using System;
using System.IO;
using System.Reflection;
using System.Threading;
using System.Threading.Tasks;

namespace RhinoReminds.Utilities
{
	public static class ExitWatcher
	{

		private static int restartDelayMs = 5 * 1000;
		private static string EntryExecutablePath => Assembly.GetEntryAssembly().Location;

		private static FileSystemWatcher watcher;
		private static bool exitSequenceStarted = false;

		public static void EnableExitOnModify() {
			Console.WriteLine("[Program/ExitWatcher] Enabling auto-exit on modification.");
			watcher = new FileSystemWatcher(Path.GetDirectoryName(EntryExecutablePath), "*.exe");
			watcher.Changed += (object sender, FileSystemEventArgs e) => doExit();

			watcher.EnableRaisingEvents = true;
		}

		private static void doExit() {
			// Don't bother if we're already exiting on a different thread or something else weird
			if (exitSequenceStarted) return;

			exitSequenceStarted = true;
			watcher.EnableRaisingEvents = false; // We're only interested in the first event raised

			Console.WriteLine($"[Program/ExitWatcher] Modification detected, waiting {restartDelayMs}ms...");
			Thread.Sleep(restartDelayMs);
			Console.WriteLine($"[Program/ExitWatcher] Wait complete, exiting with code 0");
			Environment.Exit(0);
		}
	}
}