refactor：优化了like和unlike功能

internal/video/like_handler.go

@@ -89,21 +89,3 @@ func (lh *LikeHandler) IsLiked(c *gin.Context) {
 	}
 	c.JSON(200, gin.H{"is_liked": isLiked})
 }
-
-func (lh *LikeHandler) GetLikesCount(c *gin.Context) {
-	var req LikeRequest
-	if err := c.ShouldBindJSON(&req); err != nil {
-		c.JSON(400, gin.H{"error": err.Error()})
-		return
-	}
-	if req.VideoID <= 0 {
-		c.JSON(400, gin.H{"error": "video_id is required"})
-		return
-	}
-	likesCount, err := lh.service.GetLikesCount(c.Request.Context(), req.VideoID)
-	if err != nil {
-		c.JSON(500, gin.H{"error": err.Error()})
-		return
-	}
-	c.JSON(200, gin.H{"likes_count": likesCount})
-}

internal/video/like_repo.go

@@ -34,14 +34,3 @@ func (r *LikeRepository) IsLiked(ctx context.Context, videoID, accountID uint) (
 	}
 	return count > 0, nil
 }
-
-func (r *LikeRepository) GetLikesCount(ctx context.Context, videoID uint) (int64, error) {
-	var count int64
-	err := r.db.WithContext(ctx).Model(&Like{}).
-		Where("video_id = ?", videoID).
-		Count(&count).Error
-	if err != nil {
-		return 0, err
-	}
-	return count, nil
-}

internal/video/like_service.go

@@ -4,6 +4,9 @@ import (
 	"context"
 	"errors"
 	"time"
+
+	"github.com/go-sql-driver/mysql"
+	"gorm.io/gorm"
 )
 
 type LikeService struct {
@@ -15,69 +18,49 @@ func NewLikeService(repo *LikeRepository, videoRepo *VideoRepository) *LikeServi
 	return &LikeService{repo: repo, VideoRepo: videoRepo}
 }
 
-func (s *LikeService) Like(ctx context.Context, like *Like) error {
+func isDupKey(err error) bool {
-	exists, err := s.VideoRepo.IsExist(ctx, like.VideoID)
+	var me *mysql.MySQLError
-	if err != nil {
+	return errors.As(err, &me) && me.Number == 1062
-		return err
+}
-	}
-	if !exists {
-		return errors.New("video not found")
-	}
 
-	isLiked, err := s.IsLiked(ctx, like.VideoID, like.AccountID)
+func (s *LikeService) Like(ctx context.Context, like *Like) error {
-	if err != nil {
-		return err
-	}
-	if isLiked {
-		return errors.New("user has liked this video")
-	}
 	like.CreatedAt = time.Now()
-	if err := s.repo.Like(ctx, like); err != nil {
+	return s.repo.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
-		return err
+		if err := tx.Select("id").First(&Video{}, like.VideoID).Error; err != nil {
-	}
+			if errors.Is(err, gorm.ErrRecordNotFound) {
-	likesCount, err := s.GetLikesCount(ctx, like.VideoID)
+				return errors.New("video not found")
-	if err != nil {
+			}
-		return err
+			return err
-	}
+		}
-	if err := s.VideoRepo.UpdateLikesCount(ctx, like.VideoID, likesCount); err != nil {
+		if err := tx.Create(like).Error; err != nil {
-		return err
+			if isDupKey(err) {
-	}
+				return errors.New("user has liked this video")
-	return nil
+			}
+			return err
+		}
+		if err := tx.Model(&Video{}).Where("id = ?", like.VideoID).
+			UpdateColumn("likes_count", gorm.Expr("likes_count + 1")).Error; err != nil {
+			return err
+		}
+		return nil
+	})
 }
 
 func (s *LikeService) Unlike(ctx context.Context, like *Like) error {
-	exists, err := s.VideoRepo.IsExist(ctx, like.VideoID)
+	return s.repo.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
-	if err != nil {
+		del := tx.Where("video_id = ? AND account_id = ?", like.VideoID, like.AccountID).Delete(&Like{})
-		return err
+		if del.Error != nil {
-	}
+			return del.Error
-	if !exists {
+		}
-		return errors.New("video not found")
+		if del.RowsAffected == 0 {
-	}
+			return errors.New("user has not liked this video")
+		}
 
-	isLiked, err := s.IsLiked(ctx, like.VideoID, like.AccountID)
+		return tx.Model(&Video{}).Where("id = ?", like.VideoID).
-	if err != nil {
+			UpdateColumn("likes_count", gorm.Expr("GREATEST(likes_count - 1, 0)")).Error
-		return err
+	})
-	}
-	if !isLiked {
-		return errors.New("user has not liked this video")
-	}
-	if err := s.repo.Unlike(ctx, like); err != nil {
-		return err
-	}
-	likesCount, err := s.GetLikesCount(ctx, like.VideoID)
-	if err != nil {
-		return err
-	}
-	if err := s.VideoRepo.UpdateLikesCount(ctx, like.VideoID, likesCount); err != nil {
-		return err
-	}
-	return nil
 }
 
 func (s *LikeService) IsLiked(ctx context.Context, videoID, accountID uint) (bool, error) {
 	return s.repo.IsLiked(ctx, videoID, accountID)
 }
-
-func (s *LikeService) GetLikesCount(ctx context.Context, videoID uint) (int64, error) {
-	return s.repo.GetLikesCount(ctx, videoID)
-}