实现 RemoveEmptyPenFromBatch

internal/domain/pig/pig_batch_service.go

@@ -6,6 +6,7 @@ import (
 
 	"git.huangwc.com/pig/pig-farm-controller/internal/infra/models"
 	"git.huangwc.com/pig/pig-farm-controller/internal/infra/repository"
+	"gorm.io/gorm"
 )
 
 // --- 业务错误定义 ---
@@ -25,6 +26,8 @@ var (
 	ErrPenNotFound = errors.New("指定的猪栏不存在")
 	// ErrPenNotAssociatedWithBatch 表示猪栏未与该批次关联
 	ErrPenNotAssociatedWithBatch = errors.New("猪栏未与该批次关联")
+	// ErrPenNotEmpty 表示猪栏内仍有猪只，不允许执行当前操作。
+	ErrPenNotEmpty = errors.New("猪栏内仍有猪只，无法执行此操作")
 	// ErrInvalidOperation 非法操作
 	ErrInvalidOperation = errors.New("非法操作")
 )
@@ -52,6 +55,8 @@ type PigBatchService interface {
 	MovePigsIntoPen(batchID uint, toPenID uint, quantity int, operatorID uint, remarks string) error
 	// ReclassifyPenToNewBatch 连猪带栏，整体划拨到另一个猪群
 	ReclassifyPenToNewBatch(fromBatchID uint, toBatchID uint, penID uint, operatorID uint, remarks string) error
+	// RemoveEmptyPenFromBatch 将一个猪栏移除出猪群，此方法需要在猪栏为空的情况下执行。
+	RemoveEmptyPenFromBatch(batchID uint, penID uint) error
 
 	// GetCurrentPigQuantity 获取指定猪批次的当前猪只数量。
 	GetCurrentPigQuantity(batchID uint) (int, error)
@@ -115,3 +120,48 @@ func NewPigBatchService(
 		sickSvc:         sickSvc,
 	}
 }
+
+func (s *pigBatchService) RemoveEmptyPenFromBatch(batchID uint, penID uint) error {
+	return s.uow.ExecuteInTransaction(func(tx *gorm.DB) error {
+		// 1. 检查猪批次是否存在且活跃
+		batch, err := s.pigBatchRepo.GetPigBatchByIDTx(tx, batchID)
+		if err != nil {
+			if errors.Is(err, gorm.ErrRecordNotFound) {
+				return ErrPigBatchNotFound
+			}
+			return err
+		}
+		if !batch.IsActive() {
+			return ErrPigBatchNotActive
+		}
+
+		// 2. 检查猪栏是否存在
+		pen, err := s.transferSvc.GetPenByID(tx, penID)
+		if err != nil {
+			if errors.Is(err, gorm.ErrRecordNotFound) {
+				return ErrPenNotFound
+			}
+			return err
+		}
+
+		// 3. 检查猪栏是否与当前批次关联
+		if pen.PigBatchID == nil || *pen.PigBatchID != batchID {
+			return ErrPenNotAssociatedWithBatch
+		}
+
+		// 4. 检查猪栏是否为空
+		pigsInPen, err := s.transferSvc.GetCurrentPigsInPen(tx, penID)
+		if err != nil {
+			return err
+		}
+		if pigsInPen > 0 {
+			return ErrPenNotEmpty
+		}
+
+		// 5. 释放猪栏 (将 pig_batch_id 设置为 nil，状态设置为空闲)
+		if err := s.transferSvc.ReleasePen(tx, penID); err != nil {
+			return err
+		}
+		return nil
+	})
+}