/**
 * Raycaster for GameLib.D3
 * @param graphics GameLib.D3.Graphics
 * @param apiRaycaster
 * @constructor
 */
GameLib.D3.Raycaster = function(
    graphics,
    apiRaycaster
) {

    this.graphics = graphics;
    this.graphics.isNotThreeThrow();

    if (GameLib.Utils.UndefinedOrNull(apiRaycaster)) {
        apiRaycaster = {};
    }

	if (apiRaycaster instanceof GameLib.D3.Raycaster) {
		return apiRaycaster;
	}

    GameLib.D3.API.Raycaster.call(
        this,
        apiRaycaster.id,
        apiRaycaster.name,
        apiRaycaster.position,
        apiRaycaster.direction
    );

    this.position = new GameLib.Vector3(
        this.graphics,
        this.position,
        this
    );

    this.direction = new GameLib.Vector3(
        this.graphics,
        this.direction,
        this
    );

    this.instance = this.createInstance();
};

GameLib.D3.Raycaster.prototype = Object.create(GameLib.D3.API.Raycaster.prototype);
GameLib.D3.Raycaster.prototype.constructor = GameLib.D3.Raycaster;

/**
 * Creates or updates a raycaster instance
 * @param update
 */
GameLib.D3.Raycaster.prototype.createInstance = function(update) {

    var instance = null;

    if (update) {
        instance = this.instance;
    } else {
        instance = new THREE.Raycaster();
    }

    instance.set(
        this.position.instance,
        this.direction.instance
    );

    return instance;
};

GameLib.D3.Raycaster.prototype.updateInstance = function() {
    this.instance = this.createInstance(true);
};

GameLib.D3.Raycaster.prototype.toApiObject = function() {
    return new GameLib.D3.API.Raycaster(
        this.id,
        this.name,
        this.position.toApiObject(),
        this.direction.toApiObject()
    )
};

GameLib.D3.Raycaster.FromObjectRaycaster = function(graphics, parentObject, objectRaycaster) {

    var apiRaycaster = GameLib.D3.API.Raycaster.FromObjectRaycaster(objectRaycaster);

    var raycaster = new GameLib.D3.Raycaster(
        graphics,
        apiRaycaster
    );

    return raycaster;
};

/**
 * Sets the direction and position of this raycaster
 * @param position GameLib.Vector3
 * @param direction GameLib.Vector3
 */
GameLib.D3.Raycaster.prototype.set = function(
    position,
    direction
) {
    this.position.x = position.x;
    this.position.y = position.y;
    this.position.z = position.z;

    this.direction.x = direction.x;
    this.direction.y = direction.y;
    this.direction.z = direction.z;

    this.position.updateInstance();
    this.direction.updateInstance();
};

/**
 * Sets the direction of this raycaster
 * @param direction GameLib.Vector3
 */
GameLib.D3.Raycaster.prototype.setDirection = function(
    direction
) {
    this.direction.x = direction.x;
    this.direction.y = direction.y;
    this.direction.z = direction.z;

    this.direction.updateInstance();
};

/**
 * Sets the position of this raycaster
 * @param position GameLib.Vector3
 */
GameLib.D3.Raycaster.prototype.setPosition = function(
    position
) {
    this.position.x = position.x;
    this.position.y = position.y;
    this.position.z = position.z;

    this.position.updateInstance();
};

/**
 * Gets all interesected GameLib.D3.Mesh objects
 * @param meshes [GameLib.D3.Mesh]
 */
GameLib.D3.Raycaster.prototype.getIntersectedObjects = function(meshes) {

    var meshInstances = meshes.map(
        function (mesh) {
            return mesh.instance;
        }
    );

    var intersects = this.instance.intersectObjects(meshInstances);

	return intersects.reduce(

	    function (result, intersect) {

		    meshes.map(
		        function(mesh){
					if (mesh.instance === intersect.object){
						result.push(
						    {
                                mesh : mesh,
                                distance : intersect.distance
						    }
                        );
					}
				}
            );

		    return result;
		},
		[]
    );

};


/**
 * Returns the face normal (if any) of an intersection between current ray position, direction and a provided mesh
 * @param mesh GameLib.D3.Mesh
 * @returns {null | GameLib.Vector3}
 */
GameLib.D3.Raycaster.prototype.getFaceNormal = function(mesh) {

    var normal = null;

    var intersect = this.instance.intersectObject(
        mesh.instance
    );

    if (intersect && intersect.length > 0) {

        normal = new GameLib.Vector3(
            this.graphics,
            new GameLib.API.Vector3(
                intersect[0].face.normal.x,
                intersect[0].face.normal.y,
                intersect[0].face.normal.z
            ),
            this
        );
    }

    return normal;
};

/**
 * Returns the face normal (if any) of an intersection between current ray position, direction and a provided mesh
 * @param mesh GameLib.D3.Mesh
 * @returns {null | GameLib.Vector3}
 */
GameLib.D3.Raycaster.prototype.getIntersectPoint = function(mesh) {

    var point = null;

    var intersect = this.instance.intersectObject(
        mesh.instance
    );

    if (intersect && intersect.length > 0) {
        point = new GameLib.Vector3(
            this.graphics,
            new GameLib.API.Vector3(
                intersect[0].point.x,
                intersect[0].point.y,
                intersect[0].point.z
            ),
            this
        );
    }

    return point;
};