package logic

import (
	"context"
	"fmt"

	"muyu-apiserver/pkg/tenantctx"
	"muyu-apiserver/rpc/purchase/internal/svc"
	"muyu-apiserver/rpc/purchase/pb"

	"github.com/zeromicro/go-zero/core/logx"
)

type GetPurchaseStatsByProductLogic struct {
	ctx    context.Context
	svcCtx *svc.ServiceContext
	logx.Logger
}

func NewGetPurchaseStatsByProductLogic(ctx context.Context, svcCtx *svc.ServiceContext) *GetPurchaseStatsByProductLogic {
	return &GetPurchaseStatsByProductLogic{ctx: ctx, svcCtx: svcCtx, Logger: logx.WithContext(ctx)}
}

func (l *GetPurchaseStatsByProductLogic) GetPurchaseStatsByProduct(in *pb.PurchaseStatsSummaryReq) (*pb.PurchaseStatsByProductResp, error) {
	tenantId := tenantctx.ExtractTenantId(l.ctx)

	orders, _, err := l.svcCtx.OrderModel.FindList(l.ctx, tenantId, 1, 10000, "", -1, in.StartDate, in.EndDate)
	if err != nil {
		return nil, err
	}

	type productKey struct {
		productId string
	}
	type productStats struct {
		productName string
		spec        string
		color       string
		totalQty    float64
		totalAmount float64
		orderCount  int64
	}
	statsMap := map[string]*productStats{}

	for _, o := range orders {
		if o.Status == 2 {
			continue
		}
		details, err := l.svcCtx.OrderDetailModel.FindByOrderId(l.ctx, o.OrderId)
		if err != nil {
			continue
		}
		for _, d := range details {
			s := statsMap[d.ProductId]
			if s == nil {
				s = &productStats{
					productName: d.ProductName,
					spec:        d.Spec,
					color:       d.Color,
				}
				statsMap[d.ProductId] = s
			}
			s.totalQty += d.Quantity
			s.totalAmount += d.Amount
			s.orderCount++
		}
	}

	items := make([]*pb.PurchaseStatsByProductItem, 0, len(statsMap))
	for productId, s := range statsMap {
		avgPrice := 0.0
		if s.totalQty > 0 {
			avgPrice = s.totalAmount / s.totalQty
		}
		items = append(items, &pb.PurchaseStatsByProductItem{
			ProductId:    productId,
			ProductName:  s.productName,
			Spec:         s.spec,
			Color:        s.color,
			TotalQty:     fmt.Sprintf("%.2f", s.totalQty),
			AvgUnitPrice: fmt.Sprintf("%.2f", avgPrice),
			TotalAmount:  fmt.Sprintf("%.2f", s.totalAmount),
		})
	}
	return &pb.PurchaseStatsByProductResp{List: items}, nil
}