define([ "dojo/_base/declare", "dojo/string", "dojo/_base/array", "dojo/json", "jed/jed", "dojo/_base/kernel"], function(declare, string, array, JSON, Jed, kernel) {

	var module = declare("obno.i18n.translate", null, {
	});

	/**
	 * Loads locale messages from portable object (json version) translation file. Each json stream may contain translations for multiple locales
	 * JSON content consists of one or more translation bundles. Each bundle containing translations for a specific locale.
	 * {
	 *   "bundles": [
	 *   	{
	 *      	"locale": "en-us",
	 *          "pluralForm": "the plural form for en-us",
	 *          "resources": [
	 *          	//the translations for this bundle
	 *          ]
	 *      },
	 *      {
	 *      	"locale": "el-gr",
	 *          "pluralForm": "the plural form greek",
	 *          "resources": [
	 *          	//the translations for this bundle
	 *          ]
	 *      }
	 *   ]
	 * } 
	 */
	module.loadBundle = function(poJson)
	{
		var poMsgs = JSON.parse(poJson);
		var bundles = poMsgs["bundles"] || [];
		array.forEach(bundles, function(bundle){
			var jedMsgs = {
					"domain": "messages",
					"locale_data": {
						"messages": {
							"": {
								"domain": "messages",
								"plural_forms": bundle.pluralForm || "nplurals=2; plural=(n != 1);",
								"lang": (bundle.locale || "").replace('_', '-').toLowerCase() 
							}
						}
					}
				};
				array.forEach(bundle.resources, function(msg){
					if (msg.msgID.length > 0){
						var key = msg.msgID;
						var pluralKey = msg.msgIDPlural;
						if (msg.msgCtx){
							key = msg.msgCtx + '\u0004' + key;
						}
						var translations;
						if (pluralKey){
							translations = msg.plurals || [];
						} else {
							translations = [msg.msgStr];
						}
						jedMsgs['locale_data']['messages'][key] = translations;
					}
				});
				var locale = (bundle.locale || "").replace('_', '-').toLowerCase();
				if (module.messages[locale]){
					//merge into existing messages
					var conf = module.messages[locale]["conf"];
					var oldMsgs = conf['locale_data']['messages'];
					var newMsgs = jedMsgs['locale_data']['messages'];
					for(var key in newMsgs){
						if(newMsgs.hasOwnProperty(key) && key.length > 0){
							oldMsgs[key] = newMsgs[key];
						}
					}
					module.messages[locale] = {"conf": conf, "i18n": new Jed(conf)};
				} else {
					module.messages[locale] = {"conf": jedMsgs, "i18n": new Jed(jedMsgs)};
				}			
		});
	};
	
	module.translate = function(context, singular, plural, n)
	{
		var locale = kernel.locale;
		var translations = module.messages[locale];
		if (translations){
			return translations.i18n.dcnpgettext(null, context, singular, plural, n);
		} else {
			return module.untranslated.dcnpgettext(null, context, singular, plural, n);
		}
	};
	
	module.messages = {};
	module.untranslated = new Jed({});
	
	return module;

});