/**
 * @author Wei Meng / http://about.me/menway
 *
 * Description: A THREE loader for PLY ASCII files (known as the Polygon File Format or the Stanford Triangle Format).
 *
 *
 * Limitations: ASCII decoding assumes file is UTF-8.
 *
 * Usage:
 *	var loader = new THREE.PLYLoader();
 *	loader.load('./models/ply/ascii/dolphins.ply', function (geometry) {
 *
 *		scene.add( new THREE.Mesh( geometry ) );
 *
 *	} );
 *
 * If the PLY file uses non standard property names, they can be mapped while
 * loading. For example, the following maps the properties
 * “diffuse_(red|green|blue)” in the file to standard color names.
 *
 * loader.setPropertyNameMapping( {
 *	diffuse_red: 'red',
 *	diffuse_green: 'green',
 *	diffuse_blue: 'blue'
 * } );
 *
 */


THREE.PLYLoader = function () {

	this.propertyNameMapping = {};

};

THREE.PLYLoader.prototype = {

	constructor: THREE.PLYLoader,

	setPropertyNameMapping: function ( mapping ) {

		this.propertyNameMapping = mapping;

	},

	load: function ( url, callback ) {

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

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

			var geometry = scope.parse( event.target.response );

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

			if ( callback ) callback( geometry );

		}, 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.responseType = "arraybuffer";
		request.send( null );

	},

	bin2str: function (buf) {

		var array_buffer = new Uint8Array(buf);
		var str = '';
		for (var i = 0; i < buf.byteLength; i ++) {
			str += String.fromCharCode(array_buffer[i]); // implicitly assumes little-endian
		}

		return str;

	},

	isASCII: function( data ) {

		var header = this.parseHeader( this.bin2str( data ) );

		return header.format === "ascii";

	},

	parse: function ( data ) {

		if ( data instanceof ArrayBuffer ) {

			return this.isASCII( data )
				? this.parseASCII( this.bin2str( data ) )
				: this.parseBinary( data );

		} else {

			return this.parseASCII( data );

		}

	},

	parseHeader: function ( data ) {

		var patternHeader = /ply([\s\S]*)end_header\s/;
		var headerText = "";
		var headerLength = 0;
		var result = patternHeader.exec( data );
		if ( result !== null ) {
			headerText = result [ 1 ];
			headerLength = result[ 0 ].length;
		}

		var header = {
			comments: [],
			elements: [],
			headerLength: headerLength
		};

		var lines = headerText.split( '\n' );
		var currentElement = undefined;
		var lineType, lineValues;

		function make_ply_element_property( propertValues, propertyNameMapping ) {

			var property = {
				type: propertValues[ 0 ]
			};

			if ( property.type === 'list' ) {

				property.name = propertValues[ 3 ];
				property.countType = propertValues[ 1 ];
				property.itemType = propertValues[ 2 ];

			} else {

				property.name = propertValues[ 1 ];

			}

			if ( property.name in propertyNameMapping ) {

				property.name = propertyNameMapping[ property.name ];

			}

			return property;

		}

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

			var line = lines[ i ];
			line = line.trim()
			if ( line === "" ) { continue; }
			lineValues = line.split( /\s+/ );
			lineType = lineValues.shift()
			line = lineValues.join(" ")

			switch ( lineType ) {

			case "format":

				header.format = lineValues[0];
				header.version = lineValues[1];

				break;

			case "comment":

				header.comments.push(line);

				break;

			case "element":

				if ( !(currentElement === undefined) ) {

					header.elements.push(currentElement);

				}

				currentElement = Object();
				currentElement.name = lineValues[0];
				currentElement.count = parseInt( lineValues[1] );
				currentElement.properties = [];

				break;

			case "property":

				currentElement.properties.push( make_ply_element_property( lineValues, this.propertyNameMapping ) );

				break;


			default:

				console.log("unhandled", lineType, lineValues);

			}

		}

		if ( !(currentElement === undefined) ) {

			header.elements.push(currentElement);

		}

		return header;

	},

	parseASCIINumber: function ( n, type ) {

		switch ( type ) {

		case 'char': case 'uchar': case 'short': case 'ushort': case 'int': case 'uint':
		case 'int8': case 'uint8': case 'int16': case 'uint16': case 'int32': case 'uint32':

			return parseInt( n );

		case 'float': case 'double': case 'float32': case 'float64':

			return parseFloat( n );

		}

	},

	parseASCIIElement: function ( properties, line ) {

		var values = line.split( /\s+/ );

		var element = Object();

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

			if ( properties[i].type === "list" ) {

				var list = [];
				var n = this.parseASCIINumber( values.shift(), properties[i].countType );

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

					list.push( this.parseASCIINumber( values.shift(), properties[i].itemType ) );

				}

				element[ properties[i].name ] = list;

			} else {

				element[ properties[i].name ] = this.parseASCIINumber( values.shift(), properties[i].type );

			}

		}

		return element;

	},

	parseASCII: function ( data ) {

		// PLY ascii format specification, as per http://en.wikipedia.org/wiki/PLY_(file_format)

		var geometry = new THREE.Geometry();

		var result;

		var header = this.parseHeader( data );

		var patternBody = /end_header\s([\s\S]*)$/;
		var body = "";
		if ( ( result = patternBody.exec( data ) ) !== null ) {
			body = result [ 1 ];
		}

		var lines = body.split( '\n' );
		var currentElement = 0;
		var currentElementCount = 0;
		geometry.useColor = false;

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

			var line = lines[ i ];
			line = line.trim()
			if ( line === "" ) { continue; }

			if ( currentElementCount >= header.elements[currentElement].count ) {

				currentElement ++;
				currentElementCount = 0;

			}

			var element = this.parseASCIIElement( header.elements[currentElement].properties, line );

			this.handleElement( geometry, header.elements[currentElement].name, element );

			currentElementCount ++;

		}

		return this.postProcess( geometry );

	},

	postProcess: function ( geometry ) {

		if ( geometry.useColor ) {

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

				geometry.faces[i].vertexColors = [
					geometry.colors[geometry.faces[i].a],
					geometry.colors[geometry.faces[i].b],
					geometry.colors[geometry.faces[i].c]
				];

			}

			geometry.elementsNeedUpdate = true;

		}

		geometry.computeBoundingSphere();

		return geometry;

	},

	handleElement: function ( geometry, elementName, element ) {

		if ( elementName === "vertex" ) {

			geometry.vertices.push(
				new THREE.Vector3( element.x, element.y, element.z )
			);

			if ( 'red' in element && 'green' in element && 'blue' in element ) {

				geometry.useColor = true;

				var color = new THREE.Color();
				color.setRGB( element.red / 255.0, element.green / 255.0, element.blue / 255.0 );
				geometry.colors.push( color );

			}

		} else if ( elementName === "face" ) {

			var vertex_indices = element.vertex_indices;

			if ( vertex_indices.length === 3 ) {

				geometry.faces.push(
					new THREE.Face3( vertex_indices[ 0 ], vertex_indices[ 1 ], vertex_indices[ 2 ] )
				);

			} else if ( vertex_indices.length === 4 ) {

				geometry.faces.push(
					new THREE.Face3( vertex_indices[ 0 ], vertex_indices[ 1 ], vertex_indices[ 3 ] ),
					new THREE.Face3( vertex_indices[ 1 ], vertex_indices[ 2 ], vertex_indices[ 3 ] )
				);

			}

		}

	},

	binaryRead: function ( dataview, at, type, little_endian ) {

		switch ( type ) {

			// corespondences for non-specific length types here match rply:
		case 'int8':		case 'char':	 return [ dataview.getInt8( at ), 1 ];

		case 'uint8':		case 'uchar':	 return [ dataview.getUint8( at ), 1 ];

		case 'int16':		case 'short':	 return [ dataview.getInt16( at, little_endian ), 2 ];

		case 'uint16':	case 'ushort': return [ dataview.getUint16( at, little_endian ), 2 ];

		case 'int32':		case 'int':		 return [ dataview.getInt32( at, little_endian ), 4 ];

		case 'uint32':	case 'uint':	 return [ dataview.getUint32( at, little_endian ), 4 ];

		case 'float32': case 'float':	 return [ dataview.getFloat32( at, little_endian ), 4 ];

		case 'float64': case 'double': return [ dataview.getFloat64( at, little_endian ), 8 ];

		}

	},

	binaryReadElement: function ( dataview, at, properties, little_endian ) {

		var element = Object();
		var result, read = 0;

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

			if ( properties[i].type === "list" ) {

				var list = [];

				result = this.binaryRead( dataview, at + read, properties[i].countType, little_endian );
				var n = result[0];
				read += result[1];

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

					result = this.binaryRead( dataview, at + read, properties[i].itemType, little_endian );
					list.push( result[0] );
					read += result[1];

				}

				element[ properties[i].name ] = list;

			} else {

				result = this.binaryRead( dataview, at + read, properties[i].type, little_endian );
				element[ properties[i].name ] = result[0];
				read += result[1];

			}

		}

		return [ element, read ];

	},

	parseBinary: function ( data ) {

		var geometry = new THREE.Geometry();

		var header = this.parseHeader( this.bin2str( data ) );
		var little_endian = (header.format === "binary_little_endian");
		var body = new DataView( data, header.headerLength );
		var result, loc = 0;

		for ( var currentElement = 0; currentElement < header.elements.length; currentElement ++ ) {

			for ( var currentElementCount = 0; currentElementCount < header.elements[currentElement].count; currentElementCount ++ ) {

				result = this.binaryReadElement( body, loc, header.elements[currentElement].properties, little_endian );
				loc += result[1];
				var element = result[0];

				this.handleElement( geometry, header.elements[currentElement].name, element );

			}

		}

		return this.postProcess( geometry );

	}

};

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