/**
 * System takes care of updating all the entities (based on their component data)
 * @param apiSystem R3.API.System
 * @constructor
 */
R3.System.Physics = function(
    apiSystem
) {

    R3.System.call(
        this,
        apiSystem
    );

    this.worlds         = [];
    // this.rigidBodies    = [];
    // this.wheels         = [];
    // this.vehicles       = [];

    // this.worldSubscription          = null;
    // this.rigidBodySubscription      = null;
    this.beforeRenderSubscription   = null;
    this.afterRenderSubscription    = null;




};

R3.System.Physics.prototype = Object.create(R3.System.prototype);
R3.System.Physics.prototype.constructor = R3.System.Physics;

R3.System.Physics.prototype.start = function() {

    R3.System.prototype.start.call(this);

    this.worlds         = R3.EntityManager.Instance.queryComponents(R3.Component.PHYSICS_WORLD);
    // this.rigidBodies    = R3.EntityManager.Instance.queryComponents(R3.Component.RIGID_BODY);
    // this.wheels         = R3.EntityManager.Instance.queryComponents(R3.Component.RAYCAST_WHEEL);
    // this.vehicles       = R3.EntityManager.Instance.queryComponents(R3.Component.RAYCAST_VEHICLE);



    // this.worlds.map(
    //     function(world) {
    //         world.instance.addEventListener(
    //             'postStep',
    //             function() {
    //
    //                 this.vehicles.map(
    //                     function(vehicle) {
    //                         vehicle.instance.wheelInfos.map(
    //                             function(wheelInfo, index) {
    //                                 vehicle.instance.updateWheelTransform(index);
    //                                 var t = wheelInfo.worldTransform;
    //                                 // vehicle.wheels[index].instance.position.copy(t.position);
    //                                 // vehicle.wheels[index].instance.quaternion.copy(t.quaternion);
    //
    //                                 // vehicle.raycastWheels[index].parentMesh.localPosition.x = t.position.x;
    //                                 // vehicle.raycastWheels[index].parentMesh.localPosition.y = t.position.y;
    //                                 // vehicle.raycastWheels[index].parentMesh.localPosition.z = t.position.z;
    //
    //                                 // vehicle.raycastWheels[index].parentMesh.updateInstance();
    //                             }
    //                         );
    //                     }
    //                 );
    //
    //
    //             }.bind(this)
    //         )
    //     }.bind(this)
    // );

    this.beforeRenderSubscription = this.subscribe(
        R3.Event.BEFORE_RENDER,
        this.beforeRender
    );
};

/**
 * Update script
 */
R3.System.Physics.prototype.beforeRender = function(data) {

    this.worlds.map(
        function(world) {

            if (world.instance) {

                world.instance.step(data.delta);

                world.rigidBodies.map(
                    function(rigidBody){
                        rigidBody.position.x = rigidBody.instance.position.x;
                        rigidBody.position.y = rigidBody.instance.position.y;
                        rigidBody.position.z = rigidBody.instance.position.z;

                        rigidBody.quaternion.x = rigidBody.instance.quaternion.x;
                        rigidBody.quaternion.y = rigidBody.instance.quaternion.y;
                        rigidBody.quaternion.z = rigidBody.instance.quaternion.z;
                        rigidBody.quaternion.w = rigidBody.instance.quaternion.w;

                        rigidBody.parentMesh.position.x = rigidBody.instance.position.x;
                        rigidBody.parentMesh.position.y = rigidBody.instance.position.y;
                        rigidBody.parentMesh.position.z = rigidBody.instance.position.z;

                        rigidBody.parentMesh.quaternion.x = rigidBody.instance.quaternion.x;
                        rigidBody.parentMesh.quaternion.y = rigidBody.instance.quaternion.y;
                        rigidBody.parentMesh.quaternion.z = rigidBody.instance.quaternion.z;
                        rigidBody.parentMesh.quaternion.w = rigidBody.instance.quaternion.w;

                        rigidBody.instance.getVelocityAtWorldPoint(new CANNON.Vec3(0,0,0), rigidBody.velocity.instance);

                        rigidBody.velocity.x = rigidBody.velocity.instance.x;
                        rigidBody.velocity.y = rigidBody.velocity.instance.y;
                        rigidBody.velocity.z = rigidBody.velocity.instance.z;

                        rigidBody.parentMesh.updateRotationFromAxisAngle = false;

                        rigidBody.parentMesh.updateInstance();

                        rigidBody.parentMesh.updateRotationFromAxisAngle = true;
                    }
                )
            }

        }.bind(this)
    );
};


R3.System.Physics.prototype.stop = function() {

    R3.System.prototype.stop.call(this);

    this.worlds         = [];
    this.rigidBodies    = [];
    this.wheels         = [];
    this.vehicles       = [];

    if (this.beforeRenderSubscription) {
        this.beforeRenderSubscription.remove();
    }

    if (this.afterRenderSubscription) {
        this.afterRenderSubscription.remove();
    }

};