Add the Session handler, class, and middleware

app/src/middleware/session.ts

@@ -0,0 +1,45 @@
+import { Context } from 'hono';
+
+class Session {
+  private readonly id: string;
+  private data: Record<string, any>;
+
+  public constructor(id: string, data?: Record<string, any>) {
+    this.id = id;
+    this.data = data ?? {};
+  }
+
+  public getId(): string {
+    return this.id;
+  }
+
+  public getData(key: string): any {
+    return this.data[key];
+  }
+
+  public setData(key: string, data: any): void {
+    this.data[key] = data;
+  }
+}
+
+class SessionHandler {
+  private static instance: SessionHandler;
+
+  private constructor() { }
+
+  public static getInstance(): SessionHandler {
+    if (!SessionHandler.instance) {
+      SessionHandler.instance = new SessionHandler();
+    }
+
+    return SessionHandler.instance;
+  }
+}
+
+const sessionMiddleware = async (c: Context, next: CallableFunction) => {
+  c.set('session', SessionHandler.getInstance());
+  await next();
+};
+
+export { sessionMiddleware, SessionHandler, Session };
+