/// <reference path="../../../dist/preview release/babylon.d.ts"/>


module BABYLON.GUI {
    /**
     * Class used to manage 3D user interface
     * @see http://doc.babylonjs.com/how_to/gui3d
     */
    export class GUI3DManager implements BABYLON.IDisposable {
        private _scene: Scene;
        private _sceneDisposeObserver: Nullable<Observer<Scene>>;
        private _utilityLayer: Nullable<UtilityLayerRenderer>;
        private _rootContainer: Container3D;
        private _pointerObserver: Nullable<Observer<PointerInfo>>;
        private _pointerOutObserver: Nullable<Observer<number>>;
        /** @hidden */
        public _lastPickedControl: Control3D;
        /** @hidden */
        public _lastControlOver: {[pointerId:number]: Control3D} = {};
        /** @hidden */
        public _lastControlDown: {[pointerId:number]: Control3D} = {};      

        /**
         * Observable raised when the point picked by the pointer events changed
         */
        public onPickedPointChangedObservable = new Observable<Nullable<Vector3>>();

        // Shared resources
        /** @hidden */
        public _sharedMaterials: {[key:string]: Material} = {};     

        /** Gets the hosting scene */
        public get scene(): Scene {
            return this._scene;
        }

        /** Gets associated utility layer */
        public get utilityLayer(): Nullable<UtilityLayerRenderer> {
            return this._utilityLayer;
        }

        /**
         * Creates a new GUI3DManager
         * @param scene 
         */
        public constructor(scene?: Scene) {
            this._scene = scene || Engine.LastCreatedScene!;
            this._sceneDisposeObserver = this._scene.onDisposeObservable.add(() => {
                this._sceneDisposeObserver = null;
                this._utilityLayer = null;
                this.dispose();
            })

            this._utilityLayer = new UtilityLayerRenderer(this._scene);
            this._utilityLayer.onlyCheckPointerDownEvents = false;
            this._utilityLayer.mainSceneTrackerPredicate = (mesh: Nullable<AbstractMesh>) => {
                return mesh && mesh.metadata && mesh.metadata._node;
            }

            // Root
            this._rootContainer = new Container3D("RootContainer");
            this._rootContainer._host = this;
            let utilityLayerScene = this._utilityLayer.utilityLayerScene;
            
            // Events
            this._pointerOutObserver = this._utilityLayer.onPointerOutObservable.add((pointerId) => {
                this._handlePointerOut(pointerId, true);
            });

            this._pointerObserver = utilityLayerScene.onPointerObservable.add((pi, state) => {
                this._doPicking(pi);
            });

            // Scene
            this._utilityLayer.utilityLayerScene.autoClear = false;
            this._utilityLayer.utilityLayerScene.autoClearDepthAndStencil = false;
            new BABYLON.HemisphericLight("hemi", Vector3.Up(), this._utilityLayer.utilityLayerScene);
        }

        private _handlePointerOut(pointerId: number, isPointerUp: boolean) {
            var previousControlOver = this._lastControlOver[pointerId];
            if (previousControlOver) {
                previousControlOver._onPointerOut(previousControlOver);
                delete this._lastControlOver[pointerId];
            }               
            
            if (isPointerUp) {
                if (this._lastControlDown[pointerId]) {
                    this._lastControlDown[pointerId].forcePointerUp();
                    delete this._lastControlDown[pointerId];
                }
            }        
            
            this.onPickedPointChangedObservable.notifyObservers(null);
        }

        private _doPicking(pi: PointerInfo): boolean {
            if (!this._utilityLayer || !this._utilityLayer.utilityLayerScene.activeCamera) {
                return false;                
            }

            let pointerEvent = <PointerEvent>(pi.event);

            let pointerId = pointerEvent.pointerId || 0;
            let buttonIndex = pointerEvent.button;
            
            let pickingInfo = pi.pickInfo;
            if (!pickingInfo || !pickingInfo.hit) {
                this._handlePointerOut(pointerId, pi.type === BABYLON.PointerEventTypes.POINTERUP);
                return false;
            }

            let control = <Control3D>(pickingInfo.pickedMesh!.metadata);
            if (pickingInfo.pickedPoint) {
                this.onPickedPointChangedObservable.notifyObservers(pickingInfo.pickedPoint);
            }

            if (!control._processObservables(pi.type, pickingInfo.pickedPoint!, pointerId, buttonIndex)) {

                if (pi.type === BABYLON.PointerEventTypes.POINTERMOVE) {
                    if (this._lastControlOver[pointerId]) {
                        this._lastControlOver[pointerId]._onPointerOut(this._lastControlOver[pointerId]);
                    }

                    delete this._lastControlOver[pointerId];
                }
            }

            if (pi.type === BABYLON.PointerEventTypes.POINTERUP) {
                if (this._lastControlDown[pointerEvent.pointerId]) {
                    this._lastControlDown[pointerEvent.pointerId].forcePointerUp();
                    delete this._lastControlDown[pointerEvent.pointerId];
                }

                if (pointerEvent.pointerType === "touch") {
                    this._handlePointerOut(pointerId, false);
                }
            }

            return true;
        }

        /**
         * Gets the root container
         */
        public get rootContainer(): Container3D {
            return this._rootContainer;
        }

        /**
         * Gets a boolean indicating if the given control is in the root child list
         * @param control defines the control to check
         * @returns true if the control is in the root child list
         */
        public containsControl(control: Control3D): boolean {
            return this._rootContainer.containsControl(control);
        }

        /**
         * Adds a control to the root child list
         * @param control defines the control to add
         * @returns the current manager
         */
        public addControl(control: Control3D): GUI3DManager {
           this._rootContainer.addControl(control);
           return this;
        }

        /**
         * Removes a control from the root child list
         * @param control defines the control to remove
         * @returns the current container
         */
        public removeControl(control: Control3D): GUI3DManager {
            this._rootContainer.removeControl(control);
            return this;
        }        

        /**
         * Releases all associated resources
         */
        public dispose() {
            this._rootContainer.dispose();

            for (var materialName in this._sharedMaterials) {
                if (!this._sharedMaterials.hasOwnProperty(materialName)) {
                    continue;
                }

                this._sharedMaterials[materialName].dispose();
            }

            this._sharedMaterials = {};

            if (this._pointerOutObserver && this._utilityLayer) {
                this._utilityLayer.onPointerOutObservable.remove(this._pointerOutObserver);
                this._pointerOutObserver = null;
            }

            this.onPickedPointChangedObservable.clear();

            let utilityLayerScene = this._utilityLayer ? this._utilityLayer.utilityLayerScene : null;

            if (utilityLayerScene) {
                if (this._pointerObserver) {
                    utilityLayerScene.onPointerObservable.remove(this._pointerObserver);
                    this._pointerObserver = null;
                }
            }
            if (this._scene) {
                 if (this._sceneDisposeObserver) {
                    this._scene.onDisposeObservable.remove(this._sceneDisposeObserver);
                    this._sceneDisposeObserver = null;
                }                
            }

            if (this._utilityLayer) {
                this._utilityLayer.dispose();
            }
        }
    }
}