//
//  example
//
//  Created by Bridget Went, 5/28/15.
//  Modified by Milad Nazeri, 12/10/17
//  Copyright 2015 High Fidelity, Inc.
//
//  A project to build a virtual physics classroom to simulate the solar system, gravity, and orbital physics.
//
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//
var planetConfig =
        Script.require(Script.resolvePath('Tablet/planetDefault.json?v=' + Date.now()));

var theEarth;
var theMoon;

var update;
var center =
        {   x: 0,
            y: 0,
            z: 0 };
var radius;
var velocity;
var position;

var APP_URL =
        Script.resolvePath('Tablet/planetUI.html');
var buttonActivated =
        false;
var tablet =
        Tablet.getTablet("com.highfidelity.interface.tablet.system");

var button =
        tablet.addButton({
        // icon: ICONS.icon,
        // activeIcon: ICONS.activeIcon,
        text: 'planet',
        sortOrder: 1 });

function onClicked() {
    if (buttonActivated) {
        button.editProperties({isActive: false});
        buttonActivated = false;
        tablet.gotoHomeScreen();
        tablet.webEventReceived.disconnect(onWebEventReceived); }
    else {
        tablet.gotoWebScreen(APP_URL);
        tablet.webEventReceived.connect(onWebEventReceived);
        button.editProperties({isActive: true});
        buttonActivated = true; }
}
button.clicked.connect(onClicked);

function onWebEventReceived(event) {
    var htmlEvent =
            JSON.parse(event);
    switch (htmlEvent.type){
        case 'slider':
            planetConfig[htmlEvent.id].val = htmlEvent.value;
            restart();
            break;
        default: }
    // print(JSON.stringify(htmlEvent));
}

function getGravity(){
    return (
        (Math.pow(planetConfig.referenceRadius.val, 3.0) /
        Math.pow((planetConfig.referencePeriod.val / (2.0 * Math.PI)), 2.0)) /
        planetConfig.LARGE_BODY_MASS.val);
}
function computeAcceleration(radius){
    var acc =
            -(getGravity() * planetConfig.LARGE_BODY_MASS.val) * Math.pow(radius, (-2.0));
    return acc;
};
function makeEarth(){
    print("==============================\nTHE EARTH:", theEarth);
    if (theEarth) {
        Entities.deleteEntity(theEarth);
        theEarth =
            null; };
    TheEarth =
        Entities.addEntity({
            type: "Model",
            modelURL: Script.resolvePath("Earth/earth.obj"),
            position: center,
            dimensions: {
                x: planetConfig.EARTH_SIZE.val,
                y: planetConfig.EARTH_SIZE.val,
                z: planetConfig.EARTH_SIZE.val },
            angularVelocity: {
                x: 0.0,
                y: 0.1,
                z: 0.0 },
            angularDamping: planetConfig.DAMPING.val,
            damping: planetConfig.DAMPING.val,
            ignoreCollisions: false,
            dynamic: false });
}
function makeMoon(){
    if (theMoon) {
        Entities.deleteEntity(theMoon);
        Script.update.disconnect(update);
        update =
            null;
        theMoon =
            null; }
    var initialVelocity =
            Math.sqrt((getGravity() * planetConfig.LARGE_BODY_MASS.val) / radius);
    var dimensions =
            planetConfig.MOON_SCALE.val * planetConfig.referenceDiameter.val;
    velocity =
        Vec3.multiply(initialVelocity, Vec3.normalize({
            x: 0,
            y: planetConfig.VELOCITY_OFFSET_Y.val,
            z: planetConfig.VELOCITY_OFFSET_Z.val }));
    radius =
            planetConfig.MOON_RADIUS.val * planetConfig.referenceRadius.val
    position =
        Vec3.sum(center, {
            x: radius,
            y: 0.0,
            z: 0.0 });
    theMoon =
        Entities.addEntity({
            type: "Model",
            modelURL: Script.resolvePath("Moon/moon.FBX"),
            position: position,
            dimensions: {
                x: dimensions,
                y: dimensions,
                z: dimensions },
            velocity: velocity,
            angularDamping: planetConfig.DAMPING.val,
            damping: planetConfig.DAMPING.val,
            ignoreCollisions: false,
            dynamic: false, });
    update =
        function(deltaTime){
            var between =
                Vec3.subtract(position, center);
            var speed =
                computeAcceleration(radius) * deltaTime;
            var vel =
                Vec3.multiply(speed, Vec3.normalize(between));
            // Update velocity and position
            velocity =
                Vec3.sum(velocity, vel);
            position =
                Vec3.sum(position, Vec3.multiply(deltaTime, velocity));
            Entities.editEntity(theMoon, {
                velocity: velocity,
                position: position }); }
    Script.update.connect(update);
}
function restart(){
    makeEarth();
    makeMoon();
}
function CreateSimulation() {
    MyAvatar.position =
        center;
    restart();
}

CreateSimulation();

function scriptEnding() {
    Entities.deleteEntity(theEarth);
    Entities.deleteEntity(theMoon);
    button.clicked.disconnect(onClicked);
    tablet.removeButton(button);
};

Script.scriptEnding.connect(scriptEnding);