/**
 * R3.D3.Camera
 * @param graphics R3.GraphicsRuntime
 * @param apiD3ObjectCamera GR3.D3.API.Object
 * @constructor
 */
R3.D3.Camera = function(
    graphics,
    apiD3ObjectCamera
) {

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

    if (R3.Utils.UndefinedOrNull(apiD3ObjectCamera)) {
        apiD3ObjectCamera = {
            objectType : R3.D3.API.Object.OBJECT_TYPE_CAMERA
        };
    }

    R3.D3.API.Camera.call(
        this,
        apiD3ObjectCamera,
        apiD3ObjectCamera.aspect
    );

    R3.D3.Object.call(
        this,
        this.graphics,
        this
    );
};

R3.D3.Camera.prototype = Object.create(R3.D3.Object.prototype);
R3.D3.Camera.prototype.constructor = R3.D3.Camera;

/**
 * Creates a camera instance of 'graphics' type (only THREE for now)
 * @returns {THREE.Camera}
 */
R3.D3.Camera.prototype.createInstance = function() {

    /**
     * Not all implementations of camera has aspect ratio, we, however do have an aspect ratio for all our cameras
     */
    if (R3.Utils.Defined(this.instance.aspect)) {

        var size = R3.Utils.GetWindowSize();

        this.aspect = size.width / size.height;

        this.instance.aspect = this.aspect;
    }

    R3.D3.Object.prototype.createInstance.call(this);
};

/**
 * Updates the instance with the current state
 */
R3.D3.Camera.prototype.updateInstance = function(property) {

    if (property === 'aspect') {
        if (R3.Utils.Defined(this.instance.aspect)) {
            this.instance.aspect = this.aspect;
            if (R3.Utils.Defined(this.instance.updateProjectionMatrix)) {
                this.instance.updateProjectionMatrix();
            }
        } else {
            console.warn('updating the aspect ratio of this type of camera has no effect.');
        }
        return;
    }

    R3.D3.Object.prototype.updateInstance.call(this, property);
};

/**
 * Update R3.D3.Camera from instance
 */
R3.D3.Camera.prototype.updateFromInstance = function() {

    this.aspect = this.instance.aspect;

    this.position.x = this.instance.position.x;
    this.position.y = this.instance.position.y;
    this.position.z = this.instance.position.z;

    if (this.instance.target) {
        this.lookAt.x = this.instance.target.position.x;
        this.lookAt.y = this.instance.target.position.y;
        this.lookAt.z = this.instance.target.position.z;
    } else {
        console.warn('todo: update lookAt somehow...');
    }
};

/**
 * Converts a R3.D3.Camera to a new R3.D3.API.Camera
 * @returns {R3.D3.API.Camera}
 */
R3.D3.Camera.prototype.toApiObject = function() {

    var apiD3Object = R3.D3.Object.prototype.toApiObject.call(this);

    return new R3.D3.API.Camera(
        apiD3Object,
        this.aspect
    );
};