package handler

import (
	"dianshang/internal/service"
	"dianshang/pkg/logger"
	"dianshang/pkg/response"
	"time"

	"github.com/gin-gonic/gin"
)

// AdminStatsHandler 管理后台数据统计处理器
type AdminStatsHandler struct {
	orderService   *service.OrderService
	userService    *service.UserService
	productService *service.ProductService
	refundService  *service.RefundService
}

// NewAdminStatsHandler 创建管理后台数据统计处理器
func NewAdminStatsHandler(orderService *service.OrderService, userService *service.UserService, productService *service.ProductService, refundService *service.RefundService) *AdminStatsHandler {
	return &AdminStatsHandler{
		orderService:   orderService,
		userService:    userService,
		productService: productService,
		refundService:  refundService,
	}
}

// GetDashboardStats 获取仪表盘统计数据
func (h *AdminStatsHandler) GetDashboardStats(c *gin.Context) {
	// 获取今日统计
	today := time.Now().Format("2006-01-02")
	
	// 获取昨日统计用于对比
	yesterday := time.Now().AddDate(0, 0, -1).Format("2006-01-02")
	
	// 获取本月统计
	thisMonth := time.Now().Format("2006-01")
	
	// 获取上月统计用于对比
	lastMonth := time.Now().AddDate(0, -1, 0).Format("2006-01")

	// 今日订单统计
	todayOrderStats, err := h.orderService.GetOrderStatisticsWithDateRange(today, today)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, "获取今日订单统计失败")
		return
	}

	// 昨日订单统计
	yesterdayOrderStats, err := h.orderService.GetOrderStatisticsWithDateRange(yesterday, yesterday)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, "获取昨日订单统计失败")
		return
	}

	// 本月订单统计
	thisMonthOrderStats, err := h.orderService.GetOrderStatisticsWithDateRange(thisMonth+"-01", today)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, "获取本月订单统计失败")
		return
	}

	// 上月订单统计
	lastMonthStart := time.Now().AddDate(0, -1, 0)
	lastMonthEnd := time.Date(lastMonthStart.Year(), lastMonthStart.Month()+1, 0, 0, 0, 0, 0, lastMonthStart.Location())
	lastMonthOrderStats, err := h.orderService.GetOrderStatisticsWithDateRange(lastMonth+"-01", lastMonthEnd.Format("2006-01-02"))
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, "获取上月订单统计失败")
		return
	}

	// 今日用户统计
	todayUserStats, err := h.userService.GetUserStatistics(today, today)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, "获取今日用户统计失败")
		return
	}

	// 昨日用户统计
	yesterdayUserStats, err := h.userService.GetUserStatistics(yesterday, yesterday)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, "获取昨日用户统计失败")
		return
	}

	// 上月用户统计
	lastMonthUserStats, err := h.userService.GetUserStatistics(lastMonth+"-01", lastMonthEnd.Format("2006-01-02"))
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, "获取上月用户统计失败")
		return
	}

	// 商品统计
	productStats, err := h.productService.GetProductStatistics()
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, "获取商品统计失败")
		return
	}

	// 计算增长率的辅助函数
	calculateGrowthRate := func(current, previous interface{}) float64 {
		var currentVal, previousVal float64
		
		switch v := current.(type) {
		case int64:
			currentVal = float64(v)
		case float64:
			currentVal = v
		case int:
			currentVal = float64(v)
		default:
			return 0
		}
		
		switch v := previous.(type) {
		case int64:
			previousVal = float64(v)
		case float64:
			previousVal = v
		case int:
			previousVal = float64(v)
		default:
			return 0
		}
		
		if previousVal == 0 {
			if currentVal > 0 {
				return 100 // 如果之前为0，现在有值，则为100%增长
			}
			return 0
		}
		
		return ((currentVal - previousVal) / previousVal) * 100
	}

	// 计算各项增长率
	orderGrowthRate := calculateGrowthRate(todayOrderStats["total_orders"], yesterdayOrderStats["total_orders"])
	revenueGrowthRate := calculateGrowthRate(todayOrderStats["total_amount"], yesterdayOrderStats["total_amount"])
	userGrowthRate := calculateGrowthRate(todayUserStats["new_users"], yesterdayUserStats["new_users"])
	
	// 月度增长率
	monthlyOrderGrowthRate := calculateGrowthRate(thisMonthOrderStats["total_orders"], lastMonthOrderStats["total_orders"])
	monthlyRevenueGrowthRate := calculateGrowthRate(thisMonthOrderStats["total_amount"], lastMonthOrderStats["total_amount"])

	// 构建响应数据
	dashboardStats := gin.H{
		"overview": gin.H{
			"total_users": gin.H{
				"value":       todayUserStats["total_users"],
				"growth_rate": userGrowthRate,
				"trend":       getTrend(userGrowthRate),
			},
			"total_products": gin.H{
				"value":       productStats["total_products"],
				"online":      productStats["online_products"],
				"offline":     productStats["offline_products"],
				"low_stock":   productStats["low_stock_products"],
			},
			"total_orders": gin.H{
				"value":       thisMonthOrderStats["total_orders"],
				"growth_rate": monthlyOrderGrowthRate,
				"trend":       getTrend(monthlyOrderGrowthRate),
			},
			"total_revenue": gin.H{
				"value":       thisMonthOrderStats["total_amount"],
				"growth_rate": monthlyRevenueGrowthRate,
				"trend":       getTrend(monthlyRevenueGrowthRate),
			},
		},
		"today_stats": gin.H{
			"orders": gin.H{
				"total":       todayOrderStats["total_orders"],
				"paid":        todayOrderStats["paid_orders"],
				"amount":      todayOrderStats["total_amount"],
				"paid_amount": todayOrderStats["paid_amount"],
				"growth_rate": orderGrowthRate,
				"trend":       getTrend(orderGrowthRate),
			},
			"users": gin.H{
				"new_users":    todayUserStats["new_users"],
				"active_users": todayUserStats["active_users"],
				"growth_rate":  userGrowthRate,
				"trend":        getTrend(userGrowthRate),
			},
			"revenue": gin.H{
				"amount":      todayOrderStats["total_amount"],
				"paid_amount": todayOrderStats["paid_amount"],
				"growth_rate": revenueGrowthRate,
				"trend":       getTrend(revenueGrowthRate),
			},
		},
		"comparison": gin.H{
			"yesterday": gin.H{
				"orders":     yesterdayOrderStats["total_orders"],
				"amount":     yesterdayOrderStats["total_amount"],
				"new_users":  yesterdayUserStats["new_users"],
			},
			"last_month": gin.H{
				"orders":     lastMonthOrderStats["total_orders"],
				"amount":     lastMonthOrderStats["total_amount"],
				"new_users":  lastMonthUserStats["new_users"],
			},
		},
		"product_stats": productStats,
		"update_time":   time.Now().Format("2006-01-02 15:04:05"),
	}

	response.Success(c, dashboardStats)
}

// getTrend 根据增长率获取趋势标识
func getTrend(growthRate float64) string {
	if growthRate > 0 {
		return "up"
	} else if growthRate < 0 {
		return "down"
	}
	return "stable"
}

// GetOrderTrend 获取订单趋势
func (h *AdminStatsHandler) GetOrderTrend(c *gin.Context) {
	days := c.DefaultQuery("days", "7")
	
	var startDate string
	switch days {
	case "7":
		startDate = time.Now().AddDate(0, 0, -7).Format("2006-01-02")
	case "30":
		startDate = time.Now().AddDate(0, 0, -30).Format("2006-01-02")
	case "90":
		startDate = time.Now().AddDate(0, 0, -90).Format("2006-01-02")
	default:
		startDate = time.Now().AddDate(0, 0, -7).Format("2006-01-02")
	}
	
	endDate := time.Now().Format("2006-01-02")

	trend, err := h.orderService.GetDailyOrderStatisticsWithDateRange(startDate, endDate)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, trend)
}

// GetUserTrend 获取用户增长趋势
func (h *AdminStatsHandler) GetUserTrend(c *gin.Context) {
	days := c.DefaultQuery("days", "7")
	
	var startDate string
	switch days {
	case "7":
		startDate = time.Now().AddDate(0, 0, -7).Format("2006-01-02")
	case "30":
		startDate = time.Now().AddDate(0, 0, -30).Format("2006-01-02")
	case "90":
		startDate = time.Now().AddDate(0, 0, -90).Format("2006-01-02")
	default:
		startDate = time.Now().AddDate(0, 0, -7).Format("2006-01-02")
	}
	
	endDate := time.Now().Format("2006-01-02")

	trend, err := h.userService.GetDailyUserStatistics(startDate, endDate)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, trend)
}

// GetSalesRanking 获取销售排行
func (h *AdminStatsHandler) GetSalesRanking(c *gin.Context) {
	rankType := c.DefaultQuery("type", "product") // product, category, user
	limit := c.DefaultQuery("limit", "10")
	startDate := c.Query("start_date")
	endDate := c.Query("end_date")

	// 如果没有提供日期，默认查询最近30天
	if startDate == "" || endDate == "" {
		now := time.Now()
		endDate = now.Format("2006-01-02")
		startDate = now.AddDate(0, 0, -30).Format("2006-01-02")
	}

	var ranking interface{}
	var err error

	switch rankType {
	case "product":
		ranking, err = h.productService.GetProductSalesRanking(startDate, endDate, limit)
	case "category":
		ranking, err = h.productService.GetCategorySalesRanking(startDate, endDate, limit)
	case "user":
		ranking, err = h.userService.GetUserPurchaseRanking(startDate, endDate, limit)
	default:
		response.BadRequest(c, "不支持的排行类型")
		return
	}

	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, ranking)
}

// GetRegionStats 获取地区统计
func (h *AdminStatsHandler) GetRegionStats(c *gin.Context) {
	startDate := c.Query("start_date")
	endDate := c.Query("end_date")

	// 如果没有提供日期，默认查询最近30天
	if startDate == "" || endDate == "" {
		now := time.Now()
		endDate = now.Format("2006-01-02")
		startDate = now.AddDate(0, 0, -30).Format("2006-01-02")
	}

	regionStats, err := h.orderService.GetRegionStatistics(startDate, endDate)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, regionStats)
}

// GetPaymentStats 获取支付方式统计
func (h *AdminStatsHandler) GetPaymentStats(c *gin.Context) {
	startDate := c.Query("start_date")
	endDate := c.Query("end_date")

	// 如果没有提供日期，默认查询最近30天
	if startDate == "" || endDate == "" {
		now := time.Now()
		endDate = now.Format("2006-01-02")
		startDate = now.AddDate(0, 0, -30).Format("2006-01-02")
	}

	paymentStats, err := h.orderService.GetPaymentMethodStatistics(startDate, endDate)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, paymentStats)
}

// GetRefundStats 获取退款统计
func (h *AdminStatsHandler) GetRefundStats(c *gin.Context) {
	startDate := c.Query("start_date")
	endDate := c.Query("end_date")

	// 如果没有提供日期，默认查询最近30天
	if startDate == "" || endDate == "" {
		now := time.Now()
		endDate = now.Format("2006-01-02")
		startDate = now.AddDate(0, 0, -30).Format("2006-01-02")
	}

	// 解析日期
	startTime, err := time.Parse("2006-01-02", startDate)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR_INVALID_PARAMS, "开始日期格式错误")
		return
	}
	endTime, err := time.Parse("2006-01-02", endDate)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR_INVALID_PARAMS, "结束日期格式错误")
		return
	}
	
	// 设置时间范围到一天的结束
	endTime = endTime.Add(23*time.Hour + 59*time.Minute + 59*time.Second)

	// 使用退款服务获取真实统计数据
	refundStats, err := h.refundService.GetRefundStatistics(c.Request.Context(), startTime, endTime)
	if err != nil {
		logger.Error("获取退款统计失败", "error", err)
		response.ErrorWithMessage(c, response.ERROR, "获取退款统计失败")
		return
	}

	response.Success(c, refundStats)
}

// GetRealTimeStats 获取实时统计
func (h *AdminStatsHandler) GetRealTimeStats(c *gin.Context) {
	// 获取今日实时数据
	today := time.Now().Format("2006-01-02")
	
	// 今日订单数
	todayOrders, err := h.orderService.GetOrderStatisticsWithDateRange(today, today)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, "获取今日订单统计失败")
		return
	}

	// 今日新增用户
	todayUsers, err := h.userService.GetUserStatistics(today, today)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, "获取今日用户统计失败")
		return
	}

	// 在线用户数（这里简化处理，实际应该从Redis或其他缓存中获取）
	onlineUsers := 0

	// 待处理订单数
	pendingOrders, err := h.orderService.GetPendingOrdersCount()
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, "获取待处理订单数失败")
		return
	}

	realTimeStats := gin.H{
		"today_orders":     todayOrders["total_orders"],
		"today_amount":     todayOrders["total_amount"],
		"today_new_users":  todayUsers["new_users"],
		"online_users":     onlineUsers,
		"pending_orders":   pendingOrders,
		"update_time":      time.Now().Format("2006-01-02 15:04:05"),
	}

	response.Success(c, realTimeStats)
}

// GetUserGrowthTrend 获取用户增长趋势详细数据
func (h *AdminStatsHandler) GetUserGrowthTrend(c *gin.Context) {
	days := c.DefaultQuery("days", "30")
	
	var daysInt int
	switch days {
	case "7":
		daysInt = 7
	case "30":
		daysInt = 30
	case "90":
		daysInt = 90
	default:
		daysInt = 30
	}

	trend, err := h.userService.GetUserGrowthTrend(daysInt)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, trend)
}

// GetUserActivityAnalysis 获取用户活跃度分析
func (h *AdminStatsHandler) GetUserActivityAnalysis(c *gin.Context) {
	startDate := c.Query("start_date")
	endDate := c.Query("end_date")

	// 如果没有提供日期，默认查询最近30天
	if startDate == "" || endDate == "" {
		now := time.Now()
		endDate = now.Format("2006-01-02")
		startDate = now.AddDate(0, 0, -30).Format("2006-01-02")
	}

	analysis, err := h.userService.GetUserActivityAnalysis(startDate, endDate)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, analysis)
}

// GetUserRetentionRate 获取用户留存率
func (h *AdminStatsHandler) GetUserRetentionRate(c *gin.Context) {
	days := c.DefaultQuery("days", "30")
	
	var daysInt int
	switch days {
	case "7":
		daysInt = 7
	case "30":
		daysInt = 30
	case "90":
		daysInt = 90
	default:
		daysInt = 30
	}

	retention, err := h.userService.GetUserRetentionRate(daysInt)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, retention)
}

// GetUserLevelDistribution 获取用户等级分布
func (h *AdminStatsHandler) GetUserLevelDistribution(c *gin.Context) {
	distribution, err := h.userService.GetUserLevelDistribution()
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, distribution)
}

// GetUserGeographicDistribution 获取用户地域分布
func (h *AdminStatsHandler) GetUserGeographicDistribution(c *gin.Context) {
	distribution, err := h.userService.GetUserGeographicDistribution()
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, distribution)
}

// GetUserAgeDistribution 获取用户年龄分布
func (h *AdminStatsHandler) GetUserAgeDistribution(c *gin.Context) {
	distribution, err := h.userService.GetUserAgeDistribution()
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, distribution)
}

// GetUserEngagementMetrics 获取用户参与度指标
func (h *AdminStatsHandler) GetUserEngagementMetrics(c *gin.Context) {
	startDate := c.Query("start_date")
	endDate := c.Query("end_date")

	// 如果没有提供日期，默认查询最近30天
	if startDate == "" || endDate == "" {
		now := time.Now()
		endDate = now.Format("2006-01-02")
		startDate = now.AddDate(0, 0, -30).Format("2006-01-02")
	}

	metrics, err := h.userService.GetUserEngagementMetrics(startDate, endDate)
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, metrics)
}