增加删除检查

internal/infra/repository/pig_farm_repository.go

@@ -8,8 +8,9 @@ import (
 )
 
 var (
-	ErrHouseContainsPens = errors.New("cannot delete a pig house that still contains pens")
-	ErrHouseNotFound     = errors.New("the specified pig house does not exist")
+	ErrHouseContainsPens = errors.New("请在移除所有猪圈后移除当前猪舍")
+	ErrHouseNotFound     = errors.New("猪舍不存在")
+	ErrPenInUse          = errors.New("猪栏正在被活跃批次使用，无法删除")
 )
 
 // PigFarmRepository 定义了与猪场资产（猪舍、猪栏）相关的数据库操作接口
@@ -146,7 +147,28 @@ func (r *gormPigFarmRepository) UpdatePen(pen *models.Pen) error {
 }
 
 func (r *gormPigFarmRepository) DeletePen(id uint) error {
-	result := r.db.Delete(&models.Pen{}, id)
+	return r.db.Transaction(func(tx *gorm.DB) error {
+		var pen models.Pen
+		if err := tx.First(&pen, id).Error; err != nil {
+			if errors.Is(err, gorm.ErrRecordNotFound) {
+				return gorm.ErrRecordNotFound
+			}
+			return err
+		}
+
+		// 检查猪栏是否被活跃批次使用
+		if pen.PigBatchID != 0 {
+			var pigBatch models.PigBatch
+			err := tx.First(&pigBatch, pen.PigBatchID).Error
+			if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
+				return err
+			}
+			if pigBatch.IsActive() {
+				return ErrPenInUse
+			}
+		}
+
+		result := tx.Delete(&models.Pen{}, id)
 		if result.Error != nil {
 			return result.Error
 		}
@@ -154,4 +176,5 @@ func (r *gormPigFarmRepository) DeletePen(id uint) error {
 			return gorm.ErrRecordNotFound
 		}
 		return nil
+	})
 }