class ViewController: UIViewController {

@IBOutlet weak var txtUserName: UITextField!
@IBOutlet weak var txtPassword: UITextField!
@IBOutlet weak var worgLogin: UILabel!

let user1 = ["user": "Karsten","userID":"1","userName":"Kalle","passWord":"1234" ]
let user2 = ["user": "Rene","userID":"2","userName":"Rene" ,"passWord":"1234" ]
let user3 = ["user": "Johan","userID":"3","userName":"Johan","passWord":"1234" ]

override func viewDidLoad() {
    super.viewDidLoad()
    let array = [user1,user2,user3]
    UserDefaults.standard.set(array, forKey: "users")
    // Do any additional setup after loading the view, typically from a nib.
    if UserDefaults.standard.bool(forKey: "ISUSERLOGGEDIN") == true {
        //user is already logged in just navigate him to home screen
        let homeVc = self.storyboard?.instantiateViewController(withIdentifier: "HomeVC") as! HomeVC
        self.navigationController?.pushViewController(homeVc, animated: false)
    }
}

@IBAction func authenticateUser(_ sender: Any) {
    if txtUserName.text == "userName" && txtPassword.text == "passWord" {
        UserDefaults.standard.set(true, forKey: "ISUSERLOGGEDIN")
        let homeVc = self.storyboard?.instantiateViewController(withIdentifier: "HomeVC") as! HomeVC
        self.navigationController?.pushViewController(homeVc, animated: true)
    }else {
        displayMyAlertMessage(userMessage: "Brugernavn eller Password er skrevet forkert");
        return;
    }
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

func displayMyAlertMessage(userMessage:String)
{
    let myAlert = UIAlertController(title:"Alert", message:userMessage, preferredStyle: UIAlertController.Style.alert);
    let okAction = UIAlertAction(title:"Ok", style:UIAlertAction.Style.default, handler:nil);
    myAlert.addAction(okAction);
    self.present(myAlert, animated:true, completion:nil);
   }
 }