/**
 * @author mrdoob / http://mrdoob.com/
 * @author alteredq / http://alteredqualia.com/
 * @author szimek / https://github.com/szimek/
 */

THREE.Texture = function ( image, mapping, wrapS, wrapT, magFilter, minFilter, format, type, anisotropy ) {

	Object.defineProperty( this, 'id', { value: THREE.TextureIdCount ++ } );

	this.uuid = THREE.Math.generateUUID();

	this.name = '';
	this.sourceFile = '';

	this.image = image !== undefined ? image : THREE.Texture.DEFAULT_IMAGE;
	this.mipmaps = [];

	this.mapping = mapping !== undefined ? mapping : THREE.Texture.DEFAULT_MAPPING;

	this.wrapS = wrapS !== undefined ? wrapS : THREE.ClampToEdgeWrapping;
	this.wrapT = wrapT !== undefined ? wrapT : THREE.ClampToEdgeWrapping;

	this.magFilter = magFilter !== undefined ? magFilter : THREE.LinearFilter;
	this.minFilter = minFilter !== undefined ? minFilter : THREE.LinearMipMapLinearFilter;

	this.anisotropy = anisotropy !== undefined ? anisotropy : 1;

	this.format = format !== undefined ? format : THREE.RGBAFormat;
	this.type = type !== undefined ? type : THREE.UnsignedByteType;

	this.offset = new THREE.Vector2( 0, 0 );
	this.repeat = new THREE.Vector2( 1, 1 );

	this.generateMipmaps = true;
	this.premultiplyAlpha = false;
	this.flipY = true;
	this.unpackAlignment = 4; // valid values: 1, 2, 4, 8 (see http://www.khronos.org/opengles/sdk/docs/man/xhtml/glPixelStorei.xml)

	this.version = 0;
	this.onUpdate = null;

};

THREE.Texture.DEFAULT_IMAGE = undefined;
THREE.Texture.DEFAULT_MAPPING = THREE.UVMapping;

THREE.Texture.prototype = {

	constructor: THREE.Texture,

	set needsUpdate ( value ) {

		if ( value === true ) this.update();

		this.version ++;

	},

	clone: function ( texture ) {

		if ( texture === undefined ) texture = new THREE.Texture();

		texture.image = this.image;
		texture.mipmaps = this.mipmaps.slice( 0 );

		texture.mapping = this.mapping;

		texture.wrapS = this.wrapS;
		texture.wrapT = this.wrapT;

		texture.magFilter = this.magFilter;
		texture.minFilter = this.minFilter;

		texture.anisotropy = this.anisotropy;

		texture.format = this.format;
		texture.type = this.type;

		texture.offset.copy( this.offset );
		texture.repeat.copy( this.repeat );

		texture.generateMipmaps = this.generateMipmaps;
		texture.premultiplyAlpha = this.premultiplyAlpha;
		texture.flipY = this.flipY;
		texture.unpackAlignment = this.unpackAlignment;

		return texture;

	},

	toJSON: function ( meta ) {

		if ( meta.textures[ this.uuid ] !== undefined ) {

			return meta.textures[ this.uuid ];

		}

		function getDataURL( image ) {

			var canvas;

			if ( image.toDataURL !== undefined ) {

				canvas = image;

			} else {

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

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

			}

			if ( canvas.width > 2048 || canvas.height > 2048 ) {

				return canvas.toDataURL( 'image/jpeg', 0.6 );

			} else {

				return canvas.toDataURL( 'image/png' );

			}

		}

		var output = {
			metadata: {
				version: 4.4,
				type: 'Texture',
				generator: 'Texture.toJSON'
			},

			uuid: this.uuid,
			name: this.name,

			mapping: this.mapping,

			repeat: [ this.repeat.x, this.repeat.y ],
			offset: [ this.offset.x, this.offset.y ],
			wrap: [ this.wrapS, this.wrapT ],

			minFilter: this.minFilter,
			magFilter: this.magFilter,
			anisotropy: this.anisotropy
		};

		if ( this.image !== undefined ) {

			// TODO: Move to THREE.Image

			var image = this.image;

			if ( image.uuid === undefined ) {

				image.uuid = THREE.Math.generateUUID(); // UGH

			}

			if ( meta.images[ image.uuid ] === undefined ) {

				meta.images[ image.uuid ] = {
					uuid: image.uuid,
					url: getDataURL( image )
				};

			}

			output.image = image.uuid;

		}

		meta.textures[ this.uuid ] = output;

		return output;

	},

	update: function () {

		this.dispatchEvent( { type: 'update' } );

	},

	dispose: function () {

		this.dispatchEvent( { type: 'dispose' } );

	}

};

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

THREE.TextureIdCount = 0;