/* 
 * Windows timestamp accessor (C#)
 * 
 * Copyright (c) 2022 Project Nayuki
 * All rights reserved. Contact Nayuki for licensing.
 * https://www.nayuki.io/page/windows-timestamp-accessor-library
 */

using System;
using System.IO;


public sealed class WindowsTimestampAccessor {
	
	public static int Main(string[] args) {
		if (args.Length != 0) {
			Console.Error.WriteLine("Command-line arguments must be empty");
			return 1;
		}
		
		var input = new StreamReader(Console.OpenStandardInput(),
			new System.Text.UTF8Encoding(false, false));
		while (true) {
			try {
				string command = input.ReadLine();
				if (command == null)
					break;  // End of input stream
				ProcessLine(command);
			
			} catch (Exception e) {
				if (IsKnownException(e))
					Console.WriteLine("error");
				else  // Unexpected exception
					throw e;
			}
		}
		return 0;
	}
	
	
	private static void ProcessLine(string command) {
		string[] tokens = command.Split(new char[]{'\t'});
		if (tokens.Length == 1)
			throw new ArgumentException();
		string action = tokens[0];
		string path = tokens[1];
		
		// Get a timestamp
		if (action.StartsWith("Get") && tokens.Length == 2) {
			GetSomeTime func;
			switch (action) {
				case "GetCreationTime"    :  func = Directory.GetCreationTimeUtc  ;  break;
				case "GetModificationTime":  func = Directory.GetLastWriteTimeUtc ;  break;
				case "GetAccessTime"      :  func = Directory.GetLastAccessTimeUtc;  break;
				default:  throw new ArgumentException();
			}
			if (File.Exists(path) || Directory.Exists(path))
				Console.WriteLine("ok\t{0}", func(path).Ticks);
			else
				throw new ArgumentException();
		}
		// Set a timestamp
		else if (action.StartsWith("Set") && tokens.Length == 3) {
			SetSomeTime func;
			switch (action) {
				case "SetCreationTime"    :  func = Directory.SetCreationTimeUtc  ;  break;
				case "SetModificationTime":  func = Directory.SetLastWriteTimeUtc ;  break;
				case "SetAccessTime"      :  func = Directory.SetLastAccessTimeUtc;  break;
				default:  throw new ArgumentException();
			}
			var time = new DateTime(long.Parse(tokens[2]), DateTimeKind.Utc);
			if (File.Exists(path) || Directory.Exists(path)) {
				var fi = new FileInfo(path);
				bool readOnly = fi.IsReadOnly;
				if (readOnly)
					fi.IsReadOnly = false;
				func(path, time);
				if (readOnly)
					fi.IsReadOnly = true;
				Console.WriteLine("ok");
			} else
				throw new ArgumentException();
		}
		// Unrecognized command
		else
			throw new ArgumentException();
	}
	
	private delegate DateTime GetSomeTime(string path);
	private delegate void SetSomeTime(string path, DateTime time);
	
	
	private static bool IsKnownException(Exception e) {
		return
			e is ArgumentException ||
			e is FileNotFoundException ||
			e is UnauthorizedAccessException ||
			e is PathTooLongException ||
			e is NotSupportedException ||
			e is IOException ||
			e is ArgumentOutOfRangeException;
	}
	
}