ModernUO/Server/Network/NetState.cs

/***************************************************************************
 *                                NetState.cs
 *                            -------------------
 *   begin                : May 1, 2002
 *   copyright            : (C) The RunUO Software Team
 *   email                : info@runuo.com
 *
 *   $Id$
 *
 ***************************************************************************/

/***************************************************************************
 *
 *   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.
 *
 ***************************************************************************/

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Server;
using Server.Accounting;
using Server.Network;
using Server.Items;
using Server.Gumps;
using Server.Menus;
using Server.HuePickers;
using Server.Diagnostics;

namespace Server.Network {
	public interface IPacketEncoder {
		void EncodeOutgoingPacket( NetState to, ref byte[] buffer, ref int length );
		void DecodeIncomingPacket( NetState from, ref byte[] buffer, ref int length );
	}

	public delegate void NetStateCreatedCallback( NetState ns );

	public class NetState {
		private Socket m_Socket;
		private IPAddress m_Address;
		private ByteQueue m_Buffer;
		private byte[] m_RecvBuffer;
		private SendQueue m_SendQueue;
		private bool m_Seeded;
		private bool m_Running;
		private AsyncCallback m_OnReceive, m_OnSend;
		private MessagePump m_MessagePump;
		private ServerInfo[] m_ServerInfo;
		private IAccount m_Account;
		private Mobile m_Mobile;
		private CityInfo[] m_CityInfo;
		private List<Gump> m_Gumps;
		private List<HuePicker> m_HuePickers;
		private List<IMenu> m_Menus;
		private List<SecureTrade> m_Trades;
		private int m_Sequence;
		private bool m_CompressionEnabled;
		private string m_ToString;
		private ClientVersion m_Version;
		private bool m_SentFirstPacket;
		private bool m_BlockAllPackets;

		private DateTime m_ConnectedOn;

		public DateTime ConnectedOn {
			get {
				return m_ConnectedOn;
			}
		}

		public TimeSpan ConnectedFor {
			get {
				return ( DateTime.Now - m_ConnectedOn );
			}
		}

		internal int m_Seed;
		internal int m_AuthID;

		public IPAddress Address {
			get {
				return m_Address;
			}
		}

		private ClientFlags m_Flags;

		private static bool m_Paused;

		[Flags]
		private enum AsyncState {
			Pending = 0x01,
			Paused = 0x02
		}

		private AsyncState m_AsyncState;
		private object m_AsyncLock = new object();

		public static void Pause() {
			m_Paused = true;

			for ( int i = 0; i < m_Instances.Count; ++i ) {
				NetState ns = m_Instances[i];

				lock ( ns.m_AsyncLock ) {
					ns.m_AsyncState |= AsyncState.Paused;
				}
			}
		}

		private void InternalBeginReceive() {
			m_AsyncState |= AsyncState.Pending;

			m_Socket.BeginReceive( m_RecvBuffer, 0, m_RecvBuffer.Length, SocketFlags.None, m_OnReceive, m_Socket );
		}

		public static void Resume() {
			m_Paused = false;

			for ( int i = 0; i < m_Instances.Count; ++i ) {
				NetState ns = m_Instances[i];

				if ( ns.m_Socket == null ) {
					continue;
				}

				lock ( ns.m_AsyncLock ) {
					ns.m_AsyncState &= ~AsyncState.Paused;

					try {
						if ( ( ns.m_AsyncState & AsyncState.Pending ) == 0 )
							ns.InternalBeginReceive();
					} catch ( Exception ex ) {
						TraceException( ex );
						ns.Dispose( false );
					}
				}
			}
		}

		private IPacketEncoder m_Encoder = null;

		public IPacketEncoder PacketEncoder {
			get {
				return m_Encoder;
			}
			set {
				m_Encoder = value;
			}
		}

		private static NetStateCreatedCallback m_CreatedCallback;

		public static NetStateCreatedCallback CreatedCallback {
			get {
				return m_CreatedCallback;
			}
			set {
				m_CreatedCallback = value;
			}
		}

		public bool SentFirstPacket {
			get {
				return m_SentFirstPacket;
			}
			set {
				m_SentFirstPacket = value;
			}
		}

		public bool BlockAllPackets {
			get {
				return m_BlockAllPackets;
			}
			set {
				m_BlockAllPackets = value;
			}
		}

		public ClientFlags Flags {
			get {
				return m_Flags;
			}
			set {
				m_Flags = value;
			}
		}

		public ClientVersion Version {
			get {
				return m_Version;
			}
			set {
				m_Version = value;

				if ( value >= m_Version7000 ) {
					_ProtocolChanges = ProtocolChanges.Version7000;
				} else if ( value >= m_Version60142 ) {
					_ProtocolChanges = ProtocolChanges.Version60142;
				} else if ( value >= m_Version6017 ) {
					_ProtocolChanges = ProtocolChanges.Version6017;
				} else if ( value >= m_Version6000 ) {
					_ProtocolChanges = ProtocolChanges.Version6000;
				} else if ( value >= m_Version502b ) {
					_ProtocolChanges = ProtocolChanges.Version502b;
				} else if ( value >= m_Version500a ) {
					_ProtocolChanges = ProtocolChanges.Version500a;
				} else if ( value >= m_Version407a ) {
					_ProtocolChanges = ProtocolChanges.Version407a;
				} else if ( value >= m_Version400a ) {
					_ProtocolChanges = ProtocolChanges.Version400a;
				}
			}
		}

		private static ClientVersion m_Version400a	= new ClientVersion( "4.0.0a" );
		private static ClientVersion m_Version407a	= new ClientVersion( "4.0.7a" );
		private static ClientVersion m_Version500a	= new ClientVersion( "5.0.0a" );
		private static ClientVersion m_Version502b	= new ClientVersion( "5.0.2b" );
		private static ClientVersion m_Version6000	= new ClientVersion( "6.0.0.0" );
		private static ClientVersion m_Version6017	= new ClientVersion( "6.0.1.7" );
		private static ClientVersion m_Version60142	= new ClientVersion( "6.0.14.2" );
		private static ClientVersion m_Version7000	= new ClientVersion( "7.0.0.0" );

		private ProtocolChanges _ProtocolChanges;

		private enum ProtocolChanges {
			NewSpellbook				= 0x00000001,
			DamagePacket				= 0x00000002,
			Unpack						= 0x00000004,
			BuffIcon					= 0x00000008,
			NewHaven					= 0x00000010,
			ContainerGridLines			= 0x00000020,
			ExtendedSupportedFeatures	= 0x00000040,
			StygianAbyss				= 0x00000080,

			Version400a					= NewSpellbook,
			Version407a					= Version400a | DamagePacket,
			Version500a					= Version407a | Unpack,
			Version502b					= Version500a | BuffIcon,
			Version6000					= Version502b | NewHaven,
			Version6017					= Version6000 | ContainerGridLines,
			Version60142				= Version6017 | ExtendedSupportedFeatures,
			Version7000					= Version60142 | StygianAbyss
		}

		public bool NewSpellbook { get { return ((_ProtocolChanges & ProtocolChanges.NewSpellbook) != 0); } }
		public bool DamagePacket { get { return ((_ProtocolChanges & ProtocolChanges.DamagePacket) != 0); } }
		public bool Unpack { get { return ((_ProtocolChanges & ProtocolChanges.Unpack) != 0); } }
		public bool BuffIcon { get { return ((_ProtocolChanges & ProtocolChanges.BuffIcon) != 0); } }
		public bool NewHaven { get { return ((_ProtocolChanges & ProtocolChanges.NewHaven) != 0); } }
		public bool ContainerGridLines { get { return ((_ProtocolChanges & ProtocolChanges.ContainerGridLines) != 0); } }
		public bool ExtendedSupportedFeatures { get { return ((_ProtocolChanges & ProtocolChanges.ExtendedSupportedFeatures) != 0); } }
		public bool StygianAbyss { get { return ((_ProtocolChanges & ProtocolChanges.StygianAbyss) != 0); } }

		public bool IsUOTDClient {
			get {
				return ( (m_Flags & ClientFlags.UOTD) != 0 || m_Version.Type == ClientType.UOTD );
			}
		}

		public bool IsSAClient {
			get {
				return ( m_Version.Type == ClientType.SA );
			}
		}

		public List<SecureTrade> Trades {
			get {
				return m_Trades;
			}
		}

		public void ValidateAllTrades() {
			for ( int i = m_Trades.Count - 1; i >= 0; --i ) {
				if ( i >= m_Trades.Count ) {
					continue;
				}

				SecureTrade trade = m_Trades[i];

				if ( trade.From.Mobile.Deleted || trade.To.Mobile.Deleted || !trade.From.Mobile.Alive || !trade.To.Mobile.Alive || !trade.From.Mobile.InRange( trade.To.Mobile, 2 ) || trade.From.Mobile.Map != trade.To.Mobile.Map ) {
					trade.Cancel();
				}
			}
		}

		public void CancelAllTrades() {
			for ( int i = m_Trades.Count - 1; i >= 0; --i ) {
				if ( i < m_Trades.Count ) {
					m_Trades[i].Cancel();
				}
			}
		}

		public void RemoveTrade( SecureTrade trade ) {
			m_Trades.Remove( trade );
		}

		public SecureTrade FindTrade( Mobile m ) {
			for ( int i = 0; i < m_Trades.Count; ++i ) {
				SecureTrade trade = m_Trades[i];

				if ( trade.From.Mobile == m || trade.To.Mobile == m ) {
					return trade;
				}
			}

			return null;
		}

		public SecureTradeContainer FindTradeContainer( Mobile m ) {
			for ( int i = 0; i < m_Trades.Count; ++i ) {
				SecureTrade trade = m_Trades[i];

				SecureTradeInfo from = trade.From;
				SecureTradeInfo to = trade.To;

				if ( from.Mobile == m_Mobile && to.Mobile == m ) {
					return from.Container;
				} else if ( from.Mobile == m && to.Mobile == m_Mobile ) {
					return to.Container;
				}
			}

			return null;
		}

		public SecureTradeContainer AddTrade( NetState state ) {
			SecureTrade newTrade = new SecureTrade( m_Mobile, state.m_Mobile );

			m_Trades.Add( newTrade );
			state.m_Trades.Add( newTrade );

			return newTrade.From.Container;
		}

		public bool CompressionEnabled {
			get {
				return m_CompressionEnabled;
			}
			set {
				m_CompressionEnabled = value;
			}
		}

		public int Sequence {
			get {
				return m_Sequence;
			}
			set {
				m_Sequence = value;
			}
		}

		public IEnumerable<Gump> Gumps {
			get {
				return m_Gumps;
			}
		}

		public IEnumerable<HuePicker> HuePickers {
			get {
				return m_HuePickers;
			}
		}

		public IEnumerable<IMenu> Menus {
			get {
				return m_Menus;
			}
		}

		private static int m_GumpCap = 512, m_HuePickerCap = 512, m_MenuCap = 512;

		public static int GumpCap {
			get {
				return m_GumpCap;
			}
			set {
				m_GumpCap = value;
			}
		}

		public static int HuePickerCap {
			get {
				return m_HuePickerCap;
			}
			set {
				m_HuePickerCap = value;
			}
		}

		public static int MenuCap {
			get {
				return m_MenuCap;
			}
			set {
				m_MenuCap = value;
			}
		}

		public void WriteConsole( string text ) {
			Console.WriteLine( "Client: {0}: {1}", this, text );
		}

		public void WriteConsole( string format, params object[] args ) {
			WriteConsole( String.Format( format, args ) );
		}

		public void AddMenu( IMenu menu ) {
			if ( m_Menus == null ) {
				m_Menus = new List<IMenu>();
			}

			if ( m_Menus.Count < m_MenuCap ) {
				m_Menus.Add( menu );
			} else {
				WriteConsole( "Exceeded menu cap, disconnecting..." );
				Dispose();
			}
		}

		public void RemoveMenu( IMenu menu ) {
			if ( m_Menus != null ) {
				m_Menus.Remove( menu );
			}
		}

		public void RemoveMenu( int index ) {
			if ( m_Menus != null ) {
				m_Menus.RemoveAt( index );
			}
		}

		public void ClearMenus() {
			if ( m_Menus != null ) {
				m_Menus.Clear();
			}
		}

		public void AddHuePicker( HuePicker huePicker ) {
			if ( m_HuePickers == null ) {
				m_HuePickers = new List<HuePicker>();
			}

			if ( m_HuePickers.Count < m_HuePickerCap ) {
				m_HuePickers.Add( huePicker );
			} else {
				WriteConsole( "Exceeded hue picker cap, disconnecting..." );
				Dispose();
			}
		}

		public void RemoveHuePicker( HuePicker huePicker ) {
			if ( m_HuePickers != null ) {
				m_HuePickers.Remove( huePicker );
			}
		}

		public void RemoveHuePicker( int index ) {
			if ( m_HuePickers != null ) {
				m_HuePickers.RemoveAt( index );
			}
		}

		public void ClearHuePickers() {
			if ( m_HuePickers != null ) {
				m_HuePickers.Clear();
			}
		}

		public void AddGump( Gump gump ) {
			if ( m_Gumps == null ) {
				m_Gumps = new List<Gump>();
			}

			if ( m_Gumps.Count < m_GumpCap ) {
				m_Gumps.Add( gump );
			} else {
				WriteConsole( "Exceeded gump cap, disconnecting..." );
				Dispose();
			}
		}

		public void RemoveGump( Gump gump ) {
			if ( m_Gumps != null ) {
				m_Gumps.Remove( gump );
			}
		}

		public void RemoveGump( int index ) {
			if ( m_Gumps != null ) {
				m_Gumps.RemoveAt( index );
			}
		}

		public void ClearGumps() {
			if ( m_Gumps != null ) {
				m_Gumps.Clear();
			}
		}

		public CityInfo[] CityInfo {
			get {
				return m_CityInfo;
			}
			set {
				m_CityInfo = value;
			}
		}

		public Mobile Mobile {
			get {
				return m_Mobile;
			}
			set {
				m_Mobile = value;
			}
		}

		public ServerInfo[] ServerInfo {
			get {
				return m_ServerInfo;
			}
			set {
				m_ServerInfo = value;
			}
		}

		public IAccount Account {
			get {
				return m_Account;
			}
			set {
				m_Account = value;
			}
		}

		public override string ToString() {
			return m_ToString;
		}

		private static List<NetState> m_Instances = new List<NetState>();

		public static List<NetState> Instances {
			get {
				return m_Instances;
			}
		}

		private static BufferPool m_ReceiveBufferPool = new BufferPool( "Receive", 2048, 2048 );

		public NetState( Socket socket, MessagePump messagePump )
		{
			m_Socket = socket;
			m_Buffer = new ByteQueue();
			m_Seeded = false;
			m_Running = false;
			m_RecvBuffer = m_ReceiveBufferPool.AcquireBuffer();
			m_MessagePump = messagePump;
			m_Gumps = new List<Gump>();
			m_HuePickers = new List<HuePicker>();
			m_Menus = new List<IMenu>();
			m_Trades = new List<SecureTrade>();

			m_SendQueue = new SendQueue();

			m_NextCheckActivity = DateTime.Now + TimeSpan.FromMinutes( 0.5 );

			m_Instances.Add( this );

			try {
				m_Address = Utility.Intern( ( ( IPEndPoint ) m_Socket.RemoteEndPoint ).Address );
				m_ToString = m_Address.ToString();
			} catch ( Exception ex ) {
				TraceException( ex );
				m_Address = IPAddress.None;
				m_ToString = "(error)";
			}

			m_ConnectedOn = DateTime.Now;

			if ( m_CreatedCallback != null )
			{
				m_CreatedCallback( this );
			}
		}

		public PacketHandler GetHandler( int packetID )
		{
			if ( ContainerGridLines )
				return PacketHandlers.Get6017Handler( packetID );
			else
				return PacketHandlers.GetHandler( packetID );
		}

		public virtual void Send( Packet p ) {
			if ( m_Socket == null || m_BlockAllPackets ) {
				p.OnSend();
				return;
			}

			PacketSendProfile prof = PacketSendProfile.Acquire( p.GetType() );

			int length;
			byte[] buffer = p.Compile( m_CompressionEnabled, out length );

			if ( buffer != null ) {
				if ( buffer.Length <= 0 || length <= 0 ) {
					p.OnSend();
					return;
				}

				if ( prof != null ) {
					prof.Start();
				}

				if ( m_Encoder != null ) {
					m_Encoder.EncodeOutgoingPacket( this, ref buffer, ref length );
				}

				try {
					SendQueue.Gram gram;

					lock ( m_SendQueue ) {
						gram = m_SendQueue.Enqueue( buffer, length );
					}

					if ( gram != null ) {
						try {
							m_Socket.BeginSend( gram.Buffer, 0, gram.Length, SocketFlags.None, m_OnSend, m_Socket );
						} catch ( Exception ex ) {
							TraceException( ex );
							Dispose( false );
						}
					}
				} catch ( CapacityExceededException ) {
					Console.WriteLine( "Client: {0}: Too much data pending, disconnecting...", this );
					Dispose( false );
				}

				p.OnSend();

				if ( prof != null ) {
					prof.Finish( length );
				}
			} else {
				Console.WriteLine( "Client: {0}: null buffer send, disconnecting...", this );
				using ( StreamWriter op = new StreamWriter( "null_send.log", true ) )
				{
					op.WriteLine( "{0} Client: {1}: null buffer send, disconnecting...", DateTime.Now, this );
					op.WriteLine( new System.Diagnostics.StackTrace() );
				}
				Dispose();
			}
		}

		public static void FlushAll() {
			for ( int i = 0; i < m_Instances.Count; ++i ) {
				NetState ns = m_Instances[i];

				ns.Flush();
			}
		}

		public bool Flush() {
			if ( m_Socket == null || !m_SendQueue.IsFlushReady ) {
				return false;
			}

			SendQueue.Gram gram;

			lock ( m_SendQueue ) {
				gram = m_SendQueue.CheckFlushReady();
			}

			if ( gram != null ) {
				try {
					m_Socket.BeginSend( gram.Buffer, 0, gram.Length, SocketFlags.None, m_OnSend, m_Socket );
					return true;
				} catch ( Exception ex ) {
					TraceException( ex );
					Dispose( false );
				}
			}

			return false;
		}

		private static int m_CoalesceSleep = -1;

		public static int CoalesceSleep {
			get {
				return m_CoalesceSleep;
			}
			set {
				m_CoalesceSleep = value;
			}
		}

		private void OnSend( IAsyncResult asyncResult ) {
			Socket s = (Socket)asyncResult.AsyncState;

			try {
				int bytes = s.EndSend( asyncResult );

				if ( bytes <= 0 ) {
					Dispose( false );
					return;
				}

				m_NextCheckActivity = DateTime.Now + TimeSpan.FromMinutes( 1.2 );

				if ( m_CoalesceSleep >= 0 ) {
					Thread.Sleep( m_CoalesceSleep );
				}

				SendQueue.Gram gram;

				lock ( m_SendQueue ) {
					gram = m_SendQueue.Dequeue();
				}

				if ( gram != null ) {
					try {
						s.BeginSend( gram.Buffer, 0, gram.Length, SocketFlags.None, m_OnSend, s );
					} catch ( Exception ex ) {
						TraceException( ex );
						Dispose( false );
					}
				}
			} catch ( Exception ){
				Dispose( false );
			}
		}

		public void Start() {
			m_OnReceive = new AsyncCallback( OnReceive );
			m_OnSend = new AsyncCallback( OnSend );

			m_Running = true;

			if ( m_Socket == null || m_Paused ) {
				return;
			}

			try {
				lock ( m_AsyncLock ) {
					if ( ( m_AsyncState & ( AsyncState.Pending | AsyncState.Paused ) ) == 0 ) {
						InternalBeginReceive();
					}
				}
			} catch ( Exception ex ) {
				TraceException( ex );
				Dispose( false );
			}
		}

		public void LaunchBrowser( string url ) {
			Send( new MessageLocalized( Serial.MinusOne, -1, MessageType.Label, 0x35, 3, 501231, "", "" ) );
			Send( new LaunchBrowser( url ) );
		}

		private DateTime m_NextCheckActivity;

		public bool CheckAlive() {
			if ( m_Socket == null )
				return false;

			if ( DateTime.Now < m_NextCheckActivity ) {
				return true;
			}

			Console.WriteLine( "Client: {0}: Disconnecting due to inactivity...", this );

			Dispose();
			return false;
		}

		private void OnReceive( IAsyncResult asyncResult ) {
			Socket s = (Socket)asyncResult.AsyncState;

			try {
				int byteCount = s.EndReceive( asyncResult );

				if ( byteCount > 0 ) {
					m_NextCheckActivity = DateTime.Now + TimeSpan.FromMinutes( 1.2 );

					byte[] buffer = m_RecvBuffer;

					if ( m_Encoder != null )
						m_Encoder.DecodeIncomingPacket( this, ref buffer, ref byteCount );

					lock ( m_Buffer )
						m_Buffer.Enqueue( buffer, 0, byteCount );

					m_MessagePump.OnReceive( this );

					lock ( m_AsyncLock ) {
						m_AsyncState &= ~AsyncState.Pending;

						if ( ( m_AsyncState & AsyncState.Paused ) == 0 ) {
							try {
								InternalBeginReceive();
							} catch ( Exception ex ) {
								TraceException( ex );
								Dispose( false );
							}
						}
					}
				} else {
					Dispose( false );
				}
			} catch {
				Dispose( false );
			}
		}

		public void Dispose() {
			Dispose( true );
		}

		public static void TraceException( Exception ex ) {
			try {
				using ( StreamWriter op = new StreamWriter( "network-errors.log", true ) ) {
					op.WriteLine( "# {0}", DateTime.Now );

					op.WriteLine( ex );

					op.WriteLine();
					op.WriteLine();
				}
			} catch {
			}

			try {
				Console.WriteLine( ex );
			} catch {
			}
		}

		private bool m_Disposing;

		public virtual void Dispose( bool flush ) {
			if ( m_Socket == null || m_Disposing ) {
				return;
			}

			m_Disposing = true;

			if ( flush )
				flush = Flush();

			try {
				m_Socket.Shutdown( SocketShutdown.Both );
			} catch ( SocketException ex ) {
				TraceException( ex );
			}

			try {
				m_Socket.Close();
			} catch ( SocketException ex ) {
				TraceException( ex );
			}

			if ( m_RecvBuffer != null )
				m_ReceiveBufferPool.ReleaseBuffer( m_RecvBuffer );

			m_Socket = null;

			m_Buffer = null;
			m_RecvBuffer = null;
			m_OnReceive = null;
			m_OnSend = null;
			m_Running = false;

			m_Disposed.Enqueue( this );

			if ( /*!flush &&*/ !m_SendQueue.IsEmpty ) {
				lock ( m_SendQueue )
					m_SendQueue.Clear();
			}
		}

		public static void Initialize() {
			Timer.DelayCall( TimeSpan.FromMinutes( 1.0 ), TimeSpan.FromMinutes( 1.5 ), new TimerCallback( CheckAllAlive ) );
		}

		public static void CheckAllAlive() {
			try {
				for ( int i = 0; i < m_Instances.Count; ++i ) {
					m_Instances[i].CheckAlive();
				}
			} catch ( Exception ex ) {
				TraceException( ex );
			}
		}

		private static Queue m_Disposed = Queue.Synchronized( new Queue() );

		public static void ProcessDisposedQueue() {
			int breakout = 0;

			while ( breakout < 200 && m_Disposed.Count > 0 ) {
				++breakout;

				NetState ns = ( NetState ) m_Disposed.Dequeue();

				Mobile m = ns.m_Mobile;
				IAccount a = ns.m_Account;

				if ( m != null ) {
					m.NetState = null;
					ns.m_Mobile = null;
				}

				ns.m_Gumps.Clear();
				ns.m_Menus.Clear();
				ns.m_HuePickers.Clear();
				ns.m_Account = null;
				ns.m_ServerInfo = null;
				ns.m_CityInfo = null;

				m_Instances.Remove( ns );

				if ( a != null ) {
					ns.WriteConsole( "Disconnected. [{0} Online] [{1}]", m_Instances.Count, a );
				} else {
					ns.WriteConsole( "Disconnected. [{0} Online]", m_Instances.Count );
				}
			}
		}

		public bool Running {
			get {
				return m_Running;
			}
		}

		public bool Seeded {
			get {
				return m_Seeded;
			}
			set {
				m_Seeded = value;
			}
		}

		public Socket Socket {
			get {
				return m_Socket;
			}
		}

		public ByteQueue Buffer {
			get {
				return m_Buffer;
			}
		}

		public ExpansionInfo ExpansionInfo {
			get {
				for ( int i = ExpansionInfo.Table.Length - 1; i >= 0; i-- ) {
					ExpansionInfo info = ExpansionInfo.Table[i];

					if ( ( info.RequiredClient != null && this.Version >= info.RequiredClient ) || ( ( this.Flags & info.ClientFlags ) != 0 ) ) {
						return info;
					}
				}

				return ExpansionInfo.GetInfo( Expansion.None );
			}
		}

		public Expansion Expansion {
			get {
				return ( Expansion ) this.ExpansionInfo.ID;
			}
		}

		public bool SupportsExpansion( ExpansionInfo info, bool checkCoreExpansion ) {
			if ( info == null || ( checkCoreExpansion && ( int ) Core.Expansion < info.ID ) )
				return false;

			if ( info.RequiredClient != null )
				return ( this.Version >= info.RequiredClient );

			return ( ( this.Flags & info.ClientFlags ) != 0 );
		}

		public bool SupportsExpansion( Expansion ex, bool checkCoreExpansion ) {
			return SupportsExpansion( ExpansionInfo.GetInfo( ex ), checkCoreExpansion );
		}

		public bool SupportsExpansion( Expansion ex ) {
			return SupportsExpansion( ex, true );
		}

		public bool SupportsExpansion( ExpansionInfo info ) {
			return SupportsExpansion( info, true );
		}
	}
}