feat(be): userChat 도메인 임시 기능 구현 (#41)

* feat(be): userChat service,controller,SSE 추가

* feat(be) : controller,service,repository 팀 스타일에 맞게 수정

Author: beekeeper24

src/main/kotlin/com/back/koreaTravelGuide/domain/userChat/UserChatSseEvents.kt

@@ -0,0 +1,34 @@
+package com.back.koreaTravelGuide.domain.userChat
+
+import org.springframework.stereotype.Component
+import org.springframework.web.servlet.mvc.method.annotation.SseEmitter
+import java.util.concurrent.ConcurrentHashMap
+
+// Websocket,Stomp 사용 전 임시로 만들었음
+// 테스트 후 제거 예정
+
+@Component
+class UserChatSseEvents {
+    private val emitters = ConcurrentHashMap<Long, MutableList<SseEmitter>>()
+
+    fun subscribe(roomId: Long): SseEmitter {
+        val emitter = SseEmitter(0L)
+        emitters.computeIfAbsent(roomId) { mutableListOf() }.add(emitter)
+        emitter.onCompletion { emitters[roomId]?.remove(emitter) }
+        emitter.onTimeout { emitter.complete() }
+        return emitter
+    }
+
+    fun publishNew(
+        roomId: Long,
+        lastMessageId: Long,
+    ) {
+        emitters[roomId]?.toList()?.forEach {
+            try {
+                it.send(SseEmitter.event().name("NEW").data(lastMessageId))
+            } catch (_: Exception) {
+                it.complete()
+            }
+        }
+    }
+}

src/main/kotlin/com/back/koreaTravelGuide/domain/userChat/chatmessage/entity/ChatMessage.kt

@@ -21,7 +21,7 @@ data class ChatMessage(
     val roomId: Long,
     @Column(name = "sender_id", nullable = false)
     val senderId: Long,
-    @Column(columnDefinition = "text", nullable = false)
+    @Column(nullable = false, columnDefinition = "text")
     val content: String,
     @Column(name = "created_at", nullable = false)
     val createdAt: Instant = Instant.now(),

src/main/kotlin/com/back/koreaTravelGuide/domain/userChat/chatmessage/repository/ChatMessageRepository.kt

@@ -12,4 +12,6 @@ interface ChatMessageRepository : JpaRepository<ChatMessage, Long> {
         roomId: Long,
         afterId: Long,
     ): List<ChatMessage>
+
+    fun deleteByRoomId(roomId: Long)
 }

src/main/kotlin/com/back/koreaTravelGuide/domain/userChat/chatmessage/service/ChatMessageService.kt

@@ -0,0 +1,42 @@
+package com.back.koreaTravelGuide.domain.userChat.chatmessage.service
+
+import com.back.koreaTravelGuide.domain.userChat.chatmessage.entity.ChatMessage
+import com.back.koreaTravelGuide.domain.userChat.chatmessage.repository.ChatMessageRepository
+import com.back.koreaTravelGuide.domain.userChat.chatroom.repository.ChatRoomRepository
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+
+@Service
+class ChatMessageService(
+    private val msgRepository: ChatMessageRepository,
+    private val roomRepository: ChatRoomRepository,
+) {
+    data class SendMessageReq(val senderId: Long, val content: String)
+
+    fun getlistbefore(
+        roomId: Long,
+        limit: Int,
+    ): List<ChatMessage> = msgRepository.findTop50ByRoomIdOrderByIdDesc(roomId).asReversed()
+
+    fun getlistafter(
+        roomId: Long,
+        afterId: Long,
+    ): List<ChatMessage> = msgRepository.findByRoomIdAndIdGreaterThanOrderByIdAsc(roomId, afterId)
+
+    @Transactional
+    fun deleteByRoom(roomId: Long) {
+        msgRepository.deleteByRoomId(roomId)
+    }
+
+    @Transactional
+    fun send(
+        roomId: Long,
+        req: SendMessageReq,
+    ): ChatMessage {
+        val saved = msgRepository.save(ChatMessage(roomId = roomId, senderId = req.senderId, content = req.content))
+        roomRepository.findById(roomId).ifPresent {
+            roomRepository.save(it.copy(updatedAt = saved.createdAt, lastMessageId = saved.id))
+        }
+        return saved
+    }
+}

src/main/kotlin/com/back/koreaTravelGuide/domain/userChat/chatroom/controller/ChatRoomController.kt

@@ -0,0 +1,85 @@
+package com.back.koreaTravelGuide.domain.userChat.chatroom.controller
+
+import com.back.koreaTravelGuide.common.ApiResponse
+import com.back.koreaTravelGuide.domain.userChat.UserChatSseEvents
+import com.back.koreaTravelGuide.domain.userChat.chatmessage.service.ChatMessageService
+import com.back.koreaTravelGuide.domain.userChat.chatroom.service.ChatRoomService
+import org.springframework.http.MediaType
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.DeleteMapping
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.PathVariable
+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.RequestParam
+import org.springframework.web.bind.annotation.RestController
+import org.springframework.web.servlet.mvc.method.annotation.SseEmitter
+
+// 컨트롤러는 임시로 강사님 스타일 따라서 통합해놓았음. 추후 리팩토링 예정
+@RestController
+@RequestMapping("/api/userchat/rooms")
+class ChatRoomController(
+    private val roomSvc: ChatRoomService,
+    private val msgSvc: ChatMessageService,
+    private val events: UserChatSseEvents,
+) {
+    data class StartChatReq(val guideId: Long, val userId: Long)
+
+    data class DeleteChatReq(val userId: Long)
+
+    // MVP: 같은 페어는 방 재사용
+    @PostMapping("/start")
+    fun startChat(
+        @RequestBody req: StartChatReq,
+    ): ResponseEntity<ApiResponse<Map<String, Long>>> {
+        val roomId = roomSvc.exceptOneToOneRoom(req.guideId, req.userId).id!!
+        return ResponseEntity.ok(ApiResponse(msg = "채팅방 시작", data = mapOf("roomId" to roomId)))
+    }
+
+    @DeleteMapping("/{roomId}")
+    fun deleteRoom(
+        @PathVariable roomId: Long,
+        @RequestBody req: DeleteChatReq,
+    ): ResponseEntity<ApiResponse<Unit>> {
+        roomSvc.deleteByOwner(roomId, req.userId)
+        return ResponseEntity.ok(ApiResponse("채팅방 삭제 완료"))
+    }
+
+    @GetMapping("/{roomId}")
+    fun get(
+        @PathVariable roomId: Long,
+    ) = ResponseEntity.ok(ApiResponse(msg = "채팅방 조회", data = roomSvc.get(roomId)))
+
+    @GetMapping("/{roomId}/messages")
+    fun listMessages(
+        @PathVariable roomId: Long,
+        @RequestParam(required = false) after: Long?,
+        @RequestParam(defaultValue = "50") limit: Int,
+    ): ResponseEntity<ApiResponse<Any>> {
+        val messages =
+            if (after == null) {
+                msgSvc.getlistbefore(roomId, limit)
+            } else {
+                msgSvc.getlistafter(roomId, after)
+            }
+        return ResponseEntity.ok(ApiResponse(msg = "메시지 조회", data = messages))
+    }
+
+    @PostMapping("/{roomId}/messages")
+    fun sendMessage(
+        @PathVariable roomId: Long,
+        @RequestBody req: ChatMessageService.SendMessageReq,
+    ): ResponseEntity<ApiResponse<Any>> {
+        val saved = msgSvc.send(roomId, req)
+        events.publishNew(roomId, saved.id!!)
+        return ResponseEntity.status(201).body(ApiResponse(msg = "메시지 전송", data = saved))
+    }
+
+    // SSE는 스트림이여서 ApiResponse로 감싸지 않았음
+    // WebSocket,Stomp 적용되면 바로 삭제 예정
+    @GetMapping("/{roomId}/events", produces = [MediaType.TEXT_EVENT_STREAM_VALUE])
+    fun subscribe(
+        @PathVariable roomId: Long,
+    ): SseEmitter = events.subscribe(roomId)
+}

src/main/kotlin/com/back/koreaTravelGuide/domain/userChat/chatroom/entity/ChatRoom.kt

@@ -19,8 +19,10 @@ data class ChatRoom(
     val id: Long? = null,
     @Column(nullable = false)
     val title: String,
-    @Column(name = "owner_id", nullable = false)
-    val ownerId: Long,
+    @Column(name = "guide_id", nullable = false)
+    val guideId: Long,
+    @Column(name = "user_id", nullable = false)
+    val userId: Long,
     @Column(name = "updated_at", nullable = false)
     val updatedAt: Instant = Instant.now(),
     @Column(name = "last_message_id")

src/main/kotlin/com/back/koreaTravelGuide/domain/userChat/chatroom/repository/ChatRoomRepository.kt

@@ -2,7 +2,21 @@ package com.back.koreaTravelGuide.domain.userChat.chatroom.repository
 
 import com.back.koreaTravelGuide.domain.userChat.chatroom.entity.ChatRoom
 import org.springframework.data.jpa.repository.JpaRepository
+import org.springframework.data.jpa.repository.Query
 import org.springframework.stereotype.Repository
 
 @Repository
-interface ChatRoomRepository : JpaRepository<ChatRoom, Long>
+interface ChatRoomRepository : JpaRepository<ChatRoom, Long> {
+    // 가이드,유저 방 생성시 중복 생성 방지
+    @Query(
+        """
+        select r from ChatRoom r
+        where (r.guideId = :guideId and r.userId = :userId)
+           or (r.guideId = :userId and r.userId = :guideId)
+        """,
+    )
+    fun findOneToOneRoom(
+        guideId: Long,
+        userId: Long,
+    ): ChatRoom?
+}

src/main/kotlin/com/back/koreaTravelGuide/domain/userChat/chatroom/service/ChatRoomService.kt

@@ -0,0 +1,44 @@
+package com.back.koreaTravelGuide.domain.userChat.chatroom.service
+
+import com.back.koreaTravelGuide.domain.userChat.chatroom.entity.ChatRoom
+import com.back.koreaTravelGuide.domain.userChat.chatroom.repository.ChatRoomRepository
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+import java.time.Instant
+
+@Service
+class ChatRoomService(
+    private val roomRepository: ChatRoomRepository,
+) {
+    data class CreateRoomReq(val title: String, val guideId: Long, val userId: Long)
+
+    @Transactional
+    fun exceptOneToOneRoom(
+        guideId: Long,
+        userId: Long,
+    ): ChatRoom {
+        // 1) 기존 방 재사용
+        roomRepository.findOneToOneRoom(guideId, userId)?.let { return it }
+
+        // 2) 없으면 생성 (동시요청은 DB 유니크 인덱스로 가드)
+        val title = "Guide-$guideId · User-$userId"
+        return roomRepository.save(
+            ChatRoom(title = title, guideId = guideId, userId = userId, updatedAt = Instant.now()),
+        )
+    }
+
+    fun get(roomId: Long): ChatRoom = roomRepository.findById(roomId).orElseThrow { NoSuchElementException("room not found: $roomId") }
+
+    @Transactional
+    fun deleteByOwner(
+        roomId: Long,
+        requesterId: Long,
+    ) {
+        val room = get(roomId)
+        if (room.userId != requesterId) {
+            // 예외처리 임시
+            throw IllegalArgumentException("채팅방 생성자만 삭제할 수 있습니다.")
+        }
+        roomRepository.deleteById(roomId)
+    }
+}