init commit,

03_source/frontend/src/auth/guard/guest-guard.tsx

@@ -0,0 +1,51 @@
+import { useState, useEffect } from 'react';
+
+import { useSearchParams } from 'src/routes/hooks';
+
+import { CONFIG } from 'src/global-config';
+
+import { SplashScreen } from 'src/components/loading-screen';
+
+import { useAuthContext } from '../hooks';
+
+// ----------------------------------------------------------------------
+
+type GuestGuardProps = {
+  children: React.ReactNode;
+};
+
+export function GuestGuard({ children }: GuestGuardProps) {
+  const { loading, authenticated } = useAuthContext();
+
+  const searchParams = useSearchParams();
+  const returnTo = searchParams.get('returnTo') || CONFIG.auth.redirectPath;
+
+  const [isChecking, setIsChecking] = useState(true);
+
+  const checkPermissions = async (): Promise<void> => {
+    if (loading) {
+      return;
+    }
+
+    if (authenticated) {
+      // Redirect authenticated users to the returnTo path
+      // Using `window.location.href` instead of `router.replace` to avoid unnecessary re-rendering
+      // that might be caused by the AuthGuard component
+      window.location.href = returnTo;
+      return;
+    }
+
+    setIsChecking(false);
+  };
+
+  useEffect(() => {
+    checkPermissions();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [authenticated, loading]);
+
+  if (isChecking) {
+    return <SplashScreen />;
+  }
+
+  return <>{children}</>;
+}