class Navigation {
	static initialize() {
		Navigation.barItems = document.body.querySelectorAll("tab-bar bar-button-item");

		for (var i = 0; i < Navigation.barItems.length; i++) {
			Navigation.barItems[i].addEventListener("click", Navigation.onBarItemSelected);
		}

		Navigation.onHashChanged();
	}

	static onHashChanged(event) {
		var hash = window.location.hash;

		for (var i = 0; i < Navigation.barItems.length; i++) {
			var item = Navigation.barItems[i];

			if (item.getAttribute("target") == hash) {
				if (item.className.indexOf("active") == -1) {
					item.classList.add("active");
				}
			}
			else {
				item.classList.remove("active");
			}
		}
	}

	static onBarItemSelected(event) {
		var target = event.currentTarget.getAttribute("target");

		if (!target) {
			return;
		}

		if (target.startsWith("#")) {
			window.location.hash = target;
			return;
		}
	}
}

window.addEventListener("hashchange", Navigation.onHashChanged);