using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        

        private void currentFocus(string focusOn) {
            switch (focusOn)
            {
                case "binaryTextBox":
                    binaryTextBox.Focus();
                    break;
                case "hexTextBox":
                    hexTextBox.Focus();
                    break;
                case "octalRadioButton":
                    octalTextBox.Focus();
                    break;
                case "decimalTextBox":
                    decimalTextBox.Focus();
                    break;
                default:
                    this.Focus();
                    break;
            }
        }

        private void clearTextboxes()
        {
            hexTextBox.Text = "0";
            binaryTextBox.Text = "0";
            octalTextBox.Text = "0";
            decimalTextBox.Text = "0";
        }

        private void computeButton_Click(object sender, EventArgs e)
        {
            // Define variables
            int decimalNum = 0, hexNum = 0, binNum = 0, octalNum = 0;

            try
            { // Extract data from text boxes.
                decimalNum = int.Parse(decimalTextBox.Text);
                hexNum = Convert.ToInt32(hexTextBox.Text, 16);
                binNum = Convert.ToInt32(binaryTextBox.Text, 2);
                octalNum = Convert.ToInt32(octalTextBox.Text, 8);
            }
            catch (Exception Ex)
            {
                clearTextboxes();
                MessageBox.Show("Invalid number entered into one of the textboxes!");
            }

            // What does the user want us to convert from?
            if (decimalRadioButton.Checked)
            {
                // The decimal radio button is pressed.
                hexNum = decimalNum;
                binNum = decimalNum;
                octalNum = decimalNum;
            }
            if (octalRadioButton.Checked) {
                // The octal radio button is pressed.
                hexNum = octalNum;
                binNum = octalNum;
                decimalNum = octalNum;

            }
            if (hexRadioButton.Checked)
            {
                // The hexadecimal radio button is pressed.
                binNum = hexNum;
                decimalNum = hexNum;
                octalNum = hexNum;

            }
            if (binaryRadioButton.Checked)
            {
                // The binary radio button is pressed.
                hexNum = binNum;
                decimalNum = binNum;
                octalNum = binNum;
            }
            // Print output
            decimalTextBox.Text = decimalNum.ToString();
            hexTextBox.Text = hexNum.ToString("X");
            binaryTextBox.Text = Convert.ToString(binNum, 2);
            octalTextBox.Text = Convert.ToString(octalNum, 8);
        }

        private void clearButton_Click(object sender, EventArgs e)
        {
            // Clear the textboxes.
            clearTextboxes();

            // Reset focus to the textbox that is currently selected to be converted to.
            if (decimalRadioButton.Checked)
                currentFocus("decimalTextBox");
            if (hexRadioButton.Checked)
                currentFocus("hexTextBox");
            if (binaryRadioButton.Checked)
                currentFocus("binaryTextBox");
            if (octalRadioButton.Checked)
                currentFocus("octalTextBox");
        }

        private void exitButton_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void binaryRadioButton_CheckedChanged(object sender, EventArgs e)
        {
            currentFocus("binaryTextBox");
        }

        private void hexRadioButton_CheckedChanged(object sender, EventArgs e)
        {
            currentFocus("hexTextBox");
        }

        private void decimalRadioButton_CheckedChanged(object sender, EventArgs e)
        {
            currentFocus("decimalTextBox");
        }

        private void octalRadioButton_CheckedChanged(object sender, EventArgs e)
        {
            currentFocus("octalTextBox");
        }
    }
}