https://raw.githubusercontent.com/Noble-Mushtak/KA-Contest-Judging-System/master/Client/admin/scripts/auth.js

auth.js

/*
 * Step 1: Check to make sure user is logged in (if not, leave page)
 * Step 2: Check to make sure logged in user, is an administrator (if not, leave page)
 * Step 3: Load all tools onto the page.
 */
/* The data we have on the current user. */
var userData;
/* True iff we're done with the auth checks. */
var authChecksDone = false;

/* Check if user is logged in using Firebase. */
var fbAuth = Contest_Judging_System.getFirebaseAuth();
if (fbAuth === null) {
	/* Let the user know that we're leaving the page. */
	alert("Please login on the home page. Thanks! Leaving page.");
	window.location.assign("../index.html");
}
/* Otherwise, go straight to getting the user info: */
else getUserInfo();

function getUserInfo() {
    /* Get the data we have on the user: */
    Contest_Judging_System.getUserData(fbAuth.uid, function(userDataLocal) {
        /* Set userData: */
        userData = userDataLocal;
        /* Make sure they're an admin. */
        if (userData.permLevel !== 5) {
            /* User doesn't appear to be an admin. */
            /* Let the user know that we're leaving the page. */
            alert("You do not have admin permissions! Leaving page.");
            window.location.assign("../index.html");
        }

		/* Once everything is done, set authChecksDone to true, that way we can move to the next step. */
		authChecksDone = true;
    });
}

/* Check if we're done with our authentication checks every second. */
var authChecks = setInterval(function() {
    /* If we're done with our authentication checks: */
	if (authChecksDone) {
        /* Stop loading and show the content. */
		document.querySelector("#loading").style.display = "none";
		document.querySelector(".hideWhileAuthCheck").style.display = "block";
        
        /* Stop checking if we're done with our authentication checks. */
		clearInterval(authChecks);
		console.log("Authenticated!");

		/* Welcome the user to the admin dashboard. */
		document.getElementById("welcomeMessage").textContent = document.getElementById("welcomeMessage").textContent.replace("{{name}}", userData.name);
	}
}, 1000);