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

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/service/ChatMessageService.kt

@@ -0,0 +1,37 @@
+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 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 +1,55 @@
+package com.back.koreaTravelGuide.domain.userChat.chatroom.controller
+
+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.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
+
+@RestController
+@RequestMapping("/api/userchat/rooms")
+class ChatRoomController(
+    private val roomSvc: ChatRoomService,
+    private val msgSvc: ChatMessageService,
+    private val events: UserChatSseEvents,
+) {
+    // Room API
+    @PostMapping
+    fun create(
+        @RequestBody req: ChatRoomService.CreateRoomReq,
+    ) = roomSvc.create(req)
+
+    @GetMapping("/{roomId}")
+    fun get(
+        @PathVariable roomId: Long,
+    ) = roomSvc.get(roomId)
+
+    // Message API (룸 하위 리소스)
+    @GetMapping("/{roomId}/messages")
+    fun listMessages(
+        @PathVariable roomId: Long,
+        @RequestParam(required = false) after: Long?,
+        @RequestParam(defaultValue = "50") limit: Int,
+    ) = if (after == null) msgSvc.getlistbefore(roomId, limit) else msgSvc.getlistafter(roomId, after)
+
+    @PostMapping("/{roomId}/messages")
+    fun sendMessage(
+        @PathVariable roomId: Long,
+        @RequestBody req: ChatMessageService.SendMessageReq,
+    ) = msgSvc.send(roomId, req).also { saved ->
+        events.publishNew(roomId, saved.id!!)
+    }
+
+    // SSE 구독도 여기 포함
+    @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/service/ChatRoomService.kt

@@ -0,0 +1,20 @@
+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 ownerId: Long)
+
+    @Transactional
+    fun create(req: CreateRoomReq): ChatRoom =
+        roomRepository.save(ChatRoom(title = req.title, ownerId = req.ownerId, updatedAt = Instant.now()))
+
+    fun get(roomId: Long): ChatRoom = roomRepository.findById(roomId).orElseThrow { NoSuchElementException("room not found: $roomId") }
+}