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

namespace SharedLibrary.Network
{
    public static class RCON
    {
        enum QueryType
        {
            GET_STATUS,
            GET_INFO,
            DVAR,
            COMMAND,
        }

        public static List<Player> PlayersFromStatus(String[] Status)
        {
            List<Player> StatusPlayers = new List<Player>();

            foreach (String S in Status)
            {
                String responseLine = S.Trim();

                if (Regex.Matches(responseLine, @"\d+$", RegexOptions.IgnoreCase).Count > 0 && responseLine.Length > 72) // its a client line!
                {
                    String[] playerInfo = responseLine.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
                    int cID = -1;
                    String cName = Utilities.StripColors(responseLine.Substring(46, 18)).Trim();
                    String npID = responseLine.Substring(29, 17).Trim(); // DONT TOUCH PLZ
                    int.TryParse(playerInfo[0], out cID);
                    String cIP = responseLine.Substring(72, 20).Trim().Split(':')[0];

                    Player P = new Player(cName, npID, cID, cIP);
                    StatusPlayers.Add(P);
                }
            }

            return StatusPlayers;
        }

        static string[] SendQuery(QueryType Type, Server QueryServer,  string Parameters = "")
        {
            var ServerOOBConnection = new System.Net.Sockets.UdpClient();
            ServerOOBConnection.Client.SendTimeout = 1000;
            ServerOOBConnection.Client.ReceiveTimeout = 1000;
            var Endpoint = new IPEndPoint(IPAddress.Parse(QueryServer.getIP()), QueryServer.getPort());

            string QueryString = String.Empty;

            switch (Type)
            {
                case QueryType.DVAR:
                case QueryType.COMMAND:
                    QueryString = $"ÿÿÿÿrcon {QueryServer.Password} {Parameters}";
                    break;
                case QueryType.GET_STATUS:
                    QueryString = "ÿÿÿÿ getstatus";
                    break;
            }

            byte[] Payload = GetRequestBytes(QueryString);

            int attempts = 0;
            retry:

            try
            {
              
                ServerOOBConnection.Connect(Endpoint);
                ServerOOBConnection.Send(Payload, Payload.Length);

                byte[] ReceiveBuffer = new byte[8192];
                StringBuilder QueryResponseString = new StringBuilder();

                do
                {
                    ReceiveBuffer = ServerOOBConnection.Receive(ref Endpoint);
                    QueryResponseString.Append(Encoding.ASCII.GetString(ReceiveBuffer).TrimEnd('\0'));
                } while (ServerOOBConnection.Available > 0);

                ServerOOBConnection.Close();

                if (QueryResponseString.ToString().Contains("Invalid password"))
                    throw new Exceptions.NetworkException("RCON password is invalid");

                int num = int.Parse("0a", System.Globalization.NumberStyles.AllowHexSpecifier);
                string[] SplitResponse = QueryResponseString.ToString().Split(new char[] { (char)num }, StringSplitOptions.RemoveEmptyEntries);
                return SplitResponse;
            }

            catch (SocketException)
            {
                attempts++;
                if (attempts > 5)
                {
                    var e = new Exceptions.NetworkException("Cannot communicate with server");
                    e.Data["server_address"] = ServerOOBConnection.Client.RemoteEndPoint.ToString();
                    ServerOOBConnection.Close();
                    throw e;
                }

                Thread.Sleep(1000);
                    goto retry;
            }
        }

        public static async Task<_DVAR<T>> GetDvarAsync<T>(this Server server, string dvarName)
        {          
            string[] LineSplit = await Task.FromResult(SendQuery(QueryType.DVAR, server, dvarName));

            if (LineSplit.Length != 3)
            {
                var e = new Exceptions.DvarException("DVAR does not exist");
                e.Data["dvar_name"] = dvarName;
                throw e;
            }

            string[] ValueSplit = LineSplit[1].Split(new char[] { '"' }, StringSplitOptions.RemoveEmptyEntries);

            if (ValueSplit.Length != 5)
            {
                var e = new Exceptions.DvarException("DVAR does not exist");
                e.Data["dvar_name"] = dvarName;
                throw e;
            }

            string DvarName = Regex.Replace(ValueSplit[0], @"\^[0-9]", "");
            string DvarCurrentValue = Regex.Replace(ValueSplit[2], @"\^[0-9]", "");
            string DvarDefaultValue = Regex.Replace(ValueSplit[4], @"\^[0-9]", "");

            return new _DVAR<T>(DvarName) { Value = (T)Convert.ChangeType(DvarCurrentValue, typeof(T)) };
        }

        public static async Task SetDvarAsync(this Server server, string dvarName, object dvarValue)
        {
            await Task.FromResult(SendQuery(QueryType.DVAR, server, $"{dvarName} {dvarValue}"));
        }

        public static async Task ExecuteCommandAsync(this Server server, string commandName)
        {
            await Task.FromResult(SendQuery(QueryType.COMMAND, server, commandName));
        }

        public static async Task<List<Player>> GetStatusAsync(this Server server)
        {
            string[] response = await Task.FromResult(SendQuery(QueryType.DVAR, server, "status"));
            return PlayersFromStatus(response);
        }


        static byte[] GetRequestBytes(string Request)
        {

            Byte[] initialRequestBytes = Encoding.Unicode.GetBytes(Request);
            Byte[] fixedRequest = new Byte[initialRequestBytes.Length / 2];

            for (int i = 0; i < initialRequestBytes.Length; i++)
                if (initialRequestBytes[i] != 0)
                    fixedRequest[i / 2] = initialRequestBytes[i];

            return fixedRequest;

        }
    }
}