package notification

import (
	"context"
	"errors"
)

var ErrDependencyUnavailable = errors.New("dependency unavailable")
var ErrNotificationNotFound = errors.New("notification not found")

type Service struct {
	repo *Repository
}

func NewService(repo *Repository) *Service {
	return &Service{repo: repo}
}

func (s *Service) List(ctx context.Context, userID uint64, page, pageSize int) (*PaginatedResult, error) {
	if s.repo == nil {
		return nil, ErrDependencyUnavailable
	}
	return s.repo.List(ctx, userID, page, pageSize)
}

func (s *Service) MarkRead(ctx context.Context, userID uint64, id uint64) error {
	if s.repo == nil {
		return ErrDependencyUnavailable
	}
	return s.repo.MarkRead(ctx, userID, id)
}

func (s *Service) UnreadCount(ctx context.Context, userID uint64) (*UnreadCountDTO, error) {
	if s.repo == nil {
		return nil, ErrDependencyUnavailable
	}
	count, err := s.repo.UnreadCount(ctx, userID)
	if err != nil {
		return nil, err
	}
	return &UnreadCountDTO{UnreadCount: count}, nil
}

func (s *Service) MarkAllRead(ctx context.Context, userID uint64) (int64, error) {
	if s.repo == nil {
		return 0, ErrDependencyUnavailable
	}
	return s.repo.MarkAllRead(ctx, userID)
}