ai_dianshang/server/internal/repository/product.go

package repository

import (
	"dianshang/internal/model"

	"gorm.io/gorm"
)

// ProductRepository 产品仓储
type ProductRepository struct {
	db *gorm.DB
}

// NewProductRepository 创建产品仓储
func NewProductRepository(db *gorm.DB) *ProductRepository {
	return &ProductRepository{db: db}
}

// GetDB 获取数据库连接
func (r *ProductRepository) GetDB() *gorm.DB {
	return r.db
}

// GetList 获取产品列表
func (r *ProductRepository) GetList(offset, limit int, conditions map[string]interface{}) ([]model.Product, int64, error) {
    var products []model.Product
    var total int64

    query := r.db.Model(&model.Product{})

	// 默认只查询上架商品，除非明确指定状态
	if statusValue, exists := conditions["status"]; exists {
		if statusValue == "all" {
			// 管理系统可以传递 "all" 来获取所有状态的商品
		} else {
			query = query.Where("status = ?", statusValue)
		}
	} else {
		// 默认只查询上架商品（兼容原有逻辑）
		query = query.Where("status = ?", 1)
	}

	// 添加查询条件
	var sortField string
	var sortType string
    for key, value := range conditions {
        switch key {
        case "category_id":
            // 支持包含子分类的筛选
            var catID uint
            switch v := value.(type) {
            case uint:
                catID = v
            case int:
                catID = uint(v)
            case float64:
                catID = uint(v)
            }
            if catID > 0 {
                categoryIDs, err := r.getCategoryIDsIncludingChildren(catID)
                if err == nil && len(categoryIDs) > 0 {
                    query = query.Where("category_id IN (?)", categoryIDs)
                } else {
                    // 兜底：如果获取子分类失败，退化为当前分类
                    query = query.Where("category_id = ?", catID)
                }
            }
        case "keyword":
            query = query.Where("name LIKE ? OR description LIKE ?", "%"+value.(string)+"%", "%"+value.(string)+"%")
        case "min_price":
            query = query.Where("price >= ?", value)
        case "max_price":
			query = query.Where("price <= ?", value)
		case "is_hot":
			if value.(string) == "true" {
				query = query.Where("is_hot = ?", true)
			} else if value.(string) == "false" {
				query = query.Where("is_hot = ?", false)
			}
		case "is_new":
			if value.(string) == "true" {
				query = query.Where("is_new = ?", true)
			} else if value.(string) == "false" {
				query = query.Where("is_new = ?", false)
			}
		case "is_recommend":
			if value.(string) == "true" {
				query = query.Where("is_recommend = ?", true)
			} else if value.(string) == "false" {
				query = query.Where("is_recommend = ?", false)
			}
		case "sort":
			sortField = value.(string)
		case "sort_type":
			sortType = value.(string)
		case "status":
			// 状态条件已在上面处理，这里跳过
			continue
		}
	}

	// 获取总数
	if err := query.Count(&total).Error; err != nil {
		return nil, 0, err
	}

	// 构建排序条件
	orderBy := "sort DESC, created_at DESC" // 默认排序
	if sortField != "" {
		switch sortField {
		case "price":
			if sortType == "asc" {
				orderBy = "price ASC"
			} else {
				orderBy = "price DESC"
			}
		case "sales":
			if sortType == "asc" {
				orderBy = "sales ASC"
			} else {
				orderBy = "sales DESC"
			}
		case "created_at":
			if sortType == "asc" {
				orderBy = "created_at ASC"
			} else {
				orderBy = "created_at DESC"
			}
		}
	}

	// 获取列表，预加载分类
    err := query.Preload("Category").
        Offset(offset).Limit(limit).Order(orderBy).Find(&products).Error
    return products, total, err
}

// GetByID 根据ID获取产品详情
func (r *ProductRepository) GetByID(id uint) (*model.Product, error) {
	var product model.Product
	err := r.db.Preload("Category").Preload("Specs").Preload("SKUs", "status = ?", 1).
		Where("id = ?", id).First(&product).Error
	return &product, err
}

// Create 创建产品
func (r *ProductRepository) Create(product *model.Product) error {
	return r.db.Create(product).Error
}

// Update 更新产品
func (r *ProductRepository) Update(id uint, updates map[string]interface{}) error {
	return r.db.Model(&model.Product{}).Where("id = ?", id).Updates(updates).Error
}

// Delete 删除产品（软删除）
func (r *ProductRepository) Delete(id uint) error {
	// 使用GORM软删除，只删除商品主记录
	// 关联记录保留，通过商品的deleted_at字段来判断商品是否被删除
	return r.db.Delete(&model.Product{}, id).Error
}

// UpdateStock 更新库存
func (r *ProductRepository) UpdateStock(id uint, quantity int) error {
	return r.db.Model(&model.Product{}).Where("id = ?", id).
		Update("stock", gorm.Expr("stock + ?", quantity)).Error
}

// UpdateSales 更新销量
func (r *ProductRepository) UpdateSales(id uint, quantity int) error {
	return r.db.Model(&model.Product{}).Where("id = ?", id).
		Update("sales", gorm.Expr("sales + ?", quantity)).Error
}

// DeductStock 扣减库存（支付成功时使用）
func (r *ProductRepository) DeductStock(id uint, quantity int) error {
	// 检查库存是否充足并扣减
	result := r.db.Model(&model.Product{}).
		Where("id = ? AND stock >= ?", id, quantity).
		Update("stock", gorm.Expr("stock - ?", quantity))
	
	if result.Error != nil {
		return result.Error
	}
	
	if result.RowsAffected == 0 {
		return gorm.ErrRecordNotFound // 库存不足或产品不存在
	}
	
	return nil
}

// ReserveStock 预扣库存（创建订单时使用）
func (r *ProductRepository) ReserveStock(id uint, quantity int) error {
	// 检查库存是否充足并预扣
	result := r.db.Model(&model.Product{}).
		Where("id = ? AND stock >= ?", id, quantity).
		Update("stock", gorm.Expr("stock - ?", quantity))
	
	if result.Error != nil {
		return result.Error
	}
	
	if result.RowsAffected == 0 {
		return gorm.ErrRecordNotFound // 库存不足或产品不存在
	}
	
	return nil
}

// RestoreStock 恢复库存（取消订单或支付失败时使用）
func (r *ProductRepository) RestoreStock(id uint, quantity int) error {
	return r.db.Model(&model.Product{}).Where("id = ?", id).
		Update("stock", gorm.Expr("stock + ?", quantity)).Error
}

// GetCategories 获取分类列表
func (r *ProductRepository) GetCategories() ([]model.Category, error) {
	var allCategories []model.Category
	err := r.db.Where("status = ?", 1).Order("level ASC, sort DESC, created_at ASC").Find(&allCategories).Error
	if err != nil {
		return nil, err
	}

	// 构建层级关系
	categoryMap := make(map[uint]*model.Category)
	var rootCategories []model.Category

	// 先将所有分类放入map
	for i := range allCategories {
		categoryMap[allCategories[i].ID] = &allCategories[i]
	}

	// 构建父子关系
	for i := range allCategories {
		category := &allCategories[i]
		if category.ParentID == nil {
			// 一级分类
			rootCategories = append(rootCategories, *category)
		} else {
			// 二级分类，添加到父分类的Children中
			if parent, exists := categoryMap[*category.ParentID]; exists {
				parent.Children = append(parent.Children, *category)
			}
		}
	}

	// 更新根分类的Children并设置HasChildren字段
	for i := range rootCategories {
		if parent, exists := categoryMap[rootCategories[i].ID]; exists {
			rootCategories[i].Children = parent.Children
			rootCategories[i].HasChildren = len(parent.Children) > 0
		}
		// 为子分类设置HasChildren字段
		for j := range rootCategories[i].Children {
			rootCategories[i].Children[j].HasChildren = false // 二级分类没有子分类
		}
	}

	return rootCategories, nil
}

// GetCategoryByID 根据ID获取分类
func (r *ProductRepository) GetCategoryByID(id uint) (*model.Category, error) {
	var category model.Category
	err := r.db.Where("id = ? AND status = ?", id, 1).First(&category).Error
	return &category, err
}

// CreateCategory 创建分类
func (r *ProductRepository) CreateCategory(category *model.Category) error {
	return r.db.Create(category).Error
}

// UpdateCategory 更新分类
func (r *ProductRepository) UpdateCategory(id uint, updates map[string]interface{}) error {
	return r.db.Model(&model.Category{}).Where("id = ?", id).Updates(updates).Error
}

// DeleteCategory 删除分类
func (r *ProductRepository) DeleteCategory(id uint) error {
	return r.db.Delete(&model.Category{}, id).Error
}

// GetReviews 获取产品评价列表
func (r *ProductRepository) GetReviews(productID uint, offset, limit int) ([]model.ProductReview, int64, error) {
	var reviews []model.ProductReview
	var total int64

	query := r.db.Model(&model.ProductReview{}).Where("product_id = ?", productID)

	// 获取总数
	if err := query.Count(&total).Error; err != nil {
		return nil, 0, err
	}

	// 获取列表
	err := query.Offset(offset).Limit(limit).
		Order("created_at DESC").Find(&reviews).Error
	return reviews, total, err
}

// CreateReview 创建评价
func (r *ProductRepository) CreateReview(review *model.ProductReview) error {
	return r.db.Create(review).Error
}

// GetReviewByOrderID 根据订单ID获取评价
func (r *ProductRepository) GetReviewByOrderID(userID uint, orderID uint) (*model.ProductReview, error) {
	var review model.ProductReview
	err := r.db.Where("user_id = ? AND order_id = ?", userID, orderID).First(&review).Error
	return &review, err
}

// GetReviewCount 获取产品评价统计
func (r *ProductRepository) GetReviewCount(productID uint) (map[string]interface{}, error) {
	var total int64
	var goodCount int64    // 好评数 (4-5星)
	var middleCount int64  // 中评数 (3星)
	var badCount int64     // 差评数 (1-2星)
	var hasImageCount int64 // 有图评价数

	// 获取总评价数
	if err := r.db.Model(&model.ProductReview{}).Where("product_id = ?", productID).Count(&total).Error; err != nil {
		return nil, err
	}

	// 获取好评数 (4-5星)
	if err := r.db.Model(&model.ProductReview{}).Where("product_id = ? AND rating >= ?", productID, 4).
		Count(&goodCount).Error; err != nil {
		return nil, err
	}

	// 获取中评数 (3星)
	if err := r.db.Model(&model.ProductReview{}).Where("product_id = ? AND rating = ?", productID, 3).
		Count(&middleCount).Error; err != nil {
		return nil, err
	}

	// 获取差评数 (1-2星)
	if err := r.db.Model(&model.ProductReview{}).Where("product_id = ? AND rating <= ?", productID, 2).
		Count(&badCount).Error; err != nil {
		return nil, err
	}

	// 获取有图评价数
	if err := r.db.Model(&model.ProductReview{}).Where("product_id = ? AND images IS NOT NULL AND images != ''", productID).
		Count(&hasImageCount).Error; err != nil {
		return nil, err
	}

	// 计算好评率
	var goodRate float64 = 100.0
	if total > 0 {
		goodRate = float64(goodCount) / float64(total) * 100
	}

	result := map[string]interface{}{
		"total":           total,
		"good_rate":       goodRate,
		"good_count":      goodCount,
		"middle_count":    middleCount,
		"bad_count":       badCount,
		"has_image_count": hasImageCount,
	}

	return result, nil
}

// GetProductImages 获取产品图片
func (r *ProductRepository) GetProductImages(productID uint) ([]model.ProductImage, error) {
	var images []model.ProductImage
	err := r.db.Where("product_id = ?", productID).Order("sort ASC").Find(&images).Error
	return images, err
}

// CreateProductImage 创建产品图片
func (r *ProductRepository) CreateProductImage(image *model.ProductImage) error {
	return r.db.Create(image).Error
}

// DeleteProductImage 删除产品图片
func (r *ProductRepository) DeleteProductImage(id uint) error {
	return r.db.Delete(&model.ProductImage{}, id).Error
}

// GetProductSpecs 获取产品规格
func (r *ProductRepository) GetProductSpecs(productID uint) ([]model.ProductSpec, error) {
	var specs []model.ProductSpec
	err := r.db.Where("product_id = ?", productID).Order("sort ASC").Find(&specs).Error
	return specs, err
}

// CreateProductSpec 创建产品规格
func (r *ProductRepository) CreateProductSpec(spec *model.ProductSpec) error {
	return r.db.Create(spec).Error
}

// UpdateProductSpec 更新产品规格
func (r *ProductRepository) UpdateProductSpec(id uint, updates map[string]interface{}) error {
	return r.db.Model(&model.ProductSpec{}).Where("id = ?", id).Updates(updates).Error
}

// DeleteProductSpec 删除产品规格
func (r *ProductRepository) DeleteProductSpec(id uint) error {
	return r.db.Delete(&model.ProductSpec{}, id).Error
}

// GetHotProducts 获取热门产品
func (r *ProductRepository) GetHotProducts(limit int) ([]model.Product, error) {
	var products []model.Product
	err := r.db.Preload("Category").
		Where("status = ? AND is_hot = ?", 1, 1).
		Order("sales DESC, created_at DESC").Limit(limit).Find(&products).Error
	return products, err
}

// GetRecommendProducts 获取推荐产品
func (r *ProductRepository) GetRecommendProducts(limit int) ([]model.Product, error) {
	var products []model.Product
	err := r.db.Preload("Category").
		Where("status = ? AND is_recommend = ?", 1, 1).
		Order("sort DESC, created_at DESC").Limit(limit).Find(&products).Error
	return products, err
}

// GetProductSKUs 获取产品SKU列表
func (r *ProductRepository) GetProductSKUs(productID uint) ([]model.ProductSKU, error) {
	var skus []model.ProductSKU
	err := r.db.Where("product_id = ? AND status = ?", productID, 1).
		Order("weight ASC").Find(&skus).Error
	return skus, err
}

// GetSKUByID 根据SKU ID获取SKU详情
func (r *ProductRepository) GetSKUByID(skuID uint) (*model.ProductSKU, error) {
	var sku model.ProductSKU
	err := r.db.Where("id = ? AND status = ?", skuID, 1).First(&sku).Error
	return &sku, err
}

// GetProductTags 获取产品标签列表
func (r *ProductRepository) GetProductTags() ([]model.ProductTag, error) {
	var tags []model.ProductTag
	err := r.db.Where("status = ?", 1).Order("sort ASC").Find(&tags).Error
	return tags, err
}

// GetStores 获取店铺列表
func (r *ProductRepository) GetStores() ([]model.Store, error) {
	var stores []model.Store
	err := r.db.Where("status = ?", 1).Order("sort ASC").Find(&stores).Error
	return stores, err
}

// GetStoreByID 根据ID获取店铺信息
func (r *ProductRepository) GetStoreByID(id uint) (*model.Store, error) {
	var store model.Store
	err := r.db.Where("id = ? AND status = ?", id, 1).First(&store).Error
	return &store, err
}

// GetProductStatistics 获取产品统计
func (r *ProductRepository) GetProductStatistics() (map[string]interface{}, error) {
	result := make(map[string]interface{})

	// 总商品数
	var totalProducts int64
	if err := r.db.Model(&model.Product{}).Count(&totalProducts).Error; err != nil {
		return nil, err
	}
	result["total_products"] = totalProducts

	// 上架商品数
	var onlineProducts int64
	if err := r.db.Model(&model.Product{}).Where("status = ?", 1).Count(&onlineProducts).Error; err != nil {
		return nil, err
	}
	result["online_products"] = onlineProducts

	// 下架商品数
	var offlineProducts int64
	if err := r.db.Model(&model.Product{}).Where("status = ?", 0).Count(&offlineProducts).Error; err != nil {
		return nil, err
	}
	result["offline_products"] = offlineProducts

	// 库存不足商品数（库存小于10）
	var lowStockProducts int64
	if err := r.db.Model(&model.Product{}).Where("stock < ?", 10).Count(&lowStockProducts).Error; err != nil {
		return nil, err
	}
	result["low_stock_products"] = lowStockProducts

	return result, nil
}

// GetCategorySalesStatistics 获取分类销售统计
func (r *ProductRepository) GetCategorySalesStatistics(startDate, endDate string, limit int) ([]map[string]interface{}, error) {
	var results []map[string]interface{}
	
	query := `
		SELECT 
			c.id as category_id,
			c.name as category_name,
			COALESCE(SUM(oi.quantity), 0) as sales_count,
			COALESCE(SUM(oi.total_price), 0) as sales_amount
		FROM ai_categories c
		LEFT JOIN ai_products p ON c.id = p.category_id
		LEFT JOIN order_items oi ON p.id = oi.product_id
		LEFT JOIN ai_orders o ON oi.order_id = o.id
		WHERE c.status = 1
			AND (o.created_at IS NULL OR (o.created_at >= ? AND o.created_at <= ?))
			AND (o.status IS NULL OR o.status IN (2, 3, 4, 5, 6))
		GROUP BY c.id, c.name
		ORDER BY sales_amount DESC
		LIMIT ?
	`
	
	err := r.db.Raw(query, startDate+" 00:00:00", endDate+" 23:59:59", limit).Scan(&results).Error
	return results, err
}

// BatchUpdateStatus 批量更新商品状态
func (r *ProductRepository) BatchUpdateStatus(ids []uint, status int) error {
	return r.db.Model(&model.Product{}).Where("id IN ?", ids).Update("status", status).Error
}

// BatchUpdatePrice 批量更新商品价格
func (r *ProductRepository) BatchUpdatePrice(updates []map[string]interface{}) error {
	tx := r.db.Begin()
	defer func() {
		if r := recover(); r != nil {
			tx.Rollback()
		}
	}()

	for _, update := range updates {
		if id, ok := update["id"]; ok {
			delete(update, "id")
			if err := tx.Model(&model.Product{}).Where("id = ?", id).Updates(update).Error; err != nil {
				tx.Rollback()
				return err
			}
		}
	}

	return tx.Commit().Error
}

// CountProductsByCategory 统计指定分类下的商品数量（包括子分类）
func (r *ProductRepository) CountProductsByCategory(categoryID uint) (int64, error) {
	var count int64
	
	// 获取所有子分类ID
	var categoryIDs []uint
	categoryIDs = append(categoryIDs, categoryID)
	
	// 查找所有子分类
	var childCategories []model.Category
	err := r.db.Where("parent_id = ?", categoryID).Find(&childCategories).Error
	if err != nil {
		return 0, err
	}
	
	for _, child := range childCategories {
		categoryIDs = append(categoryIDs, child.ID)
	}
	
	// 统计这些分类下的商品数量（只统计未删除的商品）
	err = r.db.Model(&model.Product{}).
		Where("category_id IN (?)", categoryIDs).
		Count(&count).Error
	
	return count, err
}

// BatchDelete 批量删除商品（软删除）
func (r *ProductRepository) BatchDelete(ids []uint) error {
	if len(ids) == 0 {
		return nil
	}

	// 使用GORM软删除，只删除商品主记录
	// 关联记录保留，通过商品的deleted_at字段来判断商品是否被删除
	return r.db.Delete(&model.Product{}, ids).Error
}

// CreateSKU 创建商品SKU
func (r *ProductRepository) CreateSKU(sku *model.ProductSKU) error {
	return r.db.Create(sku).Error
}

// UpdateSKU 更新商品SKU
func (r *ProductRepository) UpdateSKU(id uint, updates map[string]interface{}) error {
	return r.db.Model(&model.ProductSKU{}).Where("id = ?", id).Updates(updates).Error
}

// DeleteSKU 删除商品SKU
func (r *ProductRepository) DeleteSKU(id uint) error {
	// 检查SKU是否被订单引用
	var count int64
	err := r.db.Table("order_items").Where("sk_uid = ?", id).Count(&count).Error
	if err != nil {
		return err
	}
	
	if count > 0 {
		// 如果被订单引用，使用软删除（设置status=0）
		return r.db.Model(&model.ProductSKU{}).Where("id = ?", id).Update("status", 0).Error
	} else {
		// 如果没有被引用，可以进行硬删除
		return r.db.Delete(&model.ProductSKU{}, id).Error
	}
}

// UpdateProductImageSort 更新商品图片排序
func (r *ProductRepository) UpdateProductImageSort(id uint, sort int) error {
	return r.db.Model(&model.ProductImage{}).Where("id = ?", id).Update("sort", sort).Error
}

// CreateProductTag 创建商品标签
func (r *ProductRepository) CreateProductTag(tag *model.ProductTag) error {
	return r.db.Create(tag).Error
}

// UpdateProductTag 更新商品标签
func (r *ProductRepository) UpdateProductTag(id uint, updates map[string]interface{}) error {
	return r.db.Model(&model.ProductTag{}).Where("id = ?", id).Updates(updates).Error
}

// DeleteProductTag 删除商品标签
func (r *ProductRepository) DeleteProductTag(id uint) error {
	return r.db.Delete(&model.ProductTag{}, id).Error
}

// AssignTagsToProduct 为商品分配标签
func (r *ProductRepository) AssignTagsToProduct(productID uint, tagIDs []uint) error {
	// 先清除现有关联
	if err := r.db.Exec("DELETE FROM ai_product_tag_relations WHERE product_id = ?", productID).Error; err != nil {
		return err
	}

	// 添加新关联
	if len(tagIDs) > 0 {
		var relations []map[string]interface{}
		for _, tagID := range tagIDs {
			relations = append(relations, map[string]interface{}{
				"product_id": productID,
				"tag_id":     tagID,
			})
		}
		return r.db.Table("ai_product_tag_relations").Create(relations).Error
	}

	return nil
}

// GetLowStockProducts 获取低库存商品
func (r *ProductRepository) GetLowStockProducts(threshold int) ([]model.Product, error) {
	var products []model.Product
	err := r.db.Where("stock <= ? AND status = ?", threshold, 1).
		Preload("Category").Find(&products).Error
	return products, err
}

// GetInventoryStatistics 获取库存统计
func (r *ProductRepository) GetInventoryStatistics() (map[string]interface{}, error) {
	var result map[string]interface{}
	
	// 总商品数
	var totalProducts int64
	r.db.Model(&model.Product{}).Where("status = ?", 1).Count(&totalProducts)
	
	// 低库存商品数（库存小于等于10）
	var lowStockProducts int64
	r.db.Model(&model.Product{}).Where("stock <= ? AND status = ?", 10, 1).Count(&lowStockProducts)
	
	// 缺货商品数
	var outOfStockProducts int64
	r.db.Model(&model.Product{}).Where("stock = ? AND status = ?", 0, 1).Count(&outOfStockProducts)
	
	// 总库存值
	var totalStockValue float64
	r.db.Model(&model.Product{}).Where("status = ?", 1).
		Select("SUM(stock * price)").Scan(&totalStockValue)
	
	result = map[string]interface{}{
		"total_products":      totalProducts,
		"low_stock_products":  lowStockProducts,
		"out_of_stock_products": outOfStockProducts,
		"total_stock_value":   totalStockValue,
	}
	
	return result, nil
}

// GetProductsForExport 获取用于导出的商品数据
func (r *ProductRepository) GetProductsForExport(conditions map[string]interface{}) ([]model.Product, error) {
    var products []model.Product
    query := r.db.Model(&model.Product{}).Preload("Category")

    // 添加查询条件
    for key, value := range conditions {
        switch key {
        case "category_id":
            // 导出也支持子分类
            var catID uint
            switch v := value.(type) {
            case uint:
                catID = v
            case int:
                catID = uint(v)
            case float64:
                catID = uint(v)
            }
            if catID > 0 {
                categoryIDs, err := r.getCategoryIDsIncludingChildren(catID)
                if err == nil && len(categoryIDs) > 0 {
                    query = query.Where("category_id IN (?)", categoryIDs)
                } else {
                    query = query.Where("category_id = ?", catID)
                }
            }
        case "status":
            query = query.Where("status = ?", value)
        case "keyword":
            query = query.Where("name LIKE ? OR description LIKE ?", "%"+value.(string)+"%", "%"+value.(string)+"%")
        }
    }
	
	err := query.Find(&products).Error
    return products, err
}

// getCategoryIDsIncludingChildren 获取给定分类ID及其子分类ID集合（仅支持两级分类）
func (r *ProductRepository) getCategoryIDsIncludingChildren(categoryID uint) ([]uint, error) {
    // 将自身分类加入集合
    ids := []uint{categoryID}

    // 查找直接子分类（系统设计为最多二级）
    var childCategories []model.Category
    if err := r.db.Where("parent_id = ? AND status = ?", categoryID, 1).Find(&childCategories).Error; err != nil {
        return ids, err
    }
    for _, child := range childCategories {
        ids = append(ids, child.ID)
    }
    return ids, nil
}

// DeductSKUStock 扣减SKU库存
func (r *ProductRepository) DeductSKUStock(skuID uint, quantity int) error {
	// 检查SKU库存是否充足并扣减
	result := r.db.Model(&model.ProductSKU{}).
		Where("id = ? AND stock >= ?", skuID, quantity).
		Update("stock", gorm.Expr("stock - ?", quantity))
	
	if result.Error != nil {
		return result.Error
	}
	
	if result.RowsAffected == 0 {
		return gorm.ErrRecordNotFound // SKU库存不足或SKU不存在
	}
	
	return nil
}

// RestoreSKUStock 恢复SKU库存
func (r *ProductRepository) RestoreSKUStock(skuID uint, quantity int) error {
	return r.db.Model(&model.ProductSKU{}).Where("id = ?", skuID).
		Update("stock", gorm.Expr("stock + ?", quantity)).Error
}

// SyncProductStockFromSKUs 根据SKU库存同步商品总库存
func (r *ProductRepository) SyncProductStockFromSKUs(productID uint) error {
	// 计算所有SKU的库存总和
	var totalStock int
	err := r.db.Model(&model.ProductSKU{}).
		Where("product_id = ? AND status = ?", productID, 1).
		Select("COALESCE(SUM(stock), 0)").Scan(&totalStock).Error
	
	if err != nil {
		return err
	}
	
	// 更新商品总库存
	return r.db.Model(&model.Product{}).Where("id = ?", productID).
		Update("stock", totalStock).Error
}

// DeductStockWithSKU 扣减商品和SKU库存（支持SKU商品的库存扣减）
func (r *ProductRepository) DeductStockWithSKU(productID uint, skuID *uint, quantity int) error {
	tx := r.db.Begin()
	defer func() {
		if r := recover(); r != nil {
			tx.Rollback()
		}
	}()

	if skuID != nil && *skuID > 0 {
		// 有SKU的商品，先扣减SKU库存
		result := tx.Model(&model.ProductSKU{}).
			Where("id = ? AND stock >= ?", *skuID, quantity).
			Update("stock", gorm.Expr("stock - ?", quantity))
		
		if result.Error != nil {
			tx.Rollback()
			return result.Error
		}
		
		if result.RowsAffected == 0 {
			tx.Rollback()
			return gorm.ErrRecordNotFound // SKU库存不足
		}
		
		// 同步更新商品总库存
		var totalStock int
		err := tx.Model(&model.ProductSKU{}).
			Where("product_id = ? AND status = ?", productID, 1).
			Select("COALESCE(SUM(stock), 0)").Scan(&totalStock).Error
		
		if err != nil {
			tx.Rollback()
			return err
		}
		
		err = tx.Model(&model.Product{}).Where("id = ?", productID).
			Update("stock", totalStock).Error
		
		if err != nil {
			tx.Rollback()
			return err
		}
	} else {
		// 没有SKU的商品，直接扣减商品库存
		result := tx.Model(&model.Product{}).
			Where("id = ? AND stock >= ?", productID, quantity).
			Update("stock", gorm.Expr("stock - ?", quantity))
		
		if result.Error != nil {
			tx.Rollback()
			return result.Error
		}
		
		if result.RowsAffected == 0 {
			tx.Rollback()
			return gorm.ErrRecordNotFound // 商品库存不足
		}
	}

	return tx.Commit().Error
}

// RestoreStockWithSKU 恢复商品和SKU库存（支持SKU商品的库存恢复）
func (r *ProductRepository) RestoreStockWithSKU(productID uint, skuID *uint, quantity int) error {
	tx := r.db.Begin()
	defer func() {
		if r := recover(); r != nil {
			tx.Rollback()
		}
	}()

	if skuID != nil && *skuID > 0 {
		// 有SKU的商品，先恢复SKU库存
		err := tx.Model(&model.ProductSKU{}).Where("id = ?", *skuID).
			Update("stock", gorm.Expr("stock + ?", quantity)).Error
		
		if err != nil {
			tx.Rollback()
			return err
		}
		
		// 同步更新商品总库存
		var totalStock int
		err = tx.Model(&model.ProductSKU{}).
			Where("product_id = ? AND status = ?", productID, 1).
			Select("COALESCE(SUM(stock), 0)").Scan(&totalStock).Error
		
		if err != nil {
			tx.Rollback()
			return err
		}
		
		err = tx.Model(&model.Product{}).Where("id = ?", productID).
			Update("stock", totalStock).Error
		
		if err != nil {
			tx.Rollback()
			return err
		}
	} else {
		// 没有SKU的商品，直接恢复商品库存
		err := tx.Model(&model.Product{}).Where("id = ?", productID).
			Update("stock", gorm.Expr("stock + ?", quantity)).Error
		
		if err != nil {
			tx.Rollback()
			return err
		}
	}

	return tx.Commit().Error
}