// Shamelessly stolen from "cIRC", a demo-IRC-bot i found somewhere on the net
// 
// Made some corrections/modifications on it, so it's not completely original :)
// 
// All the following code should conform to the following spcifications:
//    RFC 1413 - Identification Protocol
//    RFC 2810 - IRC Architecture
//    RFC 2811 - IRC Channel Management
//    RFC 2812 - IRC Client Protocol
//    RFC 2813 - IRC Server Protocol 

using System;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Threading;

namespace System.Net 
{
	
	public delegate void CommandReceived(string IrcCommand);
	public delegate void TopicSet(string IrcChannel, string IrcTopic);
	public delegate void NamesList(string UserNames);
	public delegate void EndNamesList();
	public delegate void ServerMessage(string ServerMessage);
	public delegate void MOTD (string motd);
	public delegate void EndMOTD ();
	public delegate void Join(string IrcChannel, string IrcUser);
	public delegate void Part(string IrcChannel, string IrcUser);
	public delegate void Mode(string IrcChannel, string IrcUser, string UserMode);
	public delegate void NickChange(string UserOldNick, string UserNewNick);
	public delegate void Kick(string IrcChannel, string UserKicker, string UserKicked, string KickMessage);
	public delegate void Quit(string UserQuit, string QuitMessage);

	public class IRC 
	{
		public event CommandReceived eventReceiving;
		public event TopicSet eventTopicSet;
		public event NamesList eventNamesList;
		public event EndNamesList eventEndNamesList;
		public event ServerMessage eventServerMessage;
		public event MOTD eventMOTD;
		public event EndMOTD eventEndMOTD;
		public event Join eventJoin;
		public event Part eventPart;
		public event Mode eventMode;
		public event NickChange eventNickChange;
		public event Kick eventKick;
		public event Quit eventQuit;
		
		// All the defined errors (without network-stuff)
		
		public enum ErrorReplies
		{
			NoSuchNick = 401,			// "<nickname> :No such nick/channel"
			NoSuchServer = 402,			// "<server name> :No such server"
			NoSuchChannel = 403,		// "<channel name> :No such channel"
			CannotSendToChan = 404,		// "<channel name> :Cannot send to channel"
			TooManyChannels = 405,		// "<channel name> :You have joined too many channels"
			WasNoSuchNick = 406,		// "<nickname> :There was no such nickname"
			TooManyTargets = 407,		// "<target> :Duplicate recipients. No message delivered"
			NoOrigin = 409,				// ":No origin specified"
			NoRecipient = 411,			// ":No recipient given (<command>)"
			NoTextToSend = 412,			// ":No text to send"
			NoTopLevel = 413,			// "<mask> :No toplevel domain specified"
			WildTopLevel = 414,			// "<mask> :Wildcard in toplevel domain"
			UnknownCommand = 421,		// "<command> :Unknown command"
			NoMotd = 422,				// ":MOTD File is missing"
			NoAdminInfo = 423,			// "<server> :No administrative info available"
			FileError = 424,			// ":File error doing <file op> on <file>"
			NoNicknameGiven = 431,		// ":No nickname given"
			ErroneusNickname = 432,		// "<nick> :Erroneus nickname"
			NicknameInUse = 433,		// "<nick> :Nickname is already in use"
			NickCollision = 436,		// "<nick> :Nickname collision KILL"
			UserNotInChannel = 441,		// "<nick> <channel> :They aren't on that channel"
			NotInChannel = 442,			// "<channel> :You're not on that channel"
			UserOnChannel = 443,		// "<user> <channel> :is already on channel"
			NoLogin = 444,				// "<user> :User not logged in"
			SummonDisabled = 445,		// ":SUMMON has been disabled"
			UsersDisabled = 446,		// ":USERS has been disabled"
			NotRegistered = 451,		// ":You have not registered"
			NeedMoreParams = 461,		// "<command> :Not enough parameters"
			AlreadyRegistered = 462,	// ":You may not reregister"
			NoOperFromHost = 463, 		// ":Your host isn't among the privileged"
			PasswordMismatch = 464,		// ":Password incorrect"
			YoureBannedCreep = 465,		// ":You are banned from this server"
			KeySet = 467,				// "<channel> :Channel key already set"
			ChannelIsFull = 471,		// "<channel> :Cannot join channel (+l)"
			UnknownMode = 472,			// "<char> :is unknown mode char to me"
			InviteOnlyChan = 473,		// "<channel> :Cannot join channel (+i)"
			BannedFromChan = 474,		// "<channel> :Cannot join channel (+b)"
			BadChannelKey = 475,		// "<channel> :Cannot join channel (+k)"
			NoPrivileges = 481,			// ":Permission Denied- You're not an IRC operator"
			ChanOpPrivIsNeeded = 482,	// "<channel> :You're not channel operator"
			CantKillServer = 483,		// ":You cant kill a server!"
			NoOperHost = 491,			// ":No O-lines for your host"
			UmodeUnknownFlag = 501,		// ":Unknown MODE flag"
			UsersDontMatch = 502		// ":Cant change mode for other users"
		};
		
		public enum Replies
		{
			Welcome = 001,				// "Welcome to the Internet Relay Network <nick>!<user>@<host>", new in RFC2812
			YourHost = 002,				// "Your host is <servername>, running version <ver>", new in RFC2812
			Created = 003,				// "This server was created <date>", new in RFC2812
			MyInfo = 004,				// "<servername> <version> <available user modes> <available channel modes>", new in RFC2812
			Bounce = 005,				// "Try server <server name>, port <port number>", new in RFC2812
			None = 300,					// Dummy reply number. Not used.
			Userhost = 302,				// ":*1<reply> *( " " <reply> )"
			IsOn = 303,					// ":*1<nick> *( " " <nick> )"
			Away = 301,					// "<nick> :<away message>"
			Unaway = 305,				// ":You are no longer marked as being away"
			NowAway = 306,				// ":You have been marked as being away"
			WhoisUser = 311,			// "<nick> <user> <host> * :<real name>"
			WhoisServer = 312,			// "<nick> <server> :<server info>"
			WhoisOperator = 313,		// "<nick> :is an IRC operator"
			WhoisIdle = 317,			// "<nick> <integer> :seconds idle"
			EndOfWhois = 318,			// "<nick> :End of /WHOIS list"
			WhoisChannels = 319,		// "<nick> :{[@|+]<channel><space>}"
			WhoWasUser = 314,			// "<nick> <user> <host> * :<real name>"
			EndOfWhoWas = 369,			// "<nick> :End of WHOWAS"
			ListStart = 321,			// "Channel :Users  Name"
			List = 322,					// "<channel> <# visible> :<topic>"
			ListEnd = 323,				// ":End of /LIST"
			ChannelModeIs = 324,		// "<channel> <mode> <mode params>"
			NoTopic = 331,				// "<channel> :No topic is set"
			Topic = 332,				// "<channel> :<topic>"
			Inviting = 341,				// "<channel> <nick>"
			Summoning = 342,			// "<user> :Summoning user to IRC"
			Version = 351,				// "<version>.<debuglevel> <server> :<comments>"
			WhoReply = 352,				// "<channel> <user> <host> <server> <nick> <H|G>[*][@|+] :<hopcount> <real name>"
			EndOfWho = 315,				// "<name> :End of /WHO list"
			NameReply = 353,			// "<channel> :[[@|+]<nick> [[@|+]<nick> [...]]]"
			EndOfNames = 366,			// "<channel> :End of /NAMES list"
			Links = 364,				// 	"<mask> <server> :<hopcount> <server info>"
			EndOfLinks = 365,			// "<mask> :End of /LINKS list"
			BanList = 367,				// "<channel> <banid>"
			EndOfBanList = 368,			// "<channel> :End of channel ban list"
			Info = 371,					// ":<string>"
			EndOfInfo = 374,			// ":End of /INFO list"
			MotdStart = 375,			// ":- <server> Message of the day - "
			Motd = 372,					// ":- <text>"
			EndOfMotd = 376,			// ":End of /MOTD command"
			YoureOper = 381,			// ":You are now an IRC operator"
			Rehashing = 382,			// "<config file> :Rehashing"
			Time = 391,					// "<server> :<string showing server's local time>"
			UsersStart = 392,			// ":UserID   Terminal  Host"
			Users = 393,				// ":%-8s %-9s %-8s"
			EndOfUsers = 394,			// ":End of users"
			NoUsers = 395				// ":Nobody logged in"
		}
		
		private string ircServer;
		private int ircPort;
		private string ircNick;
		private string ircUser;
		private string ircRealName;
		private string ircChannel;
		private bool isInvisible;
		private TcpClient ircConnection;
		private NetworkStream ircStream;
		private StreamWriter ircWriter;
		private StreamReader ircReader;	
		
		public string IrcServer 
		{
			get { return this.ircServer; }
			set { this.ircServer = value; }
		}

		public int IrcPort 
		{
			get { return this.ircPort; }
			set { this.ircPort = value; }
		}
		
		public string IrcNick 
		{
			get { return this.ircNick; }
			set { this.ircNick = value; }
		}
		
		public string IrcUser 
		{
			get { return this.ircUser; }
			set { this.ircUser = value; }
		}
		
		public string IrcRealName 
		{
			get { return this.ircRealName; }
			set { this.ircRealName = value; }
		}
		
		public string IrcChannel 
		{
			get { return this.ircChannel; }
			set { this.ircChannel = value; }
		}
		
		public bool IsInvisble 
		{
			get { return this.isInvisible; }
			set { this.isInvisible = value; }
		}
		
		public TcpClient IrcConnection 
		{
			get { return this.ircConnection; }
			set { this.ircConnection = value; }
		}
		
		public NetworkStream IrcStream 
		{
			get { return this.ircStream; }
			set { this.ircStream = value; }
		}
		
		public StreamWriter IrcWriter 
		{
			get { return this.ircWriter; }
			set { this.ircWriter = value; }
		}
		
		public StreamReader IrcReader 
		{
			get { return this.ircReader; }
			set { this.ircReader = value; }
		} 
		
		public IRC(string IrcNick, string IrcChannel) 
		{
			this.IrcNick = IrcNick;
			this.IrcUser = System.Environment.MachineName;
			this.IrcRealName = "cIRC v1.0";
			this.IrcChannel = IrcChannel;
			this.IsInvisble = false;
		}
		
		public void Connect(string IrcServer, int IrcPort) 
		{
			this.IrcServer = IrcServer;
			this.IrcPort = IrcPort;

			// Connect with the IRC server.
			this.IrcConnection = new TcpClient(this.IrcServer, this.IrcPort);
			this.IrcStream = this.IrcConnection.GetStream();
			this.IrcReader = new StreamReader(this.IrcStream);
			this.IrcWriter = new StreamWriter(this.IrcStream);
		
			// Authenticate our user
			string isInvisible = this.IsInvisble ? "8" : "0";
			this.IrcWriter.WriteLine(String.Format("USER {0} {1} * :{2}", this.IrcUser, isInvisible, this.IrcRealName));
			this.IrcWriter.Flush();
			this.IrcWriter.WriteLine(String.Format("NICK {0}", this.IrcNick));
			this.IrcWriter.Flush();
			this.IrcWriter.WriteLine(String.Format("JOIN {0}", this.IrcChannel));
			this.IrcWriter.Flush();

			// Listen for commands
			while (true) 
			{
				string ircCommand;	
				
				while ((ircCommand = this.IrcReader.ReadLine()) != null) 
				{
					if (eventReceiving != null) 
					{ 
						this.eventReceiving(ircCommand); 
					}
					
					string[] commandParts = new string[ircCommand.Split(' ').Length];
					commandParts = ircCommand.Split(' ');
					
					if (commandParts[0].Substring(0, 1) == ":") 
					{
						commandParts[0] = commandParts[0].Remove(0, 1);
					}

					if (commandParts[1] == "002")
					{
						// fetch the correct servername
						// ex: irc.freenode.net -> brown.freenode.net/kornbluth.freenode.net/...
						//     irc.bluewin.ch -> irc1.bluewin.ch/irc2.bluewin.ch

						this.IrcServer = (commandParts[6].Split('['))[0];
					}
					
					if (commandParts[0] == this.IrcServer) 
					{
						try
						{
							// Server message
							switch (Int32.Parse(commandParts[1])) 
							{
								case (int) Replies.Topic: 
									this.IrcTopic(commandParts); 
									break;
								case (int) Replies.NameReply: 
									this.IrcNamesList(commandParts); 
									break;
								case (int) Replies.EndOfNames: 
									this.IrcEndNamesList(); 
									break;
								case (int) Replies.Motd: 
									this.IrcMOTD(commandParts); 
									break;
								case (int) Replies.EndOfMotd: 
									this.IrcEndMOTD();
									break;
								default: 
									this.IrcServerMessage(commandParts); 
									break;
							}
						}
						catch (FormatException ex) // because of Int32.Parse()
						{}
					} 
					else if (commandParts[0] == "PING") 
					{
						// Server PING, send PONG back
						this.IrcPing(commandParts);
					} 
					else 
					{
						// Normal message
						string commandAction = commandParts[1];

						switch (commandAction) 
						{
							case "JOIN": this.IrcJoin(commandParts); break;
							case "PART": this.IrcPart(commandParts); break;
							case "MODE": this.IrcMode(commandParts); break;
							case "NICK": this.IrcNickChange(commandParts); break;
							case "KICK": this.IrcKick(commandParts); break;
							case "QUIT": this.IrcQuit(commandParts); break;
						}
					}
				}
			
				this.IrcWriter.Close();
				this.IrcReader.Close();
				this.IrcConnection.Close();
			}
		} 
		
		private void IrcTopic(string[] IrcCommand) 
		{
			string IrcChannel = IrcCommand[3];
			string IrcTopic = "";
			
			for (int intI = 4; intI < IrcCommand.Length; intI++) 
			{
				IrcTopic += IrcCommand[intI] + " ";
			}
			
			if (eventTopicSet != null) 
			{ 
				this.eventTopicSet(IrcChannel, IrcTopic.Remove(0, 1).Trim()); 
			}
		} 
		
		private void IrcNamesList(string[] IrcCommand)
		{
		  	string UserNames = "";
		  
			for (int intI = 5; intI < IrcCommand.Length; intI++) 
			{
				UserNames += IrcCommand[intI] + " ";
			}
			
			if (eventNamesList != null)
			{ 
				this.eventNamesList(UserNames.Remove(0, 1).Trim()); 
			}
		} 

		private void IrcEndNamesList ()
		{
			if (eventEndNamesList != null)
			{
				this.eventEndNamesList();
			}
		}
		
		private void IrcServerMessage(string[] IrcCommand) 
		{
			string ServerMessage = "";
			
			for (int intI = 1; intI < IrcCommand.Length; intI++) 
			{
				ServerMessage += IrcCommand[intI] + " ";
			}
			
			if (eventServerMessage != null) 
			{ 
				this.eventServerMessage(ServerMessage.Trim());
			}
		}
		
		private void IrcMOTD (string[] IrcCommand)
		{
			string motd = "";
			
			for (int intI = 3; intI < IrcCommand.Length; intI++) 
			{
				motd += IrcCommand[intI] + " ";
			}

			if (eventMOTD != null)
			{
				this.eventMOTD(motd.Trim());
			}
		}

		private void IrcEndMOTD()
		{
			if (eventEndMOTD != null) 
			{
				this.eventEndMOTD();
			}
		}
		
		private void IrcPing (string[] IrcCommand) 
		{
			string PingHash = "";
			
			for (int intI = 1; intI < IrcCommand.Length; intI++) 
			{
				PingHash += IrcCommand[intI] + " ";
			}
			
			this.IrcWriter.WriteLine("PONG " + PingHash);
			this.IrcWriter.Flush();
		}
		
		private void IrcJoin(string[] IrcCommand) 
		{
			string IrcChannel = IrcCommand[2];
			string IrcUser = IrcCommand[0].Split('!')[0];
			
			if (eventJoin != null) 
			{ 
				this.eventJoin(IrcChannel.Remove(0, 1), IrcUser); 
			}
		} 
		
		private void IrcPart(string[] IrcCommand) 
		{
			string IrcChannel = IrcCommand[2];
			string IrcUser = IrcCommand[0].Split('!')[0];
			
			if (eventPart != null) 
			{ 
				this.eventPart(IrcChannel, IrcUser); 
			}
		}
		
		private void IrcMode(string[] IrcCommand) 
		{
			string IrcChannel = IrcCommand[2];
			string IrcUser = IrcCommand[0].Split('!')[0];
			string UserMode = "";

			for (int intI = 3; intI < IrcCommand.Length; intI++) 
			{
				UserMode += IrcCommand[intI] + " ";
			}
			
			if (UserMode.Substring(0, 1) == ":") 
			{
				UserMode = UserMode.Remove(0, 1);
			}
			
			if (eventMode != null) 
			{ 
				this.eventMode(IrcChannel, IrcUser, UserMode.Trim()); 
			}
		} 
		
		private void IrcNickChange(string[] IrcCommand) 
		{
			string UserOldNick = IrcCommand[0].Split('!')[0];
			string UserNewNick = IrcCommand[2].Remove(0, 1);
			
			if (eventNickChange != null) 
			{ 
				this.eventNickChange(UserOldNick, UserNewNick); 
			}
		}
		
		private void IrcKick(string[] IrcCommand) 
		{
			string UserKicker = IrcCommand[0].Split('!')[0];
			string UserKicked = IrcCommand[3];
			string IrcChannel = IrcCommand[2];
			string KickMessage = "";
			
			for (int intI = 4; intI < IrcCommand.Length; intI++) 
			{
				KickMessage += IrcCommand[intI] + " ";
			}
			
			if (eventKick != null) 
			{ 
				this.eventKick(IrcChannel, UserKicker, UserKicked, KickMessage.Remove(0, 1).Trim()); 
			}
		} 
		
		private void IrcQuit(string[] IrcCommand) 
		{
			string UserQuit = IrcCommand[0].Split('!')[0];
			string QuitMessage = "";
			
			for (int intI = 2; intI < IrcCommand.Length; intI++) 
			{
				QuitMessage += IrcCommand[intI] + " ";
			}
			
			if (eventQuit != null) 
			{ 
				this.eventQuit(UserQuit, QuitMessage.Remove(0, 1).Trim()); 
			}
		} 
	} 
}