//GLOBAL VARS
var userConected = null;
var email = null;
var uid = null;

/*Sign in auth:
Function that if you are not logged, on click into the icon a google popup will appeard and we will save
the data of the user in the var user. Also we catch the errors.
Docu: https://firebase.google.com/docs/auth/web/google-signin 
*/
function loginGoogle() {
    if (!firebase.auth().currentUser) {
        NOTES = [];
        var provider = new firebase.auth.GoogleAuthProvider();
        provider.addScope("https://www.googleapis.com/auth/contacts.readonly");

        firebase.auth().signInWithPopup(provider).then(function (result) {
            // This gives you a Google Access Token. You can use it to access the Google API.
            let user = result.user;
            uid = user.uid;
            email = user.email;
            alert('You have successfully logged in.');
            initUser();
        }).catch(function (error) {
            // Handle Errors here.
            var errorCode = error.code;
            if (errorCode === 'auth/account-exists-with-different-credential') {
                alert('This user does exist');
            }
        });
    }
    // Load user's notes
    loadNotes(uid);
}

/**
 * Logs out the currently logged in user.
 */
function logout() {
    firebase.auth().signOut().then(function (result) {
        alert('You have successfully logged out.');
        uid = null;
        email = null;
        MAP.clearMarkers();
        initUser();
    }).catch((error) => { console.log(error) });
}



/**
 * Used on load, checks whether the user is logged in, and sets up the interface
 * accordingly.
 */
function initUser() {

    // A user is logged in, load their notes
    if (firebase.auth().currentUser) {
        // Load user's notes
        uid = firebase.auth().currentUser.uid;
        email = firebase.auth().currentUser.email;
        $('#login-btn').attr("src", firebase.auth().currentUser.photoURL);
        $('#btn-add').show();
        $('#login-link').hide();
        $('#logout-link').show();
        $('#logout-email').show();
        $('#logout-email').html(`Logged in as ${email}`);

    } else {
        $('#login-btn').attr("src", "images/avatar.png");
        redrawNotes(NOTES);
        $('#login-link').show();
        $('#logout-link').hide();
        $('#logout-email').hide();
        $('#sidebar').html('Log in to add notes!')
    }
    loadNotes(uid);
}

/**
* Store the notes in the database
* @param uid  id value of the user in the databse. 
*/
function dbNotePush(uid, noteId, latLng, locationTitle, text) {
    let resp = db.ref("/user" + uid).push({
        uid: uid,
        noteId: noteId,
        location: latLng,
        locationTitle: locationTitle,
        text: text
    })
    let id = resp.path.o[1]
    return id
}

/**
* Update the text field in the notes collection at the database
*/
function dbUpdateNote(uid, noteId, text, dbID) {
    db.ref("/user" + uid).child(dbID).update({
        text: text
    })
}

/**
* Remove the whole note collection of an specidif user at the database
*/
function dbRemoveNote(uid, noteId, dbID) {
    db.ref("/user" + uid).child(dbID).remove();
}

/*Load the data that is stored in /useruid ans save the values of the childs of this root into the
* var data which contains {locationTitle: "...", location: "...", noteId: "..", text: "", uid: "..."}
* Documentation: https://firebase.google.com/docs/database/web/lists-of-data
*/
function loadNotes(uid) {
    MAP.clearMarkers();
    if (!uid) {
        if (!(NOTES = JSON.parse(localStorage.getItem('NOTES')))) {
            NOTES = []
        }
        for (let n of NOTES) {
            n.location = new google.maps.LatLng(n.location.lat, n.location.lng);
        }
        redrawNotes(NOTES);
        for (let n of NOTES) {
            MAP.addMarker(n.location, MAP.map, n.noteId);
        }
    }
    else {
        NOTES = [];
        var userNotes = db.ref('user' + uid);
        userNotes.once('value').then(function (snapshot) {
            snapshot.forEach(function (childSnapshot) {
                var data = childSnapshot.val();
                data.dbID = childSnapshot.W.path.o[1];
                data.location = new google.maps.LatLng(data.location.lat, data.location.lng);
                NOTES.push(data);
                MAP.addMarker(data.location, MAP.map, data.noteId);
            })
            redrawNotes(NOTES);
        })
    }

}