package notification import "errors" var ErrDependencyUnavailable = errors.New("dependency unavailable") type Service struct { repo *Repository } func NewService(repo *Repository) *Service { return &Service{repo: repo} } func (s *Service) List(userID uint64) ([]NotificationDTO, error) { if s.repo == nil { return nil, ErrDependencyUnavailable } return s.repo.List(userID) } func (s *Service) MarkRead(userID uint64, id uint64) error { if s.repo == nil { return ErrDependencyUnavailable } return s.repo.MarkRead(userID, id) }