using System;
using System.Linq;
using System.Windows.Forms;
using Microsoft.Win32;

namespace ContextHacker
{
    public partial class frmMain : Form
    {
        RegistryKey key;
        int prechange;

        public frmMain()
        {
            InitializeComponent();
            cboMenu.Enter += new EventHandler(focusevent);
        }

        private void focusevent(object sender, EventArgs e)
        {
            prechange = cboMenu.SelectedIndex;
        }

        private void cmdAdd_Click(object sender, EventArgs e)
        {
            switch (cboMenu.SelectedIndex)
            {
                case 0:
                    Registry.ClassesRoot.CreateSubKey("Directory\\Background\\shell\\" + txtText.Text);
                    key = Registry.ClassesRoot.OpenSubKey("Directory\\Background\\shell\\" + txtText.Text, true);
                    key.SetValue(null, txtText.Text);
                    if (cbExtended.CheckState == CheckState.Checked)
                        key.SetValue("Extended", "");
                    key.CreateSubKey("command");
                    key = Registry.ClassesRoot.OpenSubKey("Directory\\Background\\shell\\" + txtText.Text + "\\command", true);
                    key.SetValue(null, txtFunction.Text);
                    break;
                case 1:
                    Registry.ClassesRoot.CreateSubKey("CLSID\\{645FF040-5081-101B-9F08-00AA002F954E}\\shell\\" + txtText.Text);
                    key = Registry.ClassesRoot.OpenSubKey("CLSID\\{645FF040-5081-101B-9F08-00AA002F954E}\\shell\\" + txtText.Text, true);
                    key.SetValue(null, txtText.Text);
                    if (cbExtended.CheckState == CheckState.Checked)
                        key.SetValue("Extended", "");
                    key.CreateSubKey("command");
                    key = Registry.ClassesRoot.OpenSubKey("CLSID\\{645FF040-5081-101B-9F08-00AA002F954E}\\shell\\" + txtText.Text + "\\command", true);
                    key.SetValue(null, txtFunction.Text);
                    break;
                case 2:
                    Registry.ClassesRoot.CreateSubKey("*\\shell\\" + txtText.Text);
                    key = Registry.ClassesRoot.OpenSubKey("*\\shell\\" + txtText.Text, true);
                    key.SetValue(null, txtText.Text);
                    if (cbExtended.CheckState == CheckState.Checked)
                        key.SetValue("Extended", "");
                    key.CreateSubKey("command");
                    key = Registry.ClassesRoot.OpenSubKey("*\\shell\\" + txtText.Text + "\\command", true);
                    key.SetValue(null, txtFunction.Text);
                    break;
                case 3:
                    Registry.ClassesRoot.CreateSubKey("Directory\\shell\\" + txtText.Text);
                    key = Registry.ClassesRoot.OpenSubKey("Directory\\shell\\" + txtText.Text, true);
                    key.SetValue(null, txtText.Text);
                    if (cbExtended.CheckState == CheckState.Checked)
                        key.SetValue("Extended", "");
                    key.CreateSubKey("command");
                    key = Registry.ClassesRoot.OpenSubKey("Directory\\shell\\" + txtText.Text + "\\command", true);
                    key.SetValue(null, txtFunction.Text);
                    break;
                case 4:
                    Registry.ClassesRoot.CreateSubKey("CLSID\\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\\shell\\" + txtText.Text);
                    key = Registry.ClassesRoot.OpenSubKey("CLSID\\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\\shell\\" + txtText.Text, true);
                    key.SetValue(null, txtText.Text);
                    if (cbExtended.CheckState == CheckState.Checked)
                        key.SetValue("Extended", "");
                    key.CreateSubKey("command");
                    key = Registry.ClassesRoot.OpenSubKey("CLSID\\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\\shell\\" + txtText.Text + "\\command", true);
                    key.SetValue(null, txtFunction.Text);
                    break;
                default:
                    break;
            }
            listitems();
        }

        private void frmMain_Load(object sender, EventArgs e)
        {
            key = Registry.LocalMachine.OpenSubKey("SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion");
            cboMenu.SelectedIndex = (key.GetValue("ProductName", null).ToString().Contains("XP")) ? 2 : 0;
            key = Registry.ClassesRoot.OpenSubKey("Directory\\Background\\shell");
            if (key == null)
            {
                Registry.ClassesRoot.CreateSubKey("Directory\\Background\\shell");
            }
            key = Registry.ClassesRoot.OpenSubKey("CLSID\\{645FF040-5081-101B-9F08-00AA002F954E}\\shell");
            if (key == null)
            {
                Registry.ClassesRoot.CreateSubKey("CLSID\\{645FF040-5081-101B-9F08-00AA002F954E}\\shell");
            }
            key = Registry.ClassesRoot.OpenSubKey("*\\shell");
            if (key == null)
            {
                Registry.ClassesRoot.CreateSubKey("*\\shell");
            }
            key = Registry.ClassesRoot.OpenSubKey("Directory\\shell");
            if (key == null)
            {
                Registry.ClassesRoot.CreateSubKey("Directory\\shell");
            }
            key = Registry.ClassesRoot.OpenSubKey("CLSID\\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\\shell");
            if (key == null)
            {
                Registry.ClassesRoot.CreateSubKey("CLSID\\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\\shell");
            }
        }

        private void cboMenu_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (cboMenu.SelectedIndex == 0)
            {
                key = Registry.LocalMachine.OpenSubKey("SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion");
                if (key.GetValue("ProductName", null).ToString().Contains("XP"))
                {
                    MessageBox.Show("Windows XP does not support editing of the desktop context menu via the registry. Please select another option.", "Error");
                    cboMenu.SelectedIndex = prechange;
                }
            }
            listitems();
            prechange = cboMenu.SelectedIndex;
        }

        private void listitems()
        {
            string[] s;
            cboItem.Items.Clear();
            switch (cboMenu.SelectedIndex)
            {
                case 0:
                    key = Registry.ClassesRoot.OpenSubKey("Directory\\Background\\shell\\", true);
                    s = key.GetSubKeyNames().ToArray();
                    for (int i = 0; i < s.Length; i++)
                    {
                        cboItem.Items.Add(s[i]);
                    }
                    break;
                case 1:
                    key = Registry.ClassesRoot.OpenSubKey("CLSID\\{645FF040-5081-101B-9F08-00AA002F954E}\\shell\\", true);
                    s = key.GetSubKeyNames().ToArray();
                    for (int i = 0; i < s.Length; i++)
                    {
                        cboItem.Items.Add(s[i]);
                    }
                    break;
                case 2:
                    key = Registry.ClassesRoot.OpenSubKey("*\\shell\\", true);
                    s = key.GetSubKeyNames().ToArray();
                    for (int i = 0; i < s.Length; i++)
                    {
                        cboItem.Items.Add(s[i]);
                    }
                    break;
                case 3:
                    key = Registry.ClassesRoot.OpenSubKey("Directory\\shell\\", true);
                    s = key.GetSubKeyNames().ToArray();
                    for (int i = 0; i < s.Length; i++)
                    {
                        cboItem.Items.Add(s[i]);
                    }
                    break;
                case 4:
                    key = Registry.ClassesRoot.OpenSubKey("CLSID\\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\\shell\\", true);
                    s = key.GetSubKeyNames().ToArray();
                    for (int i = 0; i < s.Length; i++)
                    {
                        cboItem.Items.Add(s[i]);
                    }
                    break;
                default:
                    break;
            }
            if (cboItem.Items.Count > 0)
                cboItem.SelectedIndex = 0;
        }

        private void cmdRemove_Click(object sender, EventArgs e)
        {
            switch (cboMenu.SelectedIndex)
            {
                case 0:
                    Registry.ClassesRoot.DeleteSubKeyTree("Directory\\Background\\shell\\" + cboItem.SelectedItem.ToString());
                    break;
                case 1:
                    Registry.ClassesRoot.DeleteSubKeyTree("CLSID\\{645FF040-5081-101B-9F08-00AA002F954E}\\shell\\" + cboItem.SelectedItem.ToString());
                    break;
                case 2:
                    Registry.ClassesRoot.DeleteSubKeyTree("*\\Background\\shell\\" + cboItem.SelectedItem.ToString());
                    break;
                case 3:
                    Registry.ClassesRoot.DeleteSubKeyTree("Directory\\shell\\" + cboItem.SelectedItem.ToString());
                    break;
                case 4:
                    Registry.ClassesRoot.DeleteSubKeyTree("CLSID\\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\\shell\\" + cboItem.SelectedItem.ToString());
                    break;
                default:
                    break;
            }
            listitems();
        }
    }
}