using System.Globalization;
using System.Runtime.InteropServices;

namespace Geekeey.Extensions.Process.Win.Notify;

internal static class Interop
{
	public delegate bool ConsoleCtrlDelegate(uint dwCtrlEvent);

	[DllImport("kernel32.dll", SetLastError = true)]
	public static extern bool FreeConsole();

	[DllImport("kernel32.dll", SetLastError = true)]
	public static extern bool AttachConsole(uint dwProcessId);

	[DllImport("kernel32.dll", SetLastError = true)]
	public static extern bool SetConsoleCtrlHandler(ConsoleCtrlDelegate? handlerRoutine, bool add);

	[DllImport("kernel32.dll", SetLastError = true)]
	public static extern bool GenerateConsoleCtrlEvent(uint dwCtrlEvent, uint dwProcessGroupId);
}

internal static class Program
{
	public static int Main(string[] args)
	{
		var processId = uint.Parse(args[0], CultureInfo.InvariantCulture);
		var signal = uint.Parse(args[1], CultureInfo.InvariantCulture);

		// detach from the current console, if one is attached to the process.
		Interop.FreeConsole();

		var success =
			// attach to the target process group
			Interop.AttachConsole(processId) &&
			// set to ignore signals on self, so the proper exit code can be return
			Interop.SetConsoleCtrlHandler(null, true) &&
			// send the signal to the process group
			Interop.GenerateConsoleCtrlEvent(signal, 0);

		return success ? 0 : Marshal.GetLastPInvokeError();
	}
}