import { ISmartArrayLike } from "Tools";
import { Scene } from "scene";
import { Vector3 } from "Math";
import { AbstractMesh, SubMesh } from "Mesh";
import { Collider } from "Collisions";
import { Ray, Octree } from "Culling";
import { SceneComponentConstants } from "sceneComponent";
    export interface Scene {
        /**
         * @hidden
         * Backing Filed
         */
        _selectionOctree: Octree<AbstractMesh>;

        /**
         * Gets the octree used to boost mesh selection (picking)
         * @see http://doc.babylonjs.com/how_to/optimizing_your_scene_with_octrees
         */
        selectionOctree: Octree<AbstractMesh>;

        /**
         * Creates or updates the octree used to boost selection (picking)
         * @see http://doc.babylonjs.com/how_to/optimizing_your_scene_with_octrees
         * @param maxCapacity defines the maximum capacity per leaf
         * @param maxDepth defines the maximum depth of the octree
         * @returns an octree of AbstractMesh
         */
        createOrUpdateSelectionOctree(maxCapacity?: number, maxDepth?: number): Octree<AbstractMesh>;
    }

    Scene.prototype.createOrUpdateSelectionOctree = function(maxCapacity = 64, maxDepth = 2): Octree<AbstractMesh> {
        let component = this._getComponent(SceneComponentConstants.NAME_OCTREE);
        if (!component) {
            component = new OctreeSceneComponent(this);
            this._addComponent(component);
        }

        if (!this._selectionOctree) {
            this._selectionOctree = new Octree<AbstractMesh>(Octree.CreationFuncForMeshes, maxCapacity, maxDepth);
        }

        var worldExtends = this.getWorldExtends();

        // Update octree
        this._selectionOctree.update(worldExtends.min, worldExtends.max, this.meshes);

        return this._selectionOctree;
   };

    Object.defineProperty(Scene.prototype, "selectionOctree", {
        get: function(this: Scene) {
            return this._selectionOctree;
        },
        enumerable: true,
        configurable: true
    });

    export interface AbstractMesh {
        /**
         * @hidden
         * Backing Field
         */
        _submeshesOctree: Octree<SubMesh>;

        /**
         * This function will create an octree to help to select the right submeshes for rendering, picking and collision computations.
         * Please note that you must have a decent number of submeshes to get performance improvements when using an octree
         * @param maxCapacity defines the maximum size of each block (64 by default)
         * @param maxDepth defines the maximum depth to use (no more than 2 levels by default)
         * @returns the new octree
         * @see https://www.babylonjs-playground.com/#NA4OQ#12
         * @see http://doc.babylonjs.com/how_to/optimizing_your_scene_with_octrees
         */
        createOrUpdateSubmeshesOctree(maxCapacity?: number, maxDepth?: number): Octree<SubMesh>;
    }

    /**
     * This function will create an octree to help to select the right submeshes for rendering, picking and collision computations.
     * Please note that you must have a decent number of submeshes to get performance improvements when using an octree
     * @param maxCapacity defines the maximum size of each block (64 by default)
     * @param maxDepth defines the maximum depth to use (no more than 2 levels by default)
     * @returns the new octree
     * @see https://www.babylonjs-playground.com/#NA4OQ#12
     * @see http://doc.babylonjs.com/how_to/optimizing_your_scene_with_octrees
     */
    AbstractMesh.prototype.createOrUpdateSubmeshesOctree = function(maxCapacity = 64, maxDepth = 2): Octree<SubMesh> {
        const scene = this.getScene();
        let component = scene._getComponent(SceneComponentConstants.NAME_OCTREE);
        if (!component) {
            component = new OctreeSceneComponent(scene);
            scene._addComponent(component);
        }

        if (!this._submeshesOctree) {
            this._submeshesOctree = new Octree<SubMesh>(Octree.CreationFuncForSubMeshes, maxCapacity, maxDepth);
        }

        this.computeWorldMatrix(true);

        let boundingInfo = this.getBoundingInfo();

        // Update octree
        var bbox = boundingInfo.boundingBox;
        this._submeshesOctree.update(bbox.minimumWorld, bbox.maximumWorld, this.subMeshes);

        return this._submeshesOctree;
    };

    /**
     * Defines the octree scene component responsible to manage any octrees
     * in a given scene.
     */
    export class OctreeSceneComponent {
        /**
         * The component name helpfull to identify the component in the list of scene components.
         */
        public readonly name = SceneComponentConstants.NAME_OCTREE;

        /**
         * The scene the component belongs to.
         */
        public scene: Scene;

        /**
         * Indicates if the meshes have been checked to make sure they are isEnabled()
         */
        public readonly checksIsEnabled = true;

        /**
         * Creates a new instance of the component for the given scene
         * @param scene Defines the scene to register the component in
         */
        constructor(scene: Scene) {
            this.scene = scene;

            this.scene.getActiveMeshCandidates = this.getActiveMeshCandidates.bind(this);

            this.scene.getActiveSubMeshCandidates = this.getActiveSubMeshCandidates.bind(this);
            this.scene.getCollidingSubMeshCandidates = this.getCollidingSubMeshCandidates.bind(this);
            this.scene.getIntersectingSubMeshCandidates = this.getIntersectingSubMeshCandidates.bind(this);
        }

        /**
         * Registers the component in a given scene
         */
        public register(): void {
            this.scene.onMeshRemovedObservable.add((mesh: AbstractMesh) => {
                const sceneOctree = this.scene.selectionOctree;
                if (sceneOctree !== undefined && sceneOctree !== null) {
                    var index = sceneOctree.dynamicContent.indexOf(mesh);

                    if (index !== -1) {
                        sceneOctree.dynamicContent.splice(index, 1);
                    }
                }
            });

            this.scene.onMeshImportedObservable.add((mesh: AbstractMesh) => {
                const sceneOctree = this.scene.selectionOctree;
                if (sceneOctree !== undefined && sceneOctree !== null) {
                    sceneOctree.addMesh(mesh);
                }
            });
        }

        /**
         * Return the list of active meshes
         * @returns the list of active meshes
         */
        public getActiveMeshCandidates(): ISmartArrayLike<AbstractMesh> {
            if (this.scene._selectionOctree) {
                var selection = this.scene._selectionOctree.select(this.scene.frustumPlanes);
                return selection;
            }
            return this.scene._getDefaultMeshCandidates();
        }

        /**
         * Return the list of active sub meshes
         * @param mesh The mesh to get the candidates sub meshes from
         * @returns the list of active sub meshes
         */
        public getActiveSubMeshCandidates(mesh: AbstractMesh): ISmartArrayLike<SubMesh> {
            if (mesh._submeshesOctree && mesh.useOctreeForRenderingSelection) {
                var intersections = mesh._submeshesOctree.select(this.scene.frustumPlanes);
                return intersections;
            }
            return this.scene._getDefaultSubMeshCandidates(mesh);
        }

        private _tempRay = new BABYLON.Ray(Vector3.Zero(), new Vector3(1, 1, 1));
        /**
         * Return the list of sub meshes intersecting with a given local ray
         * @param mesh defines the mesh to find the submesh for
         * @param localRay defines the ray in local space
         * @returns the list of intersecting sub meshes
         */
        public getIntersectingSubMeshCandidates(mesh: AbstractMesh, localRay: Ray): ISmartArrayLike<SubMesh> {
            if (mesh._submeshesOctree && mesh.useOctreeForPicking) {
                Ray.TransformToRef(localRay, mesh.getWorldMatrix(), this._tempRay);
                var intersections = mesh._submeshesOctree.intersectsRay(this._tempRay);

                return intersections;
            }
            return this.scene._getDefaultSubMeshCandidates(mesh);
        }

        /**
         * Return the list of sub meshes colliding with a collider
         * @param mesh defines the mesh to find the submesh for
         * @param collider defines the collider to evaluate the collision against
         * @returns the list of colliding sub meshes
         */
        public getCollidingSubMeshCandidates(mesh: AbstractMesh, collider: Collider): ISmartArrayLike<SubMesh> {
            if (mesh._submeshesOctree && mesh.useOctreeForCollisions) {
                var radius = collider._velocityWorldLength + Math.max(collider._radius.x, collider._radius.y, collider._radius.z);
                var intersections = mesh._submeshesOctree.intersects(collider._basePointWorld, radius);

                return intersections;
            }
            return this.scene._getDefaultSubMeshCandidates(mesh);
        }

        /**
         * Rebuilds the elements related to this component in case of
         * context lost for instance.
         */
        public rebuild(): void {
            // Nothing to do here.
        }

        /**
         * Disposes the component and the associated ressources.
         */
        public dispose(): void {
            // Nothing to do here.
        }
    }