using System;
using System.IO;

namespace SignalEleven.CompileTime
{
	class CompileTimeRunner
	{
		private static readonly DateTime _standardWindowsDateStartPoint = new DateTime(1970, 01, 01, 0, 0, 0);
		private const int OFFSET_TO_DATESTAMP = 8;
		private const int OFFSET_TO_e_lfanew = 60;

		[STAThread]
		static void Main(string[] args)
		{
			CompileTimeRunner app = new CompileTimeRunner();

			if(args.Length == 0)
			{
				Console.WriteLine("usage: compiletime <path>");
				return;
			}

			app.Run(args[0]);
		}

		private void Run(String path)
		{
			if(path == null)
			{
				return;
			}

			byte[] fileData = new byte[2048];

			using(Stream fileStream = new FileStream(path, FileMode.Open, FileAccess.Read))
			{
				fileStream.Read(fileData, 0, 2048);
			}

			int offset = BitConverter.ToInt32(fileData, OFFSET_TO_e_lfanew);
			offset += OFFSET_TO_DATESTAMP;

			int secondsSince1970 = BitConverter.ToInt32(fileData, offset); 
			DateTime exeCompilationDate = _standardWindowsDateStartPoint.AddSeconds(secondsSince1970);

			Console.WriteLine(exeCompilationDate.ToString());
		}
	}

	/*
	 public struct IMAGE_DOS_HEADER
	 {
	  public ushort e_magic;    // 0
	  public ushort e_cblp;     // 2
	  public ushort e_cp;       // 4
	  public ushort e_crlc;     // 6
	  public ushort e_cparhdr;  // 8
	  public ushort e_minalloc; // 10
	  public ushort e_maxalloc; // 12
	  public ushort e_ss;       // 14
	  public ushort e_sp;       // 16
	  public ushort e_csum;     // 18
	  public ushort e_ip;       // 20
	  public ushort e_cs;       // 22
	  public ushort e_lfarlc;   // 24
	  public ushort e_ovno;     // 26
	  public ushort[] e_res;    // 28  [4]
	  public ushort e_oemid;    // 36
	  public ushort e_oeminfo;  // 38
	  public ushort[] d_res2;   // 40  [10]
	  public int e_lfanew;      // 60
	 }

	 public struct IMAGE_NT_HEADERS32
	 {
	  public uint Signature;         // 0
	  IMAGE_FILE_HEADER FileHeader;  // 4
	  IMAGE_OPTIONAL_HEADER32 OptionalHeader;
	 }

	 public struct IMAGE_FILE_HEADER
	 {
	  public ushort Machine;              // 4
	  public ushort NumberOfSections;     // 6
	  public uint TimeDateStamp;          // 8
	  public uint PointerToSymbolTable;
	  public uint NumberOfSymbols;
	  public ushort SizeOfOptionalHeader;
	  public ushort Characteristics;
	 }
	*/
}