(function() {
	'use strict';

	/*
	 * Catalogs module
	 */

	angular.module('i18n', [])

	.service('$L', ['$http', function ($http) {
		var url_tpl = '/lang/messages_{0}.json';
		var _defaultLang = 'en';
		var _currentLang = 'en';
		var _messages = null;

		/**
		 * It works similar to MessageFormat in Java
		 */
		var format = function() {
		    var args = arguments;

		    return this.replace(/\{(\d+)\}/g, function() {
		        return args[arguments[1]];
		    });
		};

		this.setLocale = function(newLoc) {
			_currentLang = newLoc;
			if (_currentLang === defaultLang)
				_messages = null;
			else {
				$http.get(format.apply(url_tpl, [newLoc])).success(function(data) {
					_messages = data;
					// TODO: Launch event ???
				}); 
			}
		}

		/**
		 * It accepts direct messages and templates:
		 * {
		 *  "hello": "hola",
		 *  "Hello {0}!!: "Hola {0}!!"
		 *  }
		 * $L.get('hello'); // This returns "hola"
		 * $L.get('Hello {0}!!', 'John'); // This returns: "Hola John!!" if languaje is spanish
		 */
		this.get = function(msg) {
			if (!_messages || !_messages[msg]) {
				if (arguments.length === 1) return msg;
				var params = Array.prototype.slice.call(arguments, 1);
				return format.apply(msg, params);
			}
			
			if (arguments.length === 1) return _messages[msg];
			var params = Array.prototype.slice.call(arguments, 1);
			return format.apply(_messages[msg], params);
		}
		
		var that = this;
		String.prototype.$i18n = function() {
			var args = [this];
			Array.prototype.push.apply(args, Array.prototype.slice.call(arguments, 0));
		    return that.get.apply(that, args)
		};
		
	}])
	.directive(
			'i18n',
			function($L) {
				return {
					restrict : 'A', // only activate on element attribute
					require : '',
					link : function(scope, element, attrs) {
						var txt = attrs.i18n || element.text();
						element.text($L.get(txt));
					}
				};
			});


})();