feat: #25 게시글에 좋아요 누르기 API 구현

src/main/java/com/whyranoid/walkie/controller/CommunityController.java

@@ -1,6 +1,7 @@
 package com.whyranoid.walkie.controller;
 
 import com.google.firebase.auth.FirebaseAuthException;
+import com.whyranoid.walkie.dto.PostLikeDto;
 import com.whyranoid.walkie.service.CommunityService;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.Parameter;
@@ -13,6 +14,7 @@
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
@@ -47,4 +49,13 @@ public ResponseEntity uploadPost(
     ) throws IOException, FirebaseAuthException {
         return ResponseEntity.ok(communityService.uploadPost(image, walkieId, content, colorMode, historyContent));
     }
+
+    @Operation(summary = "게시글에 좋아요 누르기")
+    @ApiResponse(responseCode = "200", content = @Content(schema = @Schema(implementation = PostLikeDto.class)),
+            description = "성공 시 요청에 게시글의 현재 좋아요 수를 넣어 반환, 중복 좋아요 시 좋아요 수에 -1을 넣어 반환, 실패 시 예외발생")
+    @PostMapping("/send-like")
+    public ResponseEntity<PostLikeDto> sendPostLike(@RequestBody PostLikeDto postLikeDto) {
+        return ResponseEntity.ok(communityService.sendPostLike(postLikeDto));
+    }
+
 }

src/main/java/com/whyranoid/walkie/domain/PostLike.java

@@ -0,0 +1,44 @@
+package com.whyranoid.walkie.domain;
+
+import lombok.AccessLevel;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.ToString;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+import javax.persistence.OneToOne;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@ToString
+public class PostLike {
+
+    @Id
+    @Column(name = "post_like_id")
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long postLikeId;
+
+    @OneToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "liker")
+    private Walkie liker;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "post")
+    private Post post;
+
+    @Builder
+    public PostLike(Long postLikeId, Walkie liker, Post post) {
+        this.postLikeId = postLikeId;
+        this.liker = liker;
+        this.post = post;
+    }
+}

src/main/java/com/whyranoid/walkie/dto/PostDto.java

@@ -0,0 +1,41 @@
+package com.whyranoid.walkie.dto;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class PostDto {
+
+    @Schema(description = "[응답] 워키 아이디", example = "3")
+    private Long viewerId;
+
+    @Schema(description = "[응답] 작성자 아이디", example = "2")
+    private Long posterId;
+
+    @Schema(description = "[응답] 게시글 pk", example = "26343")
+    private Long postId;
+
+    @Schema(description = "[응답] 좋아요 여부", example = "true")
+    private Boolean liked;
+
+    @Schema(description = "[응답] 좋아요 개수", example = "36")
+    private Integer likeCount;
+
+    @Schema(description = "[응답] 사진파일 URI", example = "")
+    private String photo;
+
+    @Schema(description = "[응답] 게시글 내용", example = "오운완.")
+    private String content;
+
+    @Schema(description = "[응답] 게시 시각", example = "2023-09-09 09:09:09")
+    private String date;
+
+    @Schema(description = "[응답] 글씨색 설정", example = "0")
+    private Integer colorMode;
+
+    @Schema(description = "[응답] 기록 데이터", example = "")
+    private String historyContent;
+}

src/main/java/com/whyranoid/walkie/dto/PostLikeDto.java

@@ -0,0 +1,45 @@
+package com.whyranoid.walkie.dto;
+
+import com.querydsl.core.annotations.QueryProjection;
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.AccessLevel;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.util.List;
+
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class PostLikeDto {
+
+    @Schema(description = "요청 필수 파라미터 - 좋아요 누른 유저의 워키 아이디", requiredMode = Schema.RequiredMode.REQUIRED, example = "3")
+    private Long likerId;
+
+    @Schema(description = "요청 필수 파라미터 - 좋아요 받은 글의 포스트 아이디", requiredMode = Schema.RequiredMode.REQUIRED, example = "6521")
+    private Long postId;
+
+    @Schema(description = "응답 파라미터 - 좋아요 누른 유저 수", example = "62")
+    private Long likerCount;
+
+    @Schema(description = "응답 파라미터 - 좋아요 누른 유저들의 프로필")
+    private List<WalkieDto> likerProfiles;
+
+    @QueryProjection
+    public PostLikeDto(Long likerId, Long postId) {
+        this.likerId = likerId;
+        this.postId = postId;
+    }
+
+    @Builder
+    public PostLikeDto(Long likerId, Long postId, Long likerCount, List<WalkieDto> likerProfiles) {
+        this.likerId = likerId;
+        this.postId = postId;
+        this.likerCount = likerCount;
+        this.likerProfiles = likerProfiles;
+    }
+
+    public void setLikerCount(Long likerCount) {
+        this.likerCount = likerCount;
+    }
+}

src/main/java/com/whyranoid/walkie/repository/PostLikeRepository.java

@@ -0,0 +1,14 @@
+package com.whyranoid.walkie.repository;
+
+import com.whyranoid.walkie.domain.Post;
+import com.whyranoid.walkie.domain.PostLike;
+import com.whyranoid.walkie.domain.Walkie;
+import com.whyranoid.walkie.repository.querydsl.PostLikeRepositoryCustom;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.List;
+
+public interface PostLikeRepository extends JpaRepository<PostLike, Long>, PostLikeRepositoryCustom {
+
+    List<PostLike> findByPostAndLiker(Post post, Walkie liker);
+}

src/main/java/com/whyranoid/walkie/repository/PostRepository.java

@@ -0,0 +1,11 @@
+package com.whyranoid.walkie.repository;
+
+import com.whyranoid.walkie.domain.Post;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.Optional;
+
+public interface PostRepository extends JpaRepository<Post, Long> {
+
+    Optional<Post> findByPostId(Long postId);
+}

src/main/java/com/whyranoid/walkie/repository/querydsl/PostLikeRepositoryCustom.java

@@ -0,0 +1,8 @@
+package com.whyranoid.walkie.repository.querydsl;
+
+public interface PostLikeRepositoryCustom {
+
+    Long findPostLikeCount(Long postId);
+
+//    PostLikeDto findPostLikePeople(Long postId);
+}

src/main/java/com/whyranoid/walkie/repository/querydsl/PostLikeRepositoryImpl.java

@@ -0,0 +1,39 @@
+package com.whyranoid.walkie.repository.querydsl;
+
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import lombok.RequiredArgsConstructor;
+
+import static com.whyranoid.walkie.domain.QPostLike.postLike;
+
+@RequiredArgsConstructor
+public class PostLikeRepositoryImpl implements PostLikeRepositoryCustom {
+
+    private final JPAQueryFactory queryFactory;
+
+    @Override
+    public Long findPostLikeCount(Long postId) {
+        return queryFactory
+                .select(postLike)
+                .from(postLike)
+                .where(postLike.post.postId.eq(postId)
+                        .and(postLike.liker.isNotNull()))
+                .stream().count();
+    }
+
+//    @Override
+//    public PostLikeDto findPostLikePeople(Long postId) {
+//        return PostLikeDto.builder()
+//                .postId(postId)
+//                .likerCount(findPostLikeCount(postId))
+//                .likerProfiles(findLikerList(postId))
+//                .build();
+//    }
+//
+//    public List<WalkieDto> findLikerList(Long postId) {
+//        return queryFactory
+//                .select(new QWalkieDto(postLike.liker))
+//                .from(postLike)
+//                .where(postLike.post.postId.eq(postId))
+//                .fetch();
+//    }
+}

src/main/java/com/whyranoid/walkie/service/CommunityService.java

@@ -6,19 +6,27 @@
 import com.google.firebase.cloud.StorageClient;
 import com.whyranoid.walkie.ApiBaseUrlSingleton;
 import com.whyranoid.walkie.domain.Post;
+import com.whyranoid.walkie.domain.PostLike;
+import com.whyranoid.walkie.domain.Walkie;
+import com.whyranoid.walkie.dto.PostLikeDto;
 import com.whyranoid.walkie.dto.response.ApiResponse;
 import com.whyranoid.walkie.repository.CommunityRepository;
+import com.whyranoid.walkie.repository.PostLikeRepository;
+import com.whyranoid.walkie.repository.PostRepository;
 import com.whyranoid.walkie.repository.WalkieRepository;
 import lombok.RequiredArgsConstructor;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.web.multipart.MultipartFile;
 
+import javax.persistence.EntityNotFoundException;
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.UUID;
 
 @Service
@@ -27,6 +35,8 @@
 public class CommunityService {
     private final CommunityRepository communityRepository;
     private final WalkieRepository walkieRepository;
+    private final PostRepository postRepository;
+    private final PostLikeRepository postLikeRepository;
 
     @Value("${app.firebase-bucket-name}")
     private String firebaseBucket;
@@ -56,4 +66,32 @@ public String uploadImage(MultipartFile image, String nameFile)
         Blob blob = bucket.create(nameFile, content, image.getContentType());
         return blob.getMediaLink();
     }
+
+    public PostLikeDto sendPostLike(PostLikeDto postLikeDto) {
+        Post post = postRepository.findByPostId(postLikeDto.getPostId()).orElseThrow(EntityNotFoundException::new);
+        Walkie liker = walkieRepository.findById(postLikeDto.getLikerId()).orElseThrow(EntityNotFoundException::new);
+
+        PostLike input = PostLike.builder()
+                .post(post)
+                .liker(liker)
+                .build();
+
+        List<PostLike> already = new ArrayList<>(postLikeRepository.findByPostAndLiker(post, liker));
+        if (!already.isEmpty()) {
+            postLikeRepository.delete(already.get(0));
+            postLikeDto.setLikerCount(-1L);
+        }
+        else {
+            postLikeRepository.save(input);
+            postLikeDto.setLikerCount(countPostLike(postLikeDto.getPostId()));
+        }
+
+        return postLikeDto;
+    }
+
+    public Long countPostLike(Long postId) {
+        Post post = postRepository.findByPostId(postId).orElseThrow(EntityNotFoundException::new);
+
+        return postLikeRepository.findPostLikeCount(postId);
+    }
 }