package usecase.vote;
   
   import model.entity.*;
   import model.repository.GenericRepository;
   import model.validation.CommentExists;
   import model.validation.PostExists;
   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 voti.
   */
  @ApplicationScoped
  @Transactional
  public class VoteService {
      private GenericRepository genericRepository;
      private CurrentUser currentUser;
  
      protected VoteService(){}
  
      @Inject
      protected VoteService(GenericRepository genericRepository, CurrentUser currentUser){
          this.genericRepository = genericRepository;
          this.currentUser = currentUser;
      }
  
      /**
       * Aggiunge un voto positivo ad un commento
       * @param id di un commento esistente
       */
      @AuthenticationRequired
      public void upvoteComment(@CommentExists int id){
          voteComment(id, (short) +1);
      }
  
      /**
       * Aggiunge un voto negativo ad un commento
       * @param id di un commento esistente
       */
      @AuthenticationRequired
      public void downvoteComment(@CommentExists int id){
          voteComment(id, (short) -1);
      }
  
      /**
       * Aggiunge un voto positivo ad un post
       * @param id di un post esistente
       */
      @AuthenticationRequired
      public void upvotePost(@PostExists int id){
          votePost(id, (short) +1);
      }
  
      /**
       * Aggiunge un voto negativo ad un post
       * @param id di un post esistente
       */
      @AuthenticationRequired
      public void downvotePost(@PostExists int id){
          votePost(id, (short) -1);
      }
  
      /**
       * Rimuove il voto ad un commento
       * @param id di un commento esistente
       */
      @AuthenticationRequired
      public void unvoteComment(@CommentExists int id){
          Comment comment = genericRepository.findById(Comment.class, id);
          User user = genericRepository.findById(User.class, currentUser.getId());
          CommentVote commentVote = comment.getVote(user);
          if(commentVote != null)
              genericRepository.remove(commentVote);
      }
  
      /**
       * Rimuove il voto ad un post
       * @param id di un post esistente
       */
      @AuthenticationRequired
      public void unvotePost(@PostExists int id){
          Post post = genericRepository.findById(Post.class,id);
          User user = genericRepository.findById(User.class, currentUser.getId());
  
          PostVote vote = post.getVote(user);
          if(vote != null)
              genericRepository.remove(vote);
      }
  
      /**
       * Aggiunge un voto ad un post
       * @param id di un post
       * @param vote tipo di voto: 1 indica voto positivo, -1 voto negativo
       */
      private void votePost(int id, short vote){
         Post post = genericRepository.findById(Post.class,id);
         User user = genericRepository.findById(User.class, currentUser.getId());
 
         PostVote postVote = new PostVote(user,post,vote);
         genericRepository.merge(postVote);
     }
 
     /**
      * Aggiunge un voto ad un commento
      * @param id di un commento
      * @param vote tipo di voto: 1 indica voto positivo, -1 voto negativo
      */
     private void voteComment(int id, short vote) {
         Comment comment = genericRepository.findById(Comment.class,id);
         User user = genericRepository.findById(User.class, currentUser.getId());
 
         CommentVote commentVote = new CommentVote(user,comment, vote);
         genericRepository.merge(commentVote);
     }
 }