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

THREE.VRMLLoader = function () {};

THREE.VRMLLoader.prototype = {

	constructor: THREE.VRMLLoader,

	// for IndexedFaceSet support
	isRecordingPoints: false,
	isRecordingFaces: false,
	points: [],
	indexes : [],

	// for Background support
	isRecordingAngles: false,
	isRecordingColors: false,
	angles: [],
	colors: [],

	recordingFieldname: null,

	load: function ( url, callback ) {

		var scope = this;
		var request = new XMLHttpRequest();

		request.addEventListener( 'load', function ( event ) {

			var object = scope.parse( event.target.responseText );

			scope.dispatchEvent( { type: 'load', content: object } );

			if ( callback ) callback( object );

		}, false );

		request.addEventListener( 'progress', function ( event ) {

			scope.dispatchEvent( { type: 'progress', loaded: event.loaded, total: event.total } );

		}, false );

		request.addEventListener( 'error', function () {

			scope.dispatchEvent( { type: 'error', message: 'Couldn\'t load URL [' + url + ']' } );

		}, false );

		request.open( 'GET', url, true );
		request.send( null );

	},

	parse: function ( data ) {

		var parseV1 = function ( lines, scene ) {

			console.warn( 'VRML V1.0 not supported yet' );

		};

		var parseV2 = function ( lines, scene ) {

			var defines = {};
			var float_pattern = /(\b|\-|\+)([\d\.e]+)/;
			var float3_pattern = /([\d\.\+\-e]+)\s+([\d\.\+\-e]+)\s+([\d\.\+\-e]+)/g;

			/**
			* Interpolates colors a and b following their relative distance
			* expressed by t.
			*
			* @param float a
			* @param float b
			* @param float t
			* @returns {Color}
			*/
			var interpolateColors = function(a, b, t) {
				var deltaR = a.r - b.r;
				var deltaG = a.g - b.g;
				var deltaB = a.b - b.b;

				var c = new THREE.Color();

				c.r = a.r - t * deltaR;
				c.g = a.g - t * deltaG;
				c.b = a.b - t * deltaB;

				return c;
			};

			/**
			 * Vertically paints the faces interpolating between the
			 * specified colors at the specified angels. This is used for the Background
			 * node, but could be applied to other nodes with multiple faces as well.
			 *
			 * When used with the Background node, default is directionIsDown is true if
			 * interpolating the skyColor down from the Zenith. When interpolationg up from
			 * the Nadir i.e. interpolating the groundColor, the directionIsDown is false.
			 *
			 * The first angle is never specified, it is the Zenith (0 rad). Angles are specified
			 * in radians. The geometry is thought a sphere, but could be anything. The color interpolation
			 * is linear along the Y axis in any case.
			 *
			 * You must specify one more color than you have angles at the beginning of the colors array.
			 * This is the color of the Zenith (the top of the shape).
			 *
			 * @param geometry
			 * @param radius
			 * @param angles
			 * @param colors
			 * @param boolean directionIsDown Whether to work bottom up or top down.
			 */
			var paintFaces = function (geometry, radius, angles, colors, directionIsDown) {

				var f, n, p, vertexIndex, color;

				var direction = directionIsDown ? 1 : -1;

				var faceIndices = [ 'a', 'b', 'c', 'd' ];

				var coord = [ ], aColor, bColor, t = 1, A = {}, B = {}, applyColor = false, colorIndex;

				for ( var k = 0; k < angles.length; k ++ ) {

					var vec = { };

					// push the vector at which the color changes
					vec.y = direction * ( Math.cos( angles[k] ) * radius);

					vec.x = direction * ( Math.sin( angles[k] ) * radius);

					coord.push( vec );

				}

				// painting the colors on the faces
				for ( var i = 0; i < geometry.faces.length ; i ++ ) {

					f  = geometry.faces[ i ];

					n = ( f instanceof THREE.Face3 ) ? 3 : 4;

					for ( var j = 0; j < n; j ++ ) {

						vertexIndex = f[ faceIndices[ j ] ];

						p = geometry.vertices[ vertexIndex ];

						for ( var index = 0; index < colors.length; index ++ ) {

							// linear interpolation between aColor and bColor, calculate proportion
							// A is previous point (angle)
							if ( index === 0 ) {

								A.x = 0;
								A.y = directionIsDown ? radius : -1 * radius;

							} else {

								A.x = coord[ index - 1 ].x;
								A.y = coord[ index - 1 ].y;

							}

							// B is current point (angle)
							B = coord[index];

							if ( undefined !== B ) {
								// p has to be between the points A and B which we interpolate
								applyColor = directionIsDown ? p.y <= A.y && p.y > B.y : p.y >= A.y && p.y < B.y;

								if (applyColor) {

									bColor = colors[ index + 1 ];

									aColor = colors[ index ];

									// below is simple linear interpolation
									t = Math.abs( p.y - A.y ) / ( A.y - B.y );

									// to make it faster, you can only calculate this if the y coord changes, the color is the same for points with the same y
									color = interpolateColors( aColor, bColor, t );

									f.vertexColors[ j ] = color;
								}

							} else if ( undefined === f.vertexColors[ j ] ) {
								colorIndex = directionIsDown ? colors.length - 1 : 0;
								f.vertexColors[ j ] = colors[ colorIndex ];

							}
						}

					}

				}
			};

			var parseProperty = function (node, line) {

				var parts = [], part, property = {}, fieldName;

				/**
				 * Expression for matching relevant information, such as a name or value, but not the separators
				 * @type {RegExp}
				 */
				var regex = /[^\s,\[\]]+/g;

				var point, index, angles, colors;

				while (null != ( part = regex.exec(line) ) ) {
					parts.push(part[0]);
				}

				fieldName = parts[0];


				// trigger several recorders
				switch (fieldName) {
					case 'skyAngle':
					case 'groundAngle':
						this.recordingFieldname = fieldName;
						this.isRecordingAngles = true;
						this.angles = [];
						break;
					case 'skyColor':
					case 'groundColor':
						this.recordingFieldname = fieldName;
						this.isRecordingColors = true;
						this.colors = [];
						break;
					case 'point':
						this.recordingFieldname = fieldName;
						this.isRecordingPoints = true;
						this.points = [];
						break;
					case 'coordIndex':
						this.recordingFieldname = fieldName;
						this.isRecordingFaces = true;
						this.indexes = [];
						break;
				}

				if (this.isRecordingFaces) {

					// the parts hold the indexes as strings
					if (parts.length > 0) {
						index = [];

						for (var ind = 0; ind < parts.length; ind ++) {

							// the part should either be positive integer or -1
							if (!/(-?\d+)/.test( parts[ind]) ) {
								continue;
							}

							// end of current face
							if (parts[ind] === "-1") {
								if (index.length > 0) {
									this.indexes.push(index);
								}

								// start new one
								index = [];
							} else {
								index.push(parseInt( parts[ind]) );
							}
						}

					}

					// end
					if (/]/.exec(line)) {
						this.isRecordingFaces = false;
						node.coordIndex = this.indexes;
					}

				} else if (this.isRecordingPoints) {

					while ( null !== ( parts = float3_pattern.exec(line) ) ) {
						point = {
							x: parseFloat(parts[1]),
							y: parseFloat(parts[2]),
							z: parseFloat(parts[3])
						};

						this.points.push(point);
					}

					// end
					if ( /]/.exec(line) ) {
						this.isRecordingPoints = false;
						node.points = this.points;
					}

				} else if ( this.isRecordingAngles ) {

					// the parts hold the angles as strings
					if ( parts.length > 0 ) {

						for ( var ind = 0; ind < parts.length; ind ++ ) {

							// the part should be a float
							if ( ! float_pattern.test( parts[ind] ) ) {
								continue;
							}

							this.angles.push( parseFloat( parts[ind] ) );
						}

					}

					// end
					if ( /]/.exec(line) ) {
						this.isRecordingAngles = false;
						node[this.recordingFieldname] = this.angles;
					}

				} else if (this.isRecordingColors) {

					while ( null !== ( parts = float3_pattern.exec(line) ) ) {

						color = {
							r: parseFloat(parts[1]),
							g: parseFloat(parts[2]),
							b: parseFloat(parts[3])
						};

						this.colors.push(color);

					}

					// end
					if (/]/.exec(line)) {
						this.isRecordingColors = false;
						node[this.recordingFieldname] = this.colors;
					}

				} else if ( parts[parts.length - 1] !== 'NULL' && fieldName !== 'children') {

					switch (fieldName) {

						case 'diffuseColor':
						case 'emissiveColor':
						case 'specularColor':
						case 'color':

							if (parts.length != 4) {
								console.warn('Invalid color format detected for ' + fieldName );
								break;
							}

							property = {
								r: parseFloat(parts[1]),
								g: parseFloat(parts[2]),
								b: parseFloat(parts[3])
							}

							break;

						case 'translation':
						case 'scale':
						case 'size':
							if (parts.length != 4) {
								console.warn('Invalid vector format detected for ' + fieldName);
								break;
							}

							property = {
								x: parseFloat(parts[1]),
								y: parseFloat(parts[2]),
								z: parseFloat(parts[3])
							}

							break;

						case 'radius':
						case 'topRadius':
						case 'bottomRadius':
						case 'height':
						case 'transparency':
						case 'shininess':
						case 'ambientIntensity':
							if (parts.length != 2) {
								console.warn('Invalid single float value specification detected for ' + fieldName);
								break;
							}

							property = parseFloat(parts[1]);

							break;

						case 'rotation':
							if (parts.length != 5) {
								console.warn('Invalid quaternion format detected for ' + fieldName);
								break;
							}

							property = {
								x: parseFloat(parts[1]),
								y: parseFloat(parts[2]),
								z: parseFloat(parts[3]),
								w: parseFloat(parts[4])
							}

							break;

						case 'ccw':
						case 'solid':
						case 'colorPerVertex':
						case 'convex':
							if (parts.length != 2) {
								console.warn('Invalid format detected for ' + fieldName);
								break;
							}

							property = parts[1] === 'TRUE' ? true : false;

							break;
					}

					node[fieldName] = property;
				}

				return property;
			};

			var getTree = function ( lines ) {

				var tree = { 'string': 'Scene', children: [] };
				var current = tree;
				var matches;
				var specification;

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

					var comment = '';

					var line = lines[ i ];

					// omit whitespace only lines
					if ( null !== ( result = /^\s+?$/g.exec( line ) ) ) {
						continue;
					}

					line = line.trim();

					// skip empty lines
					if (line === '') {
						continue;
					}

					if ( /#/.exec( line ) ) {

						var parts = line.split('#');

						// discard everything after the #, it is a comment
						line = parts[0];

						// well, let's also keep the comment
						comment = parts[1];
					}

					if ( matches = /([^\s]*){1}\s?{/.exec( line ) ) { // first subpattern should match the Node name

						var block = { 'nodeType' : matches[1], 'string': line, 'parent': current, 'children': [],'comment' : comment };
						current.children.push( block );
						current = block;

						if ( /}/.exec( line ) ) {
							// example: geometry Box { size 1 1 1 } # all on the same line
							specification = /{(.*)}/.exec( line )[ 1 ];

							// todo: remove once new parsing is complete?
							block.children.push( specification );

							parseProperty(current, specification);

							current = current.parent;

						}

					} else if ( /}/.exec( line ) ) {

						current = current.parent;

					} else if ( line !== '' ) {

						parseProperty(current, line);
						// todo: remove once new parsing is complete? we still do not parse geometry and appearance the new way
						current.children.push( line );

					}

				}

				return tree;
			}

			var parseNode = function ( data, parent ) {

				// console.log( data );

				if ( typeof data === 'string' ) {

					if ( /USE/.exec( data ) ) {

						var defineKey = /USE\s+?(\w+)/.exec( data )[ 1 ];

						if (undefined == defines[defineKey]) {
							console.warn(defineKey + ' is not defined.');
						} else {

							if ( /appearance/.exec( data ) && defineKey ) {

								parent.material = defines[ defineKey ].clone();

							} else if ( /geometry/.exec( data ) && defineKey ) {

								parent.geometry = defines[ defineKey ].clone();

								// the solid property is not cloned with clone(), is only needed for VRML loading, so we need to transfer it
								if (undefined !== defines[ defineKey ].solid && defines[ defineKey ].solid === false) {
									parent.geometry.solid = false;
									parent.material.side = THREE.DoubleSide;
								}

							} else if (defineKey) {

								var object = defines[ defineKey ].clone();
								parent.add( object );

							}

						}

					}

					return;

				}

				var object = parent;

				if ( 'Transform' === data.nodeType || 'Group' === data.nodeType ) {

					object = new THREE.Object3D();

					if ( /DEF/.exec( data.string ) ) {
						object.name = /DEF\s+(\w+)/.exec( data.string )[ 1 ];
						defines[ object.name ] = object;
					}

					if ( undefined !== data['translation'] ) {

						var t = data.translation;

						object.position.set(t.x, t.y, t.z);

					}

					if ( undefined !== data.rotation ) {

						var r = data.rotation;

						object.quaternion.setFromAxisAngle( new THREE.Vector3( r.x, r.y, r.z ), r.w );

					}

					if ( undefined !== data.scale ) {

						var s = data.scale;

						object.scale.set( s.x, s.y, s.z );

					}

					parent.add( object );

				} else if ( 'Shape' === data.nodeType ) {

					object = new THREE.Mesh();

					if ( /DEF/.exec( data.string ) ) {

						object.name = /DEF (\w+)/.exec( data.string )[ 1 ];

						defines[ object.name ] = object;
					}

					parent.add( object );

				} else if ( 'Background' === data.nodeType ) {

					var segments = 20;

					// sky (full sphere):

					var radius = 2e4;

					var skyGeometry = new THREE.SphereGeometry( radius, segments, segments );
					var skyMaterial = new THREE.MeshBasicMaterial( { fog: false, side: THREE.BackSide } );

					if ( data.skyColor.length > 1 ) {

						paintFaces( skyGeometry, radius, data.skyAngle, data.skyColor, true );

						skyMaterial.vertexColors = THREE.VertexColors

					} else {

						var color = data.skyColor[ 0 ];
						skyMaterial.color.setRGB( color.r, color.b, color.g );

					}

					scene.add( new THREE.Mesh( skyGeometry, skyMaterial ) );

					// ground (half sphere):

					if ( data.groundColor !== undefined ) {

						radius = 1.2e4;

						var groundGeometry = new THREE.SphereGeometry( radius, segments, segments, 0, 2 * Math.PI, 0.5 * Math.PI, 1.5 * Math.PI );
						var groundMaterial = new THREE.MeshBasicMaterial( { fog: false, side: THREE.BackSide, vertexColors: THREE.VertexColors } );

						paintFaces( groundGeometry, radius, data.groundAngle, data.groundColor, false );

						scene.add( new THREE.Mesh( groundGeometry, groundMaterial ) );

					}

				} else if ( /geometry/.exec( data.string ) ) {

					if ( 'Box' === data.nodeType ) {

						var s = data.size;

						parent.geometry = new THREE.BoxGeometry( s.x, s.y, s.z );

					} else if ( 'Cylinder' === data.nodeType ) {

						parent.geometry = new THREE.CylinderGeometry( data.radius, data.radius, data.height );

					} else if ( 'Cone' === data.nodeType ) {

						parent.geometry = new THREE.CylinderGeometry( data.topRadius, data.bottomRadius, data.height );

					} else if ( 'Sphere' === data.nodeType ) {

						parent.geometry = new THREE.SphereGeometry( data.radius );

					} else if ( 'IndexedFaceSet' === data.nodeType ) {

						var geometry = new THREE.Geometry();

						var indexes;

						for ( var i = 0, j = data.children.length; i < j; i ++ ) {

							var child = data.children[ i ];

							var vec;

							if ( 'Coordinate' === child.nodeType ) {

								for ( var k = 0, l = child.points.length; k < l; k ++ ) {

									var point = child.points[ k ];

									vec = new THREE.Vector3( point.x, point.y, point.z );

									geometry.vertices.push( vec );
								}

								break;
							}
						}

						var skip = 0;

						// read this: http://math.hws.edu/eck/cs424/notes2013/16_Threejs_Advanced.html
						for ( var i = 0, j = data.coordIndex.length; i < j; i ++ ) {

							indexes = data.coordIndex[i];

							// vrml support multipoint indexed face sets (more then 3 vertices). You must calculate the composing triangles here
							skip = 0;

							// todo: this is the time to check if the faces are ordered ccw or not (cw)

							// Face3 only works with triangles, but IndexedFaceSet allows shapes with more then three vertices, build them of triangles
							while ( indexes.length >= 3 && skip < ( indexes.length - 2 ) ) {

								var face = new THREE.Face3(
									indexes[0],
									indexes[skip + 1],
									indexes[skip + 2],
									null // normal, will be added later
									// todo: pass in the color, if a color index is present
								);

								skip ++;

								geometry.faces.push( face );

							}


						}

						if ( false === data.solid ) {
							parent.material.side = THREE.DoubleSide;
						}

						// we need to store it on the geometry for use with defines
						geometry.solid = data.solid;

						geometry.computeFaceNormals();
						//geometry.computeVertexNormals(); // does not show
						geometry.computeBoundingSphere();

						// see if it's a define
						if ( /DEF/.exec( data.string ) ) {
							geometry.name = /DEF (\w+)/.exec( data.string )[ 1 ];
							defines[ geometry.name ] = geometry;
						}

						parent.geometry = geometry;
					}

					return;

				} else if ( /appearance/.exec( data.string ) ) {

					for ( var i = 0; i < data.children.length; i ++ ) {

						var child = data.children[ i ];

						if ( 'Material' === child.nodeType ) {
							var material = new THREE.MeshPhongMaterial();

							if ( undefined !== child.diffuseColor ) {

								var d = child.diffuseColor;

								material.color.setRGB( d.r, d.g, d.b );

							}

							if ( undefined !== child.emissiveColor ) {

								var e = child.emissiveColor;

								material.emissive.setRGB( e.r, e.g, e.b );

							}

							if ( undefined !== child.specularColor ) {

								var s = child.specularColor;

								material.specular.setRGB( s.r, s.g, s.b );

							}

							if ( undefined !== child.transparency ) {

								var t = child.transparency;

								// transparency is opposite of opacity
								material.opacity = Math.abs( 1 - t );

								material.transparent = true;

							}

							if ( /DEF/.exec( data.string ) ) {

								material.name = /DEF (\w+)/.exec( data.string )[ 1 ];

								defines[ material.name ] = material;

							}

							parent.material = material;

							// material found, stop looping
							break;
						}

					}

					return;

				}

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

					var child = data.children[ i ];

					parseNode( data.children[ i ], object );

				}

			}

			parseNode( getTree( lines ), scene );

		};

		var scene = new THREE.Scene();

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

		var header = lines.shift();

		if ( /V1.0/.exec( header ) ) {

			parseV1( lines, scene );

		} else if ( /V2.0/.exec( header ) ) {

			parseV2( lines, scene );

		}

		return scene;

	}

};

THREE.EventDispatcher.prototype.apply( THREE.VRMLLoader.prototype );

