class _SignInState extends State<SignIn> {

  @override
  void initState() {
    super.initState();
    MsalMobile.create('assets/auth_config.json', authority).then((client) {
      setState(() {
        msal = client;
      });
      refreshSignedInStatus();
    });
  }

  /// Updates the signed in state
  refreshSignedInStatus() {
    msal.getSignedIn().then((loggedIn) {
      print('refreshing');
      setState(() async {
        isSignedIn = loggedIn;
        dynamic currentAccount = await handleGetAccount();
        if(isSignedIn) {
          Navigator.of(context).pushReplacement(

            MaterialPageRoute(
              builder: (context) => NavScreen(
                currentUser : currentAccount,
              ),
            ),
          );
        }
      });
    });
  }

  /// Gets the current and prior accounts.
  Future <dynamic> handleGetAccount() async {
    await msal.getAccount().then((result) {
      if (result.currentAccount != null) {
        return result.currentAccount.username;
      } else {
        print('no account found');
        return null;
      }
    }).catchError((exception) {
      if (exception is MsalMobileException) {
        logMsalMobileError(exception);
      } else {
        print('exception occurred');
        return null;
      }
    });
  }