using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using ChatLib.FormEventArgs;

namespace ChatLib
{
    public class ChatServer
    {
        public event EventHandler<NewUserEventArgs> OnNewClient;
        public event EventHandler<MessageEventArgs> OnNewMessage;

        private TcpListener _tcpListener;
        private Thread _thread;
        public bool Run { get; private set; }
        private readonly int _port;

        public List<User> Users { get; } = new List<User>();

        public ChatServer(int port)
        {
            _port = port;
        }

        public void Start()
        {
            if (!Run)
            {
                Run = true;

                _thread = new Thread(() =>
                {
                    _tcpListener = new TcpListener(IPAddress.Any, _port);
                    _tcpListener.Start();

                    while (Run)
                    {
                        try
                        {
                            ThreadPool.QueueUserWorkItem(objectState =>
                            {
                                var user = new User((TcpClient)objectState);
                                user.OnMessage += (sender, args) => OnNewMessage?.Invoke(sender, args);
                                Users.Add(user);
                                user.Listen();
                                OnNewClient?.Invoke(this, new NewUserEventArgs(user));
                            }, _tcpListener.AcceptTcpClient());
                        }
                        catch (Exception e)
                        {
                            Run = false;
                        }
                    }

                    _tcpListener.Stop();
                });

                _thread.Start();
            }
        }

        public void Stop()
        {
            _tcpListener.Stop();
        }

        public void Restart()
        {
            Stop();
            Start();
        }

        public void BroadcastMessage(Message message)
        {
            if(message.Msg == string.Empty)
                return;

            foreach (var user in Users)
                user.WriteMessage(message);
        }

        public void UnicastMessage(User user, Message message)
        {
            if (message.Msg == string.Empty)
                return;

            user.WriteMessage(message);
        }
    }
}