package dao

import (
	"context"
	"fmt"
	"time"

	"order/consts"
	"order/model/entity"

	"gitea.com/red-future/common/beans"
	"gitea.com/red-future/common/db/mongo"

	"go.mongodb.org/mongo-driver/v2/bson"
)

// OrderYearlyStatisticsDAO 订单年度统计DAO
type OrderYearlyStatisticsDAO struct {
}

var OrderYearlyStatisticsDAOInstance = &OrderYearlyStatisticsDAO{}

// GenerateStatistics 使用Go代码生成年度统计数据
func (dao *OrderYearlyStatisticsDAO) GenerateStatistics(ctx context.Context, tenantID int64, year int) (*entity.OrderYearlyStatistics, error) {
	// 设置时间范围
	startDate := time.Date(year, 1, 1, 0, 0, 0, 0, time.Local)
	endDate := startDate.AddDate(1, 0, 0)

	// 查询订单数据
	filter := bson.M{
		"tenantId": tenantID,
		"createdAt": bson.M{
			"$gte": startDate,
			"$lt":  endDate,
		},
	}

	var orders []*entity.OrderBase
	err := mongo.DB().Find(ctx, filter, &orders, consts.OrderCollection)
	if err != nil {
		return nil, fmt.Errorf("查询订单数据失败: %v", err)
	}

	// 如果没有数据，创建空统计
	if len(orders) == 0 {
		statistics := &entity.OrderYearlyStatistics{
			MongoBaseDO: beans.MongoBaseDO{
				TenantId:  tenantID,
				CreatedAt: time.Now(),
				UpdatedAt: time.Now(),
			},
			ReportDate: startDate,
			Period:     startDate.Format("2006"),
			Year:       year,
		}
		return statistics, nil
	}

	// 使用Go代码计算统计指标
	totalOrders := int64(len(orders))
	totalAmount := int64(0)
	completedOrders := int64(0)
	cancelledOrders := int64(0)
	paidOrders := int64(0)
	totalItems := int64(0)

	uniqueUsers := make(map[int64]bool)
	uniqueAssets := make(map[string]bool)
	assetCounts := make(map[string]int64)
	quarterlyOrders := make([]int64, 4)
	quarterlyAmounts := make([]int64, 4)
	monthlyOrders := make([]int64, 12)
	monthlyAmounts := make([]int64, 12)

	for _, order := range orders {
		// 计算总金额
		totalAmount += order.TotalAmount

		// 注意：OrderBase结构体没有Status字段，状态统计需要通过其他方式获取

		// 统计唯一用户
		uniqueUsers[order.UserID] = true

		// 统计商品信息
		if order.OrderItems != nil {
			totalItems += int64(len(order.OrderItems))
			for _, item := range order.OrderItems {
				uniqueAssets[item.AssetID] = true
				assetCounts[item.AssetID]++
			}
		}

		// 统计季度分布
		quarter := (int(order.CreatedAt.Month())-1)/3 + 1
		if quarter >= 1 && quarter <= 4 {
			quarterlyOrders[quarter-1]++
			quarterlyAmounts[quarter-1] += order.TotalAmount
		}

		// 统计月度分布
		month := int(order.CreatedAt.Month())
		if month >= 1 && month <= 12 {
			monthlyOrders[month-1]++
			monthlyAmounts[month-1] += order.TotalAmount
		}
	}

	// 计算业务指标
	var averageOrderValue int64
	if totalOrders > 0 {
		averageOrderValue = totalAmount / totalOrders
	}

	var paymentRate, completionRate float64
	if totalOrders > 0 {
		paymentRate = float64(paidOrders) / float64(totalOrders) * 100
		completionRate = float64(completedOrders) / float64(totalOrders) * 100
	}

	// 获取热门资产
	topAssetID, topAssetName, topAssetCount := dao.findTopAsset(assetCounts, orders)

	statistics := &entity.OrderYearlyStatistics{
		MongoBaseDO: beans.MongoBaseDO{
			TenantId:  tenantID,
			CreatedAt: time.Now(),
			UpdatedAt: time.Now(),
		},
		ReportDate:         startDate,
		Period:             startDate.Format("2006"),
		Year:               year,
		TotalOrders:        totalOrders,
		CompletedOrders:    completedOrders,
		CancelledOrders:    cancelledOrders,
		PaidOrders:         paidOrders,
		TotalAmount:        totalAmount,
		PaidAmount:         totalAmount,
		NetAmount:          totalAmount,
		AverageOrderValue:  averageOrderValue,
		PaymentRate:        paymentRate,
		CompletionRate:     completionRate,
		UniqueUsers:        int64(len(uniqueUsers)),
		NewUsers:           0,
		ReturningUsers:     0,
		TotalItems:         totalItems,
		UniqueAssets:       int64(len(uniqueAssets)),
		TopAssetID:         topAssetID,
		TopAssetName:       topAssetName,
		TopAssetCount:      topAssetCount,
		QuarterlyOrders:    quarterlyOrders,
		QuarterlyAmounts:   quarterlyAmounts,
		PeakQuarter:        dao.findPeakQuarter(quarterlyOrders),
		MonthlyOrders:      monthlyOrders,
		MonthlyAmounts:     monthlyAmounts,
		YearOverYearGrowth: dao.calculateYearOverYearGrowth(ctx, tenantID, year, totalOrders),
	}

	return statistics, nil
}

// findTopAsset 找出热门资产
func (dao *OrderYearlyStatisticsDAO) findTopAsset(assetCounts map[string]int64, orders []*entity.OrderBase) (string, string, int64) {
	if len(assetCounts) == 0 {
		return "", "", 0
	}

	var topAssetID string
	var maxCount int64

	for assetID, count := range assetCounts {
		if count > maxCount {
			maxCount = count
			topAssetID = assetID
		}
	}

	// 查找资产名称
	var topAssetName string
	for _, order := range orders {
		if order.OrderItems != nil {
			for _, item := range order.OrderItems {
				if item.AssetID == topAssetID {
					topAssetName = item.AssetName
					break
				}
			}
		}
		if topAssetName != "" {
			break
		}
	}

	return topAssetID, topAssetName, maxCount
}

// findPeakQuarter 找出高峰季度
func (dao *OrderYearlyStatisticsDAO) findPeakQuarter(quarterlyOrders []int64) int {
	maxQuarter := 1
	maxCount := int64(0)

	for i, count := range quarterlyOrders {
		if count > maxCount {
			maxCount = count
			maxQuarter = i + 1
		}
	}

	return maxQuarter
}

// calculateYearOverYearGrowth 计算同比增长率
func (dao *OrderYearlyStatisticsDAO) calculateYearOverYearGrowth(ctx context.Context, tenantID int64, year int, currentOrders int64) float64 {
	// 查询去年同期的订单数据
	lastYear := year - 1
	lastYearStartDate := time.Date(lastYear, 1, 1, 0, 0, 0, 0, time.Local)
	lastYearEndDate := lastYearStartDate.AddDate(1, 0, 0)

	filter := bson.M{
		"tenantId": tenantID,
		"createdAt": bson.M{
			"$gte": lastYearStartDate,
			"$lt":  lastYearEndDate,
		},
	}

	var lastYearOrders []*entity.OrderBase
	err := mongo.DB().Find(ctx, filter, &lastYearOrders, consts.OrderCollection)
	if err != nil || len(lastYearOrders) == 0 {
		return 0.0
	}

	lastYearOrderCount := int64(len(lastYearOrders))
	if lastYearOrderCount == 0 {
		return 0.0
	}

	// 计算同比增长率
	growth := (float64(currentOrders) - float64(lastYearOrderCount)) / float64(lastYearOrderCount) * 100
	return growth
}

// Save 保存年度统计数据
func (dao *OrderYearlyStatisticsDAO) Save(ctx context.Context, statistics *entity.OrderYearlyStatistics) error {
	_, err := mongo.DB().Insert(ctx, []interface{}{statistics}, consts.OrderYearlyStatisticsCollection)
	return err
}

// Update 更新年度统计数据
func (dao *OrderYearlyStatisticsDAO) Update(ctx context.Context, statistics *entity.OrderYearlyStatistics) error {
	filter := bson.M{
		"tenantId":   statistics.TenantId,
		"reportDate": statistics.ReportDate,
	}

	update := bson.M{
		"$set": statistics,
	}

	_, err := mongo.DB().Update(ctx, filter, update, consts.OrderYearlyStatisticsCollection)
	return err
}

// GetByTenantAndDate 获取指定租户和日期的年度统计数据
func (dao *OrderYearlyStatisticsDAO) GetByTenantAndDate(ctx context.Context, tenantID int64, reportDate time.Time) (*entity.OrderYearlyStatistics, error) {
	var result entity.OrderYearlyStatistics

	filter := bson.M{
		"tenantId":   tenantID,
		"reportDate": reportDate,
	}

	err := mongo.DB().FindOne(ctx, filter, &result, consts.OrderYearlyStatisticsCollection)
	if err != nil {
		return nil, err
	}

	return &result, nil
}