[Feature] 게시물 업로드, 상세 조회을 구현한다 (#34)

* feature: Profile ID를 통한 조회 추가

* feature: Post에 검증 로직 추가

* feature: 게시물 업로드 구현

* feature: 게시물 단건 조회 구현

* chore: JPA 전략을 update로 변경

src/main/java/daybyquest/global/error/exception/NotExistPostException.java

@@ -0,0 +1,10 @@
+package daybyquest.global.error.exception;
+
+import daybyquest.global.error.ExceptionCode;
+
+public class NotExistPostException extends CustomException {
+
+    public NotExistPostException() {
+        super(ExceptionCode.NOT_EXIST_POST);
+    }
+}

src/main/java/daybyquest/post/application/GetPostService.java

@@ -0,0 +1,29 @@
+package daybyquest.post.application;
+
+import daybyquest.post.dto.response.PostResponse;
+import daybyquest.post.query.PostDao;
+import daybyquest.post.query.PostData;
+import daybyquest.user.query.Profile;
+import daybyquest.user.query.ProfileDao;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+public class GetPostService {
+
+    private final PostDao postDao;
+
+    private final ProfileDao profileDao;
+
+    public GetPostService(final PostDao postDao, final ProfileDao profileDao) {
+        this.postDao = postDao;
+        this.profileDao = profileDao;
+    }
+
+    @Transactional(readOnly = true)
+    public PostResponse invoke(final Long loginId, final Long postId) {
+        final PostData postData = postDao.getByPostId(loginId, postId);
+        final Profile profile = profileDao.getById(loginId, postData.getUserId());
+        return PostResponse.of(postData, profile);
+    }
+}

src/main/java/daybyquest/post/application/SavePostService.java

@@ -0,0 +1,56 @@
+package daybyquest.post.application;
+
+import daybyquest.global.utils.MultipartFileUtils;
+import daybyquest.image.vo.Image;
+import daybyquest.image.vo.ImageIdentifierGenerator;
+import daybyquest.image.vo.Images;
+import daybyquest.post.domain.Post;
+import daybyquest.post.domain.Posts;
+import daybyquest.post.dto.request.SavePostRequest;
+import daybyquest.user.domain.Users;
+import java.util.List;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.web.multipart.MultipartFile;
+
+@Service
+public class SavePostService {
+
+    private static final String CATEGORY = "POST";
+
+    private final Users users;
+
+    private final Posts posts;
+
+    private final Images images;
+
+    private final ImageIdentifierGenerator generator;
+
+    public SavePostService(final Users users, final Posts posts, final Images images,
+            final ImageIdentifierGenerator generator) {
+        this.users = users;
+        this.posts = posts;
+        this.images = images;
+        this.generator = generator;
+    }
+
+    @Transactional
+    public Long invoke(final Long loginId, final SavePostRequest request,
+            final List<MultipartFile> files) {
+        users.validateExistentById(loginId);
+        final Post post = toEntity(loginId, request, toImageList(files));
+        return posts.save(post);
+    }
+
+    private List<Image> toImageList(final List<MultipartFile> files) {
+        return files.stream().map((file) -> {
+            final String identifier = generator.generateIdentifier(CATEGORY, file.getOriginalFilename());
+            images.upload(identifier, MultipartFileUtils.getInputStream(file));
+            return new Image(identifier);
+        }).toList();
+    }
+
+    private Post toEntity(final Long loginId, final SavePostRequest request, final List<Image> images) {
+        return new Post(loginId, request.getQuestId(), request.getContent(), images);
+    }
+}

src/main/java/daybyquest/post/domain/Post.java

@@ -1,7 +1,11 @@
 package daybyquest.post.domain;
 
+import static daybyquest.post.domain.PostState.NOT_DECIDED;
+import static daybyquest.post.domain.PostState.PREPARING;
+import static daybyquest.post.domain.PostState.SUCCESS;
 import static jakarta.persistence.GenerationType.IDENTITY;
 
+import daybyquest.global.error.exception.InvalidDomainException;
 import daybyquest.image.vo.Image;
 import jakarta.persistence.CollectionTable;
 import jakarta.persistence.Column;
@@ -28,13 +32,16 @@
 @EntityListeners(AuditingEntityListener.class)
 public class Post {
 
+    private static final int MAX_IMAGE_SIZE = 5;
+
     @Id
     @GeneratedValue(strategy = IDENTITY)
     private Long id;
 
     @Column(nullable = false)
     private Long userId;
 
+    @Column
     private Long questId;
 
     @LastModifiedDate
@@ -51,15 +58,32 @@ public class Post {
     @OrderColumn(name = "order")
     private List<Image> images;
 
-    private boolean deleted;
-
-
-    public Post(Long userId, Long questId, String content, List<Image> images, boolean deleted) {
+    public Post(Long userId, Long questId, String content, List<Image> images) {
         this.userId = userId;
         this.questId = questId;
         this.content = content;
         this.images = images;
-        this.deleted = deleted;
-        this.state = PostState.NOT_DECIDED;
+        this.state = PREPARING;
+        validateImages();
+    }
+
+    private void validateImages() {
+        if (this.images.isEmpty() || this.images.size() > MAX_IMAGE_SIZE) {
+            throw new InvalidDomainException();
+        }
+    }
+
+    public void afterRequestDeciding() {
+        if (this.state != PREPARING || this.images == null) {
+            throw new InvalidDomainException();
+        }
+        this.state = NOT_DECIDED;
+    }
+
+    public void success() {
+        if (this.state != PREPARING && this.state != NOT_DECIDED) {
+            throw new InvalidDomainException();
+        }
+        this.state = SUCCESS;
     }
 }

src/main/java/daybyquest/post/domain/PostRepository.java

@@ -3,7 +3,7 @@
 import java.util.Optional;
 import org.springframework.data.repository.Repository;
 
-public interface PostRepository extends Repository<Post, Long> {
+interface PostRepository extends Repository<Post, Long> {
 
     Post save(Post post);
 

src/main/java/daybyquest/post/domain/PostState.java

@@ -2,8 +2,10 @@
 
 public enum PostState {
 
+    PREPARING,
     SUCCESS,
     NEED_CHECK,
     FAIL,
-    NOT_DECIDED;
+    NOT_DECIDED,
+    DELETED;
 }

src/main/java/daybyquest/post/domain/Posts.java

@@ -0,0 +1,22 @@
+package daybyquest.post.domain;
+
+import daybyquest.global.error.exception.NotExistPostException;
+import org.springframework.stereotype.Component;
+
+@Component
+public class Posts {
+
+    private final PostRepository postRepository;
+
+    public Posts(final PostRepository postRepository) {
+        this.postRepository = postRepository;
+    }
+
+    public Long save(final Post post) {
+        return postRepository.save(post).getId();
+    }
+
+    public Post getById(final Long id) {
+        return postRepository.findById(id).orElseThrow(NotExistPostException::new);
+    }
+}

src/main/java/daybyquest/post/dto/request/SavePostRequest.java

@@ -0,0 +1,13 @@
+package daybyquest.post.dto.request;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor
+public class SavePostRequest {
+
+    private String content;
+
+    private Long questId;
+}

src/main/java/daybyquest/post/dto/response/PostResponse.java

@@ -0,0 +1,45 @@
+package daybyquest.post.dto.response;
+
+import daybyquest.image.vo.Image;
+import daybyquest.post.query.PostData;
+import daybyquest.user.dto.response.ProfileResponse;
+import daybyquest.user.query.Profile;
+import java.time.LocalDateTime;
+import java.util.List;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor
+public class PostResponse {
+
+    private ProfileResponse author;
+
+    private Long id;
+
+    private String content;
+
+    private LocalDateTime updatedAt;
+
+    private boolean liked;
+
+    private List<String> images;
+
+    public PostResponse(final ProfileResponse author, final Long id, final String content,
+            final LocalDateTime updatedAt, final boolean liked,
+            final List<String> images) {
+        this.author = author;
+        this.id = id;
+        this.content = content;
+        this.updatedAt = updatedAt;
+        this.liked = liked;
+        this.images = images;
+    }
+
+    public static PostResponse of(final PostData postData, final Profile profile) {
+        return new PostResponse(ProfileResponse.of(profile), postData.getId(), postData.getContent(),
+                postData.getUpdatedAt(), postData.isLiked(),
+                postData.getImages().stream().map(Image::getImageIdentifier).toList()
+        );
+    }
+}

src/main/java/daybyquest/post/presentation/PostCommandApi.java

@@ -0,0 +1,30 @@
+package daybyquest.post.presentation;
+
+import daybyquest.auth.Authorization;
+import daybyquest.auth.UserId;
+import daybyquest.post.application.SavePostService;
+import daybyquest.post.dto.request.SavePostRequest;
+import java.util.List;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestPart;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.multipart.MultipartFile;
+
+@RestController
+public class PostCommandApi {
+
+    private final SavePostService savePostService;
+
+    public PostCommandApi(final SavePostService savePostService) {
+        this.savePostService = savePostService;
+    }
+
+    @PostMapping("/post")
+    @Authorization
+    public ResponseEntity<Long> savePost(@UserId final Long loginId, @RequestPart SavePostRequest request,
+            @RequestPart List<MultipartFile> files) {
+        final Long postId = savePostService.invoke(loginId, request, files);
+        return ResponseEntity.ok(postId);
+    }
+}

src/main/java/daybyquest/post/presentation/PostQueryApi.java

@@ -0,0 +1,27 @@
+package daybyquest.post.presentation;
+
+import daybyquest.auth.Authorization;
+import daybyquest.auth.UserId;
+import daybyquest.post.application.GetPostService;
+import daybyquest.post.dto.response.PostResponse;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class PostQueryApi {
+
+    private final GetPostService getPostService;
+
+    public PostQueryApi(final GetPostService getPostService) {
+        this.getPostService = getPostService;
+    }
+
+    @GetMapping("/post/{postId}")
+    @Authorization
+    public ResponseEntity<PostResponse> getPost(@UserId final Long loginId, @PathVariable final Long postId) {
+        final PostResponse response = getPostService.invoke(loginId, postId);
+        return ResponseEntity.ok(response);
+    }
+}

src/main/java/daybyquest/post/query/PostDao.java

@@ -0,0 +1,6 @@
+package daybyquest.post.query;
+
+public interface PostDao {
+
+    PostData getByPostId(final Long userId, final Long postId);
+}

src/main/java/daybyquest/post/query/PostDaoQuerydslImpl.java

@@ -0,0 +1,48 @@
+package daybyquest.post.query;
+
+import static daybyquest.image.vo.QImage.image;
+import static daybyquest.like.domain.QPostLike.postLike;
+import static daybyquest.post.domain.QPost.post;
+
+import com.querydsl.core.types.Projections;
+import com.querydsl.jpa.JPAExpressions;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import daybyquest.global.error.exception.NotExistPostException;
+import daybyquest.image.vo.Image;
+import java.util.List;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public class PostDaoQuerydslImpl implements PostDao {
+
+    private final JPAQueryFactory factory;
+
+    public PostDaoQuerydslImpl(final JPAQueryFactory factory) {
+        this.factory = factory;
+    }
+
+    @Override
+    public PostData getByPostId(final Long userId, final Long postId) {
+        final PostData postData = factory.select(Projections.constructor(PostData.class,
+                        post.userId,
+                        post.id,
+                        post.content,
+                        post.updatedAt,
+                        JPAExpressions.selectFrom(postLike)
+                                .where(postLike.userId.eq(userId).and(postLike.postId.eq(postId)))
+                                .exists()))
+                .from(post)
+                .where(post.id.eq(postId))
+                .fetchOne();
+        if (postData == null) {
+            throw new NotExistPostException();
+        }
+        final List<Image> images = factory.select(image)
+                .from(post)
+                .leftJoin(post.images, image)
+                .where(post.id.eq(postId))
+                .fetch();
+        postData.setImages(images);
+        return postData;
+    }
+}