Initial backend repository commit.

Set up project files and add .gitignore to exclude local build/runtime artifacts.

Made-with: Cursor

internal/service/notification_service.go

@@ -0,0 +1,169 @@
+package service
+
+import (
+	"context"
+	"time"
+
+	"carrot_bbs/internal/cache"
+	"carrot_bbs/internal/model"
+	"carrot_bbs/internal/repository"
+)
+
+// 缓存TTL常量
+const (
+	NotificationUnreadCountTTL = 30 * time.Second // 通知未读数缓存30秒
+	NotificationNullTTL        = 5 * time.Second
+	NotificationCacheJitter    = 0.1
+)
+
+// NotificationService 通知服务
+type NotificationService struct {
+	notificationRepo *repository.NotificationRepository
+	cache            cache.Cache
+}
+
+// NewNotificationService 创建通知服务
+func NewNotificationService(notificationRepo *repository.NotificationRepository) *NotificationService {
+	return &NotificationService{
+		notificationRepo: notificationRepo,
+		cache:            cache.GetCache(),
+	}
+}
+
+// Create 创建通知
+func (s *NotificationService) Create(ctx context.Context, userID string, notificationType model.NotificationType, title, content string) (*model.Notification, error) {
+	notification := &model.Notification{
+		UserID:  userID,
+		Type:    notificationType,
+		Title:   title,
+		Content: content,
+		IsRead:  false,
+	}
+
+	err := s.notificationRepo.Create(notification)
+	if err != nil {
+		return nil, err
+	}
+
+	// 失效未读数缓存
+	cache.InvalidateUnreadSystem(s.cache, userID)
+
+	return notification, nil
+}
+
+// GetByUserID 获取用户通知
+func (s *NotificationService) GetByUserID(ctx context.Context, userID string, page, pageSize int, unreadOnly bool) ([]*model.Notification, int64, error) {
+	return s.notificationRepo.GetByUserID(userID, page, pageSize, unreadOnly)
+}
+
+// MarkAsRead 标记为已读
+func (s *NotificationService) MarkAsRead(ctx context.Context, id string) error {
+	err := s.notificationRepo.MarkAsRead(id)
+	if err != nil {
+		return err
+	}
+
+	// 注意：这里无法获取userID，所以不在缓存中失效
+	// 调用方应该使用MarkAsReadWithUserID方法
+
+	return nil
+}
+
+// MarkAsReadWithUserID 标记为已读（带用户ID，用于缓存失效）
+func (s *NotificationService) MarkAsReadWithUserID(ctx context.Context, id, userID string) error {
+	err := s.notificationRepo.MarkAsRead(id)
+	if err != nil {
+		return err
+	}
+
+	// 失效未读数缓存
+	cache.InvalidateUnreadSystem(s.cache, userID)
+
+	return nil
+}
+
+// MarkAllAsRead 标记所有为已读
+func (s *NotificationService) MarkAllAsRead(ctx context.Context, userID string) error {
+	err := s.notificationRepo.MarkAllAsRead(userID)
+	if err != nil {
+		return err
+	}
+
+	// 失效未读数缓存
+	cache.InvalidateUnreadSystem(s.cache, userID)
+
+	return nil
+}
+
+// Delete 删除通知
+func (s *NotificationService) Delete(ctx context.Context, id string) error {
+	return s.notificationRepo.Delete(id)
+}
+
+// GetUnreadCount 获取未读数量（带缓存）
+func (s *NotificationService) GetUnreadCount(ctx context.Context, userID string) (int64, error) {
+	cacheSettings := cache.GetSettings()
+	unreadTTL := cacheSettings.UnreadCountTTL
+	if unreadTTL <= 0 {
+		unreadTTL = NotificationUnreadCountTTL
+	}
+	nullTTL := cacheSettings.NullTTL
+	if nullTTL <= 0 {
+		nullTTL = NotificationNullTTL
+	}
+	jitter := cacheSettings.JitterRatio
+	if jitter <= 0 {
+		jitter = NotificationCacheJitter
+	}
+
+	// 生成缓存键
+	cacheKey := cache.UnreadSystemKey(userID)
+	return cache.GetOrLoadTyped[int64](
+		s.cache,
+		cacheKey,
+		unreadTTL,
+		jitter,
+		nullTTL,
+		func() (int64, error) {
+			return s.notificationRepo.GetUnreadCount(userID)
+		},
+	)
+}
+
+// DeleteNotification 删除通知（带用户验证）
+func (s *NotificationService) DeleteNotification(ctx context.Context, id, userID string) error {
+	// 先检查通知是否属于该用户
+	notification, err := s.notificationRepo.GetByID(id)
+	if err != nil {
+		return err
+	}
+	if notification.UserID != userID {
+		return ErrUnauthorizedNotification
+	}
+
+	err = s.notificationRepo.Delete(id)
+	if err != nil {
+		return err
+	}
+
+	// 失效未读数缓存
+	cache.InvalidateUnreadSystem(s.cache, userID)
+
+	return nil
+}
+
+// ClearAllNotifications 清空所有通知
+func (s *NotificationService) ClearAllNotifications(ctx context.Context, userID string) error {
+	err := s.notificationRepo.DeleteAllByUserID(userID)
+	if err != nil {
+		return err
+	}
+
+	// 失效未读数缓存
+	cache.InvalidateUnreadSystem(s.cache, userID)
+
+	return nil
+}
+
+// 错误定义
+var ErrUnauthorizedNotification = &ServiceError{Code: 403, Message: "unauthorized to delete this notification"}