package logic

import (
	"context"

	"healthapi/internal/model"
	"healthapi/internal/svc"
	"healthapi/internal/types"
	"healthapi/pkg/errorx"

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

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

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

func (l *UpdateCartLogic) UpdateCart(req *types.UpdateCartReq) (resp *types.CartItem, err error) {
	userID, err := GetUserIDFromCtx(l.ctx)
	if err != nil {
		return nil, errorx.ErrUnauthorized
	}

	var cartItem model.CartItem
	if err := l.svcCtx.DB.Where("id = ? AND user_id = ?", req.Id, userID).First(&cartItem).Error; err != nil {
		return nil, errorx.NewCodeError(404, "购物车项不存在")
	}

	// 获取商品信息
	var product model.Product
	if err := l.svcCtx.DB.First(&product, cartItem.ProductID).Error; err != nil {
		return nil, errorx.NewCodeError(404, "商品不存在")
	}

	price := product.Price
	stock := product.Stock
	skuName := ""
	image := product.MainImage

	// 如果有 SKU
	if cartItem.SkuID > 0 {
		var sku model.ProductSku
		if err := l.svcCtx.DB.First(&sku, cartItem.SkuID).Error; err == nil {
			price = sku.Price
			stock = sku.Stock
			skuName = sku.Name
			if sku.Image != "" {
				image = sku.Image
			}
		}
	}

	// 更新数量
	if req.Quantity > 0 {
		if req.Quantity > stock {
			return nil, errorx.NewCodeError(400, "库存不足")
		}
		cartItem.Quantity = req.Quantity
	}

	// 更新选中状态（使用结构体字段，因为 bool 默认值为 false）
	cartItem.Selected = req.Selected

	if err := l.svcCtx.DB.Save(&cartItem).Error; err != nil {
		return nil, err
	}

	resp = &types.CartItem{
		ID:          uint(cartItem.ID),
		ProductID:   cartItem.ProductID,
		SkuID:       cartItem.SkuID,
		ProductName: product.Name,
		SkuName:     skuName,
		Image:       image,
		Price:       price,
		Quantity:    cartItem.Quantity,
		Selected:    cartItem.Selected,
		Stock:       stock,
	}
	return resp, nil
}