using System;
using System.IO;
using Microsoft.Deployment.WindowsInstaller;

/// <summary>
/// This program patches the registry search key action in the MSI file produced by the Visual Studio Setup project,
/// to correct x64 compatibility bugs in Visual Studio Setup Projects.
/// </summary>
/// <remarks>
/// The two bugs are:
/// 1) The Visual Studio setup project incorporates the 32-bit version of InstallUtilLib.dll, which can't load x64 assemblies for reflection
/// See https://blogs.msdn.microsoft.com/heaths/2006/02/01/64-bit-managed-custom-actions-with-visual-studio/
/// 2) Registry search actions don't set the x64 bit and therefore only search the 32-bit registry
/// See https://social.msdn.microsoft.com/Forums/windows/en-US/40a2c1ee-7dd4-4289-a7d2-30b97239ae25/vs2005-setup-project-launch-conditions-registry-problem-on-x64-operating-systems
/// </remarks>
class SetupPatcher
{
    static void Main(string[] args)
    {
        if (args.Length != 1)
        {
            Console.WriteLine("ERROR: Specify the name of the MSI file as the first parameter when calling this exe");
            Environment.Exit(1);
        }

        String msiName = args[0];

        using (var db = new Database(msiName, DatabaseOpenMode.Direct))
        {
            PatchInstallUtilLib(db);
            PatchRegLocator(db);
        }
    }

    /// <summary>
    /// Replace 32 bit InstallUtilLib.dll with x64 version
    /// </summary>
    /// <param name="db"></param>
    private static void PatchInstallUtilLib(Database db)
    {
        using (View view = db.OpenView(@"UPDATE `Binary` SET `Data` = ? WHERE `Name` = 'InstallUtil'"))
        {
            using (Record rec = new Record(1))
            {
                String path = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Windows),
                    @"Microsoft.NET\\Framework64\\v4.0.30319\\InstallUtilLib.dll");
                rec.SetStream(1, path);
                view.Execute(rec);
                db.Commit();
            }
        }
    }

    private static void PatchRegLocator(Database db)
    {
        // MSI SQL syntax documented here: https://msdn.microsoft.com/en-us/library/windows/desktop/aa372021.aspx
        // Schema of RegLocator table given at https://msdn.microsoft.com/EN-US/library/aa371171.aspx
        // Look for reg search actions of the Raw type in the HKLM registry root
        String registryKey = @"SOFTWARE\\VendorName\\ProductName";

        using (View view =
            db.OpenView(
                @"UPDATE `RegLocator` SET `Type` = ? WHERE `Type` = {0} AND `Root` = {1} AND `Key` = '{2}'",
                (Int32) LocatorTypes.RawValue, (Int32) RegistryRoot.LocalMachine, registryKey))
        {
            using (Record rec = new Record(1))
            {
                rec.SetInteger(1, (Int32) (LocatorTypes.SixtyFourBit | LocatorTypes.RawValue));
                view.Execute(rec);
                db.Commit();
            }
        }
    }
}