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

THREE.Loader = function ( showStatus ) {

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

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

};

THREE.Loader.prototype = {

	constructor: THREE.Loader,

	crossOrigin: 'anonymous',

	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( '/' );
		parts.pop();
		return ( parts.length < 1 ? '.' : parts.join( '/' ) ) + '/';

	},

	initMaterials: function ( materials, texturePath ) {

		var array = [];

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

			array[ i ] = THREE.Loader.prototype.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 _this = this;

		function is_pow2( n ) {

			var l = Math.log( n ) / Math.LN2;
			return Math.floor( l ) == l;

		}

		function nearest_pow2( n ) {

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

		}

		function load_image( where, url ) {

			var image = new Image();

			image.onload = function () {

				if ( !is_pow2( this.width ) || !is_pow2( this.height ) ) {

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

					where.image.width = width;
					where.image.height = height;
					where.image.getContext( '2d' ).drawImage( this, 0, 0, width, height );

				} else {

					where.image = this;

				}

				where.needsUpdate = true;

			};

			image.crossOrigin = _this.crossOrigin;
			image.src = url;

		}

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

			var isCompressed = /\.dds$/i.test( sourceFile );
			var fullPath = texturePath + "/" + sourceFile;

			if ( isCompressed ) {

				var texture = THREE.ImageUtils.loadCompressedTexture( fullPath );

				where[ name ] = texture;

			} else {

				var texture = document.createElement( 'canvas' );

				where[ name ] = new THREE.Texture( texture );

			}

			where[ name ].sourceFile = sourceFile;

			if( repeat ) {

				where[ name ].repeat.set( repeat[ 0 ], repeat[ 1 ] );

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

			}

			if ( offset ) {

				where[ name ].offset.set( offset[ 0 ], offset[ 1 ] );

			}

			if ( wrap ) {

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

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

			}

			if ( anisotropy ) {

				where[ name ].anisotropy = anisotropy;

			}

			if ( ! isCompressed ) {

				load_image( where[ name ], fullPath );

			}

		}

		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 || m.opacity < 1.0 ) {

			mpars.transparent = m.transparent;

		}

		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.colorAmbient ) {

			mpars.ambient = rgb2hex( m.colorAmbient );

		}

		// modifiers

		if ( m.transparency ) {

			mpars.opacity = m.transparency;

		}

		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.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.mapBumpScale ) {

			mpars.bumpScale = m.mapBumpScale;

		}

		// special case for normal mapped material

		if ( m.mapNormal ) {

			var shader = THREE.ShaderLib[ "normalmap" ];
			var uniforms = THREE.UniformsUtils.clone( shader.uniforms );

			uniforms[ "tNormal" ].value = mpars.normalMap;

			if ( m.mapNormalFactor ) {

				uniforms[ "uNormalScale" ].value.set( m.mapNormalFactor, m.mapNormalFactor );

			}

			if ( mpars.map ) {

				uniforms[ "tDiffuse" ].value = mpars.map;
				uniforms[ "enableDiffuse" ].value = true;

			}

			if ( mpars.specularMap ) {

				uniforms[ "tSpecular" ].value = mpars.specularMap;
				uniforms[ "enableSpecular" ].value = true;

			}

			if ( mpars.lightMap ) {

				uniforms[ "tAO" ].value = mpars.lightMap;
				uniforms[ "enableAO" ].value = true;

			}

			// for the moment don't handle displacement texture

			uniforms[ "uDiffuseColor" ].value.setHex( mpars.color );
			uniforms[ "uSpecularColor" ].value.setHex( mpars.specular );
			uniforms[ "uAmbientColor" ].value.setHex( mpars.ambient );

			uniforms[ "uShininess" ].value = mpars.shininess;

			if ( mpars.opacity !== undefined ) {

				uniforms[ "uOpacity" ].value = mpars.opacity;

			}

			var parameters = { fragmentShader: shader.fragmentShader, vertexShader: shader.vertexShader, uniforms: uniforms, lights: true, fog: true };
			var material = new THREE.ShaderMaterial( parameters );

			if ( mpars.transparent ) {

				material.transparent = true;

			}

		} else {

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

		}

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

		return material;

	}

};