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

//https://github.com/opengsq/opengsq-dotnet/blob/main/OpenGSQ/Protocols/GameSpy2.cs
//https://github.com/opengsq/opengsq-dotnet/blob/main/OpenGSQ/ProtocolBase.cs

/*
MIT License

Copyright (c) 2021 OpenGSQ

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE. 
 
 */

namespace VeloeMonitorDataCollector.Dependencies
{
    /// <summary>
    /// Gamespy Query Protocol version 2
    /// </summary>
    public class Gs2Status
    {

        /// <summary>
        /// Represents a network endpoint as an IP address and a port number.
        /// </summary>
        protected IPEndPoint _EndPoint;

        /// <summary>
        /// Timeout in millisecond
        /// </summary>
        protected int _Timeout;

        /// <summary>
        /// Cached challenge bytes
        /// </summary>
        protected byte[] _Challenge = new byte[0];

        /// <summary>
        /// ProtocolBase
        /// </summary>
        /// <param name="address"></param>
        /// <param name="port"></param>
        /// <param name="timeout"></param>
        public Gs2Status(string address, int port, int timeout = 5000)
        {
            if (IPAddress.TryParse(address, out var ipAddress))
            {
                _EndPoint = new IPEndPoint(ipAddress, port);
            }
            else
            {
                _EndPoint = new IPEndPoint(Dns.GetHostAddresses(address)[0], port);
            }

            _Timeout = timeout;
        }
        /// <summary>
        /// Gamespy Query Protocol version 2
        /// </summary>
        /// <param name="address"></param>
        /// <param name="port"></param>
        /// <param name="timeout"></param>

        /// <summary>
        /// Retrieves information about the server including, Info, Players, and Teams.
        /// </summary>
        /// <param name="request"></param>
        /// <returns></returns>
        /// <exception cref="SocketException"></exception>
        public Status GetStatus(Request request = Request.Info | Request.Players | Request.Teams)
        {
            using (var udpClient = new UdpClient())
            {
                var responseData = ConnectAndSend(udpClient, request);

                using (var br = new BinaryReader(new MemoryStream(responseData), Encoding.UTF8))
                {
                    var status = new Status();

                    // Save Response Info
                    if (request.HasFlag(Request.Info))
                    {
                        status.Info = GetInfo(br);
                    }

                    // Save Response Players
                    if (request.HasFlag(Request.Players))
                    {
                        status.Players = GetPlayers(br);
                    }

                    // Save Response Teams
                    if (request.HasFlag(Request.Teams))
                    {
                        status.Teams = GetTeams(br);
                    }

                    return status;
                }
            }
        }

        private byte[] ConnectAndSend(UdpClient udpClient, Request request)
        {
            // Connect to remote host
            udpClient.Connect(_EndPoint);
            udpClient.Client.SendTimeout = _Timeout;
            udpClient.Client.ReceiveTimeout = _Timeout;

            // Send Request
            var requestData = new byte[] { 0xFE, 0xFD, 0x00, 0x04, 0x05, 0x06, 0x07 }.Concat(GetRequestBytes(request)).ToArray();
            udpClient.Send(requestData, requestData.Length);

            // Server response
            var responseData = udpClient.Receive(ref _EndPoint);

            // Remove the first 5 bytes { 0x00, 0x04, 0x05, 0x06, 0x07 }
            return responseData.Skip(5).ToArray();
        }

        private byte[] GetRequestBytes(Request request)
        {
            return new byte[] {
                (byte)(request.HasFlag(Request.Info) ? 0xFF : 0x00),
                (byte)(request.HasFlag(Request.Players) ? 0xFF : 0x00),
                (byte)(request.HasFlag(Request.Teams) ? 0xFF : 0x00),
            };
        }

        private Dictionary<string, string> GetInfo(BinaryReader br)
        {
            var info = new Dictionary<string, string>();

            // Read all key values
            while (br.TryReadStringEx(out var key))
            {
                info[key] = br.ReadStringEx().Trim();
            }

            return info;
        }

        private List<Dictionary<string, string>> GetPlayers(BinaryReader br)
        {
            var players = new List<Dictionary<string, string>>();

            // Skip a byte
            br.ReadByte();

            // Get player count
            var playerCount = br.ReadByte();

            // Get all keys
            var keys = new List<string>();

            while (br.TryReadStringEx(out var key))
            {
                keys.Add(key.TrimEnd('_'));
            }

            // Set all keys and values
            for (int i = 0; i < playerCount; i++)
            {
                players.Add(new Dictionary<string, string>());

                foreach (var key in keys)
                {
                    players[i][key] = br.ReadStringEx().Trim();
                }
            }

            return players;
        }

        private List<Dictionary<string, string>> GetTeams(BinaryReader br)
        {
            var teams = new List<Dictionary<string, string>>();

            // Skip a byte
            br.ReadByte();

            // Get team count
            var teamCount = br.ReadByte();

            // Get all keys
            var keys = new List<string>();

            while (br.TryReadStringEx(out var key))
            {
                keys.Add(key.TrimEnd('t').TrimEnd('_'));
            }

            // Set all keys and values
            for (int i = 0; i < teamCount; i++)
            {
                teams.Add(new Dictionary<string, string>());

                foreach (var key in keys)
                {
                    teams[i][key] = br.ReadStringEx().Trim();
                }
            }

            return teams;
        }

        /// <summary>
        /// Request Flag
        /// </summary>
        [Flags]
        public enum Request : short
        {
#pragma warning disable 1591
            Info = 1,
            Players = 2,
            Teams = 4,
        }

        public class Status
        {
            public Dictionary<string, string> Info { get; set; }

            public List<Dictionary<string, string>> Players { get; set; }

            public List<Dictionary<string, string>> Teams { get; set; }
        }
    }
}