[BE] 카카오 로그인 기능을 추가 (#123)

* feat: 카카오 OAuth2 기능 추가

* feat: 로그인 기능 추가

* feat: 테스트 전용 PlatformUserProvider 추가

* test: 로그인 관련 테스트시 쿠키를 얻을 수 있는 공용 메서드 추가

* refactor: 패키지명 변경

* feat: 카카오 로그인시, 사이트에 등록된 회원이면 등록된 정보를 반환하고, 아니라면 등록한 후 정보를 반환하는 기능 추가

* refactor: 팀 컨벤션에 맞게 리팩터링

* test: platformId를 통해 유저를 반환하는 테스트 추가

* refactor: 멤버 생성자 수정으로 인한 테스트 코드 변경

* feat: 가입된 유저라면 201 OK 반환, 가입되지 않은 유저라면 302 FOUND 반환

* refactor: 팀원 피드백 반영

* feat: 로그아웃 기능 추가

* feat: 카카오 로그인 환경 변수 설정

backend/src/main/java/com/funeat/auth/application/AuthService.java

@@ -0,0 +1,31 @@
+package com.funeat.auth.application;
+
+import com.funeat.auth.dto.SignUserDto;
+import com.funeat.auth.dto.UserInfoDto;
+import com.funeat.auth.util.PlatformUserProvider;
+import com.funeat.member.application.MemberService;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@Transactional(readOnly = true)
+public class AuthService {
+
+    private final MemberService memberService;
+    private final PlatformUserProvider platformUserProvider;
+
+    public AuthService(final MemberService memberService, final PlatformUserProvider platformUserProvider) {
+        this.memberService = memberService;
+        this.platformUserProvider = platformUserProvider;
+    }
+
+    public SignUserDto loginWithKakao(final String code) {
+        final UserInfoDto userInfoDto = platformUserProvider.getPlatformUser(code);
+        final SignUserDto signUserDto = memberService.findOrCreateMember(userInfoDto);
+        return signUserDto;
+    }
+
+    public String getLoginRedirectUri() {
+        return platformUserProvider.getRedirectURI();
+    }
+}

backend/src/main/java/com/funeat/auth/dto/KakaoTokenDto.java

@@ -0,0 +1,53 @@
+package com.funeat.auth.dto;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class KakaoTokenDto {
+
+    private final String accessToken;
+    private final String tokenType;
+    private final String refreshToken;
+    private final String expiresIn;
+    private final String scope;
+    private final String refreshTokenExpiresIn;
+
+    @JsonCreator
+    public KakaoTokenDto(@JsonProperty("access_token") final String accessToken,
+                         @JsonProperty("token_type") final String tokenType,
+                         @JsonProperty("refresh_token") final String refreshToken,
+                         @JsonProperty("expires_in") final String expiresIn,
+                         @JsonProperty("scope") final String scope,
+                         @JsonProperty("refresh_token_expires_in") final String refreshTokenExpiresIn) {
+        this.accessToken = accessToken;
+        this.tokenType = tokenType;
+        this.refreshToken = refreshToken;
+        this.expiresIn = expiresIn;
+        this.scope = scope;
+        this.refreshTokenExpiresIn = refreshTokenExpiresIn;
+    }
+
+    public String getAccessToken() {
+        return accessToken;
+    }
+
+    public String getTokenType() {
+        return tokenType;
+    }
+
+    public String getRefreshToken() {
+        return refreshToken;
+    }
+
+    public String getExpiresIn() {
+        return expiresIn;
+    }
+
+    public String getScope() {
+        return scope;
+    }
+
+    public String getRefreshTokenExpiresIn() {
+        return refreshTokenExpiresIn;
+    }
+}

backend/src/main/java/com/funeat/auth/dto/KakaoUserInfoDto.java

@@ -0,0 +1,61 @@
+package com.funeat.auth.dto;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class KakaoUserInfoDto {
+
+    private final Long id;
+    private final KakaoAccount kakaoAccount;
+
+    @JsonCreator
+    public KakaoUserInfoDto(@JsonProperty("id") final Long id,
+                            @JsonProperty("kakao_account") final KakaoAccount kakaoAccount) {
+        this.id = id;
+        this.kakaoAccount = kakaoAccount;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public KakaoAccount getKakaoAccount() {
+        return kakaoAccount;
+    }
+
+    public static class KakaoAccount {
+
+        private final KakaoProfile profile;
+
+        @JsonCreator
+        public KakaoAccount(@JsonProperty("profile") final KakaoProfile profile) {
+            this.profile = profile;
+        }
+
+        public KakaoProfile getProfile() {
+            return profile;
+        }
+    }
+
+    public static class KakaoProfile {
+
+        private final String nickname;
+        private final String profileImageUrl;
+
+        @JsonCreator
+        public KakaoProfile(
+                @JsonProperty("nickname") final String nickname,
+                @JsonProperty("profile_image_url") final String profileImageUrl) {
+            this.nickname = nickname;
+            this.profileImageUrl = profileImageUrl;
+        }
+
+        public String getNickname() {
+            return nickname;
+        }
+
+        public String getProfileImageUrl() {
+            return profileImageUrl;
+        }
+    }
+}

backend/src/main/java/com/funeat/auth/dto/LoginRequest.java

@@ -0,0 +1,14 @@
+package com.funeat.auth.dto;
+
+public class LoginRequest {
+
+    private final Long id;
+
+    public LoginRequest(final Long id) {
+        this.id = id;
+    }
+
+    public Long getId() {
+        return id;
+    }
+}

backend/src/main/java/com/funeat/auth/dto/SignUserDto.java

@@ -0,0 +1,26 @@
+package com.funeat.auth.dto;
+
+import com.funeat.member.domain.Member;
+
+public class SignUserDto {
+
+    private final boolean isSignIn;
+    private final Member member;
+
+    public SignUserDto(final boolean isSignIn, final Member member) {
+        this.isSignIn = isSignIn;
+        this.member = member;
+    }
+
+    public static SignUserDto of(final boolean isSignIn, final Member member) {
+        return new SignUserDto(isSignIn, member);
+    }
+
+    public boolean isSignIn() {
+        return isSignIn;
+    }
+
+    public Member getMember() {
+        return member;
+    }
+}

backend/src/main/java/com/funeat/auth/dto/TokenResponse.java

@@ -0,0 +1,14 @@
+package com.funeat.auth.dto;
+
+public class TokenResponse {
+
+    private String accessToken;
+
+    public TokenResponse(final String accessToken) {
+        this.accessToken = accessToken;
+    }
+
+    public String getAccessToken() {
+        return accessToken;
+    }
+}

backend/src/main/java/com/funeat/auth/dto/UserInfoDto.java

@@ -0,0 +1,40 @@
+package com.funeat.auth.dto;
+
+import com.funeat.member.domain.Member;
+
+public class UserInfoDto {
+
+    private final Long id;
+    private final String nickname;
+    private final String profileImageUrl;
+
+    public UserInfoDto(final Long id, final String nickname, final String profileImageUrl) {
+        this.id = id;
+        this.nickname = nickname;
+        this.profileImageUrl = profileImageUrl;
+    }
+
+    public static UserInfoDto from(final KakaoUserInfoDto kakaoUserInfoDto) {
+        return new UserInfoDto(
+                kakaoUserInfoDto.getId(),
+                kakaoUserInfoDto.getKakaoAccount().getProfile().getNickname(),
+                kakaoUserInfoDto.getKakaoAccount().getProfile().getProfileImageUrl()
+        );
+    }
+
+    public Member toMember() {
+        return new Member(this.nickname, this.profileImageUrl, this.id.toString());
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public String getNickname() {
+        return nickname;
+    }
+
+    public String getProfileImageUrl() {
+        return profileImageUrl;
+    }
+}

backend/src/main/java/com/funeat/auth/presentation/AuthController.java

@@ -0,0 +1,55 @@
+package com.funeat.auth.presentation;
+
+import com.funeat.auth.application.AuthService;
+import com.funeat.auth.dto.LoginRequest;
+import com.funeat.auth.dto.SignUserDto;
+import com.funeat.auth.util.AuthenticationPrincipal;
+import java.net.URI;
+import javax.servlet.http.HttpServletRequest;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class AuthController {
+
+    private final AuthService authService;
+
+    public AuthController(final AuthService authService) {
+        this.authService = authService;
+    }
+
+    @GetMapping("/api/auth/kakao")
+    public ResponseEntity<Void> kakaoLogin() {
+        return ResponseEntity.status(HttpStatus.FOUND)
+                .location(URI.create(authService.getLoginRedirectUri()))
+                .build();
+    }
+
+    @GetMapping("/login/oauth2/code/kakao")
+    public ResponseEntity<Void> loginAuthorizeUser(@RequestParam("code") final String code,
+                                                   final HttpServletRequest request) {
+        final SignUserDto signUserDto = authService.loginWithKakao(code);
+        final Long memberId = signUserDto.getMember().getId();
+        request.getSession().setAttribute("member", memberId);
+
+        if (signUserDto.isSignIn()) {
+            return ResponseEntity.status(HttpStatus.FOUND)
+                    .location(URI.create("/"))
+                    .build();
+        }
+        return ResponseEntity.status(HttpStatus.FOUND)
+                .location(URI.create("/profile"))
+                .build();
+    }
+
+    @GetMapping("/api/logout")
+    public ResponseEntity<Void> logout(@AuthenticationPrincipal final LoginRequest loginRequest,
+                                       final HttpServletRequest request) {
+        request.getSession().removeAttribute("member");
+
+        return ResponseEntity.ok().build();
+    }
+}

backend/src/main/java/com/funeat/auth/util/AuthArgumentResolver.java

@@ -0,0 +1,31 @@
+package com.funeat.auth.util;
+
+import com.funeat.auth.dto.LoginRequest;
+import java.util.Objects;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpSession;
+import org.springframework.core.MethodParameter;
+import org.springframework.stereotype.Component;
+import org.springframework.web.bind.support.WebDataBinderFactory;
+import org.springframework.web.context.request.NativeWebRequest;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.method.support.ModelAndViewContainer;
+
+@Component
+public class AuthArgumentResolver implements HandlerMethodArgumentResolver {
+
+    @Override
+    public boolean supportsParameter(MethodParameter parameter) {
+        return parameter.hasParameterAnnotation(AuthenticationPrincipal.class);
+    }
+
+    @Override
+    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
+                                  NativeWebRequest webRequest, WebDataBinderFactory binderFactory) {
+        final HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
+        final HttpSession session = Objects.requireNonNull(request).getSession();
+        final String id = String.valueOf(session.getAttribute("member"));
+
+        return new LoginRequest(Long.valueOf(id));
+    }
+}

backend/src/main/java/com/funeat/auth/util/AuthHandlerInterceptor.java

@@ -0,0 +1,20 @@
+package com.funeat.auth.util;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpSession;
+import org.springframework.stereotype.Component;
+import org.springframework.web.servlet.HandlerInterceptor;
+
+@Component
+public class AuthHandlerInterceptor implements HandlerInterceptor {
+
+    @Override
+    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
+        final HttpSession session = request.getSession();
+        if (session.getAttribute("member") == null) {
+            throw new IllegalArgumentException("login error");
+        }
+        return true;
+    }
+}

backend/src/main/java/com/funeat/auth/util/AuthenticationPrincipal.java

@@ -0,0 +1,11 @@
+package com.funeat.auth.util;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.PARAMETER)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface AuthenticationPrincipal {
+}