/**
 *
 * @param id
 * @param name
 * @param splineCurve3
 * @constructor
 */
GameLib.D3.ComponentPathFollowing = function ComponentPathFollowing(
    id,
    name,
    splineCurve3
) {
    this.id = id || GameLib.D3.Tools.RandomId();

    if (typeof name == 'undefined') {
        name = this.constructor.name;
    }

    this.name = name;
    this.parentEntity = null;
    this.splineCurve3 = splineCurve3;

    this.currentPathValue = 0.0;

    GameLib.D3.Utils.Extend(GameLib.D3.ComponentPathFollowing, GameLib.D3.ComponentInterface);
};

///////////////////////// Methods to override //////////////////////////
GameLib.D3.ComponentPathFollowing.prototype.onUpdate = function(
    deltaTime,
    parentEntity
) {

    if(this.splineCurve3) {

        if(this.currentPathValue >= 1) {
            this.currentPathValue = 0;
        }

        //To maintain a constant speed, you use .getPointAt( t ) instead of .getPoint( t ).
        //http://stackoverflow.com/questions/18400667/three-js-object-following-a-spline-path-rotation-tanget-issues-constant-sp

        var position = this.splineCurve3.getPointAt(this.currentPathValue); //getPointAt?????
        var rotation = this.splineCurve3.getTangentAt(this.currentPathValue).normalize();

        var up = new THREE.Vector3( 0, 1, 0 );

        var axis = new THREE.Vector3();
            axis.crossVectors(up, rotation).normalize();
        var radians = Math.acos(up.dot(rotation));
        var quaternion = new THREE.Quaternion().setFromAxisAngle( axis, radians );

  /*      var quaternion = new THREE.Quaternion().setFromEuler(
            new THREE.Euler(
                rotation.x,
                rotation.y,
                rotation.z
            )
        );*/

        var offset = new THREE.Vector3(1, 0, 0);
        offset = offset.applyQuaternion(quaternion).multiplyScalar(10.0);

        console.log("offset x", offset);

        // apply to parent rigidbody instead of direclty to the mesh.
        parentEntity.position.x = position.x + offset.x;
        parentEntity.position.y = position.y + offset.y;
        parentEntity.position.z = position.z + offset.z;

        parentEntity.quaternion.x = quaternion.x;
        parentEntity.quaternion.y = quaternion.y;
        parentEntity.quaternion.z = quaternion.z;
        parentEntity.quaternion.w = quaternion.w;

        this.currentPathValue += (0.5 * deltaTime);

    }
};

GameLib.D3.ComponentPathFollowing.prototype.onSetParentEntity = function(
    parentScene,
    parentEntity
) {
    if(!this.splineCurve3) {
        console.error("NO PATH GIVEN");
    }
};