/**
 * System takes care of updating all the entities (based on their component data)
 * @param apiSystem GameLib.API.System
 * @constructor
 */
GameLib.System.Animation = function(
    apiSystem
) {
    GameLib.System.call(
        this,
        apiSystem
    );

    this.animations = {};
    this.latest = {};
};

GameLib.System.Animation.prototype = Object.create(GameLib.System.prototype);
GameLib.System.Animation.prototype.constructor = GameLib.System.Animation;

GameLib.System.Animation.prototype.start = function() {

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

    this.beforeRenderSubscription = GameLib.Event.Subscribe(
        GameLib.Event.BEFORE_RENDER,
        function(data) {

            var delta = data.delta;

            for (var property in this.animations) {
                if (this.animations.hasOwnProperty(property)) {


                    if (this.animations[property].length > 0) {

                        var done = false;

                        var animationObject = this.animations[property][0];

                        if (animationObject.type === 'rotation') {

                            var increment = animationObject.animation.rotationSpeed * delta;

                            animationObject.from += increment;

                            if (Math.abs(animationObject.from - animationObject.to) < increment) {
                                animationObject.mesh.instance.rotation[animationObject.axis] = animationObject.to;
                                done = true;
                            } else {
                                animationObject.mesh.instance.rotation[animationObject.axis] = animationObject.from;
                            }
                        }

                        if (done) {
                            this.animations[property].splice(0, 1);
                        }
                    }
                }
            }

        }.bind(this)
    );

    this.animationMeshAddedSubscription = GameLib.Event.Subscribe(
        GameLib.Event.ANIMATION_MESH_ADDED,
        function(data) {

            var animation   = data.animation;
            var mesh        = data.mesh;

            /**
             * Initialize the property with the original mesh z value
             */
            this.latest[mesh.id] = {
                rotation : {
                    x : mesh.rotation.x,
                    y : mesh.rotation.y,
                    z : mesh.rotation.z
                },
                position : {
                    x : mesh.position.x,
                    y : mesh.position.y,
                    z : mesh.position.z
                },
                scale : {
                    x : mesh.scale.x,
                    y : mesh.scale.y,
                    z : mesh.scale.z
                },
                quaternion : {
                    axis : {
                        x : mesh.quaternion.axis.x,
                        y : mesh.quaternion.axis.y,
                        z : mesh.quaternion.axis.z
                    },
                    angle : mesh.quaternion.angle
                }
            };

            this.animations[mesh.id] = [];

            mesh.backupQuaternionAngleDescriptor = Object.getOwnPropertyDescriptor(mesh.quaternion, 'angle');
            mesh.backupQuaternionAxisXDescriptor = Object.getOwnPropertyDescriptor(mesh.quaternion.axis, 'x');
            mesh.backupQuaternionAxisYDescriptor = Object.getOwnPropertyDescriptor(mesh.quaternion.axis, 'y');
            mesh.backupQuaternionAxisZDescriptor = Object.getOwnPropertyDescriptor(mesh.quaternion.axis, 'z');
            mesh.backupRotationXDescriptor = Object.getOwnPropertyDescriptor(mesh.rotation, 'x');
            mesh.backupRotationYDescriptor = Object.getOwnPropertyDescriptor(mesh.rotation, 'y');
            mesh.backupRotationZDescriptor = Object.getOwnPropertyDescriptor(mesh.rotation, 'z');
            mesh.backupPositionXDescriptor = Object.getOwnPropertyDescriptor(mesh.position, 'x');
            mesh.backupPositionYDescriptor = Object.getOwnPropertyDescriptor(mesh.position, 'y');
            mesh.backupPositionZDescriptor = Object.getOwnPropertyDescriptor(mesh.position, 'z');
            mesh.backupScaleXDescriptor = Object.getOwnPropertyDescriptor(mesh.scale, 'x');
            mesh.backupScaleYDescriptor = Object.getOwnPropertyDescriptor(mesh.scale, 'y');
            mesh.backupScaleZDescriptor = Object.getOwnPropertyDescriptor(mesh.scale, 'z');

            Object.defineProperty(
                mesh.quaternion,
                'angle',
                {
                    'get': this.getQuaternionAngle(mesh, animation),
                    'set': this.setQuaternionAngle(mesh, animation),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.quaternion.axis,
                'x',
                {
                    'get': this.getQuaternionAxisX(mesh, animation),
                    'set': this.setQuaternionAxisX(mesh, animation),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.quaternion.axis,
                'y',
                {
                    'get': this.getQuaternionAxisY(mesh, animation),
                    'set': this.setQuaternionAxisY(mesh, animation),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.quaternion.axis,
                'z',
                {
                    'get': this.getQuaternionAxisZ(mesh, animation),
                    'set': this.setQuaternionAxisZ(mesh, animation),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.rotation,
                'x',
                {
                    'get': this.getRotation(mesh, 'x'),
                    'set': this.setRotation(mesh, animation, 'x'),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.rotation,
                'y',
                {
                    'get': this.getRotation(mesh, 'y'),
                    'set': this.setRotation(mesh, animation, 'y'),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.rotation,
                'z',
                {
                    'get': this.getRotation(mesh, 'z'),
                    'set': this.setRotation(mesh, animation, 'z'),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.scale,
                'x',
                {
                    'get': this.getScaleX(mesh, animation),
                    'set': this.setScaleX(mesh, animation),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.scale,
                'y',
                {
                    'get': this.getScaleY(mesh, animation),
                    'set': this.setScaleY(mesh, animation),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.scale,
                'z',
                {
                    'get': this.getScaleZ(mesh, animation),
                    'set': this.setScaleZ(mesh, animation),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.position,
                'x',
                {
                    'get': this.getPositionX(mesh, animation),
                    'set': this.setPositionX(mesh, animation),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.position,
                'y',
                {
                    'get': this.getPositionY(mesh, animation),
                    'set': this.setPositionY(mesh, animation),
                    'configurable': true
                }
            );

            Object.defineProperty(
                mesh.position,
                'z',
                {
                    'get': this.getPositionZ(mesh, animation),
                    'set': this.setPositionZ(mesh, animation),
                    'configurable': true
                }
            );
            
        }.bind(this)
    );
};

GameLib.System.Animation.prototype.getQuaternionAngle = function(mesh, animation) {

    return function() {
        return;
        /**
         * TODO: fix this shit..
         * Back up the current property descriptor
         */
        mesh.animationObject = {
            backupAngleDescriptor: Object.getOwnPropertyDescriptor(mesh.quaternion, 'angle'),
            targetAngle: mesh.quaternion.angle,
            angleIncrement: true,
            intermediateAngle: mesh.quaternion.angle,
            subscription: null,
            inProcess: false,
            blocking: animation.blocking//,
            // callbacks               : [],
            // storedValues            : []
        };

        var getIntermediateAngle = function () {
            return mesh.animationObject.intermediateAngle;
        };

        var getTargetAngle = function () {

            // if (mesh.animationObject.storedValues.length > 0) {
            //     return mesh.animationObject.storedValues[mesh.animationObject.storedValues.length - 1];
            // }

            return mesh.animationObject.targetAngle;
        };

        var animateRotation = function (value) {

            mesh.animationObject.intermediateAngle += value;

            var done = false;

            if (mesh.animationObject.angleIncrement) {
                /**
                 * We are rotating upwards
                 */
                if (mesh.animationObject.intermediateAngle >= mesh.animationObject.targetAngle) {
                    /**
                     * We need to stop
                     */
                    done = true;
                }
            } else {
                /**
                 * We are rotating downwards
                 */
                if (mesh.animationObject.intermediateAngle <= mesh.animationObject.targetAngle) {
                    /**
                     * We need to stop
                     */
                    done = true;
                }
            }

            if (done) {

                /**
                 * We clamp to our target angle
                 */
                mesh.animationObject.intermediateAngle = mesh.animationObject.targetAngle;

                /**
                 * We limit our intermediate angle between values of -pi and pi
                 */
                while (mesh.animationObject.intermediateAngle > Math.PI) {
                    mesh.animationObject.intermediateAngle -= (Math.PI * 2);
                }

                while (mesh.animationObject.intermediateAngle < -(Math.PI)) {
                    mesh.animationObject.intermediateAngle += (Math.PI * 2);
                }

                /**
                 * We apply our new intermediate angle to our target
                 */
                mesh.animationObject.targetAngle = mesh.animationObject.intermediateAngle;
            }

            /**
             * Apply the actual rotation to the mesh
             */
            mesh.updateInstanceRotationFromAxisAngle(mesh.quaternion.axis, mesh.animationObject.intermediateAngle);

            /**
             * Check again if we are done, we need to do some additional work -
             */
            if (done) {

                if (!mesh.animationObject.subscription) {
                    var message = 'mesh animation object subscription went missing for ';
                    message += mesh.name + ': ';
                    message += animation.name;
                    console.warn(message);
                    throw new Error(message);
                }

                /**
                 * Stop subscribing to before render events
                 */
                mesh.animationObject.subscription.remove();

                /**
                 * @type {null}
                 */
                mesh.animationObject.subscription = null;

                /**
                 * For some meshes, when we are done with the animation, we want to apply
                 * the current state of the mesh to the object data itself (i.e. update
                 * its vertices etc)
                 */
                if (animation.applyToMeshWhenDone) {
                    /**
                     * Now we say that our intermediate angle is zero, because we will apply our rotation
                     * and this will prevent us from re-registering a new 'animationRender' event
                     */
                    mesh.animationObject.targetAngle = 0;
                    mesh.animationObject.intermediateAngle = 0;

                    /**
                     * Apply our position, rotation and scale to the mesh
                     */
                    mesh.applyPositionRotationScale();
                }

                /**
                 * Tell our animation component that it is no longer in process...
                 * @type {boolean}
                 */
                mesh.animationObject.inProcess = false;

                // if (mesh.animationObject.callbacks.length > 0) {
                //     var callback = mesh.animationObject.callbacks[0];
                //     mesh.animationObject.callbacks.splice(0,1);
                //     callback();
                // }

                // mesh.animationObject.storedValues = [];
            }
        };
    }
};

GameLib.System.Animation.prototype.setQuaternionAngle = function(mesh, animation) {

    return function(value) {
        return;
        /**
         * TODO: update this shit
         */
        /**
         * Check if we have work to do
         */
        if (mesh.animationObject.intermediateAngle === value) {

            mesh.animationObject.inProcess = false;

            /**
             * Nothing to do
             */
            return;
        }

        /**
         * Check if we have another animation in process
         */
        if (mesh.animationObject.inProcess && mesh.animationObject.blocking) {

            console.log('another animation is already in process');

            // setTargetAngle(value);

            // GameLib.Utils.PushUnique(mesh.animationObject.storedValues, value);
            //
            // mesh.animationObject.callbacks.push(
            //     function(__value) {
            //         return function(){
            //             mesh.quaternion.angle = __value;
            //         }
            //     }(value)
            // );

            /**
             * Respond that our angle is actually our target angle (it will be that soon)
             */
            return;
        }

        /**
         * We indicate that we now have an animation in process
         * @type {boolean}
         */
        mesh.animationObject.inProcess = true;

        /**
         * Ok - all good - lets start the animation
         */
        if (mesh.animationObject.intermediateAngle > value) {
            /**
             * We will rotate towards by decrementing
             */
            mesh.animationObject.angleIncrement = false;
        } else {
            /**
             * We will rotate towards by incrementing
             */
            mesh.animationObject.angleIncrement = true;
        }

        /**
         * We say what our target angle is - when we reach our target angle, we want
         * to stop our animation
         */
        mesh.animationObject.targetAngle = value;

        /**
         * Now we subscribe to 'before render' events, and slowly increment the value
         * @type {{fn, remove}}
         */
        mesh.animationObject.subscription = GameLib.Event.Subscribe(
            GameLib.Event.BEFORE_RENDER,
            function(data) {

                var increment = Math.abs(animation.rotationSpeed);

                if (!mesh.animationObject.angleIncrement) {
                    increment *= -1;
                }

                animateRotation(data.delta * increment);
            }
        );
    }
};

GameLib.System.Animation.prototype.getQuaternionAxisX = function(mesh, animation) {
    return function() {
        return this.latest[mesh.id].quaternion.axis.x;
    }.bind(this);
};

GameLib.System.Animation.prototype.setQuaternionAxisX = function(mesh, animation) {
    return function(value) {
        this.latest[mesh.id].quaternion.axis.x = value;
    }.bind(this);
};

GameLib.System.Animation.prototype.getQuaternionAxisY = function(mesh, animation) {
    return function() {
        return this.latest[mesh.id].quaternion.axis.y;
    }.bind(this);
};

GameLib.System.Animation.prototype.setQuaternionAxisY = function(mesh, animation) {
    return function(value) {
        this.latest[mesh.id].quaternion.axis.y = value;
    }.bind(this);
};

GameLib.System.Animation.prototype.getQuaternionAxisZ = function(mesh, animation) {
    return function() {
        return this.latest[mesh.id].quaternion.axis.z;
    }.bind(this);
};

GameLib.System.Animation.prototype.setQuaternionAxisZ = function(mesh, animation) {
    return function(value) {
        this.latest[mesh.id].quaternion.axis.z = value;
    }.bind(this);
};

GameLib.System.Animation.prototype.getProperty = function(mesh, axis, property) {
    return function() {
        return this.latest[mesh.id][property][axis];
    }.bind(this);
};

GameLib.System.Animation.prototype.setProperty = function(mesh, animation, axis, property) {
    return function(value) {

        var from = Number(this.latest[mesh.id][property][axis]);

        this.latest[mesh.id][property][axis] = value;

        this.animations[mesh.id].push(
            {
                type : property,
                axis : axis,
                from : from,
                to   : value,
                animation : animation,
                mesh : mesh
            }
        );

    }.bind(this)
};

GameLib.System.Animation.prototype.getPositionX = function(mesh, axis) {
    return function() {
        return this.latest[mesh.id].position[axis];
    }.bind(this);
};

GameLib.System.Animation.prototype.setPositionX = function(mesh, animation) {
    return function(value) {
        this.latest[mesh.id].position.x = value;
    }.bind(this);
};

GameLib.System.Animation.prototype.getPositionY = function(mesh, animation) {
    return function() {
        return this.latest[mesh.id].position.y;
    }.bind(this);
};

GameLib.System.Animation.prototype.setPositionY = function(mesh, animation) {
    return function(value) {
        this.latest[mesh.id].position.y = value;
    }.bind(this);
};

GameLib.System.Animation.prototype.getPositionZ = function(mesh, animation) {
    return function() {
        return this.latest[mesh.id].position.z;
    }.bind(this);
};

GameLib.System.Animation.prototype.setPositionZ = function(mesh, animation) {
    return function(value) {
        this.latest[mesh.id].position.z = value;
    }.bind(this)
};

GameLib.System.Animation.prototype.getScaleX = function(mesh, animation) {
    return function() {
        return this.latest[mesh.id].scale.x;
    }.bind(this);
};

GameLib.System.Animation.prototype.setScaleX = function(mesh, animation) {
    return function(value) {
        this.latest[mesh.id].scale.x = value;
    }.bind(this);
};

GameLib.System.Animation.prototype.getScaleY = function(mesh, animation) {
    return function() {
        return this.latest[mesh.id].scale.y;
    }.bind(this);
};

GameLib.System.Animation.prototype.setScaleY = function(mesh, animation) {
    return function(value) {
        this.latest[mesh.id].scale.y = value;
    }.bind(this);
};

GameLib.System.Animation.prototype.getScaleZ = function(mesh, animation) {
    return function() {
        return this.latest[mesh.id].scale.z;
    }.bind(this);
};

GameLib.System.Animation.prototype.setScaleZ = function(mesh, animation) {
    return function(value) {
        this.latest[mesh.id].scale.z = value;
    }.bind(this)
};

/**
 * Stop Animation System
 */
GameLib.System.Animation.prototype.stop = function() {

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

    this.beforeRenderSubscription.remove();

    this.animationMeshAddedSubscription.remove();

    var meshes = GameLib.EntityManager.Instance.queryComponents(GameLib.D3.Mesh);

    meshes.map(
        function(mesh) {
            if (mesh.backupQuaternionAngleDescriptor) {
                Object.defineProperty(
                    mesh.quaternion,
                    'angle',
                    mesh.backupQuaternionAngleDescriptor
                );

                delete mesh.backupQuaternionAngleDescriptor;
            }

            if (mesh.backupQuaternionAxisXDescriptor) {
                Object.defineProperty(
                    mesh.quaternion.axis,
                    'x',
                    mesh.backupQuaternionAxisXDescriptor
                );

                delete mesh.backupQuaternionAxisXDescriptor;
            }

            if (mesh.backupQuaternionAxisYDescriptor) {
                Object.defineProperty(
                    mesh.quaternion.axis,
                    'y',
                    mesh.backupQuaternionAxisYDescriptor
                );

                delete mesh.backupQuaternionAxisYDescriptor;
            }

            if (mesh.backupQuaternionAxisZDescriptor) {
                Object.defineProperty(
                    mesh.quaternion.axis,
                    'z',
                    mesh.backupQuaternionAxisZDescriptor
                );

                delete mesh.backupQuaternionAxisXDescriptor;
            }

            if (mesh.backupRotationXDescriptor) {
                Object.defineProperty(
                    mesh.rotation,
                    'x',
                    mesh.backupRotationXDescriptor
                );

                delete mesh.backupRotationXDescriptor;
            }

            if (mesh.backupRotationYDescriptor) {
                Object.defineProperty(
                    mesh.rotation,
                    'y',
                    mesh.backupRotationYDescriptor
                );

                delete mesh.backupRotationYDescriptor;
            }

            if (mesh.backupRotationZDescriptor) {
                Object.defineProperty(
                    mesh.rotation,
                    'z',
                    mesh.backupRotationZDescriptor
                );

                delete mesh.backupRotationZDescriptor;
            }

            if (mesh.backupPositionXDescriptor) {
                Object.defineProperty(
                    mesh.position,
                    'x',
                    mesh.backupPositionXDescriptor
                );

                delete mesh.backupPositionXDescriptor;
            }

            if (mesh.backupPositionYDescriptor) {
                Object.defineProperty(
                    mesh.position,
                    'y',
                    mesh.backupPositionYDescriptor
                );

                delete mesh.backupPositionYDescriptor;
            }

            if (mesh.backupPositionZDescriptor) {
                Object.defineProperty(
                    mesh.position,
                    'z',
                    mesh.backupPositionZDescriptor
                );

                delete mesh.backupPositionZDescriptor;
            }

            if (mesh.backupScaleXDescriptor) {
                Object.defineProperty(
                    mesh.scale,
                    'x',
                    mesh.backupScaleXDescriptor
                );

                delete mesh.backupScaleXDescriptor;
            }

            if (mesh.backupScaleYDescriptor) {
                Object.defineProperty(
                    mesh.scale,
                    'y',
                    mesh.backupScaleYDescriptor
                );

                delete mesh.backupScaleYDescriptor;
            }

            if (mesh.backupScaleZDescriptor) {
                Object.defineProperty(
                    mesh.scale,
                    'z',
                    mesh.backupScaleZDescriptor
                );

                delete mesh.backupScaleZDescriptor;
            }
        }
    );
};