[Feature] 탈퇴한 회원 재가입 처리 로직

src/main/java/com/cmc/mercury/domain/user/entity/User.java

@@ -82,5 +82,7 @@ public void updateNickname(String nickname) {
         this.nickname = nickname;
     }
 
-    public void deleteUser() { this.userStatus = UserStatus.INACTIVE; }
+    public void updateUserStatus(UserStatus userStatus) {
+        this.userStatus = userStatus;
+    }
 }

src/main/java/com/cmc/mercury/domain/user/service/SignOffService.java

@@ -30,7 +30,7 @@ public User withdraw(User user) {
             throw new CustomException(ErrorCode.ALREADY_WITHDRAWN);
         }
 
-        user.deleteUser();
+        user.updateUserStatus(UserStatus.INACTIVE);
         user.updateRefreshToken(null); // Refresh Token 삭제
 
         return user;

src/main/java/com/cmc/mercury/domain/user/service/UserService.java

@@ -2,6 +2,7 @@
 
 import com.cmc.mercury.domain.user.entity.OAuthType;
 import com.cmc.mercury.domain.user.entity.User;
+import com.cmc.mercury.domain.user.entity.UserStatus;
 import com.cmc.mercury.domain.user.repository.UserRepository;
 import com.cmc.mercury.domain.user.response.UserTestRequest;
 import com.cmc.mercury.global.exception.CustomException;
@@ -46,6 +47,11 @@ public User createTestUser(UserTestRequest request) {
 
 
         if (existingUser != null) {
+            if (existingUser.getUserStatus() == UserStatus.INACTIVE) {
+                // 회원탈퇴한 유저 재가입
+                existingUser.updateUserStatus(UserStatus.ACTIVE);
+                userRepository.save(existingUser);
+            }
             // 기존 유저가 있으면 로그인 처리 (토큰 갱신)
             setTestUserTokens(existingUser, request.isShortLivedAccessToken());
             return existingUser;

src/main/java/com/cmc/mercury/global/oauth/service/CustomOAuth2UserService.java

@@ -33,7 +33,7 @@
 public class CustomOAuth2UserService extends DefaultOAuth2UserService {
 
     private final UserRepository userRepository;
-    private final AppleIdTokenVerifier  appleIdTokenVerifier;
+    private final AppleIdTokenVerifier appleIdTokenVerifier;
 
     @Override
     public OAuth2User loadUser(OAuth2UserRequest userRequest) throws OAuth2AuthenticationException {
@@ -98,10 +98,23 @@ public OAuth2User loadUser(OAuth2UserRequest userRequest) throws OAuth2Authentic
             Optional<User> existingUser = userRepository.findByOauthTypeAndOauthId(oAuthType, oauthId);
             boolean isNewUser = existingUser.isEmpty(); // 존재하지 않으면 회원가입
 
-            User user = existingUser.orElseGet(() -> {
+            // 기존 유저 혹은 탈퇴한 사용자인지 확인
+            User user;
+            if (!isNewUser) {
+                User existing = existingUser.get();
+                if (existing.getUserStatus() == UserStatus.INACTIVE) {
+                    log.info("탈퇴한 회원 재가입 - 상태를 ACTIVE로 변경");
+                    existing.updateUserStatus(UserStatus.ACTIVE);
+                    isNewUser = true;
+                    user = userRepository.save(existing);
+                } else {
+                    user = existing;
+                }
+            } else {
                 log.info("새로운 사용자 생성 시도");
-                return createUser(oAuth2UserInfo);
-            });
+                user = createUser(oAuth2UserInfo);
+            }
+
             log.info("사용자 조회/생성 완료: userId={}", user.getId());
 
             // 회원가입 여부를 Security Context에 저장 (OAuth2User에 포함)