import jwtDecode from "jwt-decode";
import router from "./routes";

export interface IUser {
	id: number,
	name: string,
	isAdmin: boolean
}

/**
 * The active JWT
 */
let token: string | null;

/**
 * The decoded user object
 */
let user: IUser | null;

/**
 * Check if the user is an admin
 */
export function isAdmin() {
	return user && user.isAdmin;
}

/**
 * Check if the client is authenticated
 */
export function isAuthenticated() {
	return Boolean(token);
}

/**
 * Get the logged in user (assumes authentication has been checked)
 */
export function getUser() {
	return <IUser>user;
}

/**
 * Load the token from local storage
 */
export function loadToken() {
	try {
		token = localStorage.getItem("jwt");
		user = jwtDecode(<string>token);
	} catch(e) {
		console.log("Failed to load token");
		token = null;
		user = null;
		return false;
	}
	console.log("Token loaded", token);
	return true;
}

/**
 * Delete the token from local storage
 */
export function forgetToken() {
	token = null;
	user = null;
	localStorage.removeItem("jwt");
}

/**
 * Store a JWT token in local storage
 */
export function storeToken(jwtToken: string) {
	try {
		user = jwtDecode(jwtToken);
		token = jwtToken;
		localStorage.setItem("jwt", jwtToken);
	} catch(e) {
		user = null;
		token = null;
		return false;
	}
	return true;
}

/**
 * Fetch request providing authentication and logout upon unauthorized requests
 */
 export async function authFetch(path: string, options: RequestInit = {}): Promise<Response> {
	console.log("Performing auth fetch");
	options.credentials = "include";
	options.headers = Object.assign(options.headers ?? {}, {
		"Authorization": `Bearer ${token}`
	});
	let response = await fetch(path, options);
	if (response.status === 401) {
		// forgetToken();
		console.log("Forgetting token...");
		router.push({ name: "Login" });
		throw Error("Unauthorized");
	}
	return response;
}

/**
 * @TODO Remove later
 */
(<any>window).forgetToken = forgetToken;
(<any>window).authFetch = authFetch;

/**
 * Ensure the token is loaded upon startup
 */
loadToken();