feat(chat): 채팅방 생성 API 구현

- 채팅방 생성 및 조회 기능 구현
- 외부 API 연동을 통한 세션 생성 로직 추가
- 채팅방 참여자(유저, 캐릭터) 추가 기능 구현
- UUID 기반 유저 ID 생성 로직 추가

src/main/kotlin/kr/co/vividnext/sodalive/chat/room/controller/ChatRoomController.kt

@@ -0,0 +1,45 @@
+package kr.co.vividnext.sodalive.chat.room.controller
+
+import kr.co.vividnext.sodalive.chat.room.dto.CreateChatRoomRequest
+import kr.co.vividnext.sodalive.chat.room.service.ChatRoomService
+import kr.co.vividnext.sodalive.common.ApiResponse
+import kr.co.vividnext.sodalive.common.SodaException
+import kr.co.vividnext.sodalive.member.Member
+import org.springframework.security.core.annotation.AuthenticationPrincipal
+import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.RequestBody
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+@RequestMapping("/api/chat/room")
+class ChatRoomController(
+    private val chatRoomService: ChatRoomService
+) {
+
+    /**
+     * 채팅방 생성 API
+     *
+     * 1. 캐릭터 ID, 유저 ID가 참여 중인 채팅방이 있는지 확인
+     * 2. 있으면 채팅방 ID 반환
+     * 3. 없으면 외부 API 호출
+     * 4. 성공시 외부 API에서 가져오는 sessionId를 포함하여 채팅방 생성
+     * 5. 채팅방 참여자로 캐릭터와 유저 추가
+     * 6. 채팅방 ID 반환
+     *
+     * @param member 인증된 사용자
+     * @param request 채팅방 생성 요청 DTO
+     * @return 채팅방 ID
+     */
+    @PostMapping("/create")
+    fun createChatRoom(
+        @AuthenticationPrincipal(expression = "#this == 'anonymousUser' ? null : member") member: Member?,
+        @RequestBody request: CreateChatRoomRequest
+    ) = run {
+        if (member == null) throw SodaException("로그인 정보를 확인해주세요.")
+        if (member.auth == null) throw SodaException("본인인증을 하셔야 합니다.")
+
+        val response = chatRoomService.createOrGetChatRoom(member, request.characterId)
+        ApiResponse.ok(response)
+    }
+}

src/main/kotlin/kr/co/vividnext/sodalive/chat/room/dto/ChatRoomDto.kt

@@ -0,0 +1,46 @@
+package kr.co.vividnext.sodalive.chat.room.dto
+
+/**
+ * 채팅방 생성 요청 DTO
+ */
+data class CreateChatRoomRequest(
+    val characterId: Long
+)
+
+/**
+ * 채팅방 생성 응답 DTO
+ */
+data class CreateChatRoomResponse(
+    val chatRoomId: Long
+)
+
+/**
+ * 외부 API 채팅 세션 응답 DTO
+ */
+data class ExternalChatSessionResponse(
+    val success: Boolean,
+    val message: String?,
+    val data: ExternalChatSessionData?
+)
+
+/**
+ * 외부 API 채팅 세션 데이터 DTO
+ */
+data class ExternalChatSessionData(
+    val sessionId: String,
+    val userId: String,
+    val characterId: String,
+    val character: ExternalCharacterData,
+    val status: String,
+    val createdAt: String
+)
+
+/**
+ * 외부 API 캐릭터 데이터 DTO
+ */
+data class ExternalCharacterData(
+    val id: String,
+    val name: String,
+    val age: String,
+    val gender: String
+)

src/main/kotlin/kr/co/vividnext/sodalive/chat/room/repository/CharacterChatParticipantRepository.kt

@@ -0,0 +1,36 @@
+package kr.co.vividnext.sodalive.chat.room.repository
+
+import kr.co.vividnext.sodalive.chat.character.ChatCharacter
+import kr.co.vividnext.sodalive.chat.room.CharacterChatParticipant
+import kr.co.vividnext.sodalive.chat.room.CharacterChatRoom
+import kr.co.vividnext.sodalive.member.Member
+import org.springframework.data.jpa.repository.JpaRepository
+import org.springframework.stereotype.Repository
+
+@Repository
+interface CharacterChatParticipantRepository : JpaRepository<CharacterChatParticipant, Long> {
+
+    /**
+     * 특정 채팅방에 참여 중인 멤버 참여자 찾기
+     *
+     * @param chatRoom 채팅방
+     * @param member 멤버
+     * @return 채팅방 참여자 (없으면 null)
+     */
+    fun findByChatRoomAndMemberAndIsActiveTrue(
+        chatRoom: CharacterChatRoom,
+        member: Member
+    ): CharacterChatParticipant?
+
+    /**
+     * 특정 채팅방에 참여 중인 캐릭터 참여자 찾기
+     *
+     * @param chatRoom 채팅방
+     * @param character 캐릭터
+     * @return 채팅방 참여자 (없으면 null)
+     */
+    fun findByChatRoomAndCharacterAndIsActiveTrue(
+        chatRoom: CharacterChatRoom,
+        character: ChatCharacter
+    ): CharacterChatParticipant?
+}

src/main/kotlin/kr/co/vividnext/sodalive/chat/room/repository/CharacterChatRoomRepository.kt

@@ -0,0 +1,35 @@
+package kr.co.vividnext.sodalive.chat.room.repository
+
+import kr.co.vividnext.sodalive.chat.character.ChatCharacter
+import kr.co.vividnext.sodalive.chat.room.CharacterChatRoom
+import kr.co.vividnext.sodalive.member.Member
+import org.springframework.data.jpa.repository.JpaRepository
+import org.springframework.data.jpa.repository.Query
+import org.springframework.data.repository.query.Param
+import org.springframework.stereotype.Repository
+
+@Repository
+interface CharacterChatRoomRepository : JpaRepository<CharacterChatRoom, Long> {
+
+    /**
+     * 특정 멤버와 캐릭터가 참여 중인 활성화된 채팅방을 찾는 쿼리
+     *
+     * @param member 멤버
+     * @param character 캐릭터
+     * @return 활성화된 채팅방 (없으면 null)
+     */
+    @Query(
+        """
+        SELECT DISTINCT r FROM CharacterChatRoom r
+        JOIN r.participants p1
+        JOIN r.participants p2
+        WHERE p1.member = :member AND p1.isActive = true
+        AND p2.character = :character AND p2.isActive = true
+        AND r.isActive = true
+    """
+    )
+    fun findActiveChatRoomByMemberAndCharacter(
+        @Param("member") member: Member,
+        @Param("character") character: ChatCharacter
+    ): CharacterChatRoom?
+}

src/main/kotlin/kr/co/vividnext/sodalive/chat/room/service/ChatRoomService.kt

@@ -0,0 +1,167 @@
+package kr.co.vividnext.sodalive.chat.room.service
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import kr.co.vividnext.sodalive.chat.character.service.ChatCharacterService
+import kr.co.vividnext.sodalive.chat.room.CharacterChatParticipant
+import kr.co.vividnext.sodalive.chat.room.CharacterChatRoom
+import kr.co.vividnext.sodalive.chat.room.ParticipantType
+import kr.co.vividnext.sodalive.chat.room.dto.CreateChatRoomResponse
+import kr.co.vividnext.sodalive.chat.room.dto.ExternalChatSessionResponse
+import kr.co.vividnext.sodalive.chat.room.repository.CharacterChatParticipantRepository
+import kr.co.vividnext.sodalive.chat.room.repository.CharacterChatRoomRepository
+import kr.co.vividnext.sodalive.common.SodaException
+import kr.co.vividnext.sodalive.member.Member
+import org.springframework.beans.factory.annotation.Value
+import org.springframework.http.HttpEntity
+import org.springframework.http.HttpHeaders
+import org.springframework.http.HttpMethod
+import org.springframework.http.MediaType
+import org.springframework.http.client.SimpleClientHttpRequestFactory
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+import org.springframework.web.client.RestTemplate
+import java.util.UUID
+
+@Service
+class ChatRoomService(
+    private val chatRoomRepository: CharacterChatRoomRepository,
+    private val participantRepository: CharacterChatParticipantRepository,
+    private val characterService: ChatCharacterService,
+
+    @Value("\${weraser.api-key}")
+    private val apiKey: String,
+
+    @Value("\${weraser.api-url}")
+    private val apiUrl: String,
+
+    @Value("\${server.env}")
+    private val serverEnv: String
+) {
+
+    /**
+     * 채팅방 생성 또는 조회
+     *
+     * @param member 멤버
+     * @param characterId 캐릭터 ID
+     * @return 채팅방 ID
+     */
+    @Transactional
+    fun createOrGetChatRoom(member: Member, characterId: Long): CreateChatRoomResponse {
+        // 1. 캐릭터 조회
+        val character = characterService.findById(characterId)
+            ?: throw SodaException("해당 ID의 캐릭터를 찾을 수 없습니다: $characterId")
+
+        // 2. 이미 참여 중인 채팅방이 있는지 확인
+        val existingChatRoom = chatRoomRepository.findActiveChatRoomByMemberAndCharacter(member, character)
+
+        // 3. 있으면 채팅방 ID 반환
+        if (existingChatRoom != null) {
+            return CreateChatRoomResponse(chatRoomId = existingChatRoom.id!!)
+        }
+
+        // 4. 없으면 외부 API 호출하여 세션 생성
+        val userId = generateUserId(member.id!!)
+        val sessionId = callExternalApiForChatSession(userId, character.characterUUID)
+
+        // 5. 채팅방 생성
+        val chatRoom = CharacterChatRoom(
+            sessionId = sessionId,
+            title = character.name,
+            isActive = true
+        )
+        val savedChatRoom = chatRoomRepository.save(chatRoom)
+
+        // 6. 채팅방 참여자 추가 (멤버)
+        val memberParticipant = CharacterChatParticipant(
+            chatRoom = savedChatRoom,
+            participantType = ParticipantType.USER,
+            member = member,
+            character = null,
+            isActive = true
+        )
+        participantRepository.save(memberParticipant)
+
+        // 7. 채팅방 참여자 추가 (캐릭터)
+        val characterParticipant = CharacterChatParticipant(
+            chatRoom = savedChatRoom,
+            participantType = ParticipantType.CHARACTER,
+            member = null,
+            character = character,
+            isActive = true
+        )
+        participantRepository.save(characterParticipant)
+
+        // 8. 채팅방 ID 반환
+        return CreateChatRoomResponse(chatRoomId = savedChatRoom.id!!)
+    }
+
+    /**
+     * 유저 ID 생성
+     * "$serverEnv_user_$유저번호"를 UUID로 변환
+     *
+     * @param memberId 멤버 ID
+     * @return UUID 형태의 유저 ID
+     */
+    private fun generateUserId(memberId: Long): String {
+        val userIdString = "${serverEnv}_user_$memberId"
+        return UUID.nameUUIDFromBytes(userIdString.toByteArray()).toString()
+    }
+
+    /**
+     * 외부 API 호출하여 채팅 세션 생성
+     *
+     * @param userId 유저 ID (UUID)
+     * @param characterUUID 캐릭터 UUID
+     * @return 세션 ID
+     */
+    private fun callExternalApiForChatSession(userId: String, characterUUID: String): String {
+        try {
+            val factory = SimpleClientHttpRequestFactory()
+            factory.setConnectTimeout(20000) // 20초
+            factory.setReadTimeout(20000) // 20초
+
+            val restTemplate = RestTemplate(factory)
+
+            val headers = HttpHeaders()
+            headers.set("x-api-key", apiKey)
+            headers.contentType = MediaType.APPLICATION_JSON
+
+            // 요청 바디 생성 - userId와 characterId 전달
+            val requestBody = mapOf(
+                "userId" to userId,
+                "characterId" to characterUUID
+            )
+
+            val httpEntity = HttpEntity(requestBody, headers)
+
+            val response = restTemplate.exchange(
+                "$apiUrl/api/session",
+                HttpMethod.POST,
+                httpEntity,
+                String::class.java
+            )
+
+            // 응답 파싱
+            val objectMapper = ObjectMapper()
+            val apiResponse = objectMapper.readValue(response.body, ExternalChatSessionResponse::class.java)
+
+            // success가 false이면 throw
+            if (!apiResponse.success) {
+                throw SodaException(apiResponse.message ?: "채팅방 생성에 실패했습니다. 다시 시도해 주세요.")
+            }
+
+            // success가 true이면 파라미터로 넘긴 값과 일치하는지 확인
+            val data = apiResponse.data ?: throw SodaException("채팅방 생성에 실패했습니다. 다시 시도해 주세요.")
+
+            if (data.userId != userId && data.characterId != characterUUID && data.status != "active") {
+                throw SodaException("채팅방 생성에 실패했습니다. 다시 시도해 주세요.")
+            }
+
+            // 세션 ID 반환
+            return data.sessionId
+        } catch (e: Exception) {
+            e.printStackTrace()
+            throw SodaException("${e.message}, 채팅방 생성에 실패했습니다. 다시 시도해 주세요.")
+        }
+    }
+}

src/main/resources/application.yml

@@ -1,5 +1,6 @@
 server:
     shutdown: graceful
+    env: ${SERVER_ENV}
 
 logging:
     level: