(function (win) {
	var baseSettings = {
		version: '1.0',
		backend: 'https://www.flibzee.com/labackend/check',
		form: null,
		handler: function () {
			return true;
		},
		alerter: function (messages) {
			var message = '';

			for (var key in messages) {
				if (messages.hasOwnProperty(key)) {
					message = messages[key].join("\n");
				}
			}

			alert(message);
		}
	};

	function _checkUser(name) {
		if (name.length < 6) {
			baseSettings.alerter({username: ['Bitte mindestens 6 Zeichen eingeben']});
			return false;
		}

		if (name.length > 12) {
			baseSettings.alerter({username: ['Bitte maximal 12 Zeichen eingeben']});
			return false;
		}

		if (/[^a-zA-Z0-9]/.test(name)) {
			baseSettings.alerter({username: ['Es sind keine Sonderzeichen im Username erlaubt!']});
			return false;
		}

		return true;
	}

	function _checkEmail(mail) {
		if (!mail.match(/.+@.+\..+/)) {
			baseSettings.alerter({email: ['Bitte geben Sie eine gültige E-Mail Adresse ein.']});
			return false;
		}

		return true;
	}

	function _submitCheck(user, mail) {
		if (_checkUser(user) && _checkEmail(mail)) {
			var su = document.createElement('script');
			su.type = 'text/javascript';
			su.async = false;
			su.src = baseSettings.backend + '?username=' + encodeURIComponent(user) + '&email=' +
					 encodeURIComponent(mail) + '&jsonp=window.laApi.signupResult';
			var s = document.getElementsByTagName('script')[0];
			s.parentNode.insertBefore(su, s);
		}

		return false;
	}

	win.laApi = {
		checkUsername: function (username) {
			var user = document.getElementById(username).value;
			return _checkUser(user);
		},

		checkEmail: function (email) {
			var mail = document.getElementById(email).value;
			return _checkEmail(mail);
		},

		checkSignup: function (username, email, form) {
			baseSettings.form = form;
			var user = document.getElementById(username).value;
			var mail = document.getElementById(email).value;
			return _submitCheck(user, mail);
		},

		signupResult: function (resultId, messages, alternativeNames) {
			if (resultId != 0) {
				var doAlert = baseSettings.handler(resultId, messages, alternativeNames);
				if (doAlert) {
					baseSettings.alerter(messages);
				}
			} else {
				baseSettings.form.submit();
			}
		},

		setAlert: function (callable) {
			baseSettings.alerter = callable;
		}
	}
})(window);