var username = document.getElementById("username");
var password = document.getElementById("password");
var register = document.getElementById("register");
var google = document.getElementById("google");
var login = document.getElementById("login");
var logout = document.getElementById("logout");
var provider = new firebase.auth.GoogleAuthProvider();
var db = firebase.database().ref();

register.addEventListener('click', e => {
	firebase.auth().createUserWithEmailAndPassword(username.value, password.value).catch(e => console.log(e.message));
	password.value = "";
});

login.addEventListener('click', e => {
	firebase.auth().signInWithEmailAndPassword(username.value, password.value).catch(e => console.log(e.message));
	password.value = "";
});

google.addEventListener('click', e => {
  firebase.auth().signInWithPopup(provider).catch(e => console.log(e.message));
});

logout.addEventListener('click', e => {
	firebase.auth().signOut().catch(e => console.log(e.message));
});

firebase.auth().onAuthStateChanged(firebaseUser => {
  var permission = false;
	if (firebaseUser) {
		console.log("User logged in: " + firebaseUser.email);
    db.once('value', snap => {
      snap.forEach(function(child){
        if (child.val() == firebaseUser.email) {
          permission = true;
      }
    });
      if (!permission) {
        firebaseUser.delete().catch(e => console.log(e.message));
        console.log("No Permission");
      }
    });
		logout.classList.remove('hidden');

	} else {
		console.log("Not Logged in!")
		logout.classList.add('hidden');
	}
});