/*
 * TODO Evaluate that this should really be a sepearte object
 */

/**
 * Component Loader
 * 
 * Builds component states.
 * 
 * @class componentLoader
 * @namespace zerk.game.engine
 * @module zerk
 **/
zerk.define({
	
	name: 'zerk.game.engine.componentLoader'
	
},{
	
	/**
	 * JSON loader instance
	 * 
	 * @property _jsonLoader
	 * @type zerk.jsonLoader
	 * @protected
	 **/
	_jsonLoader: null,
	
	/**
	 * Component register
	 * 
	 * @property _component
	 * @type Object
	 * @protected
	 **/
	_component: {},
	
	/**
	 * Component name to class map
	 * 
	 * @property _componentMap
	 * @type Object
	 * @protected
	 **/
	_componentMap: {},
	
	/**
	 * Class constructor
	 * 
	 * @method init
	 * @param {zerk.jsonLoader} jsonLoader JSON loader instance
	 * @param {Object} componentMap Component name to class map
	 **/
	init: function(jsonLoader,componentMap) {
		
		this._jsonLoader=jsonLoader;
		this._componentMap=componentMap;
		
	},
	
	/**
	 * Preloads given components
	 * 
	 * @method loadComponents
	 * @param {Array} components Array of component names
	 * @param {Function} successHandler Event handler for success
	 * @param {Function} errorHandler Event handler for error
	 * @async
	 **/
	loadComponents: function(components,successHandler,errorHandler) {
		
		var self=this;
		
		var componentResources={};
		
		for (var i=0;i<components.length;i++) {
			
			if (typeof this._componentMap[components[i]]=='undefined') {
				
				zerk.error({
					message: 'Component "'+components[i]+'" could not be'
						+' resolved to resource. Create a componentMap entry in'
						+' engine configuration.',
					source: this,
					componentName: components[i]
				});
				
			}
			
			var componentClass=this._componentMap[components[i]];
			
			this._component[components[i]]=zerk.create(componentClass);
			
		}
		
		successHandler();
		
	},
	
	/**
	 * Build the component states of an entity
	 * 
	 * @method buildComponents
	 * @param {config.entity} entity Entity definition
	 * @param {config.entity} config World configuration
	 * @return {config.entity} The final entity state
	 **/
	buildComponents: function(entity,config) {
		
		for (var component in entity.components) {
			
			config.components[component]=this._component[component].build(
				entity.components[component],
				config.components[component]
			);
			
		}
		
		return config;
		
	}
	
});