prepared for login

client/src/app/Main.tsx

@@ -0,0 +1,55 @@
+"use client";
+
+import { apiCall } from "@/lib";
+import { Spinner } from "@nextui-org/spinner";
+import { usePathname, useRouter } from "next/navigation";
+import React, { useEffect, useState } from "react";
+
+enum AuthState {
+	Loading,
+	LoginScreen,
+	Unauthorized,
+	LoggedIn,
+}
+
+export default function Main({ children }: { children: React.ReactNode }) {
+	const [status, setStatus] = useState(AuthState.Loading);
+
+	const router = useRouter();
+	const pathname = usePathname();
+
+	useEffect(() => {
+		void (async () => {
+			if (pathname === "/login") {
+				setStatus(AuthState.LoginScreen);
+			} else {
+				const welcomeResult = await apiCall<{
+					userName: string;
+					loggedIn: boolean;
+				}>("GET", "welcome");
+
+				if (!welcomeResult.ok) {
+					router.push("/login");
+				} else {
+					const response = await welcomeResult.json();
+
+					if (response.loggedIn) {
+						setStatus(AuthState.LoggedIn);
+					} else {
+						setStatus(AuthState.Unauthorized);
+					}
+				}
+			}
+		})();
+	});
+
+	switch (status) {
+		case AuthState.Loading:
+			return <Spinner label="Loading..." />;
+		case AuthState.LoggedIn:
+		case AuthState.LoginScreen:
+			return children;
+		case AuthState.Unauthorized:
+			return "";
+	}
+}