//
//  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 EARTH_MODEL =
        Script.resolvePath("Earth/earth.obj");
var MOON_MODEL =
        Script.resolvePath("Moon/moon.FBX");
var SKYBOX =
      Script.resolvePath('Background/starSky2.png');

var MESSAGES_CHANNEL = "com.highfidelity.planets.dataMessages";

var theEarth;
var theMoon;
// var theLight;
var theZone;

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

var ZONE_DIMENSIONS = 1000;

var radius;
var velocity;
var position;

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(){
    if (theEarth) {
        Entities.deleteEntity(theEarth);
        theEarth =
            null;
    }
    theEarth =
        Entities.addEntity({
            name: 'Planet-Earth',
            type: "Model",
            modelURL: EARTH_MODEL,
            shapeType: 'sphere',
            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",
            name: 'Planet-Moon',
            modelURL: MOON_MODEL,
            position: position,
            shapeType: 'sphere',
            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 makeZone(){
    if (theZone) {
        Entities.deleteEntity(theZone);
        theZone =
          null;
    }
    theZone =
    Entities.addEntity({
        name: 'Planet-Zone',
        type: "Zone",
        position: center,
        dimensions: {
            x: ZONE_DIMENSIONS,
            y: ZONE_DIMENSIONS,
            z: ZONE_DIMENSIONS },
        backgroundMode: "skybox",
        skybox: {
            color: { red: 0, green: 0, blue: 0 },
            url: SKYBOX } });
}
// function makeLight(){
//     if (theLight) {
//         Entities.deleteEntity(theLight);
//         theLight =
//           null;
//     }
//     var props = Entities.getEntityProperties(theEarth);
//     var rotation = props.rotation;
//     var earthVector = Quat.getFront(rotation);
//
//     var lightPosition = Vec3.sum(center, Vec3.multiply(parseFloat(planetConfig.LightDistance.val), earthVector));
//     theLight =
//     Entities.addEntity({
//         name: 'Planet-Light',
//         type: 'Light',
//         rotation: rotation,
//         position: lightPosition,
//         dimensions: {
//             x: planetConfig.LightScale,
//             y: planetConfig.LightScale,
//             z: planetConfig.LightScale
//         },
//         isSpotlight: true,
//         intensity: planetConfig.LightIntensity,
//         color: {
//             red: 255,
//             green: 255,
//             blue: 255 } });
// // }
function restart(){
    makeEarth();
    makeMoon();
    // makeLight();
    makeZone();
}
function CreateSimulation() {
    restart();
}

CreateSimulation();

Messages.subscribe(MESSAGES_CHANNEL);

function handleMessages(channel, message, sender) {
    if (channel === MESSAGES_CHANNEL) {
        var data = JSON.parse(message);
        planetConfig[data.id].val = data.value;
        restart();
    }
}

Messages.messageReceived.connect(handleMessages);

function scriptEnding() {
    Entities.deleteEntity(theEarth);
    Entities.deleteEntity(theMoon);
    Entities.deleteEntity(theZone);
    // Entities.deleteEntity(theLight);
}

Script.scriptEnding.connect(scriptEnding);