猪栏信息接口增加猪栏当前存栏量

internal/domain/pig/pig_batch_service.go

@@ -58,6 +58,8 @@ type PigBatchService interface {
 
 	// GetCurrentPigQuantity 获取指定猪批次的当前猪只数量。
 	GetCurrentPigQuantity(batchID uint) (int, error)
+	// GetCurrentPigsInPen 获取指定猪栏的当前存栏量。
+	GetCurrentPigsInPen(penID uint) (int, error)
 
 	UpdatePigBatchQuantity(operatorID uint, batchID uint, changeType models.LogChangeType, changeAmount int, changeReason string, happenedAt time.Time) error
 
@@ -163,3 +165,16 @@ func (s *pigBatchService) RemoveEmptyPenFromBatch(batchID uint, penID uint) erro
 		return nil
 	})
 }
+
+func (s *pigBatchService) GetCurrentPigsInPen(penID uint) (int, error) {
+	var currentPigs int
+	err := s.uow.ExecuteInTransaction(func(tx *gorm.DB) error {
+		pigs, err := s.transferSvc.GetCurrentPigsInPen(tx, penID)
+		if err != nil {
+			return err
+		}
+		currentPigs = pigs
+		return nil
+	})
+	return currentPigs, err
+}