import { TilesRendererBase } from '../base/TilesRendererBase.js';
import { B3DMLoader } from './B3DMLoader.js';
import { TilesGroup } from './TilesGroup.js';
import {
	Matrix4,
	Box3,
	Sphere,
	Vector3,
	Vector2,
	Math as MathUtils,
	Frustum,
	CanvasTexture,
	LoadingManager,
	ImageBitmapLoader,
} from 'three';
import { raycastTraverse, raycastTraverseFirstHit } from './raycastTraverse.js';

const DEG2RAD = MathUtils.DEG2RAD;
const tempMat = new Matrix4();
const tempMat2 = new Matrix4();
const tempVector = new Vector3();
const vecX = new Vector3();
const vecY = new Vector3();
const vecZ = new Vector3();

const X_AXIS = new Vector3( 1, 0, 0 );
const Y_AXIS = new Vector3( 0, 1, 0 );
const useImageBitmap = typeof createImageBitmap !== 'undefined';

function emptyRaycast() {}

export class TilesRenderer extends TilesRendererBase {

	get camera() {

		return this.cameras[ 0 ];

	}

	set camera( camera ) {

		const cameras = this.cameras;
		cameras.length = 1;
		cameras[ 0 ] = camera;

	}

	constructor( ...args ) {

		super( ...args );
		this.group = new TilesGroup( this );
		this.cameras = [];
		this.resolution = new Vector2();
		this.cameraInfo = [];
		this.activeTiles = new Set();
		this.visibleTiles = new Set();

	}

	/* Public API */
	getBounds( box ) {

		if ( ! this.root ) {

			return false;

		}

		const cached = this.root.cached;
		const boundingBox = cached.box;
		const obbMat = cached.boxTransform;

		if ( boundingBox ) {

			box.copy( boundingBox );
			box.applyMatrix4( obbMat );

			return true;

		} else {

			return false;

		}

	}

	raycast( raycaster, intersects ) {

		if ( ! this.root ) {

			return;

		}

		if ( raycaster.firstHitOnly ) {

			const hit = raycastTraverseFirstHit( this.root, this.group, this.activeTiles, raycaster );
			if ( hit ) {

				intersects.push( hit );

			}

		} else {

			raycastTraverse( this.root, this.group, this.activeTiles, raycaster, intersects );

		}

	}

	setResolutionFromRenderer( renderer ) {

		const resolution = this.resolution;
		renderer.getSize( resolution );
		resolution.multiplyScalar( renderer.getPixelRatio() );

	}

	/* Overriden */
	update() {

		const group = this.group;
		const cameras = this.cameras;
		const cameraInfo = this.cameraInfo;
		const resolution = this.resolution;

		if ( cameras.length === 0 ) {

			console.warn( 'TilesRenderer: no cameras to use are defined. Cannot update 3d tiles.' );
			return;

		}

		if ( resolution.width === 0 || resolution.height === 0 ) {

			console.warn( 'TilesRenderer: resolution for error calculation is not set. Cannot updated 3d tiles.' );
			return;

		}

		// automatically scale the array of cameraInfo to match the cameras
		while ( cameraInfo.length > cameras.length ) {

			cameraInfo.pop();

		}

		while ( cameraInfo.length < cameras.length ) {

			cameraInfo.push( {

				frustum: new Frustum(),
				sseDenominator: - 1,
				position: new Vector3(),
				invScale: - 1,

			} );

		}

		tempMat2.getInverse( group.matrixWorld );

		let invScale;
		tempVector.setFromMatrixScale( tempMat2 );
		invScale = tempVector.x;

		if ( Math.abs( Math.max( tempVector.x - tempVector.y, tempVector.x - tempVector.z ) ) > 1e-6 ) {

			console.warn( 'ThreeTilesRenderer : Non uniform scale used for tile which may cause issues when calculating screen space error.' );

		}

		// store the camera cameraInfo in the 3d tiles root frame
		for ( let i = 0, l = cameraInfo.length; i < l; i ++ ) {

			const camera = cameras[ i ];
			const info = cameraInfo[ i ];
			const frustum = info.frustum;
			const position = info.position;

			if ( camera.isPerspectiveCamera ) {

				info.sseDenominator = 2 * Math.tan( 0.5 * camera.fov * DEG2RAD ) / resolution.height;

			}

			info.invScale = invScale;

			tempMat.copy( group.matrixWorld );
			tempMat.premultiply( camera.matrixWorldInverse );
			tempMat.premultiply( camera.projectionMatrix );
			frustum.setFromProjectionMatrix( tempMat );

			position.set( 0, 0, 0 );
			position.applyMatrix4( camera.matrixWorld );
			position.applyMatrix4( tempMat2 );

		}

		super.update();

	}

	preprocessNode( tile, parentTile, tileSetDir ) {

		super.preprocessNode( tile, parentTile, tileSetDir );

		const transform = new Matrix4();
		if ( tile.transform ) {

			const transformArr = tile.transform;
			for ( let i = 0; i < 16; i ++ ) {

				transform.elements[ i ] = transformArr[ i ];

			}

		} else {

			transform.identity();

		}

		if ( parentTile ) {

			transform.multiply( parentTile.cached.transform );

		}

		let box = null;
		let boxTransform = null;
		let boxTransformInverse = null;
		if ( 'box' in tile.boundingVolume ) {

			const data = tile.boundingVolume.box;
			box = new Box3();
			boxTransform = new Matrix4();
			boxTransformInverse = new Matrix4();

			// get the extents of the bounds in each axis
			vecX.set( data[ 3 ], data[ 4 ], data[ 5 ] );
			vecY.set( data[ 6 ], data[ 7 ], data[ 8 ] );
			vecZ.set( data[ 9 ], data[ 10 ], data[ 11 ] );

			const scaleX = vecX.length();
			const scaleY = vecY.length();
			const scaleZ = vecZ.length();

			vecX.normalize();
			vecY.normalize();
			vecZ.normalize();

			// create the oriented frame that the box exists in
			boxTransform.set(
				vecX.x, vecY.x, vecZ.x, data[ 0 ],
				vecX.y, vecY.y, vecZ.y, data[ 1 ],
				vecX.z, vecY.z, vecZ.z, data[ 2 ],
				0, 0, 0, 1
			);
			boxTransform.premultiply( transform );
			boxTransformInverse.getInverse( boxTransform );

			// scale the box by the extents
			box.min.set( - scaleX, - scaleY, - scaleZ );
			box.max.set( scaleX, scaleY, scaleZ );

		}

		let sphere = null;
		if ( 'sphere' in tile.boundingVolume ) {

			const data = tile.boundingVolume.sphere;
			sphere = new Sphere();
			sphere.center.set( data[ 0 ], data[ 1 ], data[ 2 ] );
			sphere.radius = data[ 3 ];
			sphere.applyMatrix4( transform );

		} else if ( 'box' in tile.boundingVolume ) {

			const data = tile.boundingVolume.box;
			sphere = new Sphere();
			box.getBoundingSphere( sphere );
			sphere.center.set( data[ 0 ], data[ 1 ], data[ 2 ] );
			sphere.applyMatrix4( transform );

		}

		let region = null;
		if ( 'region' in tile.boundingVolume ) {

			console.warn( 'ThreeTilesRenderer: region bounding volume not supported.' );

		}

		tile.cached = {

			loadIndex: 0,
			transform,
			active: false,

			box,
			boxTransform,
			boxTransformInverse,
			sphere,
			region,

			scene: null,
			geometry: null,
			material: null,
			distance: Infinity

		};

	}

	parseTile( buffer, tile ) {

		tile._loadIndex = tile._loadIndex || 0;
		tile._loadIndex ++;

		const loadIndex = tile._loadIndex;
		const manager = new LoadingManager();

		if ( useImageBitmap ) {

			// TODO: We should verify that `flipY` is false on the resulting texture after load because it can't be modified after
			// the fact. Premultiply alpha default behavior is not well defined, either.
			// TODO: Determine whether or not options are supported before using this so we can force flipY false and premultiply alpha
			// behavior. Fall back to regular texture loading
			manager.addHandler(/(^blob:)|(\.png$)|(\.jpg$)|(\.jpeg$)/g, {

				load( url, onComplete ) {

					const loader = new ImageBitmapLoader();
					loader.load( url, res => {

						onComplete( new CanvasTexture( res ) );

					} );

				}

			});

		}

		return new B3DMLoader( manager ).parse( buffer ).then( res => {

			if ( tile._loadIndex !== loadIndex ) {

				return;

			}

			const upAxis = this.rootTileSet.asset && this.rootTileSet.asset.gltfUpAxis || 'y';
			const cached = tile.cached;
			const cachedTransform = cached.transform;

			const scene = res.scene;
			switch ( upAxis.toLowerCase() ) {

				case 'x':
					scene.matrix.makeRotationAxis( Y_AXIS, - Math.PI / 2 );
					break;

				case 'y':
					scene.matrix.makeRotationAxis( X_AXIS, Math.PI / 2 );
					break;

				case 'z':
					break;

			}

			scene.matrix.premultiply( cachedTransform );
			scene.matrix.decompose( scene.position, scene.quaternion, scene.scale );
			scene.traverse( c => c.frustumCulled = false );

			cached.scene = scene;

			// We handle raycasting in a custom way so remove it from here
			scene.traverse( c => {

				c.raycast = emptyRaycast;

			} );

			const materials = [];
			const geometry = [];
			const textures = [];
			scene.traverse( c => {

				if ( c.geometry ) {

					geometry.push( c.geometry );

				}

				if ( c.material ) {

					const material = c.material;
					materials.push( c.material );

					for ( const key in material ) {

						const value = material[ key ];
						if ( value && value.isTexture ) {

							textures.push( value );

						}

					}

				}

			} );

			cached.materials = materials;
			cached.geometry = geometry;
			cached.textures = textures;

		} );

	}

	disposeTile( tile ) {

		// This could get called before the tile has finished downloading
		const cached = tile.cached;
		if ( cached.scene ) {

			const materials = cached.materials;
			const geometry = cached.geometry;
			const textures = cached.textures;

			for ( let i = 0, l = geometry.length; i < l; i ++ ) {

				geometry[ i ].dispose();

			}

			for ( let i = 0, l = materials.length; i < l; i ++ ) {

				materials[ i ].dispose();

			}

			for ( let i = 0, l = textures.length; i < l; i ++ ) {

				const texture = textures[ i ];
				texture.dispose();
				if ( useImageBitmap && 'close' in texture.image ) {

					texture.image.close();

				}

			}

			cached.scene = null;
			cached.materials = null;
			cached.textures = null;
			cached.geometry = null;

		}

		tile._loadIndex ++;

	}

	setTileVisible( tile, visible ) {

		const scene = tile.cached.scene;
		const visibleTiles = this.visibleTiles;
		const group = this.group;
		if ( visible ) {

			group.add( scene );
			visibleTiles.add( tile );
			scene.updateMatrixWorld( true );

		} else {

			group.remove( scene );
			visibleTiles.delete( tile );

		}

	}

	setTileActive( tile, active ) {

		const activeTiles = this.activeTiles;
		if ( active ) {

			activeTiles.add( tile );

		} else {

			activeTiles.delete( tile );

		}

	}

	calculateError( tile ) {

		if ( tile.geometricError === 0.0 ) {

			return 0.0;

		}

		const cached = tile.cached;
		const cameras = this.cameras;
		const cameraInfo = this.cameraInfo;

		// TODO: Use the content bounding volume here?
		const boundingVolume = tile.boundingVolume;
		const resolution = this.resolution;

		if ( 'box' in boundingVolume ) {

			const boundingBox = cached.box;
			const boxTransformInverse = cached.boxTransformInverse;

			let minError = Infinity;
			for ( let i = 0, l = cameras.length; i < l; i ++ ) {

				// TODO: move this logic (and the distance scale extraction) into the update preprocess step

				// transform camera position into local frame of the tile bounding box
				// TODO: this should be the cameras world position
				const camera = cameras[ i ];
				const info = cameraInfo[ i ];
				const invScale = info.invScale;
				tempVector.copy( info.position );
				tempVector.applyMatrix4( boxTransformInverse );

				let error;
				if ( camera.isOrthographicCamera ) {

					const w = camera.right - camera.left;
					const h = camera.top - camera.bottom;
					const pixelSize = Math.max( h / resolution.height, w / resolution.width );
					error = tile.geometricError / ( pixelSize * invScale );

				} else {

					const distance = boundingBox.distanceToPoint( tempVector );
					const scaledDistance = distance * invScale;
					const sseDenominator = info.sseDenominator;
					error = tile.geometricError / ( scaledDistance * sseDenominator );

					tile.cached.distance = scaledDistance;

				}

				minError = Math.min( minError, error );

			}

			return minError;

		} else if ( 'sphere' in boundingVolume ) {

			// const sphere = cached.sphere;

			console.warn( 'ThreeTilesRenderer : Sphere bounds not supported.' );

		} else if ( 'region' in boundingVolume ) {

			// unsupported
			console.warn( 'ThreeTilesRenderer : Region bounds not supported.' );

		}

		return Infinity;

	}

	tileInView( tile ) {

		// TODO: we should use the more precise bounding volumes here if possible
		// cache the root-space planes
		// Use separating axis theorem for frustum and obb

		const sphere = tile.cached.sphere;
		if ( sphere ) {

			const cameraInfo = this.cameraInfo;
			for ( let i = 0, l = cameraInfo.length; i < l; i ++ ) {

				const frustum = cameraInfo[ i ].frustum;
				if ( frustum.intersectsSphere( sphere ) ) {

					return true;

				}

			}

			return false;

		}

		return true;

	}


}