/**
 * @author mrdoob / http://mrdoob.com/
 */

THREE.OBJLoader = function ( manager ) {

	this.manager = ( manager !== undefined ) ? manager : THREE.DefaultLoadingManager;

	this.materials = null;

	this.regexp = {
		// v float float float
		vertex_pattern           : /^v\s+([\d|\.|\+|\-|e|E]+)\s+([\d|\.|\+|\-|e|E]+)\s+([\d|\.|\+|\-|e|E]+)/,
		// vn float float float
		normal_pattern           : /^vn\s+([\d|\.|\+|\-|e|E]+)\s+([\d|\.|\+|\-|e|E]+)\s+([\d|\.|\+|\-|e|E]+)/,
		// vt float float
		uv_pattern               : /^vt\s+([\d|\.|\+|\-|e|E]+)\s+([\d|\.|\+|\-|e|E]+)/,
		// f vertex vertex vertex
		face_vertex              : /^f\s+(-?\d+)\s+(-?\d+)\s+(-?\d+)(?:\s+(-?\d+))?/,
		// f vertex/uv vertex/uv vertex/uv
		face_vertex_uv           : /^f\s+(-?\d+)\/(-?\d+)\s+(-?\d+)\/(-?\d+)\s+(-?\d+)\/(-?\d+)(?:\s+(-?\d+)\/(-?\d+))?/,
		// f vertex/uv/normal vertex/uv/normal vertex/uv/normal
		face_vertex_uv_normal    : /^f\s+(-?\d+)\/(-?\d+)\/(-?\d+)\s+(-?\d+)\/(-?\d+)\/(-?\d+)\s+(-?\d+)\/(-?\d+)\/(-?\d+)(?:\s+(-?\d+)\/(-?\d+)\/(-?\d+))?/,
		// f vertex//normal vertex//normal vertex//normal
		face_vertex_normal       : /^f\s+(-?\d+)\/\/(-?\d+)\s+(-?\d+)\/\/(-?\d+)\s+(-?\d+)\/\/(-?\d+)(?:\s+(-?\d+)\/\/(-?\d+))?/,
		// o object_name | g group_name
		object_pattern           : /^[og]\s*(.+)?/,
		// s boolean
		smoothing_pattern        : /^s\s+(\d+|on|off)/,
		// mtllib file_reference
		material_library_pattern : /^mtllib /,
		// usemtl material_name
		material_use_pattern     : /^usemtl /
	};

};

THREE.OBJLoader.prototype = {

	constructor: THREE.OBJLoader,

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

		var scope = this;

		var loader = new THREE.XHRLoader( scope.manager );
		loader.setPath( this.path );
		loader.load( url, function ( text ) {

			onLoad( scope.parse( text ) );

		}, onProgress, onError );

	},

	setPath: function ( value ) {

		this.path = value;

	},

	setMaterials: function ( materials ) {

		this.materials = materials;

	},

	_createParserState : function () {

		var state = {
			objects  : [],
			object   : {},

			vertices : [],
			normals  : [],
			uvs      : [],

			materialLibraries : [],

			startObject: function ( name, fromDeclaration ) {

				// If the current object (initial from reset) is not from a g/o declaration in the parsed
				// file. We need to use it for the first parsed g/o to keep things in sync.
				if ( this.object && this.object.fromDeclaration === false ) {

					this.object.name = name;
					this.object.fromDeclaration = ( fromDeclaration !== false );
					return;

				}

				var previousMaterial = ( this.object && typeof this.object.currentMaterial === 'function' ? this.object.currentMaterial() : undefined );

				if ( this.object && typeof this.object._finalize === 'function' ) {

					this.object._finalize( true );

				}

				this.object = {
					name : name || '',
					fromDeclaration : ( fromDeclaration !== false ),

					geometry : {
						vertices : [],
						normals  : [],
						uvs      : []
					},
					materials : [],
					smooth : true,

					startMaterial : function( name, libraries ) {

						var previous = this._finalize( false );

						// New usemtl declaration overwrites an inherited material, except if faces were declared
						// after the material, then it must be preserved for proper MultiMaterial continuation.
						if ( previous && ( previous.inherited || previous.groupCount <= 0 ) ) {

							this.materials.splice( previous.index, 1 );

						}

						var material = {
							index      : this.materials.length,
							name       : name || '',
							mtllib     : ( Array.isArray( libraries ) && libraries.length > 0 ? libraries[ libraries.length - 1 ] : '' ),
							smooth     : ( previous !== undefined ? previous.smooth : this.smooth ),
							groupStart : ( previous !== undefined ? previous.groupEnd : 0 ),
							groupEnd   : -1,
							groupCount : -1,
							inherited  : false,

							clone : function( index ) {
								var cloned = {
									index      : ( typeof index === 'number' ? index : this.index ),
									name       : this.name,
									mtllib     : this.mtllib,
									smooth     : this.smooth,
									groupStart : 0,
									groupEnd   : -1,
									groupCount : -1,
									inherited  : false
								};
								cloned.clone = this.clone.bind(cloned);
								return cloned;
							}
						};

						this.materials.push( material );

						return material;

					},

					currentMaterial : function() {

						if ( this.materials.length > 0 ) {
							return this.materials[ this.materials.length - 1 ];
						}

						return undefined;

					},

					_finalize : function( end ) {

						var lastMultiMaterial = this.currentMaterial();
						if ( lastMultiMaterial && lastMultiMaterial.groupEnd === -1 ) {

							lastMultiMaterial.groupEnd = this.geometry.vertices.length / 3;
							lastMultiMaterial.groupCount = lastMultiMaterial.groupEnd - lastMultiMaterial.groupStart;
							lastMultiMaterial.inherited = false;

						}

						// Ignore objects tail materials if no face declarations followed them before a new o/g started.
						if ( end && this.materials.length > 1 ) {

							for ( var mi = this.materials.length - 1; mi >= 0; mi-- ) {
								if ( this.materials[mi].groupCount <= 0 ) {
									this.materials.splice( mi, 1 );
								}
							}

						}

						// Guarantee at least one empty material, this makes the creation later more straight forward.
						if ( end && this.materials.length === 0 ) {

							this.materials.push({
								name   : '',
								smooth : this.smooth
							});

						}

						return lastMultiMaterial;

					}
				};

				// Inherit previous objects material.
				// Spec tells us that a declared material must be set to all objects until a new material is declared.
				// If a usemtl declaration is encountered while this new object is being parsed, it will
				// overwrite the inherited material. Exception being that there was already face declarations
				// to the inherited material, then it will be preserved for proper MultiMaterial continuation.

				if ( previousMaterial && previousMaterial.name && typeof previousMaterial.clone === "function" ) {

					var declared = previousMaterial.clone( 0 );
					declared.inherited = true;
					this.object.materials.push( declared );

				}

				this.objects.push( this.object );

			},

			finalize : function() {

				if ( this.object && typeof this.object._finalize === 'function' ) {

					this.object._finalize( true );

				}

			},

			parseVertexIndex: function ( value, len ) {

				var index = parseInt( value, 10 );
				return ( index >= 0 ? index - 1 : index + len / 3 ) * 3;

			},

			parseNormalIndex: function ( value, len ) {

				var index = parseInt( value, 10 );
				return ( index >= 0 ? index - 1 : index + len / 3 ) * 3;

			},

			parseUVIndex: function ( value, len ) {

				var index = parseInt( value, 10 );
				return ( index >= 0 ? index - 1 : index + len / 2 ) * 2;

			},

			addVertex: function ( a, b, c ) {

				var src = this.vertices;
				var dst = this.object.geometry.vertices;

				dst.push( src[ a + 0 ] );
				dst.push( src[ a + 1 ] );
				dst.push( src[ a + 2 ] );
				dst.push( src[ b + 0 ] );
				dst.push( src[ b + 1 ] );
				dst.push( src[ b + 2 ] );
				dst.push( src[ c + 0 ] );
				dst.push( src[ c + 1 ] );
				dst.push( src[ c + 2 ] );

			},

			addVertexLine: function ( a ) {

				var src = this.vertices;
				var dst = this.object.geometry.vertices;

				dst.push( src[ a + 0 ] );
				dst.push( src[ a + 1 ] );
				dst.push( src[ a + 2 ] );

			},

			addNormal : function ( a, b, c ) {

				var src = this.normals;
				var dst = this.object.geometry.normals;

				dst.push( src[ a + 0 ] );
				dst.push( src[ a + 1 ] );
				dst.push( src[ a + 2 ] );
				dst.push( src[ b + 0 ] );
				dst.push( src[ b + 1 ] );
				dst.push( src[ b + 2 ] );
				dst.push( src[ c + 0 ] );
				dst.push( src[ c + 1 ] );
				dst.push( src[ c + 2 ] );

			},

			addUV: function ( a, b, c ) {

				var src = this.uvs;
				var dst = this.object.geometry.uvs;

				dst.push( src[ a + 0 ] );
				dst.push( src[ a + 1 ] );
				dst.push( src[ b + 0 ] );
				dst.push( src[ b + 1 ] );
				dst.push( src[ c + 0 ] );
				dst.push( src[ c + 1 ] );

			},

			addUVLine: function ( a ) {

				var src = this.uvs;
				var dst = this.object.geometry.uvs;

				dst.push( src[ a + 0 ] );
				dst.push( src[ a + 1 ] );

			},

			addFace: function ( a, b, c, d, ua, ub, uc, ud, na, nb, nc, nd ) {

				var vLen = this.vertices.length;

				var ia = this.parseVertexIndex( a, vLen );
				var ib = this.parseVertexIndex( b, vLen );
				var ic = this.parseVertexIndex( c, vLen );
				var id;

				if ( d === undefined ) {

					this.addVertex( ia, ib, ic );

				} else {

					id = this.parseVertexIndex( d, vLen );

					this.addVertex( ia, ib, id );
					this.addVertex( ib, ic, id );

				}

				if ( ua !== undefined ) {

					var uvLen = this.uvs.length;

					ia = this.parseUVIndex( ua, uvLen );
					ib = this.parseUVIndex( ub, uvLen );
					ic = this.parseUVIndex( uc, uvLen );

					if ( d === undefined ) {

						this.addUV( ia, ib, ic );

					} else {

						id = this.parseUVIndex( ud, uvLen );

						this.addUV( ia, ib, id );
						this.addUV( ib, ic, id );

					}

				}

				if ( na !== undefined ) {

					// Normals are many times the same. If so, skip function call and parseInt.
					var nLen = this.normals.length;
					ia = this.parseNormalIndex( na, nLen );

					ib = na === nb ? ia : this.parseNormalIndex( nb, nLen );
					ic = na === nc ? ia : this.parseNormalIndex( nc, nLen );

					if ( d === undefined ) {

						this.addNormal( ia, ib, ic );

					} else {

						id = this.parseNormalIndex( nd, nLen );

						this.addNormal( ia, ib, id );
						this.addNormal( ib, ic, id );

					}

				}

			},

			addLineGeometry: function ( vertices, uvs ) {

				this.object.geometry.type = 'Line';

				var vLen = this.vertices.length;
				var uvLen = this.uvs.length;

				for ( var vi = 0, l = vertices.length; vi < l; vi ++ ) {

					this.addVertexLine( this.parseVertexIndex( vertices[ vi ], vLen ) );

				}

				for ( var uvi = 0, l = uvs.length; uvi < l; uvi ++ ) {

					this.addUVLine( this.parseUVIndex( uvs[ uvi ], uvLen ) );

				}

			}

		};

		state.startObject( '', false );

		return state;

	},

	parse: function ( text ) {

		console.time( 'OBJLoader' );

		var state = this._createParserState();

		if ( text.indexOf( '\r\n' ) !== - 1 ) {

			// This is faster than String.split with regex that splits on both
			text = text.replace( /\r\n/g, '\n' );

		}

		if ( text.indexOf( '\\\n' ) !== - 1) {

			// join lines separated by a line continuation character (\)
			text = text.replace( /\\\n/g, '' );

		}

		var lines = text.split( '\n' );
		var line = '', lineFirstChar = '', lineSecondChar = '';
		var lineLength = 0;
		var result = [];

		// Faster to just trim left side of the line. Use if available.
		var trimLeft = ( typeof ''.trimLeft === 'function' );

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

			line = lines[ i ];

			line = trimLeft ? line.trimLeft() : line.trim();

			lineLength = line.length;

			if ( lineLength === 0 ) continue;

			lineFirstChar = line.charAt( 0 );

			// @todo invoke passed in handler if any
			if ( lineFirstChar === '#' ) continue;

			if ( lineFirstChar === 'v' ) {

				lineSecondChar = line.charAt( 1 );

				if ( lineSecondChar === ' ' && ( result = this.regexp.vertex_pattern.exec( line ) ) !== null ) {

					// 0                  1      2      3
					// ["v 1.0 2.0 3.0", "1.0", "2.0", "3.0"]

					state.vertices.push(
						parseFloat( result[ 1 ] ),
						parseFloat( result[ 2 ] ),
						parseFloat( result[ 3 ] )
					);

				} else if ( lineSecondChar === 'n' && ( result = this.regexp.normal_pattern.exec( line ) ) !== null ) {

					// 0                   1      2      3
					// ["vn 1.0 2.0 3.0", "1.0", "2.0", "3.0"]

					state.normals.push(
						parseFloat( result[ 1 ] ),
						parseFloat( result[ 2 ] ),
						parseFloat( result[ 3 ] )
					);

				} else if ( lineSecondChar === 't' && ( result = this.regexp.uv_pattern.exec( line ) ) !== null ) {

					// 0               1      2
					// ["vt 0.1 0.2", "0.1", "0.2"]

					state.uvs.push(
						parseFloat( result[ 1 ] ),
						parseFloat( result[ 2 ] )
					);

				} else {

					throw new Error( "Unexpected vertex/normal/uv line: '" + line  + "'" );

				}

			} else if ( lineFirstChar === "f" ) {

				if ( ( result = this.regexp.face_vertex_uv_normal.exec( line ) ) !== null ) {

					// f vertex/uv/normal vertex/uv/normal vertex/uv/normal
					// 0                        1    2    3    4    5    6    7    8    9   10         11         12
					// ["f 1/1/1 2/2/2 3/3/3", "1", "1", "1", "2", "2", "2", "3", "3", "3", undefined, undefined, undefined]

					state.addFace(
						result[ 1 ], result[ 4 ], result[ 7 ], result[ 10 ],
						result[ 2 ], result[ 5 ], result[ 8 ], result[ 11 ],
						result[ 3 ], result[ 6 ], result[ 9 ], result[ 12 ]
					);

				} else if ( ( result = this.regexp.face_vertex_uv.exec( line ) ) !== null ) {

					// f vertex/uv vertex/uv vertex/uv
					// 0                  1    2    3    4    5    6   7          8
					// ["f 1/1 2/2 3/3", "1", "1", "2", "2", "3", "3", undefined, undefined]

					state.addFace(
						result[ 1 ], result[ 3 ], result[ 5 ], result[ 7 ],
						result[ 2 ], result[ 4 ], result[ 6 ], result[ 8 ]
					);

				} else if ( ( result = this.regexp.face_vertex_normal.exec( line ) ) !== null ) {

					// f vertex//normal vertex//normal vertex//normal
					// 0                     1    2    3    4    5    6   7          8
					// ["f 1//1 2//2 3//3", "1", "1", "2", "2", "3", "3", undefined, undefined]

					state.addFace(
						result[ 1 ], result[ 3 ], result[ 5 ], result[ 7 ],
						undefined, undefined, undefined, undefined,
						result[ 2 ], result[ 4 ], result[ 6 ], result[ 8 ]
					);

				} else if ( ( result = this.regexp.face_vertex.exec( line ) ) !== null ) {

					// f vertex vertex vertex
					// 0            1    2    3   4
					// ["f 1 2 3", "1", "2", "3", undefined]

					state.addFace(
						result[ 1 ], result[ 2 ], result[ 3 ], result[ 4 ]
					);

				} else {

					throw new Error( "Unexpected face line: '" + line  + "'" );

				}

			} else if ( lineFirstChar === "l" ) {

				var lineParts = line.substring( 1 ).trim().split( " " );
				var lineVertices = [], lineUVs = [];

				if ( line.indexOf( "/" ) === - 1 ) {

					lineVertices = lineParts;

				} else {

					for ( var li = 0, llen = lineParts.length; li < llen; li ++ ) {

						var parts = lineParts[ li ].split( "/" );

						if ( parts[ 0 ] !== "" ) lineVertices.push( parts[ 0 ] );
						if ( parts[ 1 ] !== "" ) lineUVs.push( parts[ 1 ] );

					}

				}
				state.addLineGeometry( lineVertices, lineUVs );

			} else if ( ( result = this.regexp.object_pattern.exec( line ) ) !== null ) {

				// o object_name
				// or
				// g group_name

				// WORKAROUND: https://bugs.chromium.org/p/v8/issues/detail?id=2869
				// var name = result[ 0 ].substr( 1 ).trim();
				var name = ( " " + result[ 0 ].substr( 1 ).trim() ).substr( 1 );

				state.startObject( name );

			} else if ( this.regexp.material_use_pattern.test( line ) ) {

				// material

				state.object.startMaterial( line.substring( 7 ).trim(), state.materialLibraries );

			} else if ( this.regexp.material_library_pattern.test( line ) ) {

				// mtl file

				state.materialLibraries.push( line.substring( 7 ).trim() );

			} else if ( ( result = this.regexp.smoothing_pattern.exec( line ) ) !== null ) {

				// smooth shading

				// @todo Handle files that have varying smooth values for a set of faces inside one geometry,
				// but does not define a usemtl for each face set.
				// This should be detected and a dummy material created (later MultiMaterial and geometry groups).
				// This requires some care to not create extra material on each smooth value for "normal" obj files.
				// where explicit usemtl defines geometry groups.
				// Example asset: examples/models/obj/cerberus/Cerberus.obj

				var value = result[ 1 ].trim().toLowerCase();
				state.object.smooth = ( value === '1' || value === 'on' );

				var material = state.object.currentMaterial();
				if ( material ) {

					material.smooth = state.object.smooth;

				}

			} else {

				// Handle null terminated files without exception
				if ( line === '\0' ) continue;

				throw new Error( "Unexpected line: '" + line  + "'" );

			}

		}

		state.finalize();

		var container = new THREE.Group();
		container.materialLibraries = [].concat( state.materialLibraries );

		for ( var i = 0, l = state.objects.length; i < l; i ++ ) {

			var object = state.objects[ i ];
			var geometry = object.geometry;
			var materials = object.materials;
			var isLine = ( geometry.type === 'Line' );

			// Skip o/g line declarations that did not follow with any faces
			if ( geometry.vertices.length === 0 ) continue;

			var buffergeometry = new THREE.BufferGeometry();

			buffergeometry.addAttribute( 'position', new THREE.BufferAttribute( new Float32Array( geometry.vertices ), 3 ) );

			if ( geometry.normals.length > 0 ) {

				buffergeometry.addAttribute( 'normal', new THREE.BufferAttribute( new Float32Array( geometry.normals ), 3 ) );

			} else {

				buffergeometry.computeVertexNormals();

			}

			if ( geometry.uvs.length > 0 ) {

				buffergeometry.addAttribute( 'uv', new THREE.BufferAttribute( new Float32Array( geometry.uvs ), 2 ) );

			}

			// Create materials

			var createdMaterials = [];

			for ( var mi = 0, miLen = materials.length; mi < miLen ; mi++ ) {

				var sourceMaterial = materials[mi];
				var material = undefined;

				if ( this.materials !== null ) {

					material = this.materials.create( sourceMaterial.name );

					// mtl etc. loaders probably can't create line materials correctly, copy properties to a line material.
					if ( isLine && material && ! ( material instanceof THREE.LineBasicMaterial ) ) {

						var materialLine = new THREE.LineBasicMaterial();
						materialLine.copy( material );
						material = materialLine;

					}

				}

				if ( ! material ) {

					material = ( ! isLine ? new THREE.MeshPhongMaterial() : new THREE.LineBasicMaterial() );
					material.name = sourceMaterial.name;

				}

				material.shading = sourceMaterial.smooth ? THREE.SmoothShading : THREE.FlatShading;

				createdMaterials.push(material);

			}

			// Create mesh

			var mesh;

			if ( createdMaterials.length > 1 ) {

				for ( var mi = 0, miLen = materials.length; mi < miLen ; mi++ ) {

					var sourceMaterial = materials[mi];
					buffergeometry.addGroup( sourceMaterial.groupStart, sourceMaterial.groupCount, mi );

				}

				var multiMaterial = new THREE.MultiMaterial( createdMaterials );
				mesh = ( ! isLine ? new THREE.Mesh( buffergeometry, multiMaterial ) : new THREE.LineSegments( buffergeometry, multiMaterial ) );

			} else {

				mesh = ( ! isLine ? new THREE.Mesh( buffergeometry, createdMaterials[ 0 ] ) : new THREE.LineSegments( buffergeometry, createdMaterials[ 0 ] ) );
			}

			mesh.name = object.name;

			container.add( mesh );

		}

		console.timeEnd( 'OBJLoader' );

		return container;

	}

};
