using Microsoft.Win32;
using System;
using System.Globalization;
using System.Linq;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace Microsoft.WindowsUpdate.PrepareForWindowsTechnicalPreview
{
    internal static class Program
    {
        public static bool DetermineLanguageEligibility()
        {
            bool flag;
            string[] strArray = new string[] { "en-us", "zn-cn", "pt-br", "en-gb", "ja-jp", "ru-ru", "de-de", "fr-fr", "ko-kr", "it-it", "es-es", "zh-tw", "sv-se", "fi-fi", "tr-tr", "ar-sa", "nl-nl", "cs-cz", "pl-pl", "th-th" };
            flag = (!Enumerable.Contains<string>(strArray, CultureInfo.get_CurrentCulture().ToString().ToLower()) ? false : true);
            return flag;
        }

        public static bool DetermineOSEligibility()
        {
            string str;
            bool servicePack;
            bool flag;
            RegistryKey registryKey = null;
            RegistryKey registryKey1 = null;
            try
            {
                registryKey = Registry.LocalMachine.OpenSubKey("SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion");
                if (null != registryKey)
                {
                    string str1 = registryKey.GetValue("ProductName").ToString();
                    if (str1 == null)
                    {
                        flag = false;
                    }
                    else
                    {
                        flag = (str1.Contains("Windows 8.1") ? true : str1.Contains("Windows 7"));
                    }
                    if (!flag)
                    {
                        servicePack = false;
                    }
                    else if (str1.ToString().Contains("Windows 7"))
                    {
                        servicePack = Program.GetServicePack();
                    }
                    else if (!str1.ToString().Contains("Windows 8.1"))
                    {
                        servicePack = false;
                    }
                    else
                    {
                        string environmentVariable = Environment.GetEnvironmentVariable("PROCESSOR_ARCHITECTURE");
                        str = ((string.IsNullOrEmpty(environmentVariable) ? false : !("x86" == environmentVariable)) ? "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Component Based Servicing\\Packages\\Package_for_KB2919355~31bf3856ad364e35~amd64~~6.3.1.14" : "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Component Based Servicing\\Packages\\Package_for_KB2919355~31bf3856ad364e35~x86~~6.3.1.14");
                        registryKey1 = Registry.LocalMachine.OpenSubKey(str);
                        servicePack = (null != registryKey1 ? "112" == registryKey1.GetValue("CurrentState").ToString() : false);
                    }
                }
                else
                {
                    servicePack = false;
                }
            }
            finally
            {
                if (null != registryKey)
                {
                    registryKey.Close();
                }
                if (null != registryKey1)
                {
                    registryKey1.Close();
                }
            }
            return servicePack;
        }

        public static bool GetServicePack()
        {
            bool flag;
            Program.OSVERSIONINFO oSVERSIONINFO = new Program.OSVERSIONINFO()
            {
                OSVersionInfoSize = Marshal.SizeOf(typeof(Program.OSVERSIONINFO))
            };
            Program.GetVersionEx(ref oSVERSIONINFO);
            flag = (!(string.Empty == oSVERSIONINFO.CSDVersion) ? true : false);
            return flag;
        }

        [DllImport("kernel32.Dll", CharSet=1, ExactSpelling=false)]
        public static extern short GetVersionEx(ref Program.OSVERSIONINFO o);

        [STAThread]
        private static void Main()
        {
            string str = "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\WindowsUpdate\\WindowsTechnicalPreview";
            string str1 = "Signup";
            string str2 = "924EADEB-2472-490D-9203-5D0A1FD5CC73";
            string str3 = "Prepare this PC";
            string str4 = "We can't prepare this PC for Windows Technical Preview.\n\nMake sure it's using either Windows 7 SP1 or Windows 8.1 Update and a language supported in Windows Technical Preview.";
            string str5 = "This PC has already been prepared for Windows Technical Preview.\n\nWindows Update will let you know when the latest preview build is ready to install on this PC in early 2015.";
            string str6 = "Get your PC ready for the latest Windows Technical Preview build from Windows Update.";
            string str7 = "Your PC is now ready for Windows Technical Preview.\n\nWindows Update will let you know when the latest preview build is ready to install on this PC in early 2015.";
            string str8 = "We can't prepare this PC for Windows Technical Preview.\n\nHere's some info regarding the error:\n\n";
            RegistryKey registryKey = null;
            RegistryKey registryKey1 = null;
            try
            {
                try
                {
                    if ((!Program.DetermineOSEligibility() ? false : Program.DetermineLanguageEligibility()))
                    {
                        registryKey = Registry.LocalMachine.OpenSubKey(str, true);
                        if (null != registryKey)
                        {
                            MessageBox.Show(str5, str3, 0);
                        }
                        else if (MessageBox.Show(str6, str3, 1) == 1)
                        {
                            registryKey1 = Registry.LocalMachine.CreateSubKey(str);
                            registryKey1.SetValue(str1, str2);
                            MessageBox.Show(str7, str3, 0);
                        }
                    }
                    else
                    {
                        MessageBox.Show(str4, str3, 0);
                    }
                }
                catch (Exception exception1)
                {
                    Exception exception = exception1;
                    MessageBox.Show(string.Concat(str8, exception.get_Message().ToString()), str3, 0);
                }
            }
            finally
            {
                if (null != registryKey)
                {
                    registryKey.Close();
                }
                if (null != registryKey1)
                {
                    registryKey1.Close();
                }
            }
        }

        public struct OSVERSIONINFO
        {
            public int OSVersionInfoSize;

            public int MajorVersion;

            public int MinorVersion;

            public int BuildNumber;

            public int PlatformId;

            public string CSDVersion;
        }
    }
}