// Main.cs
// 
// Copyright (C) 2008,2009 Bartek Jasicki
//
// This file is part of Grubng.
//
// 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 3 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, see <http://www.gnu.org/licenses/>.
//

/**
 * @namespace grubupload
 * @brief Main program namespace.*/
/** 
 * @file Main.cs
 * Provide Main program class.
 */

using System;
using System.Runtime.InteropServices;
using System.Text;
using System.IO;

namespace grubupload
{
	/**Provide Main program class.*/
	static class MainClass
	{
		/**Main program function
		 * @param args if array is empty, start server
		 * if args[0] is "configure", create default configuration for server and exit.*/
		public static void Main(string[] args)
		{
			SetProcessName("grub-upload");
			AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(MainUnhandledException);
			int argslength = args.Length;
			if (argslength != 0)
			{
				//Configure server
				if (args[0] == "configure")
				{
					Config.CreateConfig();
					Console.WriteLine("Default configuration file was created.");
					return;
				}
				//Create database
				if (args[0] == "createdb")
				{
					Database.CreateDB();
					Console.WriteLine("Database created.");
					return;
				}
				//Update configuration file
				if (args[0] == "updateconf")
				{
					Config.UpdateConfig();
					Console.WriteLine("Configuration file updated.");
					return;
				}
				//Update database
				if (args[0] == "updatedb")
				{
					Database.UpdateDB();
					Console.WriteLine("Database updated.");
					return;
				}
				//Stop server
				if ((args[0] == "stop") || (args[0] == "restart"))
				{
					int pid = Convert.ToInt32(File.ReadAllText("grub.pid"));
					System.Diagnostics.Process proc = System.Diagnostics.Process.GetProcessById(pid);
					proc.Kill();
					proc.Close();
					File.Delete("grub.pid");
					Console.WriteLine("Server stopped.");
					if (args[0] == "stop")
					{
						return;
					}
				}
				//Start server
				if ((args[0] == "start") || (args[0] == "restart"))
				{
					string arguments = "--server -O=all";
					if (args.Length == 2)
					{
						if (args[1] == "debug")
						{
							arguments = "--debug";
						}
					}
					System.Diagnostics.ProcessStartInfo procinfo = new System.Diagnostics.ProcessStartInfo();
					procinfo.FileName = "mono";
					procinfo.Arguments = arguments + " grub-upload.exe &";
					procinfo.UseShellExecute = false;
					System.Diagnostics.Process proc = System.Diagnostics.Process.Start(procinfo);
					StreamWriter streamw = File.CreateText("grub.pid");
					streamw.WriteLine(proc.Id.ToString());
					streamw.Close();
					proc.Close();
					Console.Write("Server start");
					if (arguments == "--debug")
					{
						Console.Write(" in debug mode");
					}
					Console.WriteLine();
					return;
				}
			}
			//Run server
			Server upserver = new Server();
			upserver.Run();
		}

		/**Function set process name on Unix system.
		 * Code borrowed from http://abock.org/2006/02/09/changing-process-name-in-mono/
		 * @param name New name of process*/
		public static void SetProcessName (string name)
		{
			try 
			{
				if (NativeMethods.prctl (15 /* PR_SET_NAME */, Encoding.ASCII.GetBytes (name + "\0"),
				           IntPtr.Zero, IntPtr.Zero, IntPtr.Zero) != 0) {
					throw new ApplicationException ("Error setting process name: " +
					                                Mono.Unix.Native.Stdlib.GetLastError ());
				}
			} 
			catch (EntryPointNotFoundException) 
			{
				NativeMethods.setproctitle (Encoding.ASCII.GetBytes ("%s\0"),
				              Encoding.ASCII.GetBytes (name + "\0"));
			}
		}
		
		/**Main function for catch unhandled exceptions.
		 * Write informations about exception to error.log.
		 * @param sender Unused
		 * @param args Provide informations about error (source, stacktrace,
		 * general info about error)*/
		static void MainUnhandledException(object sender, UnhandledExceptionEventArgs args)
		{
			if (sender != null)
			{
				sender = null;
			}
			Exception e = (Exception)args.ExceptionObject;
			string tdate = DateTime.Now.ToString("yyyy/MM/dd/HH:mm:ss");
			FileStream errorlog = File.Open("error.log", FileMode.Append);
			StreamWriter logstream = new StreamWriter(errorlog); 
			logstream.WriteLine(tdate + " Caught: " + e.GetType().ToString() + " " + e.Message);
			logstream.WriteLine("  Source: " + e.Source);
			logstream.WriteLine("  StackTrace: " + e.StackTrace);
			logstream.WriteLine("  TargetSite: " + e.TargetSite);
			logstream.Close();
		}
	}
	
	/**Provide p/invoke for native Unix methods.*/
	internal static class NativeMethods
	{
		[DllImport ("libc")] // GNU/Linux
		public static extern int prctl (int option, byte [] arg2, IntPtr arg3,
		                                 IntPtr arg4, IntPtr arg5);

		[DllImport ("libc")] // BSD
		public static extern void setproctitle (byte [] fmt, byte [] str_arg);
	}
}