Update package layout

lib/provider/token/TokenProvider.tsx

@@ -0,0 +1,77 @@
+import { createContext, useCallback, useContext, useMemo, useRef } from "react";
+import { defaultTokenData, fetchToken, parseToken, type TokenData } from "./TokenUtils";
+
+export interface TokenState {
+	getToken: () => Promise<string | null | undefined>;
+}
+
+const initialState: TokenState = {
+	getToken: () => new Promise(() => {})
+}
+
+const TokenContext = createContext<TokenState>(initialState);
+
+
+export default function TokenProvider({
+	apiUrl,
+	children
+}: Readonly<{
+	apiUrl: string;
+	children: React.ReactNode;
+}>){
+	const tokenRef = useRef<TokenData>(defaultTokenData);
+	const refreshPromise = useRef<Promise<string | null | undefined>>(null);
+
+	const getToken = useCallback(async () => {
+		if(refreshPromise.current){
+			return refreshPromise.current;
+		}
+
+		const { accessToken, expires } = tokenRef.current;
+
+		const isExpired = Date.now() > (expires - 5000);	//Give a 5 second buffer
+
+		if(!accessToken || isExpired){
+			refreshPromise.current = (async () => {
+				try {
+					const rawToken = (await fetchToken(apiUrl)).token;
+					const parsedToken = parseToken(rawToken);
+					tokenRef.current = parsedToken;
+					return rawToken;
+				}
+				catch(error){
+					tokenRef.current = defaultTokenData;
+					throw error;
+				}
+				finally {
+					refreshPromise.current = null;
+				}
+			})();
+			return refreshPromise.current;
+		}
+
+		return accessToken;
+	}, [apiUrl]);
+
+	const value: TokenState = useMemo(() => ({
+		getToken
+	}), [getToken]);
+
+	return (
+		<TokenContext.Provider value={value}>
+			{children}
+		</TokenContext.Provider>
+	);
+}
+
+
+// eslint-disable-next-line react-refresh/only-export-components
+export function useToken(){
+	const context = useContext(TokenContext);
+
+	if(!context){
+		throw new Error("useTOken must be called inside a TokenProvider");
+	}
+
+	return context;
+}