'use strict';

/**
 * frt-nav directive
 * should be used within bootstrap navigations to set the 'active' class on current active link (li-element)
 * dom should look like this:
 * <ul frt-nav>
 *   <li>
 *      <a ui-sref="stateName">linkName</a>
 *   </li>
 * </ul>
 */
app.directive('frtNav', function ($rootScope, $state) {
	return {

		restrict: 'A',

		link: function postLink (scope, element) {
			// all anchors within frt-nav
			var links = element.find('li').find('a');

			// whenever the state changes, reset active li element
			scope.$on('$stateChangeSuccess', function () {

				angular.forEach(links, function (link) {

					// the current <a> element (linkElement) and the surounding <li> element (listElement)
					var linkElement = angular.element(link);
					var listElement = linkElement.parent();

					// the state of current link, given by ui-sref attribute
					var stateName = linkElement.attr('ui-sref');

					// the state of current link gets compared with the app's state (current route)
					var stateClass = $state.includes(stateName) ? 'active' : ''; // 'active' is state matches, '' otherwise

					// based on calculated stateClass for current link, set or remove 'active' class on sorounding list element
					if(stateClass === 'active') {
						listElement.addClass('active');
					} else {
						listElement.removeClass('active');
					}

				});

			});
		}

	};
});