using System;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Text;
using System.Threading;
using AniNIX.Shared;

namespace AniNIX.TheRaven {

    public class Connection : IDisposable {

        private const int _ircReadTimeout = 200000; // We set this to the IRC mimimum of two minutes in microseconds

        //These privates will be the socket we use.
        private NetworkStream _networkStream = null; // This is the stream to use.
        private TcpClient _tcpClient = null; // This is the TCP socket for the stream.
        private StreamWriter _streamWriter = null; // This is the stream to write to
        private StreamReader _streamReader = null; // This is the stream to read from 
        private String _host = null; // This is DNS name or IP of the host to talk to
        private int _port = 0; // this is the port number to connect to

        /// <summary>
        /// Connect to the host, populating the socket from the configuration options
        /// </summary>
        public Connection(String host, int port) { 
            ReportMessage.Log(Verbosity.Verbose,String.Format("Connecting to host {0}...",host));
            this._host = host;
            this._port = port; 
            this._tcpClient = new TcpClient(this._host,this._port);
            this._tcpClient.ReceiveTimeout = Connection._ircReadTimeout;
            this._networkStream = this._tcpClient.GetStream();
            this._streamWriter = new StreamWriter(this._networkStream);
            this._streamReader = new StreamReader(this._networkStream);
            ReportMessage.Log(Verbosity.VeryVerbose,"... Connected.");
        }

        /// <summary>
        /// Reads a line from the socket
        /// </summary>
        /// <returns> A string read from the socket </returns>
        public IRCServerMessage Read() {
            String response = null;
            while (response == null) {
                try {
                    response = this._streamReader.ReadLine();
                } catch (IOException e) { // If the socket times out, make sure the host is still alive.
                    try {
                        IRCPongMessage pingHost = new IRCPongMessage(String.Format("PING :{0}",this._host));
                        Write(pingHost);
                        response = this._streamReader.ReadLine();
                    } catch (IOException f) { // If we get this, then the socket is dead and we need to signal
                        throw new RavenTimedOutException(String.Format("{0}\n{1}\n",e.Message,f.Message));
                    }
                } 
                if (response != null && response.Length > 3 && response.Substring(0,4).Equals("PING")) { // if the response is a PING message, PONG and read again.
                    IRCPongMessage pong = new IRCPongMessage(response);
                    Write(pong);
                    response = null;
                }
            }
            IRCServerMessage readMessage = new IRCServerMessage(response);
            ReportMessage.Log(Verbosity.VeryVerbose,readMessage.ToString());
            return readMessage;

        }

        /// <summary>
        /// Writes a line to the socket
        /// </summary>
        /// <param name="toWrite">
        /// The string to write
        /// </param>
        public void Write(IRCMessage toWrite) {
            ReportMessage.Log(Verbosity.VeryVerbose,toWrite.ToString());
            this._streamWriter.WriteLine(String.Format("{0}\r\n",toWrite.GetOutgoingIRCString()));
            this._streamWriter.Flush();
        } 

        /// <summary> 
        /// Is the user logged in?
        /// </summary>
        /// <param name="userName">
        /// The username to check
        /// </param>
        /// <returns>
        /// A boolean value representing whether the user is logged in or not
        /// </returns>
        public bool IsLoggedIn(String userName) {
            ReportMessage.Log(Verbosity.VeryVerbose,String.Format("Asking for user {0} login status.",userName));
            String outgoing = String.Format("WHOIS {0}\r\n",userName);
            ReportMessage.Log(Verbosity.VeryVerbose,String.Format("<<< {0}",outgoing.Trim()));
            this._streamWriter.WriteLine(outgoing);
            this._streamWriter.Flush();
            String[] bySpace;
            do { 
                String response = this._streamReader.ReadLine();
                ReportMessage.Log(Verbosity.VeryVerbose,String.Format(">>> {0}",response));
                bySpace = response.Split(' ');
                if (bySpace.Length > 1 && bySpace[1].Equals("330")) {
                    ReportMessage.Log(Verbosity.VeryVerbose,String.Format("User {0} is authenticated.",userName));
                    return true;
                }
            } while (bySpace.Length < 2 || !bySpace[1].Equals("318"));
            ReportMessage.Log(Verbosity.VeryVerbose,String.Format("User {0} is not authenticated.",userName));
            return false;
        }

        /// <summary> 
        /// Get the modes for a user
        /// </summary>
        /// <param name="userName">
        /// the username to check
        /// </param>
        /// <returns>
        /// A string with the modes.
        /// </returns>
        public String GetModes(String userName) {
            ReportMessage.Log(Verbosity.VeryVerbose,String.Format("Asking for user {0} mode.",userName));
            String outgoing = String.Format("MODE {0}\r\n",userName);
            ReportMessage.Log(Verbosity.VeryVerbose,String.Format("<<< {0}",outgoing.Trim()));
            this._streamWriter.WriteLine(outgoing);
            this._streamWriter.Flush();
            String[] bySpace;
            do { 
                String response = this._streamReader.ReadLine();
                ReportMessage.Log(Verbosity.VeryVerbose,String.Format(">>> {0}",response));
                bySpace = response.Split(' ');
                if (bySpace.Length > 9 && bySpace[1].Equals("330")) {
                    ReportMessage.Log(Verbosity.VeryVerbose,String.Format("User {0} has modes {1}.",userName,bySpace[4]));
                    return bySpace[4];
                }
            } while (bySpace.Length < 2 || !bySpace[1].Equals("502"));
            ReportMessage.Log(Verbosity.VeryVerbose,String.Format("Cannot get user modes -- not a netadmin.",userName));
            return "";
        }



        /* CONNECTION NEEDS TO BE DISPOSABLE BECAUSE IT HOLDS A SOCKET */

        /// <summary>
        /// Clean up this Connection, implementing IDisposable
        /// </summary>
        public void Dispose() {
            Dispose(true); // Dispose of this instance
            GC.SuppressFinalize(this); //The Garbage Collector doesn't need to finalize it.
        }

        /// <summary>
        /// Force the GarbageCollector to Dispose if programmer does not
        /// </summary>
        ~Connection() {
            Dispose(false);
            ReportMessage.Log(Verbosity.Error,"Programmer forgot to dispose of Connection. Marking for Garbage Collector");
        }

        // This bool indicates whether we are disposed of yet or not
        bool _isDisposed = false;

        /// <summary>
        /// Dispose of this Connection's resources responsibly.
        /// </summary> 
        protected virtual void Dispose(bool disposing) {
            if (!this._isDisposed) { //if we haven't already disposed of this, we should.
                if (disposing) {
                    //No managed resources for this class.
                }
                // Cleaning unmanaged resources
                this._streamReader.Dispose();
                this._streamWriter.Dispose();
                this._tcpClient.Close();
                this._networkStream.Dispose();
            }
            this._isDisposed = true;
        }
    }
}