using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

namespace MelonVPNCore
{
    public static class GUISocketServer
    {
        public static event EventHandler<ClientResponseState> Receive;
        public static event EventHandler<ConnectedClient[]> ClientListUpdate;
        public static event EventHandler<bool> RestartModeSync;

        public static void StartServer()
        {
            IPHostEntry host = Dns.GetHostEntry("localhost");
            IPAddress ipAddress = host.AddressList[0];
            IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 22036);

            try
            {
                Socket listener = new Socket(ipAddress.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
                listener.Bind(localEndPoint);
                listener.Listen(10);

                while (true)
                {
                    Socket handler = listener.Accept();

                    string data = "";
                    byte[] bytes = null;

                    while (true)
                    {
                        bytes = new byte[1024];
                        int bytesRec = handler.Receive(bytes);
                        data += Encoding.ASCII.GetString(bytes, 0, bytesRec);
                        if (data.IndexOf(Messages.EOF, StringComparison.CurrentCulture) > -1) break;
                    }

                    ClientResponseState ret = ClientResponseState.None;
                    if (data == Messages.OnlineMsg) ret = ClientResponseState.Online;
                    if (data == Messages.OfflineMsg) ret = ClientResponseState.Offline;
                    if (data == Messages.ErrorMsg) ret = ClientResponseState.ServerError;
                    if (data == Messages.StartingMsg) ret = ClientResponseState.Starting;
                    if (data == Messages.RestartingMsg) ret = ClientResponseState.Restarting;
                    bool rsm = false;
                    if (data == Messages.RestartOnMsg) rsm = true;
                    if (data == Messages.RestartOffMsg) rsm = false;
                    Console.WriteLine(data);
                    if (data.StartsWith(Messages.ClientListStartMsg, StringComparison.CurrentCulture))
                    {
                        string jsonWithEof = data.Substring(Messages.ClientListStartMsg.Length);
                        string jsonData = jsonWithEof.Substring(0, jsonWithEof.Length - Messages.EOF.Length);
                        Console.WriteLine("clients: " + jsonData);
                        ConnectedClient[] clients = ClientListParser.Parse(jsonData);
                        ClientListUpdate?.Invoke(null, clients);
                    }

                    handler.Shutdown(SocketShutdown.Both);
                    handler.Close();

                    Receive?.Invoke(null, ret);
                    RestartModeSync?.Invoke(null, rsm);
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
            }
            Console.WriteLine("GUI socket server reached the end");
        }
    }
}