package dao

import (
	"context"
	"fmt"
	"time"

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

	"gitee.com/red-future---jilin-g/common/do"
	"gitee.com/red-future---jilin-g/common/mongo"

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

// OrderQuarterlyStatisticsDAO 订单季度统计DAO
type OrderQuarterlyStatisticsDAO struct {
}

var OrderQuarterlyStatisticsDAOInstance = &OrderQuarterlyStatisticsDAO{}

// GenerateStatistics 使用Go代码生成季度统计数据
func (dao *OrderQuarterlyStatisticsDAO) GenerateStatistics(ctx context.Context, tenantID int64, year int, quarter int) (*entity.OrderQuarterlyStatistics, error) {
	// 设置时间范围
	var startDate time.Time
	switch quarter {
	case 1:
		startDate = time.Date(year, 1, 1, 0, 0, 0, 0, time.Local)
	case 2:
		startDate = time.Date(year, 4, 1, 0, 0, 0, 0, time.Local)
	case 3:
		startDate = time.Date(year, 7, 1, 0, 0, 0, 0, time.Local)
	case 4:
		startDate = time.Date(year, 10, 1, 0, 0, 0, 0, time.Local)
	default:
		return nil, fmt.Errorf("无效的季度: %d", quarter)
	}
	endDate := startDate.AddDate(0, 3, 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.OrderQuarterlyStatistics{
			MongoBaseDO: do.MongoBaseDO{
				TenantId:  tenantID,
				CreatedAt: time.Now(),
				UpdatedAt: time.Now(),
			},
			ReportDate: startDate,
			Period:     fmt.Sprintf("%d-Q%d", year, quarter),
			Quarter:    quarter,
		}
		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)
	monthlyOrders := make([]int64, 3)
	monthlyAmounts := make([]int64, 3)

	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]++
			}
		}

		// 统计月度分布
		month := int(order.CreatedAt.Month())
		quarterStartMonth := int(startDate.Month())
		if month >= quarterStartMonth && month < quarterStartMonth+3 {
			index := month - quarterStartMonth
			if index >= 0 && index < 3 {
				monthlyOrders[index]++
				monthlyAmounts[index] += 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.OrderQuarterlyStatistics{
		MongoBaseDO: do.MongoBaseDO{
			TenantId:  tenantID,
			CreatedAt: time.Now(),
			UpdatedAt: time.Now(),
		},
		ReportDate:               startDate,
		Period:                   fmt.Sprintf("%d-Q%d", year, quarter),
		Quarter:                  quarter,
		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,
		MonthlyOrders:            monthlyOrders,
		MonthlyAmounts:           monthlyAmounts,
		PeakMonth:                dao.findPeakMonth(monthlyOrders),
		QuarterOverQuarterGrowth: dao.calculateQuarterOverQuarterGrowth(ctx, tenantID, year, quarter, totalOrders),
		YearOverYearGrowth:       dao.calculateYearOverYearGrowth(ctx, tenantID, year, totalOrders),
	}

	return statistics, nil
}

// findTopAsset 找出热门资产
func (dao *OrderQuarterlyStatisticsDAO) 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
}

// findPeakMonth 找出高峰月份
func (dao *OrderQuarterlyStatisticsDAO) findPeakMonth(monthlyOrders []int64) int {
	maxMonth := 1
	maxCount := int64(0)

	for i, count := range monthlyOrders {
		if count > maxCount {
			maxCount = count
			maxMonth = i + 1
		}
	}

	return maxMonth
}

// calculateQuarterOverQuarterGrowth 计算环比增长率
func (dao *OrderQuarterlyStatisticsDAO) calculateQuarterOverQuarterGrowth(ctx context.Context, tenantID int64, year, quarter int, currentOrders int64) float64 {
	// 计算上个季度
	lastYear := year
	lastQuarter := quarter - 1
	if lastQuarter == 0 {
		lastYear = year - 1
		lastQuarter = 4
	}

	// 查询上个季度的订单数据
	var lastQuarterStartDate time.Time
	switch lastQuarter {
	case 1:
		lastQuarterStartDate = time.Date(lastYear, 1, 1, 0, 0, 0, 0, time.Local)
	case 2:
		lastQuarterStartDate = time.Date(lastYear, 4, 1, 0, 0, 0, 0, time.Local)
	case 3:
		lastQuarterStartDate = time.Date(lastYear, 7, 1, 0, 0, 0, 0, time.Local)
	case 4:
		lastQuarterStartDate = time.Date(lastYear, 10, 1, 0, 0, 0, 0, time.Local)
	default:
		return 0.0
	}
	lastQuarterEndDate := lastQuarterStartDate.AddDate(0, 3, 0)

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

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

	lastQuarterOrderCount := int64(len(lastQuarterOrders))
	if lastQuarterOrderCount == 0 {
		return 0.0
	}

	// 计算环比增长率
	growth := (float64(currentOrders) - float64(lastQuarterOrderCount)) / float64(lastQuarterOrderCount) * 100
	return growth
}

// calculateYearOverYearGrowth 计算同比增长率
func (dao *OrderQuarterlyStatisticsDAO) 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 保存季度统计数据
func (dao *OrderQuarterlyStatisticsDAO) Save(ctx context.Context, statistics *entity.OrderQuarterlyStatistics) error {
	_, err := mongo.DB().Insert(ctx, []interface{}{statistics}, consts.OrderQuarterlyStatisticsCollection)
	return err
}

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

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

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

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

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

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

	return &result, nil
}