001package usecase.post;
002
003import media.MediaRepository;
004import media.ReadLimitExceededException;
005import media.validation.Image;
006import model.entity.Post;
007import model.entity.Section;
008import model.entity.User;
009import model.repository.GenericRepository;
010import model.repository.PostRepository;
011import model.validation.PostExists;
012import model.validation.SectionExists;
013import usecase.auth.AuthenticationRequired;
014import usecase.auth.AuthorizationException;
015import usecase.auth.CurrentUser;
016import usecase.auth.DenyBannedUsers;
017
018import javax.enterprise.context.ApplicationScoped;
019import javax.inject.Inject;
020import javax.transaction.Transactional;
021import javax.validation.constraints.NotBlank;
022import javax.validation.constraints.NotNull;
023import javax.validation.constraints.Size;
024import java.io.BufferedInputStream;
025import java.io.IOException;
026import java.time.Instant;
027import java.util.List;
028import java.util.stream.Collectors;
029
030import static model.entity.Post.Type.IMG;
031import static model.entity.Post.Type.TEXT;
032import static usecase.post.PostSearchForm.SortCriteria.NEWEST;
033
034/**
035 * Classe che fornisce i servizi relativi ai post.
036 */
037@ApplicationScoped
038@Transactional
039public class PostService {
040    private GenericRepository genericRepository;
041    private PostRepository postRepo;
042    private MediaRepository bcRepo;
043    private CurrentUser currentUser;
044
045    protected PostService(){}
046
047    @Inject
048    protected PostService(GenericRepository genericRepository, PostRepository postRepo,
049                          MediaRepository bcRepo, CurrentUser currentUser){
050        this.genericRepository = genericRepository;
051        this.postRepo = postRepo;
052        this.bcRepo = bcRepo;
053        this.currentUser = currentUser;
054    }
055
056    /**
057     * Converte post in PostPage.
058     * @param post post da convertire
059     * @return PostPage con i dati di post
060     */
061    private PostPage mapPost(Post post){
062        User user = null;
063        if(currentUser.isLoggedIn())
064            user = genericRepository.findById(User.class,currentUser.getId());
065
066        //converte persistence.Post.Type in usecase.post.PostType (ew)
067        PostType postType = post.getType() == IMG ? PostType.IMG : PostType.TEXT;
068
069        return PostPage.builder()
070                .id(post.getId())
071                .title(post.getTitle())
072                .vote(post.getVote(user) == null ? 0 : post.getVote(user).getVote())
073                .votes(post.getVotesCount() == null ? 0 : post.getVotesCount())
074                .sectionName(post.getSection().getName())
075                .authorName(post.getAuthor().getUsername())
076                .sectionId(post.getSection().getId())
077                .authorId(post.getAuthor().getId())
078                .content(post.getContent())
079                .creationDate(post.getCreationDate() == null ? Instant.now() : post.getCreationDate())
080                .nComments(post.getCommentCount())
081                .type(postType)
082                .build();
083    }
084
085    /**
086     * Ritorna un entità DTO relativa ad un post
087     * @param id identificativo post
088     * @return DTO di un post
089     */
090    public PostPage getPost(@PostExists int id){
091        Post p = genericRepository.findById(Post.class,id);
092        return mapPost(p);
093    }
094
095    /**
096     * Ritorna una lista di post che rispettano determinati parametri
097     * @param form entità con i parametri di ricerca
098     * @return lista di PostPage
099     */
100    @Transactional
101    public List<PostPage> loadPosts(PostSearchForm form){
102        final int elementsPerPage = 10;
103        PostRepository.PostFinder finder = postRepo.getFinder();
104
105        finder.limit(elementsPerPage);
106
107        int page = form.getPage() > 0 ? form.getPage() : 1;
108        finder.offset((page == 1) ? 0 : (page-1) * elementsPerPage+1);
109
110        if(form.getContent() != null) {
111            finder.byContent(form.getContent());
112        }
113        if(form.isIncludeBody()){
114            finder.includeBody();
115        }
116        if(form.getSectionName() != null){
117            Section section = genericRepository.findByNaturalId(Section.class, form.getSectionName());
118            if(section != null){
119                finder.bySection(section);
120            }
121        }
122        if(form.getAuthorName() != null){
123            User user = genericRepository.findByNaturalId(User.class, form.getAuthorName());
124            if(user != null){
125                finder.byAuthor(user);
126            }
127        }
128        if(form.isOnlyFollow() && currentUser.isLoggedIn()){
129            finder.joinUserFollows(genericRepository.findById(User.class,currentUser.getId()));
130        }
131        if(form.getPostedAfter() != null){
132            finder.postedAfter(form.getPostedAfter());
133        }
134        if(form.getPostedBefore() != null){
135            finder.postedBefore(form.getPostedBefore());
136        }
137
138        //null-safe switch
139        switch(form.getOrderBy() != null ? form.getOrderBy() : NEWEST){
140            case NEWEST: default: {
141                finder.getNewest();
142                break;
143            }
144            case OLDEST:{
145                finder.getOldest();
146                break;
147            }
148            case MOSTVOTED:{
149                finder.getMostVoted();
150                break;
151            }
152        }
153        return finder.getResults().stream().map(this::mapPost).collect(Collectors.toList());
154    }
155
156    /**
157     * Elimina un post dato il suo id
158     * @param id identificativo del post
159     */
160    @AuthenticationRequired //TODO: check autore post?
161    @DenyBannedUsers
162    public void delete(@PostExists int id){
163        Post post = genericRepository.findById(Post.class,id);
164        if(currentUser.getId() != post.getAuthor().getId() && !currentUser.isAdmin())
165            throw new AuthorizationException();
166        genericRepository.remove(genericRepository.findById(User.class,id));
167    }
168
169    /**
170     * Aggiunge un post ad una sezione
171     * @param title titolo del post
172     * @param body testo del post
173     * @param sectionName nome della sezione
174     * @return identificativo del nuovo post creato
175     */
176    @AuthenticationRequired
177    @DenyBannedUsers
178    public int newPost(@NotBlank String title,
179                       @Size(max=65535) String body,
180                       @NotNull @SectionExists String sectionName){
181        User user = genericRepository.findByNaturalId(User.class, currentUser.getUsername());
182        Section section = genericRepository.findByNaturalId(Section.class,sectionName);
183
184
185        Post post = new Post();
186        post.setTitle(title);
187        post.setContent(body == null || body.isBlank() ? "" : body);
188        post.setAuthor(user);
189        post.setSection(section);
190        post.setType(TEXT);
191
192        return genericRepository.insert(post).getId();
193    }
194
195    /**
196     * Aggiunge un post ad una sezione
197     * @param title titolo del post
198     * @param content file di tipo immagine
199     * @param sectionName nome della sezione
200     * @return identificativo del nuovo post creato
201     */
202    @AuthenticationRequired
203    @DenyBannedUsers
204    public int newPost(@NotBlank @Size(max=255) String title,
205                       @NotNull @Image BufferedInputStream content,
206                       @NotNull @SectionExists String sectionName){
207        User user = genericRepository.findByNaturalId(User.class,currentUser.getUsername());
208        Section section = genericRepository.findByNaturalId(Section.class,sectionName);
209
210        String fileName;
211        try {
212            fileName = bcRepo.insert(content);
213        } catch (ReadLimitExceededException e){
214            throw new IllegalArgumentException("Il file non deve superare i 5MB");
215        } catch (IOException e) {
216            throw new RuntimeException(e);
217        }
218
219        Post post = new Post();
220        post.setTitle(title);
221        post.setAuthor(user);
222        post.setContent(fileName);
223        post.setSection(section);
224        post.setType(IMG);
225
226        return genericRepository.insert(post).getId(); //in caso di errore il file resta
227    }
228}