package service

import (
	"gorm.io/gorm"
	"psi/database"
	"psi/models"
	systemReq "psi/models/request"
	systemRes "psi/models/response"
	"psi/utils"
	"time"
)

type StatistService struct{}

// DashboardStatist 获取仪表盘统计数据
func (s *StatistService) DashboardStatist(req systemReq.DashboardStatistRequest, db ...*gorm.DB) (*systemRes.DashboardStatistResponse, error) {
	databaseConn := database.OptionalDB(db...)

	// 计算今日的时间范围（如果未指定）
	now := time.Now()
	startOfDay := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location()).Unix()
	endOfDay := time.Date(now.Year(), now.Month(), now.Day(), 23, 59, 59, 0, now.Location()).Unix()

	if req.StartDate == 0 {
		req.StartDate = startOfDay
	}
	if req.EndDate == 0 {
		req.EndDate = endOfDay
	}

	// 查询今日销售订单总数
	var totalSaleCount int64
	saleOrderQuery := databaseConn.Model(&models.SalesOrder{}).
		Where("created_at >= ? AND created_at <= ? AND is_del = ?", req.StartDate, req.EndDate, 0)
	saleOrderQuery.Count(&totalSaleCount)

	// 从 statist 表查询总入库和出库次数
	var totalReceivingCount, totalOutboundCount int64
	statistQuery := databaseConn.Model(&models.Statist{}).
		Where("stat_date >= ? AND stat_date <= ? AND is_del = ?", req.StartDate, req.EndDate, 0)

	var statistList []models.Statist
	if err := statistQuery.Find(&statistList).Error; err != nil {
		return nil, utils.NewError("查询统计数据失败")
	}

	if len(statistList) == 0 {
		return &systemRes.DashboardStatistResponse{
			TotalReceivingCount: 0,
			TotalOutboundCount:  0,
			TotalSaleCount:      totalSaleCount,
			UserStats:           []systemRes.UserStatItem{},
		}, nil
	}

	for _, stat := range statistList {
		totalReceivingCount += stat.ReceivingNum
		totalOutboundCount += stat.OutboundNum
	}

	// 查询个人统计数据
	var userStats []systemRes.UserStatItem

	// 按用户分组统计
	type UserStatGroup struct {
		CreateBy       int64 `gorm:"column:create_by"`
		TotalReceiving int64 `gorm:"column:total_receiving"`
		TotalOutbound  int64 `gorm:"column:total_outbound"`
	}

	var userStatGroups []UserStatGroup
	databaseConn.Model(&models.Statist{}).
		Select("create_by, SUM(receiving_num) as total_receiving, SUM(outbound_num) as total_outbound").
		Where("stat_date >= ? AND stat_date <= ? AND is_del = ?", req.StartDate, req.EndDate, 0).
		Group("create_by").
		Scan(&userStatGroups)

	// 获取用户信息并构建返回数据
	for _, group := range userStatGroups {
		var employee models.Employee
		if err := database.DB.Where("id = ?", group.CreateBy).First(&employee).Error; err == nil {
			userStats = append(userStats, systemRes.UserStatItem{
				UserID:         employee.ID,
				UserName:       employee.Username,
				ReceivingCount: group.TotalReceiving,
				OutboundCount:  group.TotalOutbound,
			})
		}
	}

	return &systemRes.DashboardStatistResponse{
		TotalReceivingCount: totalReceivingCount,
		TotalOutboundCount:  totalOutboundCount,
		TotalSaleCount:      totalSaleCount,
		UserStats:           userStats,
	}, nil
}

// GetWarehouseStatist 获取仓库统计数据
func (s *StatistService) GetWarehouseStatist(req systemReq.WarehouseStatistRequest, db ...*gorm.DB) (*systemRes.WarehouseStatistResponse, error) {
	databaseConn := database.OptionalDB(db...)

	now := time.Now()
	startOfDay := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location()).Unix()
	endOfDay := time.Date(now.Year(), now.Month(), now.Day(), 23, 59, 59, 0, now.Location()).Unix()
	yesterdayStart := time.Date(now.Year(), now.Month(), now.Day()-1, 0, 0, 0, 0, now.Location()).Unix()
	yesterdayEnd := time.Date(now.Year(), now.Month(), now.Day()-1, 23, 59, 59, 0, now.Location()).Unix()

	if req.StartDate == 0 {
		req.StartDate = startOfDay
	}
	if req.EndDate == 0 {
		req.EndDate = endOfDay
	}

	type WarehouseStat struct {
		ProductTotal   int64 `gorm:"column:product_total"`
		InventoryTotal int64 `gorm:"column:inventory_total"`
	}

	var warehouseStat WarehouseStat
	databaseConn.Table("(?) as p", databaseConn.Model(&models.Product{}).Where("is_del = ?", 0).Select("COUNT(*) as product_total")).
		Select(`
			p.product_total,
			COALESCE((SELECT SUM(quantity) FROM inventory WHERE is_del = ?), 0) as inventory_total
		`, 0).
		Scan(&warehouseStat)

	type DailyStat struct {
		TodayInbound      int64 `gorm:"column:today_inbound"`
		TodayOutbound     int64 `gorm:"column:today_outbound"`
		YesterdayInbound  int64 `gorm:"column:yesterday_inbound"`
		YesterdayOutbound int64 `gorm:"column:yesterday_outbound"`
	}

	var dailyStat DailyStat
	databaseConn.Model(&models.Statist{}).
		Select(`
			COALESCE(SUM(CASE WHEN stat_date >= ? AND stat_date <= ? THEN receiving_num ELSE 0 END), 0) as today_inbound,
			COALESCE(SUM(CASE WHEN stat_date >= ? AND stat_date <= ? THEN outbound_num ELSE 0 END), 0) as today_outbound,
			COALESCE(SUM(CASE WHEN stat_date >= ? AND stat_date <= ? THEN receiving_num ELSE 0 END), 0) as yesterday_inbound,
			COALESCE(SUM(CASE WHEN stat_date >= ? AND stat_date <= ? THEN outbound_num ELSE 0 END), 0) as yesterday_outbound
		`, req.StartDate, req.EndDate, req.StartDate, req.EndDate, yesterdayStart, yesterdayEnd, yesterdayStart, yesterdayEnd).
		Where("is_del = ?", 0).
		Scan(&dailyStat)

	return &systemRes.WarehouseStatistResponse{
		ProductTotal:      warehouseStat.ProductTotal,
		InventoryTotal:    warehouseStat.InventoryTotal,
		TodayInbound:      dailyStat.TodayInbound,
		TodayOutbound:     dailyStat.TodayOutbound,
		YesterdayInbound:  dailyStat.YesterdayInbound,
		YesterdayOutbound: dailyStat.YesterdayOutbound,
	}, nil
}

// GetOrderStatist 获取订单统计数据
func (s *StatistService) GetOrderStatist(req systemReq.OrderStatistRequest, db ...*gorm.DB) (*systemRes.OrderStatistResponse, error) {
	databaseConn := database.OptionalDB(db...)

	now := time.Now()
	startOfDay := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location()).Unix()
	endOfDay := time.Date(now.Year(), now.Month(), now.Day(), 23, 59, 59, 0, now.Location()).Unix()
	yesterdayStart := time.Date(now.Year(), now.Month(), now.Day()-1, 0, 0, 0, 0, now.Location()).Unix()
	yesterdayEnd := time.Date(now.Year(), now.Month(), now.Day()-1, 23, 59, 59, 0, now.Location()).Unix()

	if req.StartDate == 0 {
		req.StartDate = startOfDay
	}
	if req.EndDate == 0 {
		req.EndDate = endOfDay
	}

	const (
		StatusDraft     = 1
		StatusConfirmed = 2
		StatusShipped   = 5
		StatusCancelled = 6
	)

	type OrderDailyStat struct {
		TodayQuantity      int64 `gorm:"column:today_quantity"`
		TodayAmount        int64 `gorm:"column:today_amount"`
		TodayShipped       int64 `gorm:"column:today_shipped"`
		TodayUnshipped     int64 `gorm:"column:today_unshipped"`
		TodayPending       int64 `gorm:"column:today_pending"`
		YesterdayQuantity  int64 `gorm:"column:yesterday_quantity"`
		YesterdayAmount    int64 `gorm:"column:yesterday_amount"`
		YesterdayShipped   int64 `gorm:"column:yesterday_shipped"`
		YesterdayUnshipped int64 `gorm:"column:yesterday_unshipped"`
		YesterdayPending   int64 `gorm:"column:yesterday_pending"`
	}

	var orderStat OrderDailyStat
	databaseConn.Model(&models.SalesOrder{}).
		Select(`
			COALESCE(SUM(CASE WHEN created_at >= ? AND created_at <= ? THEN 1 ELSE 0 END), 0) as today_quantity,
			COALESCE(SUM(CASE WHEN created_at >= ? AND created_at <= ? THEN total_amount ELSE 0 END), 0) as today_amount,
			COALESCE(SUM(CASE WHEN created_at >= ? AND created_at <= ? AND status = ? THEN 1 ELSE 0 END), 0) as today_shipped,
			COALESCE(SUM(CASE WHEN created_at >= ? AND created_at <= ? AND status NOT IN (?, ?) THEN 1 ELSE 0 END), 0) as today_unshipped,
			COALESCE(SUM(CASE WHEN created_at >= ? AND created_at <= ? AND status IN (?, ?) THEN 1 ELSE 0 END), 0) as today_pending,
			COALESCE(SUM(CASE WHEN created_at >= ? AND created_at <= ? THEN 1 ELSE 0 END), 0) as yesterday_quantity,
			COALESCE(SUM(CASE WHEN created_at >= ? AND created_at <= ? THEN total_amount ELSE 0 END), 0) as yesterday_amount,
			COALESCE(SUM(CASE WHEN created_at >= ? AND created_at <= ? AND status = ? THEN 1 ELSE 0 END), 0) as yesterday_shipped,
			COALESCE(SUM(CASE WHEN created_at >= ? AND created_at <= ? AND status NOT IN (?, ?) THEN 1 ELSE 0 END), 0) as yesterday_unshipped,
			COALESCE(SUM(CASE WHEN created_at >= ? AND created_at <= ? AND status IN (?, ?) THEN 1 ELSE 0 END), 0) as yesterday_pending
		`, req.StartDate, req.EndDate, req.StartDate, req.EndDate, req.StartDate, req.EndDate, StatusShipped, req.StartDate, req.EndDate, StatusShipped, StatusCancelled, req.StartDate, req.EndDate, StatusDraft, StatusConfirmed,
			yesterdayStart, yesterdayEnd, yesterdayStart, yesterdayEnd, yesterdayStart, yesterdayEnd, StatusShipped, yesterdayStart, yesterdayEnd, StatusShipped, StatusCancelled, yesterdayStart, yesterdayEnd, StatusDraft, StatusConfirmed).
		Where("is_del = ?", 0).
		Scan(&orderStat)

	return &systemRes.OrderStatistResponse{
		Today: systemRes.OrderStatItem{
			Quantity:  orderStat.TodayQuantity,
			Amount:    orderStat.TodayAmount,
			Shipped:   orderStat.TodayShipped,
			Unshipped: orderStat.TodayUnshipped,
			Pending:   orderStat.TodayPending,
		},
		Yesterday: systemRes.OrderStatItem{
			Quantity:  orderStat.YesterdayQuantity,
			Amount:    orderStat.YesterdayAmount,
			Shipped:   orderStat.YesterdayShipped,
			Unshipped: orderStat.YesterdayUnshipped,
			Pending:   orderStat.YesterdayPending,
		},
	}, nil
}