[Feat/#100] 회원 탈퇴 API 구현

src/main/java/com/comma/soomteum/domain/auth/service/AuthService.java

@@ -37,11 +37,17 @@ public LoginResponseDto socialLogin(String providerId, String email) {
                                 .providerId(providerId)
                                 .nickname("유저" + providerId)
                                 .email(email)
-                                .isActive(true)
                                 .build()
                 ));
 
-        boolean isNewUser = user.getCreatedAt() != null &&
+        // 탈퇴한 회원이 다시 로그인하는 경우 계정 복구
+        boolean isReturningUser = false;
+        if (user.isWithdrawn()) {
+            user.reactivate();
+            isReturningUser = true;
+        }
+
+        boolean isNewUser = !isReturningUser && user.getCreatedAt() != null &&
                 user.getUpdatedAt() != null &&
                 user.getCreatedAt().equals(user.getUpdatedAt());
 

src/main/java/com/comma/soomteum/domain/token/repository/TokenRepository.java

@@ -1,11 +1,13 @@
 package com.comma.soomteum.domain.token.repository;
 
 import com.comma.soomteum.domain.token.entity.Token;
+import com.comma.soomteum.domain.user.entity.User;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 import java.util.Optional;
 
 
 public interface TokenRepository extends JpaRepository<Token, Long>  {
     Optional<Token> findByRefreshToken(String refreshToken);
+    void deleteByUser(User user);
 }

src/main/java/com/comma/soomteum/domain/user/controller/UserController.java

@@ -4,6 +4,7 @@
 import com.comma.soomteum.domain.user.entity.User;
 import com.comma.soomteum.domain.user.dto.UserNicknameRequestDto;
 import com.comma.soomteum.domain.user.dto.UserProfileResponseDto;
+import com.comma.soomteum.domain.user.dto.UserWithdrawResponseDto;
 import com.comma.soomteum.domain.user.service.UserService;
 import com.comma.soomteum.global.response.ApiResponse;
 import io.swagger.v3.oas.annotations.Operation;
@@ -35,4 +36,10 @@ public ApiResponse<UserProfileResponseDto> getUserProfile(@Parameter(hidden = tr
     public ApiResponse<UserProfileResponseDto> updateNickname(@Parameter(hidden = true) @LoginUser User user, @Valid @RequestBody UserNicknameRequestDto userNicknameRequestDto) {
         return ApiResponse.ok(userService.updateNickname(user.getUserId(), userNicknameRequestDto));
     }
+
+    @Operation(summary = "회원 탈퇴", description = "사용자의 계정을 탈퇴 처리합니다.")
+    @PatchMapping("/withdraw")
+    public ApiResponse<UserWithdrawResponseDto> withdrawUser(@Parameter(hidden = true) @LoginUser User user) {
+        return ApiResponse.ok(userService.withdrawUser(user.getUserId()));
+    }
 }

src/main/java/com/comma/soomteum/domain/user/dto/UserWithdrawResponseDto.java

@@ -0,0 +1,21 @@
+package com.comma.soomteum.domain.user.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class UserWithdrawResponseDto {
+
+    private String message;
+
+    public static UserWithdrawResponseDto of() {
+        return UserWithdrawResponseDto.builder()
+                .message("회원 탈퇴가 완료되었습니다.")
+                .build();
+    }
+}

src/main/java/com/comma/soomteum/domain/user/entity/User.java

@@ -1,6 +1,7 @@
 package com.comma.soomteum.domain.user.entity;
 
 import com.comma.soomteum.domain.BaseEntity;
+import com.comma.soomteum.domain.user.enums.UserStatus;
 import jakarta.persistence.*;
 import lombok.*;
 
@@ -24,9 +25,27 @@ public class User extends BaseEntity {
 
     private String email;
 
-    private Boolean isActive;
+    @Enumerated(EnumType.STRING)
+    @Column(nullable = false)
+    private UserStatus status = UserStatus.ACTIVE;
 
     public void updateNickname(String nickname) {
         this.nickname = nickname;
     }
+
+    public void withdraw() {
+        this.status = UserStatus.WITHDRAWN;
+    }
+
+    public void reactivate() {
+        this.status = UserStatus.ACTIVE;
+    }
+
+    public boolean isWithdrawn() {
+        return this.status == UserStatus.WITHDRAWN;
+    }
+
+    public boolean isActive() {
+        return this.status == UserStatus.ACTIVE;
+    }
 }

src/main/java/com/comma/soomteum/domain/user/enums/UserStatus.java

@@ -0,0 +1,6 @@
+package com.comma.soomteum.domain.user.enums;
+
+public enum UserStatus {
+    ACTIVE,     // 활성 회원
+    WITHDRAWN   // 탈퇴 회원
+}

src/main/java/com/comma/soomteum/domain/user/service/UserService.java

@@ -1,7 +1,9 @@
 package com.comma.soomteum.domain.user.service;
 
+import com.comma.soomteum.domain.token.repository.TokenRepository;
 import com.comma.soomteum.domain.user.dto.UserNicknameRequestDto;
 import com.comma.soomteum.domain.user.dto.UserProfileResponseDto;
+import com.comma.soomteum.domain.user.dto.UserWithdrawResponseDto;
 import com.comma.soomteum.domain.user.entity.User;
 import com.comma.soomteum.domain.user.repository.UserRepository;
 import com.comma.soomteum.global.response.CustomException;
@@ -16,6 +18,7 @@
 public class UserService {
 
     private final UserRepository userRepository;
+    private final TokenRepository tokenRepository;
 
     /**
      * 마이페이지 - 이메일, 닉네임 조회
@@ -36,4 +39,26 @@ public UserProfileResponseDto updateNickname(Long userId, UserNicknameRequestDto
         user.updateNickname(userNicknameRequestDto.getNickname());
         return UserProfileResponseDto.fromEntity(user);
     }
+
+    /**
+     * 회원 탈퇴
+     **/
+    @Transactional
+    public UserWithdrawResponseDto withdrawUser(Long userId) {
+        User user = userRepository.findById(userId)
+                .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
+
+        // 이미 탈퇴한 회원인지 확인
+        if (user.isWithdrawn()) {
+            throw new CustomException(ErrorCode.ALREADY_WITHDRAWN_USER);
+        }
+
+        // 해당 사용자의 모든 토큰 삭제
+        tokenRepository.deleteByUser(user);
+
+        // 회원 상태를 탈퇴로 변경 (isActive = null)
+        user.withdraw();
+
+        return UserWithdrawResponseDto.of();
+    }
 }

src/main/java/com/comma/soomteum/global/response/ErrorCode.java

@@ -63,6 +63,7 @@ public enum ErrorCode {
     DUPLICATE_EMAIL(409_001, HttpStatus.CONFLICT, "이미 사용 중인 이메일입니다."),
     ALREADY_LIKED_PLACE(409_002, HttpStatus.CONFLICT, "이미 좋아요를 누른 장소입니다."),
     NOT_LIKED_PLACE(409_003, HttpStatus.CONFLICT, "좋아요를 누르지 않은 장소입니다."),
+    ALREADY_WITHDRAWN_USER(409_004, HttpStatus.CONFLICT, "이미 탈퇴한 회원입니다."),
 
 
     // ========================