/**
 * @author dforrer / https://github.com/dforrer
 * Developed as part of a project at University of Applied Sciences and Arts Northwestern Switzerland (www.fhnw.ch)
 */

/**
 * @param object THREE.Object3D
 * @param mapName string
 * @param newMap THREE.Texture
 * @constructor
 */

var SetMaterialMapCommand = function ( object, mapName, newMap, materialSlot ) {

	Command.call( this );

	this.type = 'SetMaterialMapCommand';
	this.name = 'Set Material.' + mapName;

	this.object = object;
	this.material = this.editor.getObjectMaterial( object, materialSlot );

	this.oldMap = ( object !== undefined ) ? this.material[ mapName ] : undefined;
	this.newMap = newMap;

	this.mapName = mapName;

};

SetMaterialMapCommand.prototype = {

	execute: function () {

		this.material[ this.mapName ] = this.newMap;
		this.material.needsUpdate = true;

		this.editor.signals.materialChanged.dispatch( this.material );

	},

	undo: function () {

		this.material[ this.mapName ] = this.oldMap;
		this.material.needsUpdate = true;

		this.editor.signals.materialChanged.dispatch( this.material );

	},

	toJSON: function () {

		var output = Command.prototype.toJSON.call( this );

		output.objectUuid = this.object.uuid;
		output.mapName = this.mapName;
		output.newMap = serializeMap( this.newMap );
		output.oldMap = serializeMap( this.oldMap );

		return output;

		// serializes a map (THREE.Texture)

		function serializeMap ( map ) {

			if ( map === null || map === undefined ) return null;

			var meta = {
				geometries: {},
				materials: {},
				textures: {},
				images: {}
			};

			var json = map.toJSON( meta );
			var images = extractFromCache( meta.images );
			if ( images.length > 0 ) json.images = images;
			json.sourceFile = map.sourceFile;

			return json;

		}

		// Note: The function 'extractFromCache' is copied from Object3D.toJSON()

		// extract data from the cache hash
		// remove metadata on each item
		// and return as array
		function extractFromCache ( cache ) {

			var values = [];
			for ( var key in cache ) {

				var data = cache[ key ];
				delete data.metadata;
				values.push( data );

			}
			return values;

		}

	},

	fromJSON: function ( json ) {

		Command.prototype.fromJSON.call( this, json );

		this.object = this.editor.objectByUuid( json.objectUuid );
		this.mapName = json.mapName;
		this.oldMap = parseTexture( json.oldMap );
		this.newMap = parseTexture( json.newMap );

		function parseTexture ( json ) {

			var map = null;
			if ( json !== null ) {

				var loader = new THREE.ObjectLoader();
				var images = loader.parseImages( json.images );
				var textures  = loader.parseTextures( [ json ], images );
				map = textures[ json.uuid ];
				map.sourceFile = json.sourceFile;

			}
			return map;

		}

	}

};