/**
 * @author mrdoob / http://mrdoob.com/
 * @author Alex Pletzer
 *
 * Updated on 22.03.2017
 * VTK header is now parsed and used to extract all the compressed data
 * @author Andrii Iudin https://github.com/andreyyudin
 * @author Paul Kibet Korir https://github.com/polarise
 * @author Sriram Somasundharam https://github.com/raamssundar
 */

import {
	BufferAttribute,
	BufferGeometry,
	FileLoader,
	Float32BufferAttribute,
	Loader,
	LoaderUtils
} from "../../../build/three.module.js";
import { Zlib } from "../libs/inflate.module.min.js";

var VTKLoader = function ( manager ) {

	Loader.call( this, manager );

};

VTKLoader.prototype = Object.assign( Object.create( Loader.prototype ), {

	constructor: VTKLoader,

	load: function ( url, onLoad, onProgress, onError ) {

		var scope = this;

		var loader = new FileLoader( scope.manager );
		loader.setPath( scope.path );
		loader.setResponseType( 'arraybuffer' );
		loader.load( url, function ( text ) {

			onLoad( scope.parse( text ) );

		}, onProgress, onError );

	},

	parse: function ( data ) {

		function parseASCII( data ) {

			// connectivity of the triangles
			var indices = [];

			// triangles vertices
			var positions = [];

			// red, green, blue colors in the range 0 to 1
			var colors = [];

			// normal vector, one per vertex
			var normals = [];

			var result;

			// pattern for detecting the end of a number sequence
			var patWord = /^[^\d.\s-]+/;

			// pattern for reading vertices, 3 floats or integers
			var pat3Floats = /(\-?\d+\.?[\d\-\+e]*)\s+(\-?\d+\.?[\d\-\+e]*)\s+(\-?\d+\.?[\d\-\+e]*)/g;

			// pattern for connectivity, an integer followed by any number of ints
			// the first integer is the number of polygon nodes
			var patConnectivity = /^(\d+)\s+([\s\d]*)/;

			// indicates start of vertex data section
			var patPOINTS = /^POINTS /;

			// indicates start of polygon connectivity section
			var patPOLYGONS = /^POLYGONS /;

			// indicates start of triangle strips section
			var patTRIANGLE_STRIPS = /^TRIANGLE_STRIPS /;

			// POINT_DATA number_of_values
			var patPOINT_DATA = /^POINT_DATA[ ]+(\d+)/;

			// CELL_DATA number_of_polys
			var patCELL_DATA = /^CELL_DATA[ ]+(\d+)/;

			// Start of color section
			var patCOLOR_SCALARS = /^COLOR_SCALARS[ ]+(\w+)[ ]+3/;

			// NORMALS Normals float
			var patNORMALS = /^NORMALS[ ]+(\w+)[ ]+(\w+)/;

			var inPointsSection = false;
			var inPolygonsSection = false;
			var inTriangleStripSection = false;
			var inPointDataSection = false;
			var inCellDataSection = false;
			var inColorSection = false;
			var inNormalsSection = false;

			var lines = data.split( '\n' );

			for ( var i in lines ) {

				var line = lines[ i ].trim();

				if ( line.indexOf( 'DATASET' ) === 0 ) {

					var dataset = line.split( ' ' )[ 1 ];

					if ( dataset !== 'POLYDATA' ) throw new Error( 'Unsupported DATASET type: ' + dataset );

				} else if ( inPointsSection ) {

					// get the vertices
					while ( ( result = pat3Floats.exec( line ) ) !== null ) {

						if ( patWord.exec( line ) !== null ) break;

						var x = parseFloat( result[ 1 ] );
						var y = parseFloat( result[ 2 ] );
						var z = parseFloat( result[ 3 ] );
						positions.push( x, y, z );

					}

				} else if ( inPolygonsSection ) {

					if ( ( result = patConnectivity.exec( line ) ) !== null ) {

						// numVertices i0 i1 i2 ...
						var numVertices = parseInt( result[ 1 ] );
						var inds = result[ 2 ].split( /\s+/ );

						if ( numVertices >= 3 ) {

							var i0 = parseInt( inds[ 0 ] );
							var i1, i2;
							var k = 1;
							// split the polygon in numVertices - 2 triangles
							for ( var j = 0; j < numVertices - 2; ++ j ) {

								i1 = parseInt( inds[ k ] );
								i2 = parseInt( inds[ k + 1 ] );
								indices.push( i0, i1, i2 );
								k ++;

							}

						}

					}

				} else if ( inTriangleStripSection ) {

					if ( ( result = patConnectivity.exec( line ) ) !== null ) {

						// numVertices i0 i1 i2 ...
						var numVertices = parseInt( result[ 1 ] );
						var inds = result[ 2 ].split( /\s+/ );

						if ( numVertices >= 3 ) {

							var i0, i1, i2;
							// split the polygon in numVertices - 2 triangles
							for ( var j = 0; j < numVertices - 2; j ++ ) {

								if ( j % 2 === 1 ) {

									i0 = parseInt( inds[ j ] );
									i1 = parseInt( inds[ j + 2 ] );
									i2 = parseInt( inds[ j + 1 ] );
									indices.push( i0, i1, i2 );

								} else {

									i0 = parseInt( inds[ j ] );
									i1 = parseInt( inds[ j + 1 ] );
									i2 = parseInt( inds[ j + 2 ] );
									indices.push( i0, i1, i2 );

								}

							}

						}

					}

				} else if ( inPointDataSection || inCellDataSection ) {

					if ( inColorSection ) {

						// Get the colors

						while ( ( result = pat3Floats.exec( line ) ) !== null ) {

							if ( patWord.exec( line ) !== null ) break;

							var r = parseFloat( result[ 1 ] );
							var g = parseFloat( result[ 2 ] );
							var b = parseFloat( result[ 3 ] );
							colors.push( r, g, b );

						}

					} else if ( inNormalsSection ) {

						// Get the normal vectors

						while ( ( result = pat3Floats.exec( line ) ) !== null ) {

							if ( patWord.exec( line ) !== null ) break;

							var nx = parseFloat( result[ 1 ] );
							var ny = parseFloat( result[ 2 ] );
							var nz = parseFloat( result[ 3 ] );
							normals.push( nx, ny, nz );

						}

					}

				}

				if ( patPOLYGONS.exec( line ) !== null ) {

					inPolygonsSection = true;
					inPointsSection = false;
					inTriangleStripSection = false;

				} else if ( patPOINTS.exec( line ) !== null ) {

					inPolygonsSection = false;
					inPointsSection = true;
					inTriangleStripSection = false;

				} else if ( patTRIANGLE_STRIPS.exec( line ) !== null ) {

					inPolygonsSection = false;
					inPointsSection = false;
					inTriangleStripSection = true;

				} else if ( patPOINT_DATA.exec( line ) !== null ) {

					inPointDataSection = true;
					inPointsSection = false;
					inPolygonsSection = false;
					inTriangleStripSection = false;

				} else if ( patCELL_DATA.exec( line ) !== null ) {

					inCellDataSection = true;
					inPointsSection = false;
					inPolygonsSection = false;
					inTriangleStripSection = false;

				} else if ( patCOLOR_SCALARS.exec( line ) !== null ) {

					inColorSection = true;
					inNormalsSection = false;
					inPointsSection = false;
					inPolygonsSection = false;
					inTriangleStripSection = false;

				} else if ( patNORMALS.exec( line ) !== null ) {

					inNormalsSection = true;
					inColorSection = false;
					inPointsSection = false;
					inPolygonsSection = false;
					inTriangleStripSection = false;

				}

			}

			var geometry = new BufferGeometry();
			geometry.setIndex( indices );
			geometry.setAttribute( 'position', new Float32BufferAttribute( positions, 3 ) );

			if ( normals.length === positions.length ) {

				geometry.setAttribute( 'normal', new Float32BufferAttribute( normals, 3 ) );

			}

			if ( colors.length !== indices.length ) {

				// stagger

				if ( colors.length === positions.length ) {

					geometry.setAttribute( 'color', new Float32BufferAttribute( colors, 3 ) );

				}

			} else {

				// cell

				geometry = geometry.toNonIndexed();
				var numTriangles = geometry.attributes.position.count / 3;

				if ( colors.length === ( numTriangles * 3 ) ) {

					var newColors = [];

					for ( var i = 0; i < numTriangles; i ++ ) {

						var r = colors[ 3 * i + 0 ];
						var g = colors[ 3 * i + 1 ];
						var b = colors[ 3 * i + 2 ];

						newColors.push( r, g, b );
						newColors.push( r, g, b );
						newColors.push( r, g, b );

					}

					geometry.setAttribute( 'color', new Float32BufferAttribute( newColors, 3 ) );

				}

			}

			return geometry;

		}

		function parseBinary( data ) {

			var count, pointIndex, i, numberOfPoints, s;
			var buffer = new Uint8Array( data );
			var dataView = new DataView( data );

			// Points and normals, by default, are empty
			var points = [];
			var normals = [];
			var indices = [];

			// Going to make a big array of strings
			var vtk = [];
			var index = 0;

			function findString( buffer, start ) {

				var index = start;
				var c = buffer[ index ];
				var s = [];
				while ( c !== 10 ) {

					s.push( String.fromCharCode( c ) );
					index ++;
					c = buffer[ index ];

				}

				return { start: start,
					end: index,
					next: index + 1,
					parsedString: s.join( '' ) };

			}

			var state, line;

			while ( true ) {

				// Get a string
				state = findString( buffer, index );
				line = state.parsedString;

				if ( line.indexOf( 'DATASET' ) === 0 ) {

					var dataset = line.split( ' ' )[ 1 ];

					if ( dataset !== 'POLYDATA' ) throw new Error( 'Unsupported DATASET type: ' + dataset );

				} else if ( line.indexOf( 'POINTS' ) === 0 ) {

					vtk.push( line );
					// Add the points
					numberOfPoints = parseInt( line.split( ' ' )[ 1 ], 10 );

					// Each point is 3 4-byte floats
					count = numberOfPoints * 4 * 3;

					points = new Float32Array( numberOfPoints * 3 );

					pointIndex = state.next;
					for ( i = 0; i < numberOfPoints; i ++ ) {

						points[ 3 * i ] = dataView.getFloat32( pointIndex, false );
						points[ 3 * i + 1 ] = dataView.getFloat32( pointIndex + 4, false );
						points[ 3 * i + 2 ] = dataView.getFloat32( pointIndex + 8, false );
						pointIndex = pointIndex + 12;

					}

					// increment our next pointer
					state.next = state.next + count + 1;

				} else if ( line.indexOf( 'TRIANGLE_STRIPS' ) === 0 ) {

					var numberOfStrips = parseInt( line.split( ' ' )[ 1 ], 10 );
					var size = parseInt( line.split( ' ' )[ 2 ], 10 );
					// 4 byte integers
					count = size * 4;

					indices = new Uint32Array( 3 * size - 9 * numberOfStrips );
					var indicesIndex = 0;

					pointIndex = state.next;
					for ( i = 0; i < numberOfStrips; i ++ ) {

						// For each strip, read the first value, then record that many more points
						var indexCount = dataView.getInt32( pointIndex, false );
						var strip = [];
						pointIndex += 4;
						for ( s = 0; s < indexCount; s ++ ) {

							strip.push( dataView.getInt32( pointIndex, false ) );
							pointIndex += 4;

						}

						// retrieves the n-2 triangles from the triangle strip
						for ( var j = 0; j < indexCount - 2; j ++ ) {

							if ( j % 2 ) {

								indices[ indicesIndex ++ ] = strip[ j ];
								indices[ indicesIndex ++ ] = strip[ j + 2 ];
								indices[ indicesIndex ++ ] = strip[ j + 1 ];

							} else {


								indices[ indicesIndex ++ ] = strip[ j ];
								indices[ indicesIndex ++ ] = strip[ j + 1 ];
								indices[ indicesIndex ++ ] = strip[ j + 2 ];

							}

						}

					}

					// increment our next pointer
					state.next = state.next + count + 1;

				} else if ( line.indexOf( 'POLYGONS' ) === 0 ) {

					var numberOfStrips = parseInt( line.split( ' ' )[ 1 ], 10 );
					var size = parseInt( line.split( ' ' )[ 2 ], 10 );
					// 4 byte integers
					count = size * 4;

					indices = new Uint32Array( 3 * size - 9 * numberOfStrips );
					var indicesIndex = 0;

					pointIndex = state.next;
					for ( i = 0; i < numberOfStrips; i ++ ) {

						// For each strip, read the first value, then record that many more points
						var indexCount = dataView.getInt32( pointIndex, false );
						var strip = [];
						pointIndex += 4;
						for ( s = 0; s < indexCount; s ++ ) {

							strip.push( dataView.getInt32( pointIndex, false ) );
							pointIndex += 4;

						}

						// divide the polygon in n-2 triangle
						for ( var j = 1; j < indexCount - 1; j ++ ) {

							indices[ indicesIndex ++ ] = strip[ 0 ];
							indices[ indicesIndex ++ ] = strip[ j ];
							indices[ indicesIndex ++ ] = strip[ j + 1 ];

						}

					}

					// increment our next pointer
					state.next = state.next + count + 1;

				} else if ( line.indexOf( 'POINT_DATA' ) === 0 ) {

					numberOfPoints = parseInt( line.split( ' ' )[ 1 ], 10 );

					// Grab the next line
					state = findString( buffer, state.next );

					// Now grab the binary data
					count = numberOfPoints * 4 * 3;

					normals = new Float32Array( numberOfPoints * 3 );
					pointIndex = state.next;
					for ( i = 0; i < numberOfPoints; i ++ ) {

						normals[ 3 * i ] = dataView.getFloat32( pointIndex, false );
						normals[ 3 * i + 1 ] = dataView.getFloat32( pointIndex + 4, false );
						normals[ 3 * i + 2 ] = dataView.getFloat32( pointIndex + 8, false );
						pointIndex += 12;

					}

					// Increment past our data
					state.next = state.next + count;

				}

				// Increment index
				index = state.next;

				if ( index >= buffer.byteLength ) {

					break;

				}

			}

			var geometry = new BufferGeometry();
			geometry.setIndex( new BufferAttribute( indices, 1 ) );
			geometry.setAttribute( 'position', new BufferAttribute( points, 3 ) );

			if ( normals.length === points.length ) {

				geometry.setAttribute( 'normal', new BufferAttribute( normals, 3 ) );

			}

			return geometry;

		}

		function Float32Concat( first, second ) {

		    var firstLength = first.length, result = new Float32Array( firstLength + second.length );

		    result.set( first );
		    result.set( second, firstLength );

		    return result;

		}

		function Int32Concat( first, second ) {

		    var firstLength = first.length, result = new Int32Array( firstLength + second.length );

		    result.set( first );
		    result.set( second, firstLength );

		    return result;

		}

		function parseXML( stringFile ) {

			// Changes XML to JSON, based on https://davidwalsh.name/convert-xml-json

			function xmlToJson( xml ) {

				// Create the return object
				var obj = {};

				if ( xml.nodeType === 1 ) { // element

					// do attributes

					if ( xml.attributes ) {

						if ( xml.attributes.length > 0 ) {

							obj[ 'attributes' ] = {};

							for ( var j = 0; j < xml.attributes.length; j ++ ) {

								var attribute = xml.attributes.item( j );
								obj[ 'attributes' ][ attribute.nodeName ] = attribute.nodeValue.trim();

							}

						}

					}

				} else if ( xml.nodeType === 3 ) { // text

					obj = xml.nodeValue.trim();

				}

				// do children
				if ( xml.hasChildNodes() ) {

					for ( var i = 0; i < xml.childNodes.length; i ++ ) {

						var item = xml.childNodes.item( i );
						var nodeName = item.nodeName;

						if ( typeof obj[ nodeName ] === 'undefined' ) {

							var tmp = xmlToJson( item );

							if ( tmp !== '' ) obj[ nodeName ] = tmp;

						} else {

							if ( typeof obj[ nodeName ].push === 'undefined' ) {

								var old = obj[ nodeName ];
								obj[ nodeName ] = [ old ];

							}

							var tmp = xmlToJson( item );

							if ( tmp !== '' ) obj[ nodeName ].push( tmp );

						}

					}

				}

				return obj;

			}

			// Taken from Base64-js
			function Base64toByteArray( b64 ) {

				var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array;
				var i;
				var lookup = [];
				var revLookup = [];
				var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
				var len = code.length;

				for ( i = 0; i < len; i ++ ) {

					lookup[ i ] = code[ i ];

				}

				for ( i = 0; i < len; ++ i ) {

					revLookup[ code.charCodeAt( i ) ] = i;

				}

				revLookup[ '-'.charCodeAt( 0 ) ] = 62;
				revLookup[ '_'.charCodeAt( 0 ) ] = 63;

				var j, l, tmp, placeHolders, arr;
				var len = b64.length;

				if ( len % 4 > 0 ) {

					throw new Error( 'Invalid string. Length must be a multiple of 4' );

				}

				placeHolders = b64[ len - 2 ] === '=' ? 2 : b64[ len - 1 ] === '=' ? 1 : 0;
				arr = new Arr( len * 3 / 4 - placeHolders );
				l = placeHolders > 0 ? len - 4 : len;

				var L = 0;

				for ( i = 0, j = 0; i < l; i += 4, j += 3 ) {

					tmp = ( revLookup[ b64.charCodeAt( i ) ] << 18 ) | ( revLookup[ b64.charCodeAt( i + 1 ) ] << 12 ) | ( revLookup[ b64.charCodeAt( i + 2 ) ] << 6 ) | revLookup[ b64.charCodeAt( i + 3 ) ];
					arr[ L ++ ] = ( tmp & 0xFF0000 ) >> 16;
					arr[ L ++ ] = ( tmp & 0xFF00 ) >> 8;
					arr[ L ++ ] = tmp & 0xFF;

				}

				if ( placeHolders === 2 ) {

					tmp = ( revLookup[ b64.charCodeAt( i ) ] << 2 ) | ( revLookup[ b64.charCodeAt( i + 1 ) ] >> 4 );
					arr[ L ++ ] = tmp & 0xFF;

				} else if ( placeHolders === 1 ) {

					tmp = ( revLookup[ b64.charCodeAt( i ) ] << 10 ) | ( revLookup[ b64.charCodeAt( i + 1 ) ] << 4 ) | ( revLookup[ b64.charCodeAt( i + 2 ) ] >> 2 );
					arr[ L ++ ] = ( tmp >> 8 ) & 0xFF;
					arr[ L ++ ] = tmp & 0xFF;

				}

				return arr;

			}

			function parseDataArray( ele, compressed ) {

				var numBytes = 0;

				if ( json.attributes.header_type === 'UInt64' ) {

					numBytes = 8;

				}	else if ( json.attributes.header_type === 'UInt32' ) {

					numBytes = 4;

				}


				// Check the format
				if ( ele.attributes.format === 'binary' && compressed ) {

					var rawData, content, byteData, blocks, cSizeStart, headerSize, padding, dataOffsets, currentOffset;

					if ( ele.attributes.type === 'Float32' ) {

						var txt = new Float32Array( );

					} else if ( ele.attributes.type === 'Int64' ) {

						var txt = new Int32Array( );

					}

					// VTP data with the header has the following structure:
					// [#blocks][#u-size][#p-size][#c-size-1][#c-size-2]...[#c-size-#blocks][DATA]
					//
					// Each token is an integer value whose type is specified by "header_type" at the top of the file (UInt32 if no type specified). The token meanings are:
					// [#blocks] = Number of blocks
					// [#u-size] = Block size before compression
					// [#p-size] = Size of last partial block (zero if it not needed)
					// [#c-size-i] = Size in bytes of block i after compression
					//
					// The [DATA] portion stores contiguously every block appended together. The offset from the beginning of the data section to the beginning of a block is
					// computed by summing the compressed block sizes from preceding blocks according to the header.

					rawData = ele[ '#text' ];

					byteData = Base64toByteArray( rawData );

					blocks = byteData[ 0 ];
					for ( var i = 1; i < numBytes - 1; i ++ ) {

						blocks = blocks | ( byteData[ i ] << ( i * numBytes ) );

					}

					headerSize = ( blocks + 3 ) * numBytes;
					padding = ( ( headerSize % 3 ) > 0 ) ? 3 - ( headerSize % 3 ) : 0;
					headerSize = headerSize + padding;

					dataOffsets = [];
					currentOffset = headerSize;
					dataOffsets.push( currentOffset );

					// Get the blocks sizes after the compression.
					// There are three blocks before c-size-i, so we skip 3*numBytes
					cSizeStart = 3 * numBytes;

					for ( var i = 0; i < blocks; i ++ ) {

						var currentBlockSize = byteData[ i * numBytes + cSizeStart ];

						for ( var j = 1; j < numBytes - 1; j ++ ) {

							// Each data point consists of 8 bytes regardless of the header type
							currentBlockSize = currentBlockSize | ( byteData[ i * numBytes + cSizeStart + j ] << ( j * 8 ) );

						}

						currentOffset = currentOffset + currentBlockSize;
						dataOffsets.push( currentOffset );

					}

					for ( var i = 0; i < dataOffsets.length - 1; i ++ ) {

						var inflate = new Zlib.Inflate( byteData.slice( dataOffsets[ i ], dataOffsets[ i + 1 ] ), { resize: true, verify: true } ); // eslint-disable-line no-undef
						content = inflate.decompress();
						content = content.buffer;

						if ( ele.attributes.type === 'Float32' ) {

							content = new Float32Array( content );
							txt = Float32Concat( txt, content );

						} else if ( ele.attributes.type === 'Int64' ) {

							content = new Int32Array( content );
							txt = Int32Concat( txt, content );

						}

					}

					delete ele[ '#text' ];

					if ( ele.attributes.type === 'Int64' ) {

						if ( ele.attributes.format === 'binary' ) {

							txt = txt.filter( function ( el, idx ) {

								if ( idx % 2 !== 1 ) return true;

							} );

						}

					}

				} else {

					if ( ele.attributes.format === 'binary' && ! compressed ) {

						var content = Base64toByteArray( ele[ '#text' ] );

						//  VTP data for the uncompressed case has the following structure:
						// [#bytes][DATA]
						// where "[#bytes]" is an integer value specifying the number of bytes in the block of data following it.
						content = content.slice( numBytes ).buffer;

					} else {

						if ( ele[ '#text' ] ) {

							var content = ele[ '#text' ].split( /\s+/ ).filter( function ( el ) {

								if ( el !== '' ) return el;

							} );

						} else {

							var content = new Int32Array( 0 ).buffer;

						}

					}

					delete ele[ '#text' ];

					// Get the content and optimize it
					if ( ele.attributes.type === 'Float32' ) {

						var txt = new Float32Array( content );

					} else if ( ele.attributes.type === 'Int32' ) {

						var txt = new Int32Array( content );

					} else if ( ele.attributes.type === 'Int64' ) {

						var txt = new Int32Array( content );

						if ( ele.attributes.format === 'binary' ) {

							txt = txt.filter( function ( el, idx ) {

								if ( idx % 2 !== 1 ) return true;

							} );

						}

					}

				} // endif ( ele.attributes.format === 'binary' && compressed )

				return txt;

			}

			// Main part
			// Get Dom
			var dom = null;

			if ( window.DOMParser ) {

				try {

					dom = ( new DOMParser() ).parseFromString( stringFile, 'text/xml' );

				} catch ( e ) {

					dom = null;

				}

			} else if ( window.ActiveXObject ) {

				try {

					dom = new ActiveXObject( 'Microsoft.XMLDOM' ); // eslint-disable-line no-undef
					dom.async = false;

					if ( ! dom.loadXML( /* xml */ ) ) {

						throw new Error( dom.parseError.reason + dom.parseError.srcText );

					}

				} catch ( e ) {

					dom = null;

				}

			} else {

				throw new Error( 'Cannot parse xml string!' );

			}

			// Get the doc
			var doc = dom.documentElement;
			// Convert to json
			var json = xmlToJson( doc );
			var points = [];
			var normals = [];
			var indices = [];

			if ( json.PolyData ) {

				var piece = json.PolyData.Piece;
				var compressed = json.attributes.hasOwnProperty( 'compressor' );

				// Can be optimized
				// Loop through the sections
				var sections = [ 'PointData', 'Points', 'Strips', 'Polys' ];// +['CellData', 'Verts', 'Lines'];
				var sectionIndex = 0, numberOfSections = sections.length;

				while ( sectionIndex < numberOfSections ) {

					var section = piece[ sections[ sectionIndex ] ];

					// If it has a DataArray in it

					if ( section && section.DataArray ) {

						// Depending on the number of DataArrays

						if ( Object.prototype.toString.call( section.DataArray ) === '[object Array]' ) {

							var arr = section.DataArray;

						} else {

							var arr = [ section.DataArray ];

						}

						var dataArrayIndex = 0, numberOfDataArrays = arr.length;

						while ( dataArrayIndex < numberOfDataArrays ) {

							// Parse the DataArray
							if ( ( '#text' in arr[ dataArrayIndex ] ) && ( arr[ dataArrayIndex ][ '#text' ].length > 0 ) ) {

								arr[ dataArrayIndex ].text = parseDataArray( arr[ dataArrayIndex ], compressed );

							}

							dataArrayIndex ++;

						}

						switch ( sections[ sectionIndex ] ) {

							// if iti is point data
							case 'PointData':

								var numberOfPoints = parseInt( piece.attributes.NumberOfPoints );
								var normalsName = section.attributes.Normals;

								if ( numberOfPoints > 0 ) {

									for ( var i = 0, len = arr.length; i < len; i ++ ) {

										if ( normalsName === arr[ i ].attributes.Name ) {

											var components = arr[ i ].attributes.NumberOfComponents;
											normals = new Float32Array( numberOfPoints * components );
											normals.set( arr[ i ].text, 0 );

										}

									}

								}

								break;

							// if it is points
							case 'Points':

								var numberOfPoints = parseInt( piece.attributes.NumberOfPoints );

								if ( numberOfPoints > 0 ) {

									var components = section.DataArray.attributes.NumberOfComponents;
									points = new Float32Array( numberOfPoints * components );
									points.set( section.DataArray.text, 0 );

								}

								break;

							// if it is strips
							case 'Strips':

								var numberOfStrips = parseInt( piece.attributes.NumberOfStrips );

								if ( numberOfStrips > 0 ) {

									var connectivity = new Int32Array( section.DataArray[ 0 ].text.length );
									var offset = new Int32Array( section.DataArray[ 1 ].text.length );
									connectivity.set( section.DataArray[ 0 ].text, 0 );
									offset.set( section.DataArray[ 1 ].text, 0 );

									var size = numberOfStrips + connectivity.length;
									indices = new Uint32Array( 3 * size - 9 * numberOfStrips );

									var indicesIndex = 0;

									for ( var i = 0, len = numberOfStrips; i < len; i ++ ) {

										var strip = [];

										for ( var s = 0, len1 = offset[ i ], len0 = 0; s < len1 - len0; s ++ ) {

											strip.push( connectivity[ s ] );

											if ( i > 0 ) len0 = offset[ i - 1 ];

										}

										for ( var j = 0, len1 = offset[ i ], len0 = 0; j < len1 - len0 - 2; j ++ ) {

											if ( j % 2 ) {

												indices[ indicesIndex ++ ] = strip[ j ];
												indices[ indicesIndex ++ ] = strip[ j + 2 ];
												indices[ indicesIndex ++ ] = strip[ j + 1 ];

											} else {

												indices[ indicesIndex ++ ] = strip[ j ];
												indices[ indicesIndex ++ ] = strip[ j + 1 ];
												indices[ indicesIndex ++ ] = strip[ j + 2 ];

											}

											if ( i > 0 ) len0 = offset[ i - 1 ];

										}

									}

								}

								break;

							// if it is polys
							case 'Polys':

								var numberOfPolys = parseInt( piece.attributes.NumberOfPolys );

								if ( numberOfPolys > 0 ) {

									var connectivity = new Int32Array( section.DataArray[ 0 ].text.length );
									var offset = new Int32Array( section.DataArray[ 1 ].text.length );
									connectivity.set( section.DataArray[ 0 ].text, 0 );
									offset.set( section.DataArray[ 1 ].text, 0 );

									var size = numberOfPolys + connectivity.length;
									indices = new Uint32Array( 3 * size - 9 * numberOfPolys );
									var indicesIndex = 0, connectivityIndex = 0;
									var i = 0, len = numberOfPolys, len0 = 0;

									while ( i < len ) {

										var poly = [];
										var s = 0, len1 = offset[ i ];

										while ( s < len1 - len0 ) {

											poly.push( connectivity[ connectivityIndex ++ ] );
											s ++;

										}

										var j = 1;

										while ( j < len1 - len0 - 1 ) {

											indices[ indicesIndex ++ ] = poly[ 0 ];
											indices[ indicesIndex ++ ] = poly[ j ];
											indices[ indicesIndex ++ ] = poly[ j + 1 ];
											j ++;

										}

										i ++;
										len0 = offset[ i - 1 ];

									}

								}

								break;

							default:
								break;

						}

					}

					sectionIndex ++;

				}

				var geometry = new BufferGeometry();
				geometry.setIndex( new BufferAttribute( indices, 1 ) );
				geometry.setAttribute( 'position', new BufferAttribute( points, 3 ) );

				if ( normals.length === points.length ) {

					geometry.setAttribute( 'normal', new BufferAttribute( normals, 3 ) );

				}

				return geometry;

			} else {

				throw new Error( 'Unsupported DATASET type' );

			}

		}

		function getStringFile( data ) {

			var stringFile = '';
			var charArray = new Uint8Array( data );
			var i = 0;
			var len = charArray.length;

			while ( len -- ) {

				stringFile += String.fromCharCode( charArray[ i ++ ] );

			}

			return stringFile;

		}

		// get the 5 first lines of the files to check if there is the key word binary
		var meta = LoaderUtils.decodeText( new Uint8Array( data, 0, 250 ) ).split( '\n' );

		if ( meta[ 0 ].indexOf( 'xml' ) !== - 1 ) {

			return parseXML( getStringFile( data ) );

		} else if ( meta[ 2 ].includes( 'ASCII' ) ) {

			return parseASCII( getStringFile( data ) );

		} else {

			return parseBinary( data );

		}

	}

} );

export { VTKLoader };
