feat(be): AI 챗 컨트롤러 및 REST API 엔드포인트 구현

- AiChatController 6개 엔드포인트 완성
  * GET /sessions (세션 목록)
  * POST /sessions (세션 생성)
  * DELETE /sessions/{id} (세션 삭제)
  * GET /sessions/{id}/messages (메시지 조회)
  * POST /sessions/{id}/messages (메시지 전송)
  * PATCH /sessions/{id}/title (제목 수정)

- Service Layer Entity 반환으로 리팩토링
- Controller Layer DTO 변환 책임 분리
- getSessionWithOwnershipCheck 헬퍼 메서드 적용
- ChatController → AiChatController 리네임
- DTO 구조 정리 및 신규 DTO 추가

Author: Mrbaeksang

build.gradle.kts

@@ -34,6 +34,11 @@ dependencies {
     implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
     implementation("org.jetbrains.kotlin:kotlin-reflect")
 
+    // jwt
+    implementation("io.jsonwebtoken:jjwt-api:0.12.6")
+    runtimeOnly("io.jsonwebtoken:jjwt-impl:0.12.6")
+    runtimeOnly("io.jsonwebtoken:jjwt-jackson:0.12.6")
+
     // Spring AI - 1.1.0-M2 (최신 버전) - 새로운 artifact명
     implementation("org.springframework.ai:spring-ai-starter-model-openai:1.1.0-M2")
     // Spring AI - JDBC 채팅 메모리 저장소 (PostgreSQL 대화 기록 저장)

setup-git-hooks.sh

@@ -1,4 +1,4 @@
-package com.back.koreaTravelGuide.application
+package com.back.koreaTravelGuide
 
 // TODO: 메인 애플리케이션 클래스 - 스프링 부트 시작점 및 환경변수 로딩
 import io.github.cdimascio.dotenv.dotenv

src/main/kotlin/com/back/koreaTravelGuide/application/KoreaTravelGuideApplication.kt renamed to src/main/kotlin/com/back/koreaTravelGuide/KoreaTravelGuideApplication.kt

@@ -0,0 +1,39 @@
+package com.back.koreaTravelGuide.security
+
+import com.back.koreaTravelGuide.domain.user.enums.UserRole
+import com.back.koreaTravelGuide.domain.user.repository.UserRepository
+import jakarta.servlet.http.HttpServletRequest
+import jakarta.servlet.http.HttpServletResponse
+import org.springframework.security.core.Authentication
+import org.springframework.security.oauth2.core.user.OAuth2User
+import org.springframework.security.web.authentication.SimpleUrlAuthenticationSuccessHandler
+import org.springframework.stereotype.Component
+import org.springframework.transaction.annotation.Transactional
+
+@Component
+class CustomOAuth2LoginSuccessHandler(
+    private val jwtTokenProvider: JwtTokenProvider,
+    private val userRepository: UserRepository,
+) : SimpleUrlAuthenticationSuccessHandler() {
+    @Transactional
+    override fun onAuthenticationSuccess(
+        request: HttpServletRequest,
+        response: HttpServletResponse,
+        authentication: Authentication,
+    ) {
+        val oAuth2User = authentication.principal as OAuth2User
+        val email = oAuth2User.attributes["email"] as String
+
+        val user = userRepository.findByEmail(email)!!
+
+        if (user.role == UserRole.PENDING) {
+            val registerToken = jwtTokenProvider.createRegisterToken(user.id!!)
+            val targetUrl = "http://localhost:3000/signup/role?token=$registerToken"
+            redirectStrategy.sendRedirect(request, response, targetUrl)
+        } else {
+            val accessToken = jwtTokenProvider.createAccessToken(user.id!!, user.role)
+            val targetUrl = "http://localhost:3000/oauth/callback?accessToken=$accessToken"
+            redirectStrategy.sendRedirect(request, response, targetUrl)
+        }
+    }
+}

src/main/kotlin/com/back/koreaTravelGuide/common/config/SecurityConfig.kt

@@ -0,0 +1,11 @@
+package com.back.koreaTravelGuide.security
+
+import org.springframework.security.core.GrantedAuthority
+import org.springframework.security.oauth2.core.user.DefaultOAuth2User
+
+class CustomOAuth2User(
+    val id: Long,
+    val email: String,
+    authorities: Collection<GrantedAuthority>,
+    attributes: Map<String, Any>,
+) : DefaultOAuth2User(authorities, attributes, "email")

src/main/kotlin/com/back/koreaTravelGuide/common/security/CustomOAuth2LoginSuccessHandler.kt

@@ -0,0 +1,67 @@
+package com.back.koreaTravelGuide.security
+
+import com.back.koreaTravelGuide.domain.user.entity.User
+import com.back.koreaTravelGuide.domain.user.enums.UserRole
+import com.back.koreaTravelGuide.domain.user.repository.UserRepository
+import org.springframework.security.core.authority.SimpleGrantedAuthority
+import org.springframework.security.oauth2.client.userinfo.DefaultOAuth2UserService
+import org.springframework.security.oauth2.client.userinfo.OAuth2UserRequest
+import org.springframework.security.oauth2.core.user.OAuth2User
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+
+@Service
+class CustomOAuth2UserService(
+    private val userRepository: UserRepository,
+) : DefaultOAuth2UserService() {
+    @Transactional
+    override fun loadUser(userRequest: OAuth2UserRequest): OAuth2User {
+        val oAuth2User = super.loadUser(userRequest)
+        val provider = userRequest.clientRegistration.registrationId
+        val attributes = oAuth2User.attributes
+
+        val oAuthUserInfo =
+            when (provider) {
+                "google" -> parseGoogle(attributes)
+                else -> throw IllegalArgumentException("지원하지 않는 소셜 로그인입니다.")
+            }
+
+        val user =
+            userRepository.findByOauthProviderAndOauthId(provider, oAuthUserInfo.oauthId)
+                ?: userRepository.save(
+                    User(
+                        oauthProvider = provider,
+                        oauthId = oAuthUserInfo.oauthId,
+                        email = oAuthUserInfo.email,
+                        nickname = oAuthUserInfo.nickname,
+                        profileImageUrl = oAuthUserInfo.profileImageUrl,
+                        role = UserRole.PENDING,
+                    ),
+                )
+
+        val authorities = listOf(SimpleGrantedAuthority("ROLE_${user.role.name}"))
+
+        return CustomOAuth2User(
+            id = user.id!!,
+            email = user.email,
+            authorities = authorities,
+            attributes = attributes,
+        )
+    }
+
+    private fun parseGoogle(attributes: Map<String, Any>): OAuthUserInfo {
+        return OAuthUserInfo(
+            oauthId = attributes["sub"] as String,
+            email = attributes["email"] as String,
+            nickname = attributes["name"] as String,
+            profileImageUrl = attributes["picture"] as String?,
+        )
+    }
+}
+
+data class OAuthUserInfo(
+    val oauthId: String,
+    val email: String,
+    val nickname: String,
+    val profileImageUrl: String?,
+)

src/main/kotlin/com/back/koreaTravelGuide/common/security/CustomOAuth2User.kt

@@ -0,0 +1,37 @@
+package com.back.koreaTravelGuide.security
+
+import jakarta.servlet.FilterChain
+import jakarta.servlet.http.HttpServletRequest
+import jakarta.servlet.http.HttpServletResponse
+import org.springframework.security.core.context.SecurityContextHolder
+import org.springframework.stereotype.Component
+import org.springframework.web.filter.OncePerRequestFilter
+
+@Component
+class JwtAuthenticationFilter(
+    private val jwtTokenProvider: JwtTokenProvider,
+) : OncePerRequestFilter() {
+    override fun doFilterInternal(
+        request: HttpServletRequest,
+        response: HttpServletResponse,
+        filterChain: FilterChain,
+    ) {
+        val token = resolveToken(request)
+
+        if (token != null && jwtTokenProvider.validateToken(token)) {
+            val authentication = jwtTokenProvider.getAuthentication(token)
+            SecurityContextHolder.getContext().authentication = authentication
+        }
+
+        filterChain.doFilter(request, response)
+    }
+
+    private fun resolveToken(request: HttpServletRequest): String? {
+        val bearerToken = request.getHeader("Authorization")
+        return if (bearerToken != null && bearerToken.startsWith("Bearer ")) {
+            bearerToken.substring(7)
+        } else {
+            null
+        }
+    }
+}

src/main/kotlin/com/back/koreaTravelGuide/common/security/CustomOAuth2UserService.kt

@@ -0,0 +1,78 @@
+package com.back.koreaTravelGuide.security
+
+import com.back.koreaTravelGuide.domain.user.enums.UserRole
+import io.jsonwebtoken.Claims
+import io.jsonwebtoken.Jwts
+import io.jsonwebtoken.security.Keys
+import org.springframework.beans.factory.annotation.Value
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken
+import org.springframework.security.core.Authentication
+import org.springframework.security.core.authority.SimpleGrantedAuthority
+import org.springframework.stereotype.Component
+import java.util.Base64
+import java.util.Date
+import javax.crypto.SecretKey
+
+@Component
+class JwtTokenProvider(
+    @Value("\${jwt.secret-key}") private val secretKey: String,
+    @Value("\${jwt.access-token-expiration-minutes}") private val accessTokenExpirationMinutes: Long,
+) {
+    private val key: SecretKey by lazy {
+        Keys.hmacShaKeyFor(Base64.getEncoder().encode(secretKey.toByteArray()))
+    }
+
+    fun createAccessToken(
+        userId: Long,
+        role: UserRole,
+    ): String {
+        val now = Date()
+        val expiryDate = Date(now.time + accessTokenExpirationMinutes * 60 * 1000)
+
+        return Jwts.builder()
+            .subject(userId.toString())
+            .claim("role", "ROLE_${role.name}")
+            .issuedAt(now)
+            .expiration(expiryDate)
+            .signWith(key)
+            .compact()
+    }
+
+    fun createRegisterToken(userId: Long): String {
+        val now = Date()
+        val expiryDate = Date(now.time + 5 * 60 * 1000)
+
+        return Jwts.builder()
+            .subject(userId.toString())
+            .issuedAt(now)
+            .expiration(expiryDate)
+            .signWith(key)
+            .compact()
+    }
+
+    fun validateToken(token: String): Boolean {
+        try {
+            getClaimsFromToken(token)
+            return true
+        } catch (e: Exception) {
+            return false
+        }
+    }
+
+    fun getAuthentication(token: String): Authentication {
+        val claims = getClaimsFromToken(token)
+        val userId = claims.subject.toLong()
+        val role = claims["role"] as? String ?: "ROLE_PENDING"
+        val authorities = listOf(SimpleGrantedAuthority(role))
+
+        return UsernamePasswordAuthenticationToken(userId, null, authorities)
+    }
+
+    private fun getClaimsFromToken(token: String): Claims {
+        return Jwts.parser()
+            .verifyWith(key)
+            .build()
+            .parseSignedClaims(token)
+            .payload
+    }
+}

src/main/kotlin/com/back/koreaTravelGuide/common/security/JwtAuthenticationFilter.kt

@@ -0,0 +1,52 @@
+package com.back.koreaTravelGuide.common.config
+
+import com.back.koreaTravelGuide.security.CustomOAuth2LoginSuccessHandler
+import com.back.koreaTravelGuide.security.CustomOAuth2UserService
+import com.back.koreaTravelGuide.security.JwtAuthenticationFilter
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import org.springframework.security.config.annotation.web.builders.HttpSecurity
+import org.springframework.security.config.annotation.web.invoke
+import org.springframework.security.config.http.SessionCreationPolicy
+import org.springframework.security.web.SecurityFilterChain
+import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter
+
+@Configuration
+class SecurityConfig(
+    private val customOAuth2UserService: CustomOAuth2UserService,
+    private val customOAuth2LoginSuccessHandler: CustomOAuth2LoginSuccessHandler,
+    private val jwtAuthenticationFilter: JwtAuthenticationFilter,
+) {
+    @Bean
+    fun filterChain(http: HttpSecurity): SecurityFilterChain {
+        http {
+            // 기본 보안 기능
+            csrf { disable() }
+            formLogin { disable() }
+            httpBasic { disable() }
+            logout { disable() }
+
+            sessionManagement {
+                sessionCreationPolicy = SessionCreationPolicy.STATELESS
+            }
+
+            oauth2Login {
+                userInfoEndpoint {
+                    userService = customOAuth2UserService
+                }
+                authenticationSuccessHandler = customOAuth2LoginSuccessHandler
+            }
+
+            authorizeHttpRequests {
+                authorize("/api/auth/**", permitAll)
+                authorize("/swagger-ui/**", "/v3/api-docs/**", permitAll)
+                authorize("/h2-console/**", permitAll)
+                authorize("/favicon.ico", permitAll)
+                authorize(anyRequest, authenticated)
+            }
+            addFilterBefore(jwtAuthenticationFilter, UsernamePasswordAuthenticationFilter::class.java)
+        }
+
+        return http.build()
+    }
+}