override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    if API.User.CURRENT_USER != nil {
        // segue to the Tab Bar Controller
        self.performSegue(withIdentifier: "signInToTabBar", sender: nil)

    }
}

@IBAction func SignInButton(_ sender: Any) {

    view.endEditing(true)

    guard
        let email = emailTextField.text, !email.isEmpty,
        let password = passwordTextField.text, !password.isEmpty
        else {

            self.showErrorAlert(message: "Username or email or passowrd should not be empty")
            return
    }
    // show the progress to the user
    ProgressHUD.show("Starting sign-in...", interaction: false)

    // use the signIn class method of the AuthService class
    AuthService.signIn(email: emailTextField.text!, password: passwordTextField.text!, onSuccess: {
        // on success segue to the Tab Bar Controller
        API.User.observeCurrentUser { user in

            guard let currentUser = Auth.auth().currentUser else {
                return
            }

            PrefsManager.sharedinstance.UIDfirebase = currentUser.uid
            PrefsManager.sharedinstance.username  = user.username!
            PrefsManager.sharedinstance.userEmail = user.email!
            PrefsManager.sharedinstance.imageURL  = user.profileImageURL!

            ProgressHUD.showSuccess("Sucessfully signed in.")
            self.performSegue(withIdentifier: "signInToTabBar", sender: nil)

        }

    }, onError: { errorString in
        ProgressHUD.dismiss()
        self.showErrorAlert(message: errorString ?? "Server error")
    })

}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{


    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell") as! MenuTableViewCell

    cell.menuName.text = menuName[indexPath.row]
    cell.menuIcon.image = UIImage(named: menuImage[indexPath.row])


    return cell

}

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

  //        tableView.deselectRow(at: indexPath, animated: true)

    let row = indexPath.row

    if row == 0{

        let storyboard = UIStoryboard(name: "Home", bundle: nil)

        let obj = storyboard.instantiateViewController(withIdentifier: "HomeViewController") as! HomeViewController
        let navController = UINavigationController(rootViewController: obj)
        navController.setViewControllers([obj], animated:true)
        navController.tabBarController?.tabBar.isHidden = false
        self.revealViewController().setFront(navController, animated: true)
        self.revealViewController().setFrontViewPosition(FrontViewPosition.left, animated: true)

    } else if row == 1{

        let storyboard = UIStoryboard(name: "Bookings", bundle: nil)
        let obj = storyboard.instantiateViewController(withIdentifier: "BookingsViewController") as! BookingsViewController
        let navController = UINavigationController(rootViewController: obj)
        navController.setViewControllers([obj], animated:true)
        self.revealViewController().setFront(navController, animated: true)
        self.revealViewController().setFrontViewPosition(FrontViewPosition.left, animated: true)


    } else if row == 2 {

        let storyboard = UIStoryboard(name: "Profile", bundle: nil)
        let obj = storyboard.instantiateViewController(withIdentifier: "profileViewController") as! profileViewController
        let navController = UINavigationController(rootViewController: obj)
        navController.setViewControllers([obj], animated:true)
        self.revealViewController().setFront(navController, animated: true)
        self.revealViewController().setFrontViewPosition(FrontViewPosition.left, animated: true)

    } else if row == 3 {
        print(indexPath)
        // Log out user from Firebase
        AuthService.signOut(onSuccess: {
            // Present the Sign In VC
    //                PrefsManager.sharedinstance.logoutprefences()
            let storyboard = UIStoryboard(name: "Main", bundle: nil)
            let signInVC = storyboard.instantiateViewController(withIdentifier: "signInViewController")
                        self.present(signInVC, animated: true)

  //                self.navigationController?.pushViewController(signInVC, animated: true)

        }) { (errorMessage) in

            ProgressHUD.showError(errorMessage)

        }



    }


}

override func viewDidAppear(_ animated: Bool) {

    if API.User.CURRENT_USER != nil {
        // segue to the Tab Bar Controller
        self.performSegue(withIdentifier: "signInToTabBar", sender: nil)

    }

    super.viewDidAppear(true)
    self.tabBarController?.tabBar.isHidden = false

}