Feat - 프롬프트 좋아요 및 취소 기능

src/main/java/com/progbe/domain/prompt/controller/PromptController.java

@@ -1,9 +1,6 @@
 package com.progbe.domain.prompt.controller;
 
-import com.progbe.domain.prompt.dto.PromptCreateRequest;
-import com.progbe.domain.prompt.dto.PromptListResponse;
-import com.progbe.domain.prompt.dto.PromptResponse;
-import com.progbe.domain.prompt.dto.PromptUpdateRequest;
+import com.progbe.domain.prompt.dto.*;
 import com.progbe.domain.prompt.service.PromptService;
 import com.progbe.global.common.ApiResponse;
 import jakarta.validation.Valid;
@@ -108,5 +105,18 @@ public ResponseEntity<ApiResponse<Void>> deletePrompt(
         promptService.deletePrompt(promptId, userId);
         return ResponseEntity.ok(ApiResponse.success(null));
     }
+
+    /**
+     * 좋아요 생성 및 취소 기능
+     * @param promptId
+     * @param userDetails
+     * @return
+     */
+    @PostMapping("/{promptId}/like")
+    public ApiResponse<PromptLikeResponse> likePrompt(@PathVariable Long promptId, @AuthenticationPrincipal UserDetails userDetails) {
+        Long userId = Long.parseLong(userDetails.getUsername());
+        PromptLikeResponse likePrompt = promptService.likePrompt(promptId, userId);
+        return ApiResponse.success(likePrompt);
+    }
 }
 

src/main/java/com/progbe/domain/prompt/dto/LikeStatus.java

@@ -0,0 +1,5 @@
+package com.progbe.domain.prompt.dto;
+
+public enum LikeStatus {
+    LIKE, UNLIKE
+}

src/main/java/com/progbe/domain/prompt/dto/PromptLikeResponse.java

@@ -0,0 +1,9 @@
+package com.progbe.domain.prompt.dto;
+
+public record PromptLikeResponse(
+    String likeStatus
+) {
+    public static PromptLikeResponse of(LikeStatus likeStatus) {
+        return new PromptLikeResponse(likeStatus.name());
+    }
+}

src/main/java/com/progbe/domain/prompt/entity/PromptLikeEntity.java

@@ -1,33 +1,16 @@
 package com.progbe.domain.prompt.entity;
 
 import com.progbe.domain.user.entity.UserEntity;
+import com.progbe.global.common.BaseEntity;
 import jakarta.persistence.*;
-import lombok.AccessLevel;
-import lombok.Builder;
-import lombok.Getter;
-import lombok.NoArgsConstructor;
-import org.springframework.data.annotation.CreatedDate;
+import lombok.*;
 import org.springframework.data.jpa.domain.support.AuditingEntityListener;
 
-import java.time.LocalDateTime;
-
 @Entity
-@Table(
-        name = "prompt_likes",
-        indexes = {
-                @Index(name = "idx_prompt_likes_prompt_id", columnList = "prompt_id")
-        },
-        uniqueConstraints = {
-                @UniqueConstraint(
-                        name = "pk_prompt_likes_user_prompt",
-                        columnNames = {"user_id", "prompt_id"}
-                )
-        }
-)
 @Getter
-@NoArgsConstructor(access = AccessLevel.PROTECTED)
 @EntityListeners(AuditingEntityListener.class)
-public class PromptLikeEntity {
+@Builder
+public class PromptLikeEntity extends BaseEntity {
 
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
@@ -42,13 +25,18 @@ public class PromptLikeEntity {
     @JoinColumn(name = "prompt_id", nullable = false)
     private PromptEntity prompt;
 
-    @CreatedDate
-    @Column(name = "created_at", updatable = false)
-    private LocalDateTime createdAt;
+    public PromptLikeEntity() { }
 
-    @Builder
-    public PromptLikeEntity(UserEntity user, PromptEntity prompt) {
+    public PromptLikeEntity(Long id, UserEntity user, PromptEntity prompt) {
+        this.id = id;
         this.user = user;
         this.prompt = prompt;
     }
+
+    public static PromptLikeEntity from(UserEntity user, PromptEntity prompt) {
+        return PromptLikeEntity.builder()
+                .user(user)
+                .prompt(prompt)
+                .build();
+    }
 }

src/main/java/com/progbe/domain/prompt/repository/PromptLikeRepository.java

@@ -0,0 +1,14 @@
+package com.progbe.domain.prompt.repository;
+
+import com.progbe.domain.prompt.entity.PromptEntity;
+import com.progbe.domain.prompt.entity.PromptLikeEntity;
+import com.progbe.domain.user.entity.UserEntity;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+import java.util.Optional;
+
+@Repository
+public interface PromptLikeRepository extends JpaRepository<PromptLikeEntity, Long> {
+    Optional<PromptLikeEntity> findByUserAndPrompt(UserEntity user, PromptEntity prompt);
+}

src/main/java/com/progbe/domain/prompt/service/PromptService.java

@@ -4,7 +4,9 @@
 import com.progbe.domain.category.repository.CategoryRepository;
 import com.progbe.domain.prompt.dto.*;
 import com.progbe.domain.prompt.entity.PromptEntity;
+import com.progbe.domain.prompt.entity.PromptLikeEntity;
 import com.progbe.domain.prompt.mapper.PromptMapper;
+import com.progbe.domain.prompt.repository.PromptLikeRepository;
 import com.progbe.domain.prompt.repository.PromptRepository;
 import com.progbe.domain.user.entity.UserEntity;
 import com.progbe.domain.user.repository.UserRepository;
@@ -17,6 +19,7 @@
 import org.springframework.transaction.annotation.Transactional;
 
 import java.util.List;
+import java.util.Optional;
 
 @Service
 @RequiredArgsConstructor
@@ -25,6 +28,7 @@ public class PromptService {
     private final PromptRepository promptRepository;
     private final CategoryRepository categoryRepository;
     private final UserRepository userRepository;
+    private final PromptLikeRepository promptLikeRepository;
     private final PromptMapper promptMapper;
 
     /**
@@ -107,4 +111,26 @@ public void deletePrompt(Long promptId, Long userId) {
         prompt.delete();
         promptRepository.save(prompt);
     }
+
+    // 좋아요 생성 (#32)
+    // 좋아요 눌렀는지를 확인하기 위해 null 값이 허용되는 Optional 전략 사용
+    public PromptLikeResponse likePrompt(Long promptId, Long userId) {
+        UserEntity user = userRepository.findById(userId)
+                .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
+
+        PromptEntity prompt = promptRepository.findById(promptId)
+                .orElseThrow(() -> new CustomException(ErrorCode.PROMPT_NOT_FOUND));
+
+        Optional<PromptLikeEntity> existingLike = promptLikeRepository.findByUserAndPrompt(user, prompt);
+
+        if (existingLike.isPresent()) {
+            promptLikeRepository.delete(existingLike.get());
+            return PromptLikeResponse.of(LikeStatus.UNLIKE);
+        }
+
+        PromptLikeEntity newLike = PromptLikeEntity.from(user, prompt);
+
+        promptLikeRepository.save(newLike);
+        return PromptLikeResponse.of(LikeStatus.LIKE);
+    }
 }