'use strict';

/**
 * THREE.GCodeLoader is used to load gcode files usually used for 3D printing or CNC applications.
 *
 * Gcode files are composed by commands used by machines to create objects.
 *
 * @class THREE.GCodeLoader
 * @param {Manager} manager Loading manager.
 * @author tentone
 * @author joewalnes
 */
THREE.GCodeLoader = function ( manager ) {

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

}

THREE.GCodeLoader.prototype.load = function ( url, onLoad, onProgress, onError ) {

	var self = this;

	var loader = new THREE.FileLoader( self.manager );
	loader.load( url, function ( text ) {

		onLoad( self.parse( text ) );

	}, onProgress, onError );

};

THREE.GCodeLoader.prototype.parse = function ( data ) {

	var currentState = { x: 0, y: 0, z: 0, e: 0, f: 0, extruding: false };
	var currentLayer = undefined;
	var relative = false;

	var box = new THREE.Box3();
	var layers = [];
	
	var pathMaterial = new THREE.LineBasicMaterial( { color: 0xFFFF00 } );
	pathMaterial.name = 'path';

	var extrudingMaterial = new THREE.LineBasicMaterial( { color: 0xFFFFFF } );
	extrudingMaterial.name = 'extruded';

	function newLayer( line ) {

		currentLayer = { lines: [], currentLayer: layers.length, z: line.z };
		layers.push( currentLayer );

	}

	function getLineGroup( line ) {

		if ( currentLayer === undefined ) {
			newLayer( line );
		}

		var grouptype = line.extruding ? 1 : 0;

		if ( currentLayer.lines[ grouptype ] === undefined ) {

			currentLayer.lines[ grouptype ] = {

				type: grouptype,
				feed: line.e,
				extruding: line.extruding,
				geometry: new THREE.Geometry(),
				material: line.extruding ? extrudingMaterial : pathMaterial,
				segmentCount: 0
				
			};

		}

		return currentLayer.lines[ grouptype ];
	}

	//Create lie segment between p1 and p2
	function addSegment( p1, p2 ) {

		var group = getLineGroup( p2 );
		var geometry = group.geometry;
		
		group.segmentCount ++;
		geometry.vertices.push( new THREE.Vector3( p1.x, p1.y, p1.z ) );
		geometry.vertices.push( new THREE.Vector3( p2.x, p2.y, p2.z ) );

		if ( p2.extruding ) {

			box.min.set( Math.min( box.min.x, p2.x ), Math.min( box.min.y, p2.y ), Math.min( box.min.z, p2.z ) );
			box.max.set( Math.max( box.max.x, p2.x ), Math.max( box.max.y, p2.y ), Math.max( box.max.z, p2.z ) );
		
		}

	}

	function delta( v1, v2 ) {

		return relative ? v2 : v2 - v1;

	}

	function absolute ( v1, v2 ) {

		return relative ? v1 + v2 : v2;

	}

	var lines = data.replace( /;.+/g,'' ).split( '\n' );

	for ( var i = 0; i < lines.length; i ++ ) {
		var tokens = lines[ i ].split( ' ' );
		var cmd = tokens[0].toUpperCase();

		//Argumments
		var args = {};
		tokens.splice( 1 ).forEach( function ( token ) { 

			if ( token[0] !== undefined ) {

				var key = token[0].toLowerCase(); 
				var value = parseFloat( token.substring( 1 ) ); 
				args[ key ] = value;

			}

		} ); 

		//Process commands
		//G0/G1 – Linear Movement
		if ( cmd === 'G0' || cmd === 'G1' ) {

			var line = {
				x: args.x !== undefined ? absolute( currentState.x, args.x ) : currentState.x,
				y: args.y !== undefined ? absolute( currentState.y, args.y ) : currentState.y,
				z: args.z !== undefined ? absolute( currentState.z, args.z ) : currentState.z,
				e: args.e !== undefined ? absolute( currentState.e, args.e ) : currentState.e,
				f: args.f !== undefined ? absolute( currentState.f, args.f ) : currentState.f,
			};

			//Layer change detection is or made by watching Z, it's made by watching when we extrude at a new Z position
			if ( delta( currentState.e, line.e ) > 0 ) {

				line.extruding = delta( currentState.e, line.e ) > 0;

				if ( currentLayer == undefined || line.z != currentLayer.z ) {
					newLayer( line );
				}

			}

			addSegment( currentState, line );
			currentState = line;
		}
		//G2/G3 - Arc Movement ( G2 clock wise and G3 counter clock wise )
		else if ( cmd === 'G2' || cmd === 'G3' ) {

			console.warn( 'THREE.GCodeLoader: Arc command not supported' );
		}
		//G90: Set to Absolute Positioning
		else if ( cmd === 'G90' ) {

			relative = false;

		}
		//G91: Set to Relative Positioning
		else if ( cmd === 'G91' ) {

			relative = true;

		}
		//G92: Set Position
		else if ( cmd === 'G92' ) {

			var line = currentState;
			line.x = args.x !== undefined ? args.x : line.x;
			line.y = args.y !== undefined ? args.y : line.y;
			line.z = args.z !== undefined ? args.z : line.z;
			line.e = args.e !== undefined ? args.e : line.e;
			currentState = line;

		}
		else {

			console.warn( 'THREE.GCodeLoader: Command not supported:' + cmd );

		}
	}

	var object = new THREE.Object3D();
	object.name = 'gcode';

	for ( var i = 0; i < layers.length; i ++ ) {
		var layer = layers[ i ];

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

			var line = layer.lines[ j ];

			if ( line !== undefined ) {
				var segments = new THREE.LineSegments( line.geometry, line.material );
				segments.name = 'layer' + i;
				object.add( segments );
			}
		}
	}

	return object;
};