/**
 * 统计分析控制器
 *
 * 功能：处理数据分析和报表的业务逻辑
 */

const Analytics = require('../models/Analytics');
const { success } = require('../utils/response');
const { ValidationError } = require('../middleware/errorHandler');

/**
 * 获取综合仪表盘数据
 * GET /api/analytics/dashboard
 */
const getDashboard = async (req, res, next) => {
  try {
    const { start_date, end_date } = req.query;

    const dashboard = await Analytics.getDashboard(
      start_date || null,
      end_date || null
    );

    res.json(success(dashboard, '获取仪表盘数据成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取销售趋势
 * GET /api/analytics/sales-trend
 */
const getSalesTrend = async (req, res, next) => {
  try {
    const { start_date, end_date } = req.query;

    console.log('📊 getSalesTrend 请求参数:', { start_date, end_date });

    if (!start_date || !end_date) {
      throw new ValidationError('请提供开始日期和结束日期');
    }

    const trend = await Analytics.getSalesTrend(start_date, end_date);

    console.log('📊 Model返回数据条数:', trend ? trend.length : 0);
    console.log('📊 数据样例:', trend ? trend.slice(0, 2) : 'null');

    res.json(success({
      period: { start_date, end_date },
      data: trend
    }, '获取销售趋势成功'));
  } catch (err) {
    console.error('❌ getSalesTrend错误:', err);
    next(err);
  }
};

/**
 * 获取热门菜品排行
 * GET /api/analytics/top-dishes
 */
const getTopDishes = async (req, res, next) => {
  try {
    const { limit = 10, start_date, end_date } = req.query;

    const dishes = await Analytics.getTopDishes(
      parseInt(limit),
      start_date || null,
      end_date || null
    );

    res.json(success({
      count: dishes.length,
      dishes
    }, '获取热门菜品成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取分类销售统计
 * GET /api/analytics/category-sales
 */
const getCategorySales = async (req, res, next) => {
  try {
    const { start_date, end_date } = req.query;

    const categories = await Analytics.getCategorySales(
      start_date || null,
      end_date || null
    );

    res.json(success({
      count: categories.length,
      categories
    }, '获取分类销售统计成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取营业时段分析
 * GET /api/analytics/hourly-analysis
 */
const getHourlyAnalysis = async (req, res, next) => {
  try {
    const { start_date, end_date } = req.query;

    const hourlyData = await Analytics.getHourlyAnalysis(
      start_date || null,
      end_date || null
    );

    res.json(success({
      data: hourlyData
    }, '获取时段分析成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取会员消费排行
 * GET /api/analytics/top-members
 */
const getTopMembers = async (req, res, next) => {
  try {
    const { limit = 10, start_date, end_date } = req.query;

    const members = await Analytics.getTopMembers(
      parseInt(limit),
      start_date || null,
      end_date || null
    );

    res.json(success({
      count: members.length,
      members
    }, '获取会员排行成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取订单类型统计
 * GET /api/analytics/order-types
 */
const getOrderTypeStats = async (req, res, next) => {
  try {
    const { start_date, end_date } = req.query;

    const orderTypes = await Analytics.getOrderTypeStats(
      start_date || null,
      end_date || null
    );

    res.json(success({
      data: orderTypes
    }, '获取订单类型统计成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取支付方式统计
 * GET /api/analytics/payment-methods
 */
const getPaymentMethodStats = async (req, res, next) => {
  try {
    const { start_date, end_date } = req.query;

    const paymentMethods = await Analytics.getPaymentMethodStats(
      start_date || null,
      end_date || null
    );

    res.json(success({
      data: paymentMethods
    }, '获取支付方式统计成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取月度对比报表
 * GET /api/analytics/monthly-comparison
 */
const getMonthlyComparison = async (req, res, next) => {
  try {
    const { months = 6 } = req.query;

    const monthlyData = await Analytics.getMonthlyComparison(parseInt(months));

    res.json(success({
      months: parseInt(months),
      data: monthlyData
    }, '获取月度对比成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取库存价值报表
 * GET /api/analytics/inventory-value
 */
const getInventoryValue = async (req, res, next) => {
  try {
    const inventoryValue = await Analytics.getInventoryValue();

    res.json(success(inventoryValue, '获取库存价值报表成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取优惠券使用统计
 * GET /api/analytics/coupon-stats
 */
const getCouponStats = async (req, res, next) => {
  try {
    const { start_date, end_date } = req.query;

    const couponStats = await Analytics.getCouponStats(
      start_date || null,
      end_date || null
    );

    res.json(success({
      count: couponStats.length,
      coupons: couponStats
    }, '获取优惠券统计成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取预订转化率
 * GET /api/analytics/reservation-conversion
 */
const getReservationConversion = async (req, res, next) => {
  try {
    const { start_date, end_date } = req.query;

    const conversion = await Analytics.getReservationConversion(
      start_date || null,
      end_date || null
    );

    res.json(success(conversion, '获取预订转化率成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 导出综合报表（CSV格式）
 * GET /api/analytics/export
 */
const exportReport = async (req, res, next) => {
  try {
    const { start_date, end_date, type = 'sales' } = req.query;

    if (!start_date || !end_date) {
      throw new ValidationError('请提供开始日期和结束日期');
    }

    let data;
    let filename;

    switch (type) {
      case 'sales':
        data = await Analytics.getSalesTrend(start_date, end_date);
        filename = `sales_report_${start_date}_${end_date}.csv`;
        break;
      case 'dishes':
        data = await Analytics.getTopDishes(100, start_date, end_date);
        filename = `dishes_report_${start_date}_${end_date}.csv`;
        break;
      case 'members':
        data = await Analytics.getTopMembers(100, start_date, end_date);
        filename = `members_report_${start_date}_${end_date}.csv`;
        break;
      default:
        throw new ValidationError('无效的报表类型');
    }

    // 生成CSV内容
    if (data.length === 0) {
      throw new ValidationError('该时间段内没有数据');
    }

    const headers = Object.keys(data[0]).join(',');
    const rows = data.map(row => Object.values(row).join(',')).join('\n');
    const csv = `${headers}\n${rows}`;

    // 设置响应头
    res.setHeader('Content-Type', 'text/csv; charset=utf-8');
    res.setHeader('Content-Disposition', `attachment; filename="${filename}"`);

    res.send('\ufeff' + csv); // 添加BOM以支持中文
  } catch (err) {
    next(err);
  }
};

// 导出所有控制器函数
module.exports = {
  getDashboard,
  getSalesTrend,
  getTopDishes,
  getCategorySales,
  getHourlyAnalysis,
  getTopMembers,
  getOrderTypeStats,
  getPaymentMethodStats,
  getMonthlyComparison,
  getInventoryValue,
  getCouponStats,
  getReservationConversion,
  exportReport
};