/**
 * @author alteredq / http://alteredqualia.com/
 */

THREE.Loader = function ( showStatus ) {

	this.showStatus = showStatus;
	this.statusDomElement = showStatus ? THREE.Loader.prototype.addStatusElement() : null;

	this.imageLoader = new THREE.ImageLoader();

	this.onLoadStart = function () {};
	this.onLoadProgress = function () {};
	this.onLoadComplete = function () {};

};

THREE.Loader.prototype = {

	constructor: THREE.Loader,

	crossOrigin: undefined,

	addStatusElement: function () {

		var e = document.createElement( 'div' );

		e.style.position = 'absolute';
		e.style.right = '0px';
		e.style.top = '0px';
		e.style.fontSize = '0.8em';
		e.style.textAlign = 'left';
		e.style.background = 'rgba(0,0,0,0.25)';
		e.style.color = '#fff';
		e.style.width = '120px';
		e.style.padding = '0.5em 0.5em 0.5em 0.5em';
		e.style.zIndex = 1000;

		e.innerHTML = 'Loading ...';

		return e;

	},

	updateProgress: function ( progress ) {

		var message = 'Loaded ';

		if ( progress.total ) {

			message += ( 100 * progress.loaded / progress.total ).toFixed( 0 ) + '%';


		} else {

			message += ( progress.loaded / 1024 ).toFixed( 2 ) + ' KB';

		}

		this.statusDomElement.innerHTML = message;

	},

	extractUrlBase: function ( url ) {

		var parts = url.split( '/' );

		if ( parts.length === 1 ) return './';

		parts.pop();

		return parts.join( '/' ) + '/';

	},

	initMaterials: function ( materials, texturePath ) {

		var array = [];

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

			array[ i ] = this.createMaterial( materials[ i ], texturePath );

		}

		return array;

	},

	needsTangents: function ( materials ) {

		for ( var i = 0, il = materials.length; i < il; i ++ ) {

			var m = materials[ i ];

			if ( m instanceof THREE.ShaderMaterial ) return true;

		}

		return false;

	},

	createMaterial: function ( m, texturePath ) {

		var scope = this;

		function nearest_pow2( n ) {

			var l = Math.log( n ) / Math.LN2;
			return Math.pow( 2, Math.round(  l ) );

		}

		function create_texture( where, name, sourceFile, repeat, offset, wrap, anisotropy ) {

			var fullPath = texturePath + sourceFile;

			var texture;

			var loader = THREE.Loader.Handlers.get( fullPath );

			if ( loader !== null ) {

				texture = loader.load( fullPath );

			} else {

				texture = new THREE.Texture();

				loader = scope.imageLoader;
				loader.crossOrigin = scope.crossOrigin;
				loader.load( fullPath, function ( image ) {

					if ( THREE.Math.isPowerOfTwo( image.width ) === false ||
						 THREE.Math.isPowerOfTwo( image.height ) === false ) {

						var width = nearest_pow2( image.width );
						var height = nearest_pow2( image.height );

						var canvas = document.createElement( 'canvas' );
						canvas.width = width;
						canvas.height = height;

						var context = canvas.getContext( '2d' );
						context.drawImage( image, 0, 0, width, height );

						texture.image = canvas;

					} else {

						texture.image = image;

					}

					texture.needsUpdate = true;

				} );

			}

			texture.sourceFile = sourceFile;

			if ( repeat ) {

				texture.repeat.set( repeat[ 0 ], repeat[ 1 ] );

				if ( repeat[ 0 ] !== 1 ) texture.wrapS = THREE.RepeatWrapping;
				if ( repeat[ 1 ] !== 1 ) texture.wrapT = THREE.RepeatWrapping;

			}

			if ( offset ) {

				texture.offset.set( offset[ 0 ], offset[ 1 ] );

			}

			if ( wrap ) {

				var wrapMap = {
					'repeat': THREE.RepeatWrapping,
					'mirror': THREE.MirroredRepeatWrapping
				};

				if ( wrapMap[ wrap[ 0 ] ] !== undefined ) texture.wrapS = wrapMap[ wrap[ 0 ] ];
				if ( wrapMap[ wrap[ 1 ] ] !== undefined ) texture.wrapT = wrapMap[ wrap[ 1 ] ];

			}

			if ( anisotropy ) {

				texture.anisotropy = anisotropy;

			}

			where[ name ] = texture;

		}

		function rgb2hex( rgb ) {

			return ( rgb[ 0 ] * 255 << 16 ) + ( rgb[ 1 ] * 255 << 8 ) + rgb[ 2 ] * 255;

		}

		// defaults

		var mtype = 'MeshLambertMaterial';
		var mpars = { color: 0xeeeeee, opacity: 1.0, map: null, lightMap: null, normalMap: null, bumpMap: null, wireframe: false };

		// parameters from model file

		if ( m.shading ) {

			var shading = m.shading.toLowerCase();

			if ( shading === 'phong' ) mtype = 'MeshPhongMaterial';
			else if ( shading === 'basic' ) mtype = 'MeshBasicMaterial';

		}

		if ( m.blending !== undefined && THREE[ m.blending ] !== undefined ) {

			mpars.blending = THREE[ m.blending ];

		}

		if ( m.transparent !== undefined ) {

			mpars.transparent = m.transparent;

		}

		if ( m.opacity !== undefined && m.opacity < 1.0 ) {

			mpars.transparent = true;

		}

		if ( m.depthTest !== undefined ) {

			mpars.depthTest = m.depthTest;

		}

		if ( m.depthWrite !== undefined ) {

			mpars.depthWrite = m.depthWrite;

		}

		if ( m.visible !== undefined ) {

			mpars.visible = m.visible;

		}

		if ( m.flipSided !== undefined ) {

			mpars.side = THREE.BackSide;

		}

		if ( m.doubleSided !== undefined ) {

			mpars.side = THREE.DoubleSide;

		}

		if ( m.wireframe !== undefined ) {

			mpars.wireframe = m.wireframe;

		}

		if ( m.vertexColors !== undefined ) {

			if ( m.vertexColors === 'face' ) {

				mpars.vertexColors = THREE.FaceColors;

			} else if ( m.vertexColors ) {

				mpars.vertexColors = THREE.VertexColors;

			}

		}

		// colors

		if ( m.colorDiffuse ) {

			mpars.color = rgb2hex( m.colorDiffuse );

		} else if ( m.DbgColor ) {

			mpars.color = m.DbgColor;

		}

		if ( m.colorSpecular ) {

			mpars.specular = rgb2hex( m.colorSpecular );

		}

		if ( m.colorEmissive ) {

			mpars.emissive = rgb2hex( m.colorEmissive );

		}

		// modifiers

		if ( m.transparency !== undefined ) {

			console.warn( 'THREE.Loader: transparency has been renamed to opacity' );
			m.opacity = m.transparency;

		}

		if ( m.opacity !== undefined ) {

			mpars.opacity = m.opacity;

		}

		if ( m.specularCoef ) {

			mpars.shininess = m.specularCoef;

		}

		// textures

		if ( m.mapDiffuse && texturePath ) {

			create_texture( mpars, 'map', m.mapDiffuse, m.mapDiffuseRepeat, m.mapDiffuseOffset, m.mapDiffuseWrap, m.mapDiffuseAnisotropy );

		}

		if ( m.mapLight && texturePath ) {

			create_texture( mpars, 'lightMap', m.mapLight, m.mapLightRepeat, m.mapLightOffset, m.mapLightWrap, m.mapLightAnisotropy );

		}

		if ( m.mapAO && texturePath ) {

			create_texture( mpars, 'aoMap', m.mapAO, m.mapAORepeat, m.mapAOOffset, m.mapAOWrap, m.mapAOAnisotropy );

		}

		if ( m.mapBump && texturePath ) {

			create_texture( mpars, 'bumpMap', m.mapBump, m.mapBumpRepeat, m.mapBumpOffset, m.mapBumpWrap, m.mapBumpAnisotropy );

		}

		if ( m.mapNormal && texturePath ) {

			create_texture( mpars, 'normalMap', m.mapNormal, m.mapNormalRepeat, m.mapNormalOffset, m.mapNormalWrap, m.mapNormalAnisotropy );

		}

		if ( m.mapSpecular && texturePath ) {

			create_texture( mpars, 'specularMap', m.mapSpecular, m.mapSpecularRepeat, m.mapSpecularOffset, m.mapSpecularWrap, m.mapSpecularAnisotropy );

		}

		if ( m.mapAlpha && texturePath ) {

			create_texture( mpars, 'alphaMap', m.mapAlpha, m.mapAlphaRepeat, m.mapAlphaOffset, m.mapAlphaWrap, m.mapAlphaAnisotropy );

		}

		//

		if ( m.mapBumpScale ) {

			mpars.bumpScale = m.mapBumpScale;

		}

		if ( m.mapNormalFactor ) {

			mpars.normalScale = new THREE.Vector2( m.mapNormalFactor, m.mapNormalFactor );

		}

		var material = new THREE[ mtype ]( mpars );

		if ( m.DbgName !== undefined ) material.name = m.DbgName;

		return material;

	}

};

THREE.Loader.Handlers = {

	handlers: [],

	add: function ( regex, loader ) {

		this.handlers.push( regex, loader );

	},

	get: function ( file ) {

		for ( var i = 0, l = this.handlers.length; i < l; i += 2 ) {

			var regex = this.handlers[ i ];
			var loader  = this.handlers[ i + 1 ];

			if ( regex.test( file ) ) {

				return loader;

			}

		}

		return null;

	}

};