using System;

using Android.App;
using Android.Content;
using Android.OS;
using Android.Widget;

namespace CreditCardValidation.Droid
{
    [Activity(Label = "@string/app_name", MainLauncher = true, Icon = "@drawable/icon", Theme = "@android:style/Theme.Holo.Light")]
    public class MainActivity : Activity
    {
        EditText _creditCardTextField;
        TextView _errorMessagesTextField;
        Button _validateButton;

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);

            _errorMessagesTextField = FindViewById<TextView>(Resource.Id.errorMessagesText);
            _creditCardTextField = FindViewById<EditText>(Resource.Id.creditCardNumberText);
            _validateButton = FindViewById<Button>(Resource.Id.validateButton);
            _validateButton.Click += (sender, e) =>{
                                         _errorMessagesTextField.Text = String.Empty;
                                         string errMessage;

                                         if (IsCCValid(out errMessage))
                                         {
                                             Intent i = new Intent(this, typeof(CreditCardValidationSuccess));
                                             StartActivity(i);
                                         }
                                         else
                                         {
                                             RunOnUiThread(() => { _errorMessagesTextField.Text = errMessage; });
                                         }
                                     };
        }

        bool IsCCValid(out string errMessage)
        {
            errMessage = "";

            if (_creditCardTextField.Text.Length < 16)
            {
                errMessage = "Credit card number is to short.";
                return false;
            }
            if (_creditCardTextField.Text.Length > 16)
            {
                errMessage = "Credit card number is to long.";
                return false;
            }

            return true;
        }
    }
}