/**
 * @author sunag / http://www.sunag.com.br/
 */

THREE.NodeBuilder = function ( material ) {

	this.material = material;

	this.caches = [];
	this.slots = [];

	this.keywords = {};

	this.parsing = false;
	this.optimize = true;

	this.update();

};

THREE.NodeBuilder.type = {
	float: 'fv1',
	vec2: 'v2',
	vec3: 'v3',
	vec4: 'v4',
	mat4: 'v4',
	int: 'iv1'
};

THREE.NodeBuilder.constructors = [
	'float',
	'vec2',
	'vec3',
	'vec4'
];

THREE.NodeBuilder.elements = [
	'x',
	'y',
	'z',
	'w'
];

THREE.NodeBuilder.prototype = {

	constructor: THREE.NodeBuilder,

	addCache: function ( name, requires ) {

		this.caches.push( {
			name: name || '',
			requires: requires || {}
		} );

		return this.update();

	},

	removeCache: function () {

		this.caches.pop();

		return this.update();

	},

	addSlot: function ( name ) {

		this.slots.push( {
			name: name || ''
		} );

		return this.update();

	},

	removeSlot: function () {

		this.slots.pop();

		return this.update();

	},

	isCache: function ( name ) {

		var i = this.caches.length;

		while ( i -- ) {

			if ( this.caches[ i ].name == name ) return true;

		}

		return false;

	},

	isSlot: function ( name ) {

		var i = this.slots.length;

		while ( i -- ) {

			if ( this.slots[ i ].name == name ) return true;

		}

		return false;

	},

	update: function () {

		var cache = this.caches[ this.caches.length - 1 ];
		var slot = this.slots[ this.slots.length - 1 ];

		this.slot = slot ? slot.name : '';
		this.cache = cache ? cache.name : '';
		this.requires = cache ? cache.requires : {};

		return this;

	},

	require: function ( name, node ) {

		this.requires[ name ] = node;

		return this;

	},

	include: function ( node, parent, source ) {

		this.material.include( this, node, parent, source );

		return this;

	},

	colorToVector: function ( color ) {

		return color.replace( 'r', 'x' ).replace( 'g', 'y' ).replace( 'b', 'z' ).replace( 'a', 'w' );

	},

	getConstructorFromLength: function ( len ) {

		return THREE.NodeBuilder.constructors[ len - 1 ];

	},

	getFormatName: function ( format ) {

		return format.replace( /c/g, 'v3' ).replace( /fv1/g, 'v1' ).replace( /iv1/g, 'i' );

	},

	isFormatMatrix: function ( format ) {

		return /^m/.test( format );

	},

	getFormatLength: function ( format ) {

		return parseInt( this.getFormatName( format ).substr( 1 ) );

	},

	getFormatFromLength: function ( len ) {

		if ( len == 1 ) return 'fv1';

		return 'v' + len;

	},

	format: function ( code, from, to ) {

		var format = this.getFormatName( to + '=' + from );

		switch ( format ) {

			case 'v1=v2': return code + '.x';
			case 'v1=v3': return code + '.x';
			case 'v1=v4': return code + '.x';
			case 'v1=i': return 'float(' + code + ')';

			case 'v2=v1': return 'vec2(' + code + ')';
			case 'v2=v3': return code + '.xy';
			case 'v2=v4': return code + '.xy';
			case 'v2=i': return 'vec2(float(' + code + '))';

			case 'v3=v1': return 'vec3(' + code + ')';
			case 'v3=v2': return 'vec3(' + code + ',0.0)';
			case 'v3=v4': return code + '.xyz';
			case 'v3=i': return 'vec2(float(' + code + '))';

			case 'v4=v1': return 'vec4(' + code + ')';
			case 'v4=v2': return 'vec4(' + code + ',0.0,1.0)';
			case 'v4=v3': return 'vec4(' + code + ',1.0)';
			case 'v4=i': return 'vec4(float(' + code + '))';

			case 'i=v1': return 'int(' + code + ')';
			case 'i=v2': return 'int(' + code + '.x)';
			case 'i=v3': return 'int(' + code + '.x)';
			case 'i=v4': return 'int(' + code + '.x)';

		}

		return code;

	},

	getTypeByFormat: function ( format ) {

		return THREE.NodeBuilder.type[ format ] || format;

	},

	getUuid: function ( uuid, useCache ) {

		useCache = useCache !== undefined ? useCache : true;

		if ( useCache && this.cache ) uuid = this.cache + '-' + uuid;

		return uuid;

	},

	getElementByIndex: function ( index ) {

		return THREE.NodeBuilder.elements[ index ];

	},

	getIndexByElement: function ( elm ) {

		return THREE.NodeBuilder.elements.indexOf( elm );

	},

	isShader: function ( shader ) {

		return this.shader == shader;

	},

	setShader: function ( shader ) {

		this.shader = shader;

		return this;

	}
};
