/*
 * Util.ProjectInfo.cs
 * Authors: Adam Nabinger
 * Copyright (c) 2007-2008 Cornell University

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

using System;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Reflection;
using System.Security.Cryptography;
using System.Text;

namespace Util
{
	/// <summary>
	/// Miscellaneous Information
	/// </summary>
	public static class ProjectInfo
	{
		#region Fields

		// The information string related to SVN
		private static readonly string SVNInfo;

		// The information string related to system
		private static readonly string SystemInfo;

		// The information string related to time
		private static readonly string TimeInfo;

		// The fully qualified path to the directory from which the game was run.
		private static readonly string homedirectory;

		#endregion

		#region Properties

		/// <summary>
		/// The information string related to SVN
		/// </summary>
		internal static string SVNInfoString { get { return SVNInfo; } }

		/// <summary>
		/// The information string related to system
		/// </summary>
		internal static string SystemInfoString { get { return SystemInfo; } }

		/// <summary>
		/// The information string related to time
		/// </summary>
		internal static string TimeInfoString { get { return TimeInfo; } }

		/// <summary>
		/// The fully qualified path to the directory from which the game was run.
		/// </summary>
		public static string HomeDirectory { get { return homedirectory; } }

		/// <summary>
		/// The Highest committed revision number at this time this project is compiled.
		/// </summary>
		public static string SVNRevisionNumber { get { return SVNRes.RevisionNumber; } }

		/// <summary>
		/// The Date of the highest commited revision.
		/// </summary>
		public static string SVNRevisionDate { get { return SVNRes.RevisionDate; } }

		/// <summary>
		/// The Date and Time this project was compiled.
		/// </summary>
		public static string BuildDate { get { return SVNRes.BuildDate; } }

		#endregion

		#region Creation

		/// <summary>
		/// Constructor
		/// </summary>
		static ProjectInfo()
		{
			string temploc = Assembly.GetEntryAssembly().Location;
			homedirectory = temploc.Substring(0, temploc.LastIndexOf('\\'));

			StringBuilder sb = new StringBuilder();
#if DEBUG
			sb.Append("This log was generated by DEBUG build from ");
#else
			sb.Append("This log was generated by build from ");
#endif
			sb.Append(BuildDate);
			sb.Append(" from SVN Revision ");
			sb.Append(SVNRevisionNumber);
			sb.Append(" (");
			sb.Append(SVNRevisionDate);
			sb.Append(").");
			SVNInfo = sb.ToString();

			sb = new StringBuilder();
			sb.Append("Running on ");
			sb.Append(Environment.OSVersion.ToString());
			sb.Append("; Using .NET ");
			sb.Append(Environment.Version.ToString());
			sb.Append(". (");
			sb.Append(GetHash());
			sb.Append(")");
			SystemInfo = sb.ToString();

			sb = new StringBuilder();
			sb.Append("Started on ");
			sb.Append(DateTime.Now.ToString());
			sb.Append(". Timer Resolution is ");
			sb.Append(Stopwatch.Frequency.ToString("d", CultureInfo.CurrentCulture));
			sb.Append(" per second.");
			TimeInfo = sb.ToString();
		}

		#endregion

		#region Getters

		/// <summary>
		/// Compute a hash string of the executing exe file.
		/// </summary>
		private static string GetHash()
		{
			MD5 md5 = MD5.Create();
			StringBuilder sb = new StringBuilder();
			using (FileStream fs = new FileStream(Assembly.GetEntryAssembly().Location, FileMode.Open, FileAccess.Read, FileShare.Read))
			{
				foreach (byte b in md5.ComputeHash(fs))
				{
					sb.Append(b.ToString("x2", CultureInfo.CurrentCulture).ToLower(CultureInfo.CurrentCulture));
				}
			}
			return sb.ToString();
		}

		#endregion
	}
}