import {
	BufferGeometry,
	FileLoader,
	Float32BufferAttribute,
	Loader,
	LoaderUtils,
	Points,
	PointsMaterial
} from 'three';

class PCDLoader extends Loader {

	constructor( manager ) {

		super( manager );

		this.littleEndian = true;

	}

	load( url, onLoad, onProgress, onError ) {

		const scope = this;

		const loader = new FileLoader( scope.manager );
		loader.setPath( scope.path );
		loader.setResponseType( 'arraybuffer' );
		loader.setRequestHeader( scope.requestHeader );
		loader.setWithCredentials( scope.withCredentials );
		loader.load( url, function ( data ) {

			try {

				onLoad( scope.parse( data, url ) );

			} catch ( e ) {

				if ( onError ) {

					onError( e );

				} else {

					console.error( e );

				}

				scope.manager.itemError( url );

			}

		}, onProgress, onError );

	}

	parse( data, url ) {

		// from https://gitlab.com/taketwo/three-pcd-loader/blob/master/decompress-lzf.js

		function decompressLZF( inData, outLength ) {

			const inLength = inData.length;
			const outData = new Uint8Array( outLength );
			let inPtr = 0;
			let outPtr = 0;
			let ctrl;
			let len;
			let ref;
			do {

				ctrl = inData[ inPtr ++ ];
				if ( ctrl < ( 1 << 5 ) ) {

					ctrl ++;
					if ( outPtr + ctrl > outLength ) throw new Error( 'Output buffer is not large enough' );
					if ( inPtr + ctrl > inLength ) throw new Error( 'Invalid compressed data' );
					do {

						outData[ outPtr ++ ] = inData[ inPtr ++ ];

					} while ( -- ctrl );

				} else {

					len = ctrl >> 5;
					ref = outPtr - ( ( ctrl & 0x1f ) << 8 ) - 1;
					if ( inPtr >= inLength ) throw new Error( 'Invalid compressed data' );
					if ( len === 7 ) {

						len += inData[ inPtr ++ ];
						if ( inPtr >= inLength ) throw new Error( 'Invalid compressed data' );

					}

					ref -= inData[ inPtr ++ ];
					if ( outPtr + len + 2 > outLength ) throw new Error( 'Output buffer is not large enough' );
					if ( ref < 0 ) throw new Error( 'Invalid compressed data' );
					if ( ref >= outPtr ) throw new Error( 'Invalid compressed data' );
					do {

						outData[ outPtr ++ ] = outData[ ref ++ ];

					} while ( -- len + 2 );

				}

			} while ( inPtr < inLength );

			return outData;

		}

		function parseHeader( data ) {

			const PCDheader = {};
			const result1 = data.search( /[\r\n]DATA\s(\S*)\s/i );
			const result2 = /[\r\n]DATA\s(\S*)\s/i.exec( data.substr( result1 - 1 ) );

			PCDheader.data = result2[ 1 ];
			PCDheader.headerLen = result2[ 0 ].length + result1;
			PCDheader.str = data.substr( 0, PCDheader.headerLen );

			// remove comments

			PCDheader.str = PCDheader.str.replace( /\#.*/gi, '' );

			// parse

			PCDheader.version = /VERSION (.*)/i.exec( PCDheader.str );
			PCDheader.fields = /FIELDS (.*)/i.exec( PCDheader.str );
			PCDheader.size = /SIZE (.*)/i.exec( PCDheader.str );
			PCDheader.type = /TYPE (.*)/i.exec( PCDheader.str );
			PCDheader.count = /COUNT (.*)/i.exec( PCDheader.str );
			PCDheader.width = /WIDTH (.*)/i.exec( PCDheader.str );
			PCDheader.height = /HEIGHT (.*)/i.exec( PCDheader.str );
			PCDheader.viewpoint = /VIEWPOINT (.*)/i.exec( PCDheader.str );
			PCDheader.points = /POINTS (.*)/i.exec( PCDheader.str );

			// evaluate

			if ( PCDheader.version !== null )
				PCDheader.version = parseFloat( PCDheader.version[ 1 ] );

			if ( PCDheader.fields !== null )
				PCDheader.fields = PCDheader.fields[ 1 ].split( ' ' );

			if ( PCDheader.type !== null )
				PCDheader.type = PCDheader.type[ 1 ].split( ' ' );

			if ( PCDheader.width !== null )
				PCDheader.width = parseInt( PCDheader.width[ 1 ] );

			if ( PCDheader.height !== null )
				PCDheader.height = parseInt( PCDheader.height[ 1 ] );

			if ( PCDheader.viewpoint !== null )
				PCDheader.viewpoint = PCDheader.viewpoint[ 1 ];

			if ( PCDheader.points !== null )
				PCDheader.points = parseInt( PCDheader.points[ 1 ], 10 );

			if ( PCDheader.points === null )
				PCDheader.points = PCDheader.width * PCDheader.height;

			if ( PCDheader.size !== null ) {

				PCDheader.size = PCDheader.size[ 1 ].split( ' ' ).map( function ( x ) {

					return parseInt( x, 10 );

				} );

			}

			if ( PCDheader.count !== null ) {

				PCDheader.count = PCDheader.count[ 1 ].split( ' ' ).map( function ( x ) {

					return parseInt( x, 10 );

				} );

			} else {

				PCDheader.count = [];

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

					PCDheader.count.push( 1 );

				}

			}

			PCDheader.offset = {};

			let sizeSum = 0;

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

				if ( PCDheader.data === 'ascii' ) {

					PCDheader.offset[ PCDheader.fields[ i ] ] = i;

				} else {

					PCDheader.offset[ PCDheader.fields[ i ] ] = sizeSum;
					sizeSum += PCDheader.size[ i ] * PCDheader.count[ i ];

				}

			}

			// for binary only

			PCDheader.rowSize = sizeSum;

			return PCDheader;

		}

		const textData = LoaderUtils.decodeText( new Uint8Array( data ) );

		// parse header (always ascii format)

		const PCDheader = parseHeader( textData );

		// parse data

		const position = [];
		const normal = [];
		const color = [];

		// ascii

		if ( PCDheader.data === 'ascii' ) {

			const offset = PCDheader.offset;
			const pcdData = textData.substr( PCDheader.headerLen );
			const lines = pcdData.split( '\n' );

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

				if ( lines[ i ] === '' ) continue;

				const line = lines[ i ].split( ' ' );

				if ( offset.x !== undefined ) {

					position.push( parseFloat( line[ offset.x ] ) );
					position.push( parseFloat( line[ offset.y ] ) );
					position.push( parseFloat( line[ offset.z ] ) );

				}

				if ( offset.rgb !== undefined ) {

					const rgb = parseFloat( line[ offset.rgb ] );
					const r = ( rgb >> 16 ) & 0x0000ff;
					const g = ( rgb >> 8 ) & 0x0000ff;
					const b = ( rgb >> 0 ) & 0x0000ff;
					color.push( r / 255, g / 255, b / 255 );

				}

				if ( offset.normal_x !== undefined ) {

					normal.push( parseFloat( line[ offset.normal_x ] ) );
					normal.push( parseFloat( line[ offset.normal_y ] ) );
					normal.push( parseFloat( line[ offset.normal_z ] ) );

				}

			}

		}

		// binary-compressed

		// normally data in PCD files are organized as array of structures: XYZRGBXYZRGB
		// binary compressed PCD files organize their data as structure of arrays: XXYYZZRGBRGB
		// that requires a totally different parsing approach compared to non-compressed data

		if ( PCDheader.data === 'binary_compressed' ) {

			const sizes = new Uint32Array( data.slice( PCDheader.headerLen, PCDheader.headerLen + 8 ) );
			const compressedSize = sizes[ 0 ];
			const decompressedSize = sizes[ 1 ];
			const decompressed = decompressLZF( new Uint8Array( data, PCDheader.headerLen + 8, compressedSize ), decompressedSize );
			const dataview = new DataView( decompressed.buffer );

			const offset = PCDheader.offset;

			for ( let i = 0; i < PCDheader.points; i ++ ) {

				if ( offset.x !== undefined ) {

					position.push( dataview.getFloat32( ( PCDheader.points * offset.x ) + PCDheader.size[ 0 ] * i, this.littleEndian ) );
					position.push( dataview.getFloat32( ( PCDheader.points * offset.y ) + PCDheader.size[ 1 ] * i, this.littleEndian ) );
					position.push( dataview.getFloat32( ( PCDheader.points * offset.z ) + PCDheader.size[ 2 ] * i, this.littleEndian ) );

				}

				if ( offset.rgb !== undefined ) {

					color.push( dataview.getUint8( ( PCDheader.points * offset.rgb ) + PCDheader.size[ 3 ] * i + 0 ) / 255.0 );
					color.push( dataview.getUint8( ( PCDheader.points * offset.rgb ) + PCDheader.size[ 3 ] * i + 1 ) / 255.0 );
					color.push( dataview.getUint8( ( PCDheader.points * offset.rgb ) + PCDheader.size[ 3 ] * i + 2 ) / 255.0 );

				}

				if ( offset.normal_x !== undefined ) {

					normal.push( dataview.getFloat32( ( PCDheader.points * offset.normal_x ) + PCDheader.size[ 4 ] * i, this.littleEndian ) );
					normal.push( dataview.getFloat32( ( PCDheader.points * offset.normal_y ) + PCDheader.size[ 5 ] * i, this.littleEndian ) );
					normal.push( dataview.getFloat32( ( PCDheader.points * offset.normal_z ) + PCDheader.size[ 6 ] * i, this.littleEndian ) );

				}

			}

		}

		// binary

		if ( PCDheader.data === 'binary' ) {

			const dataview = new DataView( data, PCDheader.headerLen );
			const offset = PCDheader.offset;

			for ( let i = 0, row = 0; i < PCDheader.points; i ++, row += PCDheader.rowSize ) {

				if ( offset.x !== undefined ) {

					position.push( dataview.getFloat32( row + offset.x, this.littleEndian ) );
					position.push( dataview.getFloat32( row + offset.y, this.littleEndian ) );
					position.push( dataview.getFloat32( row + offset.z, this.littleEndian ) );

				}

				if ( offset.rgb !== undefined ) {

					color.push( dataview.getUint8( row + offset.rgb + 2 ) / 255.0 );
					color.push( dataview.getUint8( row + offset.rgb + 1 ) / 255.0 );
					color.push( dataview.getUint8( row + offset.rgb + 0 ) / 255.0 );

				}

				if ( offset.normal_x !== undefined ) {

					normal.push( dataview.getFloat32( row + offset.normal_x, this.littleEndian ) );
					normal.push( dataview.getFloat32( row + offset.normal_y, this.littleEndian ) );
					normal.push( dataview.getFloat32( row + offset.normal_z, this.littleEndian ) );

				}

			}

		}

		// build geometry

		const geometry = new BufferGeometry();

		if ( position.length > 0 ) geometry.setAttribute( 'position', new Float32BufferAttribute( position, 3 ) );
		if ( normal.length > 0 ) geometry.setAttribute( 'normal', new Float32BufferAttribute( normal, 3 ) );
		if ( color.length > 0 ) geometry.setAttribute( 'color', new Float32BufferAttribute( color, 3 ) );

		geometry.computeBoundingSphere();

		// build material

		const material = new PointsMaterial( { size: 0.005 } );

		if ( color.length > 0 ) {

			material.vertexColors = true;

		} else {

			material.color.setHex( Math.random() * 0xffffff );

		}

		// build point cloud

		const mesh = new Points( geometry, material );
		let name = url.split( '' ).reverse().join( '' );
		name = /([^\/]*)/.exec( name );
		name = name[ 1 ].split( '' ).reverse().join( '' );
		mesh.name = name;

		return mesh;

	}

}

export { PCDLoader };