using System.Diagnostics;
using System.Runtime.Versioning;
using System.Text;

namespace Geekeey.Extensions.Process;

internal partial class ProcessHandle
{
	private const string CSharpSourceText =
		"""
		[DllImport("kernel32.dll", SetLastError = true)]
		public static extern bool FreeConsole();

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

		[DllImport("kernel32.dll", SetLastError = true)]
		public static extern bool SetConsoleCtrlHandler(uint p, bool a);

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

		public static int NotifyCtrlEvent(uint pid, uint sig)
		{
			// detach from the current console, if one is attached to the process.
			FreeConsole();

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

			return success ? 0 : Marshal.GetLastWin32Error();
		}
		""";

	private const string PowerShellSourceText =
		"""
		Add-Type -Namespace 'Win32' -Name 'Notify' -Language CSharp -MemberDefinition '{0}';
		exit [Win32.Notify]::NotifyCtrlEvent({1}, {2})
		""";

	[SupportedOSPlatform("windows")]
	private static bool SendCtrlSignal(int processId, ConsoleCtrlEvent ctrl)
	{
		using var process = new System.Diagnostics.Process();

		var text = string.Format(PowerShellSourceText, CSharpSourceText, processId, (uint)ctrl);
		text = Convert.ToBase64String(Encoding.Unicode.GetBytes(text));

		process.StartInfo = new ProcessStartInfo
		{
			FileName = "powershell.exe",
			Arguments = $"-NoLogo -NoProfile -ExecutionPolicy Bypass -EncodedCommand {text}",
			CreateNoWindow = true,
			UseShellExecute = false
		};

		if (!process.Start())
			return false;

		if (!process.WaitForExit(30_000))
			return false;

		return process.ExitCode == 0;
	}

	internal enum ConsoleCtrlEvent
	{
		CTRL_C_EVENT = 0, // SIGINT
		CTRL_BREAK_EVENT = 1, // SIGQUIT
		CTRL_CLOSE_EVENT = 2, // SIGHUP
		CTRL_LOGOFF_EVENT = 5, // SIGHUP
		CTRL_SHUTDOWN_EVENT = 6, // SIGTERM
	}
}