package usecase.follow;
   
   import model.entity.Follow;
   import model.entity.Section;
   import model.entity.User;
   import model.repository.GenericRepository;
   import model.validation.SectionExists;
   import usecase.auth.AuthenticationRequired;
   import usecase.auth.CurrentUser;
  
  import javax.enterprise.context.ApplicationScoped;
  import javax.inject.Inject;
  import javax.transaction.Transactional;
  
  /**
   * Classe che fornisce i servizi relativi ai follow.
   */
  @ApplicationScoped
  @Transactional
  public class FollowService {
      private GenericRepository genericRepository;
      private CurrentUser currentUser;
  
      protected FollowService(){}
  
      @Inject
      protected FollowService(GenericRepository genericRepository, CurrentUser currentUser){
          this.genericRepository = genericRepository;
          this.currentUser = currentUser;
      }
  
      /**
       * Permette di seguire una sezione
       * @param sectionId identificativo sezione
       */
      @AuthenticationRequired
      public void follow(@SectionExists int sectionId){
          User user = genericRepository.findById(User.class, currentUser.getId());
          Section section = genericRepository.findById(Section.class,sectionId);
          genericRepository.insert(new Follow(user,section));
      }
  
      /**
       * Permette di togliere il follow ad una sezione
       * @param sectionId identificativo sezione
       */
      @AuthenticationRequired
      public void unFollow(@SectionExists int sectionId){
          User user = genericRepository.findById(User.class, currentUser.getId());
          Section section = genericRepository.findById(Section.class,sectionId);
          Follow follow = section.getFollow(user);
  
          if(follow != null)
              genericRepository.remove(follow);
      }
  
  }