using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace Serveur
{
    class Program
    {
        static List<TcpClient> _clientlist = new List<TcpClient>();
        static List<NetworkStream> _streamlist = new List<NetworkStream>();
        static TcpListener _server = new TcpListener(IPAddress.Any, 3790);
        static string filename = null;
        static List<FileStream> _filelist = new List<FileStream>();
        static TcpClient _client;

        static void Main(string[] args)
        {
            _server.Start(5);
            Console.WriteLine("Server OK");
            Begin();
            Console.ReadLine();
            try
            {
                foreach (FileStream _file in _filelist)
                {
                    _file.Close();
                }
            }
            catch { }
        }

        static void Begin()
        {
            _server.BeginAcceptSocket(new AsyncCallback(AcceptCallback), _server);
        }

        static void AcceptCallback(IAsyncResult AR)
        {
            _filelist.Add(new FileStream("initfile", FileMode.OpenOrCreate));
            _filelist[_filelist.Count - 1].Close();
            try
            {
                _client = _server.EndAcceptTcpClient(AR);
            }
            catch(SocketException e)
            {
                Console.WriteLine("Error " + e);
            }
            _clientlist.Add(_client);
            Console.WriteLine("Client connected");
            clientsgestion(_clientlist.Count, _filelist.Count - 1);
            Thread _thread = new Thread(new ThreadStart(Thread_Start));
            _server.BeginAcceptSocket(new AsyncCallback(AcceptCallback), _server);
        }

        static void clientsgestion(int clientnumber, int filenumber)
        {
            int streamnumber = 0;
            try
            {
                _streamlist.Add(_clientlist[clientnumber - 1].GetStream());
                streamnumber = _streamlist.Count;
            }
            catch(Exception e) { Console.WriteLine(e); }
            int i;
            byte[] _buffer = new byte[4096];
            bool firstmessage = true;
            try
            {
                while ((i = _streamlist[_streamlist.Count -1].Read(_buffer, 0, _buffer.Length)) != 0)
                {
                    string data = Encoding.UTF8.GetString(_buffer, 0, i);
                    if (firstmessage)
                    {
                        filename = createfile(data, filenumber);
                        firstmessage = false;
                    }
                    else if (!command(data, streamnumber, filenumber))
                    {
                        write(data, filenumber);
                    }
                }
            }
            catch(Exception e)
            { Console.WriteLine(e); }
        }

        static string createfile(string name, int filenumber)
        {
            _filelist[filenumber] = File.OpenWrite(name);
            _filelist[filenumber].Close();
            return name;
        }

        static bool command(string data, int streamnumber, int filenumber)
        {
            if (data.ToLower() == "get messages")
            {
                sendmessages(streamnumber, filenumber);
                return true;
            }
            else
                return false;
        }

        static void sendmessages(int streamnumber, int filenumber)
        {
            _filelist[filenumber] = File.OpenRead(filename);
            byte[] _buffer = new byte[4096];
            int i;
            while((i = _filelist[filenumber].Read(_buffer, 0, _buffer.Length)) !=0)
            {
                _streamlist[streamnumber-1].Write(_buffer, 0, i);
                break;
            }
            _filelist[filenumber].Close();
            _filelist[filenumber] = File.Open(filename, FileMode.Truncate);
            _filelist[filenumber].Close();
        }
        static void write(string message, int filenumber)
        {
            byte[] _buffer = Encoding.UTF8.GetBytes(DateTime.Now.ToString()+": " + message + Environment.NewLine);
            _filelist[filenumber] = File.Open(filename, FileMode.Append);
            _filelist[filenumber].Write(_buffer, 0, _buffer.Length);
            _filelist[filenumber].Close();
        }

        static void Thread_Start()
        {
            _server.BeginAcceptSocket(new AsyncCallback(AcceptCallback), _server);
        }

    }
}