feat(be): implement participant presence in study rooms

apps/backend/apps/client/src/app.module.ts

@@ -1,7 +1,8 @@
 import { MailerModule } from '@nestjs-modules/mailer'
+import { BullModule } from '@nestjs/bullmq'
 import { CacheModule } from '@nestjs/cache-manager'
 import { Module, type OnApplicationBootstrap } from '@nestjs/common'
-import { ConfigModule } from '@nestjs/config'
+import { ConfigModule, ConfigService } from '@nestjs/config'
 import { APP_FILTER, APP_GUARD, HttpAdapterHost } from '@nestjs/core'
 import type { Server } from 'http'
 import { OpenTelemetryModule } from 'nestjs-otel'
@@ -12,6 +13,7 @@ import { ClientExceptionFilter } from '@libs/exception'
 import { openTelemetryModuleOption } from '@libs/instrumentation'
 import { pinoLoggerModuleOption } from '@libs/logger'
 import { PrismaModule } from '@libs/prisma'
+import { RedisModule } from '@libs/redis'
 import { AnnouncementModule } from './announcement/announcement.module'
 import { AppController } from './app.controller'
 import { AppService } from './app.service'
@@ -55,7 +57,20 @@ import { WorkbookModule } from './workbook/workbook.module'
     NotificationModule,
     LoggerModule.forRoot(pinoLoggerModuleOption),
     OpenTelemetryModule.forRoot(openTelemetryModuleOption),
-    StudyModule
+    StudyModule,
+    RedisModule,
+    BullModule.forRootAsync({
+      inject: [ConfigService],
+      useFactory: (configService: ConfigService) => ({
+        connection: {
+          host: configService.get<string>('REDIS_HOST'),
+          port: configService.get<number>('REDIS_PORT'),
+          password: configService.get<string>('REDIS_PASSWORD'),
+          db: 1
+        },
+        prefix: 'bull-client'
+      })
+    })
   ],
   controllers: [AppController],
   providers: [

apps/backend/apps/client/src/main.ts

@@ -2,11 +2,13 @@ import { ValidationPipe } from '@nestjs/common'
 import { NestFactory } from '@nestjs/core'
 import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger'
 import cookieParser from 'cookie-parser'
+import type Redis from 'ioredis'
 import Instrumentation from '@libs/instrumentation'
+import { REDIS_CLIENT, RedisIoAdapter } from '@libs/redis'
 
 /**
-  TODO: 가능하면 `app.module.ts`에서 PrismaModule 처럼 IoC 리팩터링 필요  
-  지금은 Instrumentation.start가 AppModule 보다 먼저 실행되어야 함  
+  TODO: 가능하면 `app.module.ts`에서 PrismaModule 처럼 IoC 리팩터링 필요
+  지금은 Instrumentation.start가 AppModule 보다 먼저 실행되어야 함
   자세한 이유는 [이 comment](https://github.com/skkuding/codedang/pull/2705#discussion_r2072945663)를 참고해주세요.
 */
 const bootstrap = async () => {
@@ -29,6 +31,13 @@ const bootstrap = async () => {
   app.useGlobalInterceptors(new LoggerErrorInterceptor())
   app.useGlobalPipes(new ValidationPipe({ whitelist: true }))
   app.use(cookieParser())
+
+  // Redis WebSocket adapter 연결
+  const redisClient = app.get<Redis>(REDIS_CLIENT)
+  const redisIoAdapter = new RedisIoAdapter(app, redisClient)
+  await redisIoAdapter.connectToRedis() // redis 연결
+  app.useWebSocketAdapter(redisIoAdapter) // adapter 등록
+
   if (process.env.APP_ENV !== 'production' && process.env.APP_ENV !== 'stage') {
     app.enableCors({
       origin: 'http://localhost:5525',

apps/backend/apps/client/src/study/interface/study-socket.interface.ts

@@ -0,0 +1,31 @@
+// Room
+export interface RoomState {
+  endAt: number
+  leaderId: number | null
+}
+
+export interface RoomMember {
+  userId: number
+  userName: string
+  joinedAt: number
+}
+
+// Socket Response
+export interface SocketResponse<T = undefined> {
+  success: boolean
+  message?: string
+  data?: T
+  code?: string
+}
+
+export interface JoinResponse {
+  members: RoomMember[]
+  endAt: number
+  remainMs: number
+  leaderId: number | null
+}
+
+// PayLoad
+export interface JoinPayload {
+  groupId: number
+}

apps/backend/apps/client/src/study/study-room.processor.ts

@@ -0,0 +1,41 @@
+import { Processor, WorkerHost } from '@nestjs/bullmq'
+import { Logger } from '@nestjs/common'
+import { Job } from 'bullmq'
+import {
+  STUDY_ROOM_QUEUE,
+  JOB_RECONNECT_EXPIRE,
+  JOB_ROOM_REMINDER,
+  JOB_ROOM_END
+} from '@libs/constants'
+import { StudyRoomService } from './study-room.service'
+
+@Processor(STUDY_ROOM_QUEUE)
+export class StudyRoomProcessor extends WorkerHost {
+  private readonly logger = new Logger(StudyRoomProcessor.name)
+
+  constructor(private readonly studyRoomService: StudyRoomService) {
+    super()
+  }
+
+  async process(job: Job): Promise<void> {
+    switch (job.name) {
+      case JOB_ROOM_REMINDER:
+        await this.studyRoomService.reminderRoom(job.data.groupId)
+        break
+
+      case JOB_ROOM_END:
+        await this.studyRoomService.endRoom(job.data.groupId)
+        break
+
+      case JOB_RECONNECT_EXPIRE:
+        await this.studyRoomService.handleReconnectExpiry(job.data)
+        break
+
+      default:
+        this.logger.warn(
+          `Unknown job name: ${job.name}`,
+          JSON.stringify(job.data)
+        )
+    }
+  }
+}