};

export async function executeNaturalLanguageQuery(
  question: string,
  context: QueryContext = {}
) {
  const q = question.toLowerCase().trim();

  // 工具函数：安全转义 LIKE
  const escapeLike = (str: string) => str.replace(/[%_]/g, '\\$&');

  // 场景 1: 商家 GMV（支持时间范围）
  if ((q.includes('gmv') || q.includes('销售额')) && q.includes('商家')) {
    const nameMatch = q.match(/商家\s*["']?([a-zA-Z0-9\u4e00-\u9fa5]+)["']?/);
    const merchantName = nameMatch ? nameMatch[1] : null;
    if (!merchantName) throw new Error('请指定商家名称');

    let timeFilter = '';
    let params: any[] = [`%${escapeLike(merchantName)}%`];

    if (q.includes('昨天')) {
      timeFilter = 'AND DATE(FROM_UNIXTIME(o.create_time)) = CURDATE() - INTERVAL 1 DAY';
    } else if (q.includes('上周')) {
      timeFilter = 'AND YEARWEEK(FROM_UNIXTIME(o.create_time), 1) = YEARWEEK(CURDATE() - INTERVAL 1 WEEK, 1)';
    } else if (q.includes('上月')) {
      timeFilter = 'AND DATE_FORMAT(FROM_UNIXTIME(o.create_time), "%Y-%m") = DATE_FORMAT(CURDATE() - INTERVAL 1 MONTH, "%Y-%m")';
    }

    const sql = `
      SELECT 
        m.merch_name AS merchant,
        COALESCE(SUM(o.order_money), 0) AS gmv,
        COUNT(o.order_id) AS order_count
      FROM lucky_merch m
      LEFT JOIN lucky_order o ON m.site_id = o.site_id
      WHERE m.merch_name LIKE ? ${timeFilter}
      GROUP BY m.merch_id, m.merch_name
    `;
    const [rows] = await pool.execute(sql, params);
    return (rows as any[])[0] || null;
  }

  // 场景 2: 订单状态
  if (q.includes('订单') && (q.includes('状态') || q.includes('详情'))) {
    const idMatch = q.match(/订单\s*["']?([a-zA-Z0-9]+)["']?/);
    const orderId = idMatch ? idMatch[1] : null;
    if (!orderId) throw new Error('请提供订单编号或ID');

    const sql = `
      SELECT 
        order_no, 
        order_status_name AS status,
        pay_status,
        delivery_status,
        order_money,
        name AS buyer_name,
        mobile,
        create_time
      FROM lucky_order 
      WHERE order_no = ? OR order_id = ?
    `;
    const [rows] = await pool.execute(sql, [orderId, isNaN(Number(orderId)) ? null : Number(orderId)]);
    return (rows as any[])[0] || null;
  }

  // 场景 3: 用户信息
  if (q.includes('用户') && (q.includes('信息') || q.includes('详情') || q.includes('资料'))) {
    const idMatch = q.match(/用户\s*["']?(\d+)["']?/);
    const userId = idMatch && idMatch[1] !== undefined ? parseInt(idMatch[1]) : null;
    if (!userId) throw new Error('请提供用户ID');

    const sql = `
      SELECT member_id, nickname, mobile, email
      FROM lucky_member 
      WHERE member_id = ?
    `;
    const [rows] = await pool.execute(sql, [userId]);
    return (rows as any[])[0] || null;
  }

  // 场景 4: 商品销量
  if (q.includes('商品') && q.includes('销量')) {
    const nameMatch = q.match(/商品\s*["']?([a-zA-Z0-9\u4e00-\u9fa5\s]+)["']?/);
    const goodsName = nameMatch && nameMatch[1] ? nameMatch[1].trim() : null;
    if (!goodsName) throw new Error('请指定商品名称');

    const sql = `
      SELECT 
        g.goods_name,
        SUM(og.num) AS total_sold
      FROM lucky_goods g
      JOIN lucky_order_goods og ON g.goods_id = og.goods_id
      WHERE g.goods_name LIKE ?
      GROUP BY g.goods_id, g.goods_name
    `;
    const [rows] = await pool.execute(sql, [`%${escapeLike(goodsName)}%`]);
    return Array.isArray(rows) && rows.length > 0 ? rows[0] : null;
  }

  // 场景 5: 退款率（按商家）
  if (q.includes('退款率') && q.includes('商家')) {
    const nameMatch = q.match(/商家\s*["']?([a-zA-Z0-9\u4e00-\u9fa5]+)["']?/);
    const merchantName = nameMatch ? nameMatch[1] : null;
    if (!merchantName) throw new Error('请指定商家名称');

    const sql = `
      SELECT 
        m.merch_name,
        COUNT(o.order_id) AS total_orders,
        SUM(CASE WHEN o.refund_status > 0 THEN 1 ELSE 0 END) AS refunded_orders,
        ROUND(
          SUM(CASE WHEN o.refund_status > 0 THEN 1 ELSE 0 END) * 100.0 / COUNT(o.order_id), 
          2
        ) AS refund_rate_percent
      FROM lucky_merch m
      JOIN lucky_order o ON m.site_id = o.site_id
      WHERE m.merch_name LIKE ?
      GROUP BY m.merch_id, m.merch_name
    `;
    const [rows] = await pool.execute(sql, [`%${escapeLike(merchantName)}%`]);
    return (rows as any)[0] || null;
  }

  // 场景 6: 未发货订单
  if (q.includes('未发货') && q.includes('订单')) {
    const sql = `
      SELECT 
        order_no, 
        name AS buyer, 
        order_money, 
        create_time
      FROM lucky_order 
      WHERE delivery_status = 0  -- 假设 0=未发货
      ORDER BY create_time DESC
      LIMIT 20
    `;
    const [rows] = await pool.execute(sql);
    return rows;
  }

  // 场景 7: 正常营业商户
  if (q.includes('商户') && (q.includes('列表') || q.includes('所有'))) {
    const sql = `
      SELECT 
        merch_id, 
        merch_name, 
        status, 
        balance, 
        create_time
      FROM lucky_merch 
      WHERE status = 1  -- 1=正常
      ORDER BY sort ASC
    `;
    const [rows] = await pool.execute(sql);
    return rows;
  }

  // 场景 8: 商户提现记录
  if (q.includes('提现') && q.includes('商户')) {
    const nameMatch = q.match(/商户\s*["']?([a-zA-Z0-9\u4e00-\u9fa5]+)["']?/);
    const merchantName = nameMatch ? nameMatch[1] : null;
    if (!merchantName) throw new Error('请指定商户名称');

    const sql = `
      SELECT 
        withdraw_no,
        apply_money,
        money AS arrived_amount,
        status_name,
        apply_time
      FROM lucky_merch_withdraw w
      JOIN lucky_merch m ON w.merch_id = m.merch_id
      WHERE m.merch_name LIKE ?
      ORDER BY apply_time DESC
      LIMIT 10
    `;
    const [rows] = await pool.execute(sql, [`%${escapeLike(merchantName)}%`]);
    return rows;
  }

  // 场景 9: 用户充值记录
  if (q.includes('充值') && q.includes('用户')) {
    const idMatch = q.match(/用户\s*["']?(\d+)["']?/);
    const userId = idMatch && idMatch[1] ? parseInt(idMatch[1]) : null;
    if (!userId) throw new Error('请提供用户ID');

    const sql = `
      SELECT 
        order_no,
        money AS amount,
        status,
        create_time,
        pay_time
      FROM lucky_member_recharge_order 
      WHERE member_id = ?
      ORDER BY create_time DESC
    `;
    const [rows] = await pool.execute(sql, [userId]);
    return rows;
  }

  // 场景 10: 邀请奖励
  if (q.includes('邀请') && q.includes('奖励')) {
    const idMatch = q.match(/用户\s*["']?(\d+)["']?/);
    const userId = idMatch && idMatch[1] ? parseInt(idMatch[1]) : null;
    if (!userId) throw new Error('请提供用户ID');

    const sql = `
      SELECT 
        recommend_name AS activity,
        point,
        balance,
        create_time
      FROM lucky_member_recommend_award 
      WHERE member_id = ?
      ORDER BY create_time DESC
    `;
    const [rows] = await pool.execute(sql, [userId]);
    return rows;
  }

  // 场景 11: 系统公告
  if (q.includes('公告') || q.includes('通知')) {
    const sql = `
      SELECT 
        title,
        content,
        create_time,
        is_top
      FROM lucky_notice 
      ORDER BY is_top DESC, create_time DESC
      LIMIT 5
    `;
    const [rows] = await pool.execute(sql);
    return rows;
  }

  // 场景 12: 店铺笔记
  if (q.includes('笔记') || q.includes('文章')) {
    const titleMatch = q.match(/笔记\s*["']?([a-zA-Z0-9\u4e00-\u9fa5\s]+)["']?/);
    const noteTitle = titleMatch && titleMatch[1] ? titleMatch[1].trim() : null;

    let sql = `
      SELECT note_title, note_abstract, release_time, read_num
      FROM lucky_notes 
      WHERE status = 1  -- 已发布
    `;
    let params: any[] = [];

    if (noteTitle) {
      sql += ' AND note_title LIKE ?';
      params.push(`%${escapeLike(noteTitle)}%`);
    }
    sql += ' ORDER BY release_time DESC LIMIT 5';

    const [rows] = await pool.execute(sql, params);
    return rows;
  }

  // 场景 13: 通过登录用户或者商家名称获得 uniacid
  if ((q.includes('uniacid') || q.includes('平台id')) && (q.includes('商家') || q.includes('用户'))) {
    // 处理通过用户ID查询
    if (q.includes('用户')) {
      const idMatch = q.match(/用户\s*["']?(\d+)["']?/);
      const userId = idMatch && idMatch[1] !== undefined ? parseInt(idMatch[1]) : null;
      if (!userId) throw new Error('请指定用户ID');

      const sql = `
        SELECT u.uniacid, u.uid, u.username, u.site_id
        FROM lucky_user u
        WHERE u.uid = ?
        LIMIT 1
      `;
      const [rows] = await pool.execute(sql, [userId]);
      return (rows as any[])[0] || null;
    }
    // 处理通过商家名称查询
    else {
      const nameMatch = q.match(/商家\s*["']?([a-zA-Z0-9\u4e00-\u9fa5]+)["']?/);
      const merchantName = nameMatch ? nameMatch[1] : null;
      if (!merchantName) throw new Error('请指定商家名称');

      const sql = `
        SELECT DISTINCT u.uniacid, m.merch_name, m.site_id
        FROM lucky_merch m
        JOIN lucky_user u ON m.site_id = u.site_id
        WHERE m.merch_name LIKE ?
        LIMIT 1
      `;
      const [rows] = await pool.execute(sql, [`%${escapeLike(merchantName)}%`]);
      return (rows as any[])[0] || null;
    }
  }

  // 场景 14: 获得当前有多少商家用户
  if ((q.includes('多少') || q.includes('数量') || q.includes('个数')) && q.includes('商家') && q.includes('用户')) {
    const sql = `
      SELECT COUNT(DISTINCT u.uid) AS merchant_user_count
      FROM lucky_user u
      JOIN lucky_merch m ON u.site_id = m.site_id
      WHERE u.status = 1 AND m.status = 1
    `;
    const [rows] = await pool.execute(sql);
    return (rows as any[])[0] || { merchant_user_count: 0 };
  }

  // 默认兜底
  throw new Error(`
    无法理解该问题。支持的查询包括：
    - 商家 GMV（如“TechStore 昨天的 GMV”）
    - 订单状态（如“订单 L20251127001 状态”）
    - 用户/商品/提现/充值/公告等信息
    - 通过商家名称查询商家的 uniacid
    - 获得当前有多少商家用户
  `.trim());
}