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后端 Go+Gin：认证/CSRF/限流、板块、帖子、评论、点赞、通知、用户资料、置顶推荐；前端 Next.js 16：发帖/编辑/删除、搜索、分页、点赞、通知中心、设置；基础设施 docker-compose 与配置模板；添加 .gitignore 与专有许可证（保留所有权利）

backend/service/notification.go

@@ -0,0 +1,82 @@
+package service
+
+import (
+	"github.com/freefire/jiang13-bbs/model"
+	"gorm.io/gorm"
+)
+
+// NotificationService 通知服务
+type NotificationService struct {
+	db *gorm.DB
+}
+
+func NewNotificationService(db *gorm.DB) *NotificationService {
+	return &NotificationService{db: db}
+}
+
+// Create 创建通知（actorID == userID 时跳过，不通知自己）
+func (s *NotificationService) Create(userID, actorID uint, notifType string, postID, commentID uint, content string) {
+	if userID == 0 || actorID == 0 || userID == actorID {
+		return
+	}
+	// 截断内容预览
+	if len(content) > 200 {
+		content = content[:200]
+	}
+	n := &model.Notification{
+		UserID:    userID,
+		ActorID:   actorID,
+		Type:      notifType,
+		PostID:    postID,
+		CommentID: commentID,
+		Content:   content,
+		IsRead:    false,
+	}
+	// 通知创建失败不影响主流程，忽略错误
+	_ = s.db.Create(n).Error
+}
+
+// List 获取用户通知列表（分页，按时间倒序）
+func (s *NotificationService) List(userID uint, page, size int) ([]model.Notification, int64, error) {
+	if page < 1 {
+		page = 1
+	}
+	if size < 1 || size > 50 {
+		size = 20
+	}
+	query := s.db.Model(&model.Notification{}).Where("user_id = ?", userID)
+	var total int64
+	if err := query.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+	var list []model.Notification
+	offset := (page - 1) * size
+	if err := query.Order("created_at DESC").Offset(offset).Limit(size).
+		Preload("Actor").Preload("Post").Find(&list).Error; err != nil {
+		return nil, 0, err
+	}
+	return list, total, nil
+}
+
+// UnreadCount 获取未读通知数
+func (s *NotificationService) UnreadCount(userID uint) (int64, error) {
+	var total int64
+	err := s.db.Model(&model.Notification{}).Where("user_id = ? AND is_read = ?", userID, false).Count(&total).Error
+	return total, err
+}
+
+// MarkRead 标记单条通知为已读（校验归属）
+func (s *NotificationService) MarkRead(id, userID uint) error {
+	result := s.db.Model(&model.Notification{}).
+		Where("id = ? AND user_id = ?", id, userID).
+		Update("is_read", true)
+	return result.Error
+}
+
+// MarkAllRead 标记用户所有通知为已读
+func (s *NotificationService) MarkAllRead(userID uint) error {
+	result := s.db.Model(&model.Notification{}).
+		Where("user_id = ? AND is_read = ?", userID, false).
+		Update("is_read", true)
+	return result.Error
+}