Add WebSocket integration

package.json

@@ -45,6 +45,7 @@
     "react-router-dom": "^6.3.0",
     "react-sortablejs": "^6.1.4",
     "react-toastify": "^9.1.1",
+    "socket.io-client": "^4.8.0",
     "sortablejs": "^1.15.2",
     "swr": "^2.2.5",
     "tailwind-merge": "^2.2.0",

src/api/socket.ts

@@ -0,0 +1,73 @@
+import { io, Socket } from "socket.io-client";
+import backendApi from "./backend";
+
+const SOCKET_URL = 'ws://' + backendApi.BACKEND_URL.split('//')[1];
+
+class OptionalSocket {
+    private socket: Socket | null;
+
+    constructor() {
+        this.socket = null;
+    }
+
+    set(socket: Socket) {
+        this.socket = socket;
+    }
+
+    unset() {
+        this.socket = null;
+    }
+
+    use<T>(callback: (socket: Socket) => T): T {
+        if (!this.socket) {
+            throw new Error('Socket is not connected');
+        }
+        return callback(this.socket);
+    }
+}
+
+class SessionsSocket {
+    private url: string;
+    private socket: OptionalSocket;
+
+    constructor(url: string) {
+        this.url = url;
+        this.socket = new OptionalSocket();
+    }
+
+    connect() {
+        const newSocket = io(this.url, {
+            auth: {
+                token: 'dummy',  // TODO: Replace with actual federated authentication token
+            }
+        });
+        this.socket.set(newSocket);
+        console.log('Connected to socket');
+    }
+
+    disconnect() {
+        this.socket.use(socket => socket.disconnect());
+        this.socket.unset();
+
+        console.log('Disconnected from socket');
+    }
+
+    on(event: string, callback: (...args: any[]) => void) {
+        this.socket.use(socket => socket.on(event, callback));
+    }
+
+    off(event: string, callback?: (...args: any[]) => void) {
+        this.socket.use(socket => socket.off(event, callback));
+    }
+
+    emit(event: string, ...args: any[]) {
+        this.socket.use(socket => socket.emit(event, args));
+    }
+}
+
+const sessionsSocket = new SessionsSocket(SOCKET_URL);
+
+export {
+    sessionsSocket,
+    SOCKET_URL,
+};