update

internal/repository/street_snap_repository.go

@@ -223,10 +223,11 @@ func (r *streetSnapRepository) Popular(ctx context.Context, limit int) ([]model.
 
 // snapEditable 后台可编辑的街拍字段白名单（键即列名）。
 var snapEditable = map[string]bool{
-	"title": true,
-	"year":  true,
-	"city":  true,
-	"cover": true,
+	"title":    true,
+	"title_cn": true,
+	"year":     true,
+	"city":     true,
+	"cover":    true,
 }
 
 func (r *streetSnapRepository) GetForEdit(ctx context.Context, id uint32) (*model.StreetSnap, []model.StreetSnapImage, error) {
@@ -274,21 +275,49 @@ func (r *streetSnapRepository) UpdateSnap(ctx context.Context, id uint32, fields
 func (r *streetSnapRepository) DeleteSnapImage(ctx context.Context, imageID uint32) error {
 	return r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
 		var img model.StreetSnapImage
-		err := tx.Select("snap_id").Where("id = ?", imageID).First(&img).Error
+		err := tx.Select("snap_id, image").Where("id = ?", imageID).First(&img).Error
 		if errors.Is(err, gorm.ErrRecordNotFound) {
 			return nil
 		}
 		if err != nil {
 			return err
 		}
+		// 取出父记录的封面，判断被删图是否正是封面（防止封面悬空指向已删图 —— 设计规格 §12 唯一真数据丢失窗口）。
+		var snap model.StreetSnap
+		if err := tx.Select("cover").Where("id = ?", img.SnapID).First(&snap).Error; err != nil {
+			return err
+		}
 		if err := tx.Model(&model.StreetSnapImage{}).
 			Where("id = ? AND is_deleted = 0", imageID).
 			Updates(map[string]any{"is_deleted": 1, "updated_at": uint32(time.Now().Unix())}).Error; err != nil {
 			return err
 		}
-		return tx.Exec(`UPDATE street_snaps SET image_count =
+		if err := tx.Exec(`UPDATE street_snaps SET image_count =
 			(SELECT COUNT(*) FROM street_snap_images WHERE snap_id = ? AND is_deleted = 0)
-			WHERE id = ?`, img.SnapID, img.SnapID).Error
+			WHERE id = ?`, img.SnapID, img.SnapID).Error; err != nil {
+			return err
+		}
+		// 被删图是封面：重指向另一张存活图（无存活图则清空），避免封面悬空。
+		if snap.Cover == img.Image {
+			cover := ""
+			var survivor struct {
+				Image string `gorm:"column:image"`
+			}
+			serr := tx.Raw(
+				"SELECT image FROM street_snap_images WHERE snap_id = ? AND is_deleted = 0 ORDER BY id ASC LIMIT 1",
+				img.SnapID,
+			).Scan(&survivor).Error
+			if serr == nil {
+				cover = survivor.Image
+			} else if !errors.Is(serr, gorm.ErrRecordNotFound) {
+				return serr
+			}
+			if err := tx.Model(&model.StreetSnap{}).Where("id = ?", img.SnapID).
+				Updates(map[string]any{"cover": cover, "updated_at": uint32(time.Now().Unix())}).Error; err != nil {
+				return err
+			}
+		}
+		return nil
 	})
 }
 
@@ -326,6 +355,13 @@ func (r *streetSnapRepository) SoftDeleteSnapImages(ctx context.Context, snapID
 		Updates(map[string]any{"is_deleted": 1, "updated_at": uint32(time.Now().Unix())}).Error; err != nil {
 		return nil, err
 	}
+	// 全部图片软删：封面必然悬空（封面本就指向被删图之一），直接清空避免悬空指针。
+	if err := r.db.WithContext(ctx).
+		Model(&model.StreetSnap{}).
+		Where("id = ?", snapID).
+		Updates(map[string]any{"cover": "", "updated_at": uint32(time.Now().Unix())}).Error; err != nil {
+		return nil, err
+	}
 	return keys, nil
 }