Implement login, add useUser hook

pages/user/current.tsx

@@ -0,0 +1,30 @@
+import Layout from '@/components/ui/Layout';
+import Spinner from '@/components/ui/Spinner';
+import withPageAuthRequired from '@/config/auth/withPageAuthRequired';
+import useUser from '@/hooks/useUser';
+import { GetServerSideProps, NextPage } from 'next';
+
+const ProtectedPage: NextPage = () => {
+  const { user, isLoading, error } = useUser();
+
+  return (
+    <Layout>
+      <div className="flex h-full flex-col items-center justify-center">
+        <h1 className="text-7xl font-bold text-white">Hello!</h1>
+        <>
+          {isLoading && <Spinner />}
+          {error && <p>Something went wrong.</p>}
+          {user && (
+            <div>
+              <p>{user.username}</p>
+            </div>
+          )}
+        </>
+      </div>
+    </Layout>
+  );
+};
+
+export const getServerSideProps: GetServerSideProps = withPageAuthRequired();
+
+export default ProtectedPage;