feat: stabilize social backend contracts

src/modules/chat/chat.gateway.ts

@@ -14,6 +14,7 @@ import { Server, Socket } from 'socket.io';
 import { ChatRealtimeService } from './chat-realtime.service';
 import { ChatService } from './chat.service';
 import { SendMessageDto } from './dto/send-message.dto';
+import { UsersService } from '../users/users.service';
 
 type SocketWithUser = Socket & { data: { userId?: string } };
 
@@ -21,12 +22,14 @@ type SocketWithUser = Socket & { data: { userId?: string } };
 export class ChatGateway implements OnGatewayInit, OnGatewayConnection, OnGatewayDisconnect {
   @WebSocketServer()
   server!: Server;
+  private readonly connectionCountsByUser = new Map<string, number>();
 
   constructor(
     private readonly chatService: ChatService,
     private readonly chatRealtimeService: ChatRealtimeService,
     private readonly jwtService: JwtService,
     private readonly configService: ConfigService,
+    private readonly usersService: UsersService,
   ) {}
 
   afterInit(server: Server) {
@@ -49,6 +52,8 @@ export class ChatGateway implements OnGatewayInit, OnGatewayConnection, OnGatewa
         return;
       }
       client.data.userId = payload.sub;
+      this.incrementUserConnection(payload.sub);
+      await this.usersService.setPresence(payload.sub, true);
       await client.join(this.userRoom(payload.sub));
       this.server.to(this.userRoom(payload.sub)).emit('presence', { userId: payload.sub, online: true });
     } catch {
@@ -59,7 +64,11 @@ export class ChatGateway implements OnGatewayInit, OnGatewayConnection, OnGatewa
   handleDisconnect(client: SocketWithUser) {
     const userId = client.data.userId;
     if (userId) {
-      this.server.to(this.userRoom(userId)).emit('presence', { userId, online: false });
+      const remainingConnections = this.decrementUserConnection(userId);
+      if (remainingConnections === 0) {
+        void this.usersService.setPresence(userId, false);
+        this.server.to(this.userRoom(userId)).emit('presence', { userId, online: false });
+      }
     }
   }
 
@@ -140,4 +149,18 @@ export class ChatGateway implements OnGatewayInit, OnGatewayConnection, OnGatewa
   private conversationRoom(conversationId: string): string {
     return `conversation:${conversationId}`;
   }
+
+  private incrementUserConnection(userId: string): void {
+    this.connectionCountsByUser.set(userId, (this.connectionCountsByUser.get(userId) ?? 0) + 1);
+  }
+
+  private decrementUserConnection(userId: string): number {
+    const nextCount = Math.max(0, (this.connectionCountsByUser.get(userId) ?? 1) - 1);
+    if (nextCount === 0) {
+      this.connectionCountsByUser.delete(userId);
+      return 0;
+    }
+    this.connectionCountsByUser.set(userId, nextCount);
+    return nextCount;
+  }
 }