// Complete solution with integrated fallback
// AJAX by KockaAdmiralac
// Fallback by Speedit
// Assembly by Colouratura
var messageWallExists = function (name) {
	return new Promise(function (resolve, reject) {
		$.nirvana
			.getJson('WikiFeaturesSpecialController', 'index')
			.done(function (d) {
				var disabled = 
					d.features.filter(function (t) {
						return t.name === 'wgEnableWallExt' && t.enabled;
					}).length === 0;
 
				if (disabled) {
					reject();
				} else {
					resolve();
				}
			})
			.error(function () {
				var wall = '.wds-global-navigation__dropdown-link[data-tracking-label="account.message-wall"]';
 
				if ($(wall).length === 0) {
					reject();
				} else {
					resolve();
				}
			});
	});
};
 
messageWallExists(mw.config.get('wgUserName')).then(
	function () {
		console.log('Message walls exist on this wiki');
	},
	function () {
		console.log('Message walls do not exist on this wiki');
	}
);