/**
 * EGroupware clientside API object
 *
 * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
 * @package etemplate
 * @subpackage api
 * @link http://www.egroupware.org
 * @author Hadi Nategh <hn-AT-stylite.de>
 * @version $Id: $
 */

/*egw:uses
	egw_core;
*/

/**
 * Methods to display browser notification
 *
 * @augments Class
 * @param {string} _app application name object is instanciated for
 * @param {object} _wnd window object is instanciated for
 *
 * @return {object} defined functions of module
 */
egw.extend('notification', egw.MODULE_WND_LOCAL, function(_app, _wnd)
{
	"use strict";

	// Notification permission, the default value is 'default' which is equivalent to 'denied'
	var permission = 'default';
	// Keeps alive notifications
	var alive_notifications = [];

	if (typeof Notification != 'undefined')
	{
		permission = Notification.permission;
	}

	return {

		/**
		 *
		 * @param {string} _title a string to be shown as notification message
		 * @param {object} _options an object of Notification possible options:
		 *		options = {
		 *			dir:  // direction of notification to be shown rtl, ltr or auto
		 *			lang: // a valid BCP 47 language tag
		 *			body: // DOM body
		 *			icon: // parse icon URL, default icon is app icon
		 *			tag: // a string value used for tagging an instance of notification, default is app name
		 *			requireInteraction: // boolean value indicating that a notification should remain active until the user clicks or dismisses it
		 *			onclick: // Callback function dispatches on click on notification message
		 *			onshow: // Callback function dispatches when notification is shown
		 *			onclose: // Callback function dispateches on notification close
		 *			onerror: // Callback function dispatches on error, default is a egw.debug log
		 *		}
		 *	@return {boolean} false if Notification is not supported by browser
		 */
		notification: function (_title, _options)
		{
			// Check if the notification is supported by  browser
			if (typeof Notification == 'undefined') return false;

			var self = this;
			// Check and ask for permission
			if (Notification && Notification.requestPermission && permission === 'default') Notification.requestPermission (function(_permission){
				permission = _permission;
				if (permission === 'granted') self.notification(_title,_options);
			});

			// All options including callbacks
			var options = _options || {};

			// Options used for creating Notification instane
			var inst_options = {
				tag: options.tag || egw.app_name(),
				dir: options.dir || 'ltr',
				lang: options.lang || egw.preference('lang', 'common'),
				body: options.body || '',
				icon: options.icon || egw.image('navbar', egw.app_name()),
				requireInteraction: options.requireInteraction || false
			};

			// Create an  instance of Notification object
			var notification = new Notification(_title, inst_options);

			//set timer to close shown notification in 10 s, some browsers do not
			//close it automatically.
			setTimeout(notification.close.bind(notification), 10000);

			// Callback function dispatches on click on notification message
			notification.onclick = options.onclick || '';
			// Callback function dispatches when notification is shown
			notification.onshow = options.onshow || '';
			// Callback function dispateches on notification close
			notification.onclose = options.onclose || '';
			// Callback function dispatches on error
			notification.onerror = options.onerror || function (e) {egw.debug('Notification failed because of ' + e);};

			// Collect all running notifications in case if want to close them all,
			// for instance on logout action.
			alive_notifications.push(notification);
		},

		/**
		 * Check Notification availability by browser
		 *
		 * @returns {Boolean} true if notification is supported and permitted otherwise false
		 */
		checkNotification: function () {
			// Check if the notification is supported by  browser
			if (typeof Notification == 'undefined') return false;
			
			// Ask for permission if there's nothing decided yet
			if (Notification && Notification.requestPermission && permission == 'default') {
				Notification.requestPermission (function(_permission){
					permission = _permission;
				});
			}
			return (Notification && Notification.requestPermission && permission == 'granted');
		},

		/**
		 * Check if there's any runnig notifications and will close them all
		 *
		 */
		killAliveNotifications: function ()
		{
			if (alive_notifications && alive_notifications.length > 0)
			{
				for (var i=0; i<alive_notifications.length;i++)
				{
					if (typeof alive_notifications[i].close == 'function') alive_notifications[i].close();
				}
				alive_notifications = [];
			}
		}
	};
});