using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;

namespace Sarand.Net.Standard.Base.Utils
{
	//=======================================================================
	public static class AssemblyUtil
	{
		//-------------------------------------------------------------------
		#region Gets the build date and time (by reading the COFF header)
		// http://msdn.microsoft.com/en-us/library/ms680313

		/*
		struct _IMAGE_FILE_HEADER
		{
			public ushort Machine;
			public ushort NumberOfSections;
			public uint TimeDateStamp;
			public uint PointerToSymbolTable;
			public uint NumberOfSymbols;
			public ushort SizeOfOptionalHeader;
			public ushort Characteristics;
		};
		*/

		static DateTime GetBuildDateTime (Assembly assembly)
		{
			/*
			// Not available until .Net Standard 1.5.
			var path = assembly.GetName().CodeBase;
			if (File.Exists(path))
			{
				var buffer = new byte[Math.Max(Marshal.SizeOf(typeof(_IMAGE_FILE_HEADER)), 4)];
				using (var fileStream = new FileStream(path, FileMode.Open, FileAccess.Read))
				{
					fileStream.Position = 0x3C;
					fileStream.Read(buffer, 0, 4);
					fileStream.Position = BitConverter.ToUInt32(buffer, 0); // COFF header offset
					fileStream.Read(buffer, 0, 4); // "PE\0\0"
					fileStream.Read(buffer, 0, buffer.Length);
				}
				var pinnedBuffer = GCHandle.Alloc(buffer, GCHandleType.Pinned);
				try
				{
					var coffHeader = (_IMAGE_FILE_HEADER)Marshal.PtrToStructure(pinnedBuffer.AddrOfPinnedObject(), typeof(_IMAGE_FILE_HEADER));

					return TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1) + new TimeSpan(coffHeader.TimeDateStamp * TimeSpan.TicksPerSecond));
				}
				finally
				{
					pinnedBuffer.Free();
				}
			}
			*/
			return new DateTime();
		}
		#endregion

		//-------------------------------------------------------------------
	}
	//=======================================================================
}