feat: Add CommentsService (#11)

src/main/java/com/beotkkot/qtudy/service/comments/CommentService.java

@@ -0,0 +1,134 @@
+package com.beotkkot.qtudy.service.comments;
+
+import com.beotkkot.qtudy.domain.comments.Comments;
+import com.beotkkot.qtudy.domain.posts.Posts;
+import com.beotkkot.qtudy.dto.object.CommentListItem;
+import com.beotkkot.qtudy.dto.request.comments.CommentsRequestDto;
+import com.beotkkot.qtudy.dto.response.ResponseDto;
+import com.beotkkot.qtudy.dto.response.comments.CommentsResponseDto;
+import com.beotkkot.qtudy.dto.response.comments.GetCommentsAllResponseDto;
+import com.beotkkot.qtudy.repository.comments.CommentsRepository;
+import com.beotkkot.qtudy.repository.posts.PostsRepository;
+import com.beotkkot.qtudy.repository.user.UserRepository;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Service
+@Slf4j
+@RequiredArgsConstructor
+@Transactional(readOnly = true)
+public class CommentService {
+
+    private final CommentsRepository commentRepo;
+    private final PostsRepository postRepo;
+    private final UserRepository userRepo;
+
+    @Transactional
+    public ResponseEntity<? super CommentsResponseDto> saveComment(Long postId, Long userUid, CommentsRequestDto dto) {
+
+        try {
+            if (!postRepo.existsById(postId)) {
+                // 존재하지 않는 포스트
+                return CommentsResponseDto.notExistedPost();
+            } else if (userRepo.findByKakaoId(userUid) == null) {
+                // 존재하지 않는 유저
+                return CommentsResponseDto.notExistedUser();
+            } else {
+                // 댓글 엔티티 생성
+                Comments comment = dto.toEntity(postId);
+                comment.setContent(dto.getContent());
+                comment.setUserUid(userUid);
+
+                // 댓글 저장
+                commentRepo.save(comment);
+
+                // postRespo의 commentCount 업데이트
+                int commentCount = commentRepo.countByPostId(postId);
+                List<Posts> posts = postRepo.findAllByPostId(postId);
+                for (Posts post : posts) {
+                    post.setCommentCount(commentCount);
+                }
+            }
+        } catch (Exception exception) {
+            log.info("error " + exception.getMessage());
+            return ResponseDto.databaseError();
+        }
+        return CommentsResponseDto.success();
+    }
+
+    public ResponseEntity<? super GetCommentsAllResponseDto> getAllComment(Long postId, int page) {
+        List<CommentListItem> commentListItems = new ArrayList<>();
+        Pageable pageable = PageRequest.of(page, 4, Sort.by("createdAt").descending());
+        try {
+            Posts post = postRepo.findByPostId(postId);
+            List<Comments> comments = commentRepo.findAllByPostId(postId, pageable).getContent();
+
+            for (Comments comment : comments) {
+                commentListItems.add(CommentListItem.of(comment));
+            }
+        } catch (Exception exception) {
+            log.info("error ", exception.getMessage());
+            return ResponseDto.databaseError();
+        }
+        GetCommentsAllResponseDto responseDto = new GetCommentsAllResponseDto(commentListItems, page);
+        return responseDto.success(commentListItems, page);
+    }
+
+    @Transactional
+    public ResponseEntity<? super CommentsResponseDto> patchComment(Long postId, Long commentId, Long userUid, CommentsRequestDto dto) {
+
+        try {
+            if (userRepo.findByKakaoId(userUid) == null) {
+                return CommentsResponseDto.notExistedUser();
+            } else if (!postRepo.existsById(postId)) {
+                return CommentsResponseDto.notExistedPost();
+            } else if (!commentRepo.existsById(commentId)) {
+                return CommentsResponseDto.notExistedComment();
+            } else {
+                // 댓글 수정
+                Comments comment = commentRepo.findById(commentId).get();
+                comment.setContent(dto.getContent());
+                System.out.println("content = " + comment.getContent());
+            }
+        } catch (Exception exception) {
+            log.info("error " + exception.getMessage());
+            return ResponseDto.databaseError();
+        }
+        return CommentsResponseDto.success();
+    }
+
+    @Transactional
+    public ResponseEntity<? super CommentsResponseDto> deleteComment(Long postId, Long commentId, Long userUid) {
+        try {
+            if (userRepo.findByKakaoId(userUid) == null) {
+                return CommentsResponseDto.notExistedUser();
+            } else if (!postRepo.existsById(postId)) {
+                return CommentsResponseDto.notExistedPost();
+            } else if (!commentRepo.existsById(commentId)) {
+                return CommentsResponseDto.notExistedComment();
+            } else {
+                // 댓글 삭제
+                Comments comment = commentRepo.findById(commentId).get();
+                commentRepo.delete(comment);
+
+                // postRespo의 commentCount 업데이트
+                int commentCount = commentRepo.countByPostId(postId);
+                Posts post = postRepo.findByPostId(postId);
+                post.setCommentCount(commentCount);
+            }
+        } catch (Exception exception) {
+            log.info("error " + exception.getMessage());
+            return ResponseDto.databaseError();
+        }
+        return CommentsResponseDto.success();
+    }
+}