Combot/IRCServices/IRC.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;
using Combot.IRCServices.Messaging;
using Combot.IRCServices.Commanding;
using Combot.IRCServices.TCP;

namespace Combot.IRCServices
{
    public partial class IRC
    {
        public List<Channel> Channels = new List<Channel>();
        public Messages Message;
        public Commands Command;
        public event Action ConnectEvent;
        public event Action DisconnectEvent;
        public event Action<TCPError> TCPErrorEvent;
        public event Action<Exception> ExceptionThrown;
        public string Nickname;
        public Dictionary<string, PrivilegeMode> PrivilegeMapping = new Dictionary<string, PrivilegeMode>() { { "+", PrivilegeMode.v }, { "%", PrivilegeMode.h }, { "@", PrivilegeMode.o }, { "&", PrivilegeMode.a }, { "~", PrivilegeMode.q }, { "!", PrivilegeMode.q } };

        private int ReadTimeout;
        private int AllowedFailedReads;
        private int MessageSendDelay;
        private Thread TCPReader;
        private Thread KeepAlive;
        private DateTime LastMessageSend;
        private event Action<string> TCPMessageEvent;
        private readonly TCPInterface _TCP;
        private readonly ReaderWriterLockSlim ChannelRWLock;
        private readonly ReaderWriterLockSlim MessageSendLock;

        public IRC(int maxMessageLength, int messageSendDelay = 0, int readTimeout = 5000, int allowedFailedReads = 0)
        {
            Nickname            = string.Empty;
            ChannelRWLock       = new ReaderWriterLockSlim();
            MessageSendLock     = new ReaderWriterLockSlim();
            ReadTimeout         = readTimeout;
            AllowedFailedReads  = allowedFailedReads;
            LastMessageSend     = DateTime.Now;
            MessageSendDelay    = messageSendDelay;

            _TCP    = new TCPInterface();
            Message = new Messages(this);
            Command = new Commands(this, maxMessageLength, messageSendDelay);

            TCPMessageEvent                 += Message.ParseTCPMessage;
            _TCP.TCPConnectionEvent         += HandleTCPConnection;
            _TCP.TCPErrorEvent              += HandleTCPError;
            Message.ErrorMessageEvent       += HandleErrorMessage;
            Message.PingEvent               += HandlePing;
            Message.ServerReplyEvent        += HandleReply;
            Message.ChannelModeChangeEvent  += HandleChannelModeChange;
            Message.UserModeChangeEvent     += HandleUserModeChange;
            Message.NickChangeEvent         += HandleNickChange;
            Message.JoinChannelEvent        += HandleJoin;
            Message.PartChannelEvent        += HandlePart;
            Message.KickEvent               += HandleKick;
            Message.QuitEvent               += HandleQuit;
        }

        /// <summary>
        /// Starts a TCP connection to the specified host.
        /// </summary>
        /// <param name="IP">The IP address of the host.</param>
        /// <param name="port">The port for the tcp connection.</param>
        /// <param name="readTimeout">The timeout for read operations in milliseconds.</param>
        /// <param name="allowedFailedCount">Number of times a read can fail before disconnecting.</param>
        /// <returns></returns>
        public bool Connect(IPAddress IP, int port)
        {
            bool result = false;
            try
            {
                if (!_TCP.Connected)
                {
                    result = _TCP.Connect(IP, port, ReadTimeout, AllowedFailedReads);
                    if (result)
                    {
                        TCPReader = new Thread(ReadTCPMessages);
                        TCPReader.IsBackground = true;
                        TCPReader.Start();

                        KeepAlive = new Thread(() => CheckConnection(IP, port));
                        KeepAlive.IsBackground = true;
                        KeepAlive.Start();

                        if (ConnectEvent != null)
                        {
                            ConnectEvent();
                        }
                    }
                }
            }
            catch(Exception ex)
            {
                ThrowException(ex);
            }
            return result;
        }

        /// <summary>
        /// Disconencts from the active TCP connection.
        /// </summary>
        /// <returns></returns>
        public void Disconnect()
        {
            try
            {
                if (_TCP.Connected)
                {
                    _TCP.Disconnect();
                }

                if (KeepAlive.IsAlive)
                {
                    KeepAlive.Join();
                }

                if (TCPReader.IsAlive)
                {
                    TCPReader.Join();
                }

                ChannelRWLock.EnterWriteLock();
                Channels = new List<Channel>();
                ChannelRWLock.ExitWriteLock();

                if (DisconnectEvent != null)
                {
                    DisconnectEvent();
                }
            }
            catch (Exception ex)
            {
                ThrowException(ex, "Disconnect Exception");
            }
        }

        /// <summary>
        /// Logs in the specified nick using their Username and Realname.
        /// </summary>
        /// <param name="serverName">The server's name.</param>
        /// <param name="nick">The nick information for the login.</param>
        public void Login(string serverName, Nick nick)
        {
            try
            {
                Nickname = nick.Nickname;
                Command.SendNick(nick.Nickname);
                Command.SendUser(nick.Username, nick.Host, serverName, nick.Realname);
            }
            catch (Exception ex)
            {
                ThrowException(ex, "Login Exception.");
            }
        }

        /// <summary>
        /// Parses a given mode and parameter string to generate a channel mode list.
        /// </summary>
        /// <param name="modeString">The mode string that contains the mode info.</param>
        /// <param name="parameterString">The parameter string that is associated with the mode info.</param>
        /// <returns></returns>
        public List<ChannelModeInfo> ParseChannelModeString(string modeString, string parameterString)
        {
            List<ChannelModeInfo> modeInfos = new List<ChannelModeInfo>();
            try
            {
                string[] modeArgs = parameterString.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
                char[] modeInfo = modeString.ToCharArray();
                bool set = true;
                int argIndex = 0;
                foreach (char mode in modeInfo)
                {
                    if (mode.Equals('-'))
                    {
                        set = false;
                    }
                    else if (mode.Equals('+'))
                    {
                        set = true;
                    }
                    else
                    {
                        ChannelModeInfo newMode = new ChannelModeInfo();
                        newMode.Set = set;
                        ChannelMode foundMode;
                        bool validMode = Enum.TryParse(mode.ToString(), false, out foundMode);
                        if (validMode)
                        {
                            newMode.Mode = foundMode;
                            if (modeArgs.GetUpperBound(0) >= argIndex)
                            {
                                switch (newMode.Mode)
                                {
                                    case ChannelMode.k:
                                    case ChannelMode.l:
                                    case ChannelMode.b:
                                    case ChannelMode.e:
                                    case ChannelMode.I:
                                    case ChannelMode.v:
                                    case ChannelMode.h:
                                    case ChannelMode.o:
                                    case ChannelMode.a:
                                    case ChannelMode.q:
                                        newMode.Parameter = modeArgs[argIndex];
                                        argIndex++;
                                        break;
                                    default:
                                        newMode.Parameter = string.Empty;
                                        break;
                                }
                            }
                            else
                            {
                                newMode.Parameter = string.Empty;
                            }
                            modeInfos.Add(newMode);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                ThrowException(ex, "Unable to parse Channel Mode.");
            }
            return modeInfos;
        }

        public List<UserModeInfo> ParseUserModeString(string modeString)
        {
            List<UserModeInfo> userModes = new List<UserModeInfo>();
            try
            {
                bool set = true;
                char[] modeArr = modeString.ToCharArray();
                for (int i = 1; i <= modeArr.GetUpperBound(0); i++)
                {
                    UserModeInfo newMode = new UserModeInfo();
                    if (modeArr[i].Equals('-'))
                    {
                        set = false;
                    }
                    else if (modeArr[i].Equals('+'))
                    {
                        set = true;
                    }
                    else if (modeArr[i].Equals('*'))
                    {
                        newMode.Mode = UserMode.o;
                        newMode.Set = set;
                        userModes.Add(newMode);
                    }
                    else
                    {
                        UserMode foundMode;
                        bool validMode = Enum.TryParse(modeArr[i].ToString(), false, out foundMode);
                        if (validMode)
                        {
                            newMode.Mode = foundMode;
                            newMode.Set = set;
                            userModes.Add(newMode);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                ThrowException(ex, "Unable to parse User Mode.");
            }
            return userModes;
        }

        private void ReadTCPMessages()
        {
            while (_TCP.Connected)
            {
                string response = ReadTCPMessage();
                if (TCPMessageEvent != null && response != null && response != string.Empty)
                {
                    TCPMessageEvent(response);
                }
            }
        }

        private string ReadTCPMessage()
        {
            if (_TCP.Connected)
            {
                return _TCP.Read();
            }
            return null;
        }

        internal void SendTCPMessage(string message)
        {
            if (_TCP.Connected)
            {
                MessageSendLock.EnterWriteLock();
                TimeSpan sinceLastMessage = (DateTime.Now - LastMessageSend);
                if (sinceLastMessage.TotalMilliseconds < MessageSendDelay)
                {
                    Thread.Sleep((int)(MessageSendDelay - sinceLastMessage.TotalMilliseconds));
                }
                LastMessageSend = DateTime.Now;
                string replaceWith = string.Empty;
                string parsedMessage = message.Replace("\r\n", replaceWith).Replace("\n", replaceWith).Replace("\r", replaceWith);
                _TCP.Write(parsedMessage);
                MessageSendLock.ExitWriteLock();
            }
        }

        private void CheckConnection(IPAddress IP, int port)
        {
            int diconnectCount = 0;
            bool disconnectActivated = false;
            while (_TCP.Connected)
            {
                Thread.Sleep(5000); 
                bool stillConnected = NetworkInterface.GetIsNetworkAvailable();

                if (stillConnected)
                {
                    Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                    try
                    {
                        s.Connect(IP, port);
                    }
                    catch
                    {
                        stillConnected = false;
                    }
                }

                if (!stillConnected)
                {
                    diconnectCount++;
                }
                else
                {
                    diconnectCount = 0;
                }

                if (diconnectCount >= 5 && !disconnectActivated)
                {
                    disconnectActivated = true;
                    Task.Run(() =>
                    {
                        Disconnect();
                    });
                }
            }
        }

        /// <summary>
        /// Responds with PONG on a PING with the specified arguments.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void HandlePing(object sender, PingInfo e)
        {
            Command.SendPong(e.Message);
        }

        private void HandleTCPConnection(int e)
        {
            if (DisconnectEvent != null)
            {
                DisconnectEvent();
            }
        }

        private void HandleTCPError(TCPError e)
        {
            if (TCPErrorEvent != null)
            {
                TCPErrorEvent(e);
            }
        }

        private void HandleErrorMessage(object sender, ErrorMessage e)
        {
            Disconnect();
        }

        private void HandleReply(object sender, IReply e)
        {
            if (e.GetType() == typeof(ServerReplyMessage))
            {
                ServerReplyMessage msg = (ServerReplyMessage)e;
                switch (msg.ReplyCode)
                {
                    // If we get a WHO response, we parse and add the nicks to the specified channel if they are not there already.
                    case IRCReplyCode.RPL_WHOREPLY:
                        ChannelRWLock.EnterWriteLock();
                        string[] msgSplit = msg.Message.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
                        if (msgSplit.GetUpperBound(0) > 0)
                        {
                            string target = msgSplit[0];
                            if (target.StartsWith("&") || target.StartsWith("#"))
                            {
                                if (msgSplit.GetUpperBound(0) >= 7)
                                {
                                    string nickname = msgSplit[4];
                                    string realname = msgSplit[7];
                                    string username = msgSplit[1];
                                    string host = msgSplit[2];
                                    string modeString = msgSplit[5];
                                    Channel channel = Channels.Find(chan => chan.Name == target);
                                    if (channel != null)
                                    {
                                        Nick nick = channel.GetNick(nickname);
                                        bool nickFound = true;
                                        if (nick == null)
                                        {
                                            nickFound = false;
                                            nick = new Nick();
                                        }
                                        nick.Nickname = nickname;
                                        nick.Host = host;
                                        nick.Realname = realname;
                                        nick.Username = username;
                                        nick.Modes = new List<UserMode>();
                                        nick.Privileges = new List<PrivilegeMode>();
                                        char[] modeArr = modeString.ToCharArray();
                                        for (int i = 1; i <= modeArr.GetUpperBound(0); i++)
                                        {
                                            if (PrivilegeMapping.ContainsKey(modeArr[i].ToString()))
                                            {
                                                nick.Privileges.Add(PrivilegeMapping[modeArr[i].ToString()]);
                                            }
                                            else if (modeArr[i].ToString() == "*")
                                            {
                                                nick.Modes.Add(UserMode.o);
                                            }
                                            else
                                            {
                                                UserMode foundMode;
                                                bool valid = Enum.TryParse(modeArr[i].ToString(), false, out foundMode);
                                                if (valid)
                                                {
                                                    nick.Modes.Add(foundMode);
                                                }
                                            }
                                        }
                                        if (!nickFound)
                                        {
                                            channel.AddNick(nick);
                                        }
                                    }
                                }
                            }
                        }
                        ChannelRWLock.ExitWriteLock();
                        break;
                    // On a topic reply, update the channel's topic
                    case IRCReplyCode.RPL_TOPIC:
                        ChannelRWLock.EnterWriteLock();
                        string[] topicSplit = msg.Message.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
                        if (topicSplit.GetUpperBound(0) > 0)
                        {
                            string topicChan = topicSplit[0];
                            Channel topicChannel = Channels.Find(chan => chan.Name == topicChan);
                            if (topicChannel != null)
                            {
                                topicChannel.Topic = topicSplit[1].Remove(0, 1);
                            }
                        }
                        ChannelRWLock.ExitWriteLock();
                        break;
                    default:
                        break;
                }
            }
            else
            {
                ServerErrorMessage msg = (ServerErrorMessage)e;
            }
        }

        /// <summary>
        /// Update a channel's mode.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void HandleChannelModeChange(object sender, ChannelModeChangeInfo e)
        {
            ChannelRWLock.EnterWriteLock();
            Channel channel = Channels.Find(chan => chan.Name == e.Channel);
            if (channel != null)
            {
                foreach (ChannelModeInfo mode in e.Modes)
                {
                    switch (mode.Mode)
                    {
                        case ChannelMode.v:
                        case ChannelMode.h:
                        case ChannelMode.o:
                        case ChannelMode.a:
                        case ChannelMode.q:
                            Nick changedNick = channel.GetNick(mode.Parameter);
                            if (changedNick != null)
                            {
                                PrivilegeMode priv;
                                Enum.TryParse(mode.Mode.ToString(), out priv);
                                if (mode.Set)
                                {
                                    changedNick.AddPrivilege(priv);
                                }
                                else
                                {
                                    changedNick.RemovePrivilege(priv);
                                }
                            }
                            break;
                        case ChannelMode.b:
                            if (mode.Set)
                            {
                                channel.AddBan(mode.Parameter);
                            }
                            else
                            {
                                channel.RemoveBan(mode.Parameter);
                            }
                            break;
                        case ChannelMode.k:
                            if (mode.Set)
                            {
                                channel.AddMode(mode.Mode);
                                channel.Key = mode.Parameter;
                            }
                            else
                            {
                                channel.RemoveMode(mode.Mode);
                                channel.Key = string.Empty;
                            }
                            break;
                        default:
                            if (mode.Set)
                            {
                                channel.AddMode(mode.Mode);
                            }
                            else
                            {
                                channel.RemoveMode(mode.Mode);
                            }
                            break;
                    }
                }
                Command.SendWho(channel.Name);
            }
            ChannelRWLock.ExitWriteLock();
        }

        /// <summary>
        /// Update a nick's mode.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void HandleUserModeChange(object sender, UserModeChangeInfo e)
        {
            ChannelRWLock.EnterWriteLock();
            for (int i = 0; i < Channels.Count; i++)
            {
                Nick changedNick = Channels[i].GetNick(e.Nick.Nickname);
                if (changedNick != null)
                {
                    foreach (UserModeInfo mode in e.Modes)
                    {
                        if (mode.Set)
                        {
                            changedNick.AddMode(mode.Mode);
                        }
                        else
                        {
                            changedNick.RemoveMode(mode.Mode);
                        }
                    }
                }
            }
            ChannelRWLock.ExitWriteLock();
        }

        /// <summary>
        /// Update a nick to use their new nickname.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void HandleNickChange(object sender, NickChangeInfo e)
        {
            ChannelRWLock.EnterWriteLock();
            for (int i = 0; i < Channels.Count; i++)
            {
                Nick newNick = Channels[i].GetNick(e.OldNick.Nickname);
                if (newNick != null)
                {
                    if (e.OldNick.Nickname == Nickname)
                    {
                        Nickname = e.NewNick.Nickname;
                    }
                    newNick.Nickname = e.NewNick.Nickname;
                }
            }
            ChannelRWLock.ExitWriteLock();
        }

        /// <summary>
        /// Add a nick to a channel on join.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void HandleJoin(object sender, JoinChannelInfo e)
        {
            ChannelRWLock.EnterWriteLock();
            Channel channel = Channels.Find(chan => chan.Name == e.Channel);
            if (channel != null)
            {
                channel.AddNick(e.Nick);
            }
            else
            {
                Channel newChannel = new Channel();
                newChannel.Name = e.Channel;
                newChannel.Nicks.Add(e.Nick);
                Channels.Add(newChannel);
                Command.SendWho(newChannel.Name);
            }
            ChannelRWLock.ExitWriteLock();
        }

        /// <summary>
        /// Remove a nick from a channel on part.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void HandlePart(object sender, PartChannelInfo e)
        {
            ChannelRWLock.EnterWriteLock();
            Channel channel = Channels.Find(chan => chan.Name == e.Channel);
            if (channel != null)
            {
                if (e.Nick.Nickname == Nickname)
                {
                    Channels.Remove(channel);
                }
                else
                {
                    channel.RemoveNick(e.Nick.Nickname);
                }
            }
            ChannelRWLock.ExitWriteLock();
        }

        /// <summary>
        /// Remove a nick from a channel on kick.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void HandleKick(object sender, KickInfo e)
        {
            ChannelRWLock.EnterWriteLock();
            Channel channel = Channels.Find(chan => chan.Name == e.Channel);
            if (channel != null)
            {
                if (e.KickedNick.Nickname == Nickname)
                {
                    Channels.Remove(channel);
                }
                else
                {
                    channel.RemoveNick(e.KickedNick.Nickname);
                }
            }
            ChannelRWLock.ExitWriteLock();
        }

        /// <summary>
        /// Remove a nick from all channels on quit.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void HandleQuit(object sender, QuitInfo e)
        {
            ChannelRWLock.EnterWriteLock();
            for (int i = 0; i < Channels.Count; i++)
            {
                Channels[i].RemoveNick(e.Nick.Nickname);
            }
            ChannelRWLock.ExitWriteLock();
        }

        private void ThrowException(Exception ex)
        {
            ThrowException(ex, "Irc Service threw exception.");
        }

        private void ThrowException(Exception ex, string message)
        {
            Exception newEx = new Exception(message, ex);
            if (ExceptionThrown != null)
            {
                ExceptionThrown(newEx);
            }
        }
    }
}