feat: Add customer order management module including repository, service, and configuration.

backend/internal/repository/cu_order_repository.go

@@ -139,12 +139,17 @@ func (r *cuOrderRepository) Delete(id string) error {
 
 func (r *cuOrderRepository) CheckTrialOrderExists(cuUserID string, currentMonth string) (bool, error) {
 	var count int64
-	startOfMonth := currentMonth + "-01"
-	endOfMonth := currentMonth + "-31"
+	startOfMonth := currentMonth + "-01 00:00:00"
+	endOfMonth := currentMonth + "-31 23:59:59"
 
 	err := r.db.Model(&models.CuOrder{}).
-		Where("cu_user_id = ? AND package_id = ? AND status = ? AND created_at >= ? AND created_at <= ? AND deleted_at IS NULL",
-			cuUserID, "trial", "paid", startOfMonth, endOfMonth).
+		Where("cu_user_id = ? AND (status = 'paid' OR status = 'pending') AND created_at >= ? AND created_at <= ? AND deleted_at IS NULL",
+			cuUserID, startOfMonth, endOfMonth).
+		// We need to join with package to check package type because package_id might be a UUID, not 'trial'.
+		// But if the order already recorded the type somewhere or if we just assume 'trial' is the package ID?
+		// Actually, let's just use a subquery or join to verify package type is trial.
+		Joins("JOIN packages ON packages.id = cu_orders.package_id").
+		Where("packages.type = ?", string(models.PackageTypeTrial)).
 		Count(&count).Error
 
 	return count > 0, err

backend/internal/service/cu_order_service.go

@@ -106,6 +106,30 @@ func (s *cuOrderService) CreatePendingOrder(ctx context.Context, cuUserID, custo
 		return nil, err
 	}
 
+	// 对于试用版，进行特殊检查
+	if pkgEntity.Type == string(models.PackageTypeTrial) {
+		// 试用版不支持批量购买
+		if req.LicenseCount != 1 {
+			return nil, i18n.NewI18nError("600004", lang) // 试用版不支持批量购买
+		}
+
+		// 检查购买时间限制
+		now := time.Now()
+		if now.Day() > 25 {
+			return nil, i18n.NewI18nError("600003", lang) // 试用版购买时间限制
+		}
+
+		// 每个用户每月只能有一个试用版（包括pending的）
+		currentMonth := now.Format("2006-01")
+		exists, err := s.repo.CheckTrialOrderExists(cuUserID, currentMonth)
+		if err != nil {
+			return nil, i18n.NewI18nError("900004", lang, err.Error())
+		}
+		if exists {
+			return nil, i18n.NewI18nError("600005", lang) // 当月已购买试用版
+		}
+	}
+
 	// 再次校验数量（防御性校验）
 	if req.LicenseCount > maxDevices {
 		return nil, i18n.NewI18nError("601005", lang)