class VoteServiceTest {

    private VoteService voteService;
    private ArticleVote updatedVote;
    private ArticleVote vote;
    private Article article;
    private User user;

    @BeforeEach
    void setUp() {
        initObjects();
        voteService = new VoteService();
    }

    @Test
    void addVoteUp() {
        vote.setVoteType(VoteType.VOTE_UP.toString());
        Assert.assertEquals(1, voteService.addVote(article, vote).getVotes());
    }

    @Test
    void addVoteDown() {
        vote.setVoteType(VoteType.VOTE_DOWN.toString());
        Assert.assertEquals(-1, voteService.addVote(article, vote).getVotes());
    }

    @Test
    void updateVoteFromUpToDown() {
        vote.setVoteType(VoteType.VOTE_UP.toString());
        article.setVotes(1);
        user.getArticleVotes().add(vote);
        updatedVote.setVoteType(VoteType.VOTE_DOWN.toString());

        Assert.assertEquals(-1, voteService.updateVote(article, updatedVote, vote).getVotes());
    }

    @Test
    void updateVoteFromDownToUp() {
        vote.setVoteType(VoteType.VOTE_DOWN.toString());
        article.setVotes(-1);
        user.getArticleVotes().add(vote);
        updatedVote.setVoteType(VoteType.VOTE_UP.toString());

        Assert.assertEquals(1, voteService.updateVote(article, updatedVote, vote).getVotes());
    }

    @Test
    void updateVoteFromUpToUp() {
        vote.setVoteType(VoteType.VOTE_UP.toString());
        article.setVotes(1);
        user.getArticleVotes().add(vote);
        updatedVote.setVoteType(VoteType.VOTE_UP.toString());

        Assert.assertEquals(1, voteService.updateVote(article, updatedVote, vote).getVotes());
    }

    private void initObjects() {
        user = new User();
        user.setUsername("user");
        user.setPassword("password");

        article = new Article();
        article.setId(1L);
        article.setTitle("Testing");
        article.setVotes(0);
        article.setUser(user);
        user.getAddedArticles().add(article);

        vote = new ArticleVote();
        vote.setUser(user);
        vote.setArticle(article);

        updatedVote = new ArticleVote();
        updatedVote.setArticle(article);
        updatedVote.setUser(user);

    }
}

@Service
public class VoteService {

    public Activity addVote(Activity activity, Vote vote) {
        if (vote.getVoteType().equals(VoteType.VOTE_UP.toString())) {
            activity.setVotes(activity.getVotes() + 1);
        } else {
            activity.setVotes(activity.getVotes() - 1);
        }
        return activity;
    }

    public Activity updateVote(Activity activity, Vote vote, Vote previousVote) {
        if (previousVote.getVoteType().equals(vote.getVoteType())) {
            return activity;
        } else {
            previousVote.setVoteType(vote.getVoteType());

            if (vote.getVoteType().equals(VoteType.VOTE_UP.toString())) {
                activity.setVotes(activity.getVotes() + 2);
            } else {
                activity.setVotes(activity.getVotes() - 2);
            }
            return activity;
        }

    }
}