⚡ add like functionality with Like model, implement like/unlike methods, and update Post and Comment models to track like counts

internal/repo/init.go

@@ -126,8 +126,10 @@ func migrate() error {
 	return GetDB().AutoMigrate(
 		&model.Comment{},
 		&model.Label{},
+		&model.Like{},
 		&model.OidcConfig{},
 		&model.Post{},
 		&model.Session{},
-		&model.User{})
+		&model.User{},
+		&model.UserOpenID{})
 }

internal/repo/like.go

@@ -0,0 +1,86 @@
+package repo
+
+import (
+	"errors"
+	"github.com/snowykami/neo-blog/internal/model"
+	"github.com/snowykami/neo-blog/pkg/constant"
+	"gorm.io/gorm"
+)
+
+type likeRepo struct{}
+
+var Like = &likeRepo{}
+
+// Like 用户点赞，幂等
+func (l *likeRepo) Like(userID, targetID uint, targetType string) error {
+	err := l.checkTargetType(targetType)
+	if err != nil {
+		return err
+	}
+	var existingLike model.Like
+	err = GetDB().Where("target_type = ? AND target_id = ? AND user_id = ?", targetType, targetID, userID).First(&existingLike).Error
+	if err == nil {
+		return nil
+	}
+	if !errors.Is(err, gorm.ErrRecordNotFound) {
+		return err
+	}
+
+	like := &model.Like{
+		TargetType: targetType,
+		TargetID:   targetID,
+		UserID:     userID,
+	}
+
+	return GetDB().Create(like).Error
+}
+
+// UnLike 取消点赞
+func (l *likeRepo) UnLike(userID, targetID uint, targetType string) error {
+	err := l.checkTargetType(targetType)
+	if err != nil {
+		return err
+	}
+	return GetDB().Where("target_type = ? AND target_id = ? AND user_id = ?",
+		targetType, targetID, userID).Delete(&model.Like{}).Error
+}
+
+// IsLiked 检查是否点赞
+func (l *likeRepo) IsLiked(userID, targetID uint, targetType string) (bool, error) {
+	err := l.checkTargetType(targetType)
+	if err != nil {
+		return false, err
+	}
+	var like model.Like
+	err = GetDB().Where("target_type = ? AND target_id = ? AND user_id = ?", targetType, targetID, userID).First(&like).Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return false, nil
+		}
+		return false, err
+	}
+	return true, nil
+}
+
+// Count 点赞计数
+func (l *likeRepo) Count(targetID uint, targetType string) (int64, error) {
+	err := l.checkTargetType(targetType)
+	if err != nil {
+		return 0, err
+	}
+	var count int64
+	err = GetDB().Model(&model.Like{}).Where("target_type = ? AND target_id = ?", targetType, targetID).Count(&count).Error
+	if err != nil {
+		return 0, err
+	}
+	return count, nil
+}
+
+func (l *likeRepo) checkTargetType(targetType string) error {
+	switch targetType {
+	case constant.TargetTypePost, constant.TargetTypeComment:
+		return nil
+	default:
+		return errors.New("invalid target type")
+	}
+}