feat: 카카오 로그인 api 구현

build.gradle

@@ -55,6 +55,8 @@ dependencies {
     annotationProcessor "jakarta.annotation:jakarta.annotation-api"
     annotationProcessor "jakarta.persistence:jakarta.persistence-api"
 
+    implementation 'org.springframework.boot:spring-boot-starter-webflux'
+
     // Redis
     implementation 'org.springframework.boot:spring-boot-starter-data-redis'
 

src/docs/asciidoc/auth-api.adoc

@@ -12,4 +12,27 @@ include::{snippetsDir}/loginUser/1/http-response.adoc[]
 include::{snippetsDir}/loginUser/1/response-fields.adoc[]
 
 ==== 실패 Response
-include::{snippetsDir}/loginUser/2/http-response.adoc[]
+include::{snippetsDir}/loginUser/2/http-response.adoc[]
+
+---
+
+=== **2. 카카오 로그인**
+
+카카오 로그인 api 입니다.
+
+==== Request
+include::{snippetsDir}/kakaoLogin/1/http-request.adoc[]
+
+==== 성공 Response
+성공 1. 카카오 로그인 성공, 서비스에 가입된 유저인 경우
+include::{snippetsDir}/kakaoLogin/1/http-response.adoc[]
+include::{snippetsDir}/kakaoLogin/1/response-fields.adoc[]
+
+성공 2. 카카오 로그인은 성공했지만, 서비스에 가입된 유저가 아닌 경우 (세션에 카카오 유저 정보를 임시로 등록하고 응답 쿠키에 SESSION 등록, 만료시간 5분)
+include::{snippetsDir}/kakaoLogin/2/http-response.adoc[]
+
+==== 실패 Response
+실패 1.
+include::{snippetsDir}/kakaoLogin/3/http-response.adoc[]
+실패 2.
+include::{snippetsDir}/kakaoLogin/4/http-response.adoc[]

src/main/java/com/ftm/server/application/dto/command/KakaoAuthCommand.java

@@ -0,0 +1,16 @@
+package com.ftm.server.application.dto.command;
+
+import com.ftm.server.web.dto.request.KakaoLoginRequest;
+import lombok.Getter;
+
+@Getter
+public class KakaoAuthCommand extends SocialAuthCommand {
+
+    private KakaoAuthCommand(String authorizationCode) {
+        super(authorizationCode);
+    }
+
+    public static KakaoAuthCommand from(KakaoLoginRequest request) {
+        return new KakaoAuthCommand(request.getAuthorizationCode());
+    }
+}

src/main/java/com/ftm/server/application/dto/command/SocialAuthCommand.java

@@ -0,0 +1,13 @@
+package com.ftm.server.application.dto.command;
+
+import lombok.Getter;
+
+@Getter
+public abstract class SocialAuthCommand {
+
+    private final String authorizationCode;
+
+    protected SocialAuthCommand(String authorizationCode) {
+        this.authorizationCode = authorizationCode;
+    }
+}

src/main/java/com/ftm/server/application/dto/query/FindSocialUserQuery.java

@@ -0,0 +1,20 @@
+package com.ftm.server.application.dto.query;
+
+import com.ftm.server.domain.enums.SocialProvider;
+import lombok.Getter;
+
+@Getter
+public class FindSocialUserQuery {
+
+    private final SocialProvider socialProvider;
+    private final String socialId;
+
+    private FindSocialUserQuery(SocialProvider socialProvider, String socialId) {
+        this.socialProvider = socialProvider;
+        this.socialId = socialId;
+    }
+
+    public static FindSocialUserQuery of(SocialProvider socialProvider, String socialId) {
+        return new FindSocialUserQuery(socialProvider, socialId);
+    }
+}

src/main/java/com/ftm/server/application/port/AuthenticationPort.java

@@ -1,6 +1,7 @@
 package com.ftm.server.application.port;
 
 import com.ftm.server.application.dto.command.UserLoginCommand;
+import com.ftm.server.domain.entity.User;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 import org.springframework.security.core.Authentication;
@@ -11,6 +12,9 @@ public interface AuthenticationPort {
     // 일반 유저 인증 객체 생성
     Authentication createAuthenticationFromCredentials(UserLoginCommand command);
 
+    // 소셜 유저 인증 객체 생성
+    Authentication createAuthenticationFromSocial(User user);
+
     // 인증 세션 등록 (시큐리티 컨텍스트 저장)
     void saveAuthenticatedSession(
             Authentication authentication,

src/main/java/com/ftm/server/application/port/SocialAuthClientPort.java

@@ -0,0 +1,10 @@
+package com.ftm.server.application.port;
+
+import com.ftm.server.application.dto.command.SocialAuthCommand;
+import com.ftm.server.infrastructure.oauth.SocialAuthUser;
+
+public interface SocialAuthClientPort<T extends SocialAuthCommand, R extends SocialAuthUser> {
+
+    // OAuthClient 인증 (소셜 인증)
+    R authenticate(T command);
+}

src/main/java/com/ftm/server/application/port/repository/UserRepository.java

@@ -1,6 +1,7 @@
 package com.ftm.server.application.port.repository;
 
 import com.ftm.server.domain.entity.User;
+import com.ftm.server.domain.enums.SocialProvider;
 import java.util.Optional;
 import org.springframework.data.jpa.repository.JpaRepository;
 
@@ -9,4 +10,6 @@ public interface UserRepository extends JpaRepository<User, Long> {
     Boolean existsByEmail(String email);
 
     Optional<User> findByEmail(String email);
+
+    Optional<User> findBySocialProviderAndSocialId(SocialProvider socialProvider, String socialId);
 }

src/main/java/com/ftm/server/application/service/UserService.java

@@ -3,10 +3,12 @@
 import com.ftm.server.application.dto.command.GeneralUserCreationCommand;
 import com.ftm.server.application.dto.query.FindByEmailQuery;
 import com.ftm.server.application.dto.query.FindByIdQuery;
+import com.ftm.server.application.dto.query.FindSocialUserQuery;
 import com.ftm.server.application.port.repository.UserRepository;
 import com.ftm.server.common.exception.CustomException;
 import com.ftm.server.domain.entity.User;
 import com.ftm.server.domain.vo.EmailDuplicationVo;
+import java.util.Optional;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Service;
@@ -28,6 +30,11 @@ public User queryUser(FindByIdQuery query) {
                 .orElseThrow(() -> CustomException.USER_NOT_FOUND);
     }
 
+    public Optional<User> querySocialUser(FindSocialUserQuery query) {
+        return userRepository.findBySocialProviderAndSocialId(
+                query.getSocialProvider(), query.getSocialId());
+    }
+
     public User createGeneralUser(GeneralUserCreationCommand command) {
         User user = User.createGeneralUser(command);
         userRepository.save(user);

src/main/java/com/ftm/server/application/usecase/auth/KakaoLoginUseCase.java

@@ -0,0 +1,49 @@
+package com.ftm.server.application.usecase.auth;
+
+import com.ftm.server.application.dto.command.KakaoAuthCommand;
+import com.ftm.server.application.dto.query.FindByUserIdQuery;
+import com.ftm.server.application.dto.query.FindSocialUserQuery;
+import com.ftm.server.application.port.SocialAuthClientPort;
+import com.ftm.server.application.service.UserImageService;
+import com.ftm.server.application.service.UserService;
+import com.ftm.server.common.annotation.UseCase;
+import com.ftm.server.domain.entity.User;
+import com.ftm.server.domain.entity.UserImage;
+import com.ftm.server.domain.vo.PendingSocialUserVo;
+import com.ftm.server.domain.vo.SocialLoginOutcomeVo;
+import com.ftm.server.domain.vo.SocialLoginSuccessVo;
+import com.ftm.server.domain.vo.UserSummaryVo;
+import com.ftm.server.infrastructure.oauth.kakao.KakaoAuthUser;
+import java.util.Optional;
+import lombok.RequiredArgsConstructor;
+
+@UseCase
+@RequiredArgsConstructor
+public class KakaoLoginUseCase {
+
+    private final SocialAuthClientPort<KakaoAuthCommand, KakaoAuthUser> oAuthClientPort;
+    private final UserService userService;
+    private final UserImageService userImageService;
+
+    public SocialLoginOutcomeVo kakaoLogin(KakaoAuthCommand command) {
+        // 카카오 인증 수행
+        KakaoAuthUser kakaoUser = oAuthClientPort.authenticate(command);
+
+        Optional<User> saved =
+                userService.querySocialUser(
+                        FindSocialUserQuery.of(
+                                kakaoUser.getSocialProvider(), kakaoUser.getSocialId()));
+
+        // 가입된 회원인 경우
+        if (saved.isPresent()) {
+            User user = saved.get();
+            UserImage image =
+                    userImageService.queryUserImageByUserId(FindByUserIdQuery.of(user.getId()));
+
+            return SocialLoginSuccessVo.from(user, UserSummaryVo.of(user, image));
+        }
+
+        // 가입된 회원이 아닌 경우
+        return PendingSocialUserVo.from(kakaoUser.getSocialProvider(), kakaoUser.getSocialId());
+    }
+}

src/main/java/com/ftm/server/common/config/WebClientConfig.java

@@ -0,0 +1,18 @@
+package com.ftm.server.common.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@Configuration
+public class WebClientConfig {
+
+    @Bean
+    public WebClient webClient(WebClient.Builder builder) {
+        return builder.defaultHeader(
+                        HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_FORM_URLENCODED_VALUE)
+                .build();
+    }
+}

src/main/java/com/ftm/server/common/consts/StaticConsts.java

@@ -0,0 +1,9 @@
+package com.ftm.server.common.consts;
+
+public class StaticConsts {
+
+    public static final String AUTHORIZATION_HEADER_PREFIX = "Bearer ";
+    public static final String AUTHORIZATION_GRANT_TYPE = "authorization_code";
+    public static final String PENDING_SOCIAL_USER_SESSION_KEY = "PENDING_SOCIAL_USER_INFO";
+    public static final int PENDING_SOCIAL_USER_SESSION_TTL = 300; //  5분
+}

src/main/java/com/ftm/server/common/response/enums/ErrorResponseCode.java

@@ -29,7 +29,11 @@ public enum ErrorResponseCode {
 
     // 500번
     UNKNOWN_SERVER_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "E500_001", "알 수 없는 서버 에러가 발생했습니다."),
-    FAIL_TO_SEND_EMAIL(HttpStatus.INTERNAL_SERVER_ERROR, "E500_002", "서버 내부 문제로 메일 전송에 실패했습니다.");
+    FAIL_TO_SEND_EMAIL(HttpStatus.INTERNAL_SERVER_ERROR, "E500_002", "서버 내부 문제로 메일 전송에 실패했습니다."),
+
+    // 502번 (외부 서비스에서 문제 발생)
+    KAKAO_AUTH_TOKEN_EXCHANGE_FAILED(HttpStatus.BAD_GATEWAY, "E502_001", "카카오 인증 토큰 요청에 실패했습니다."),
+    KAKAO_USER_PROFILE_FETCH_FAILED(HttpStatus.BAD_GATEWAY, "E502_002", "카카오 사용자 정보 요청에 실패했습니다.");
 
     private final HttpStatus httpStatus;
     private final String code;

src/main/java/com/ftm/server/domain/entity/User.java

@@ -118,4 +118,15 @@ public static User createGeneralUser(GeneralUserCreationCommand command) {
                 .role(UserRole.USER)
                 .build();
     }
+
+    public static User createTestKakaoUser() {
+        return User.builder()
+                .nickname("test")
+                .socialProvider(SocialProvider.KAKAO)
+                .socialId("test_kakao_id")
+                .groomingScore(0)
+                .isDeleted(false)
+                .role(UserRole.USER)
+                .build();
+    }
 }

src/main/java/com/ftm/server/domain/vo/PendingSocialUserVo.java

@@ -0,0 +1,22 @@
+package com.ftm.server.domain.vo;
+
+import com.ftm.server.domain.enums.SocialProvider;
+import lombok.Getter;
+
+/** 가입이 필요한 소셜 유저인 경우 VO */
+@Getter
+public class PendingSocialUserVo extends SocialLoginOutcomeVo {
+
+    private final SocialProvider socialProvider;
+    private final String socialId;
+
+    private PendingSocialUserVo(SocialProvider socialProvider, String socialId) {
+        super(false);
+        this.socialProvider = socialProvider;
+        this.socialId = socialId;
+    }
+
+    public static PendingSocialUserVo from(SocialProvider socialProvider, String socialId) {
+        return new PendingSocialUserVo(socialProvider, socialId);
+    }
+}

src/main/java/com/ftm/server/domain/vo/SocialLoginOutcomeVo.java

@@ -0,0 +1,15 @@
+package com.ftm.server.domain.vo;
+
+import java.io.Serializable;
+import lombok.Getter;
+
+/** 소셜 로그인 결과 VO */
+@Getter
+public abstract class SocialLoginOutcomeVo implements Serializable {
+
+    private final boolean registered;
+
+    protected SocialLoginOutcomeVo(boolean registered) {
+        this.registered = registered;
+    }
+}

src/main/java/com/ftm/server/domain/vo/SocialLoginSuccessVo.java

@@ -0,0 +1,22 @@
+package com.ftm.server.domain.vo;
+
+import com.ftm.server.domain.entity.User;
+import lombok.Getter;
+
+/** 가입된 유저라 로그인에 성공한 경우 VO */
+@Getter
+public class SocialLoginSuccessVo extends SocialLoginOutcomeVo {
+
+    private final User user;
+    private final UserSummaryVo userSummaryVo;
+
+    private SocialLoginSuccessVo(User user, UserSummaryVo userSummaryVo) {
+        super(true);
+        this.user = user;
+        this.userSummaryVo = userSummaryVo;
+    }
+
+    public static SocialLoginSuccessVo from(User user, UserSummaryVo userSummaryVo) {
+        return new SocialLoginSuccessVo(user, userSummaryVo);
+    }
+}

src/main/java/com/ftm/server/infrastructure/oauth/SocialAuthUser.java

@@ -0,0 +1,16 @@
+package com.ftm.server.infrastructure.oauth;
+
+import com.ftm.server.domain.enums.SocialProvider;
+import lombok.Getter;
+
+@Getter
+public abstract class SocialAuthUser {
+
+    private final SocialProvider socialProvider;
+    private final String socialId;
+
+    protected SocialAuthUser(SocialProvider socialProvider, String socialId) {
+        this.socialProvider = socialProvider;
+        this.socialId = socialId;
+    }
+}

src/main/java/com/ftm/server/infrastructure/oauth/kakao/KakaoAuthUser.java

@@ -0,0 +1,17 @@
+package com.ftm.server.infrastructure.oauth.kakao;
+
+import com.ftm.server.domain.enums.SocialProvider;
+import com.ftm.server.infrastructure.oauth.SocialAuthUser;
+import lombok.Getter;
+
+@Getter
+public class KakaoAuthUser extends SocialAuthUser {
+
+    private KakaoAuthUser(String socialId) {
+        super(SocialProvider.KAKAO, socialId);
+    }
+
+    public static KakaoAuthUser from(String socialId) {
+        return new KakaoAuthUser(socialId);
+    }
+}

src/main/java/com/ftm/server/infrastructure/oauth/kakao/KakaoErrorResponse.java

@@ -0,0 +1,15 @@
+package com.ftm.server.infrastructure.oauth.kakao;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor
+public class KakaoErrorResponse {
+
+    private String error;
+
+    @JsonProperty("error_description")
+    private String errorDescription;
+}