using DroneClient.Models;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using TelemetryIO;
using TelemetryIO.Models;

namespace TelemetryIO
{
    internal class TelemetryServer : TelemetryIO.BaseCommHandler
    {
        ConcurrentQueue<byte[]> sendQueue = new ConcurrentQueue<byte[]>();
        Telemetry telemetry = Telemetry.Instance;
        MonitorContainer monitoring = MonitorContainer.Instance;
        private bool isClientConnected = false;

        public event EventHandler OnTeleClientConnected = delegate { };
        public event EventHandler OnTeleClientDisconnected = delegate { };

        public bool isClientAvailable { get { return isClientConnected; } }

        public TelemetryServer()
        {

        }
        public override void Close()
        {
            throw new NotImplementedException();
        }

        public override void CloseConnection()
        {
            throw new NotImplementedException();
        }

        public override bool IsOpen()
        {
            return true;
        }

        public async override Task Open()
        {
            await StartServerAsync();
            //Console.ReadLine();
        }

        public async Task StartServerAsync()
        {
            var listener = new TcpListener(IPAddress.Any, Port);
            listener.Start();
            Console.WriteLine("Server is running");
            try
            {
                while (true)
                {
                    //if (isClientConnected) await Task.Delay(25);
                    var client = await listener.AcceptTcpClientAsync();
                    StrikeOnTeleClientConnected();
                    isClientConnected = true;
                    Debug.WriteLine("Client is connected");
                    //this.client = client;
                    var readTask = StartReadingAsync(client);
                    var writeTask = SendMessageAsync(client);
                    await readTask;
                    await writeTask;
                }
            }
            catch (IOException ex) when (IsNetworkError(ex))
            {
                // Специальная обработка сетевых ошибок
                Debug.WriteLine($"Ошибка при запуске сервера: {ex.Message}");
            }
            catch (Exception ex)
            {
                Debug.WriteLine("An error occurred: " + ex.Message);
            }
            finally
            {
                listener.Stop();
            }
        }

        public async Task SendMessageAsync(TcpClient c)
        {
            if (c.GetStream() == null || !c.Connected)
            {
                Console.WriteLine("Not connected to server");
                return;
            }

            while (c.Connected)
            {
                if (sendQueue.TryDequeue(out byte[] buffer))
                {
                    try
                    {
                        await c.GetStream().WriteAsync(buffer, 0, buffer.Length);
                        Debug.WriteLine($"Sent");
                    }
                    catch (IOException ex) when (IsNetworkError(ex))
                    {
                        // Специальная обработка сетевых ошибок
                        Debug.WriteLine($"Клиент отключился: {ex.Message}");
                        HandleDisconnectedClient(c);
                    }
                    catch (Exception ex)
                    {
                        Debug.WriteLine($"Error sending message: {ex.Message}");
                    }
                }
            }
        }

        public async override Task StartReadingAsync(object C)
        {
            TcpClient client;
            if (C is TcpClient) client = (TcpClient)C;
            else
            {
                return;
            }
            try
            {
                using NetworkStream stream = client.GetStream();

                while (client.Connected)
                {
                    byte[] buffer = new byte[1024];
                    int bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length);
                    //string response = await reader.ReadLineAsync();
                    if (bytesRead > 0)
                    {
                        EnqueueData(buffer, bytesRead);
                    }
                    data_extract();
                }
            }
            catch (IOException ex) when (IsNetworkError(ex))
            {
                // Специальная обработка сетевых ошибок
                Debug.WriteLine($"Клиент отключился: {ex.Message}");
                HandleDisconnectedClient(client);
            }
            catch (Exception ex)
            {
                Debug.WriteLine($"Error sending message: {ex.Message}");
            }
        }

        protected override void ProcessCommand(int cmd, int slot, byte[] data, int offset, int len)
        {
            Debug.WriteLine(@"server cmd = " + cmd);

            switch (cmd)
            {
                case TELE_CMD_HELLO:
                    byte[] load = telemetry.getSlot(cmd, offset, len);
                    putRequest(prepareTelegram(cmd, 0, load, 0, load.Length));
                    break;

                case TELE_CMD_RD_ONCE:
                    byte[] load1 = telemetry.getSlot(slot, offset, len);
                    putRequest(prepareTelegram(cmd, slot, load1, offset, load1.Length));
                    break;

                case TELE_CMD_WR:
                    setData(data, slot, offset, len);
                    sendVoidAnswer(TELE_CMD_WR);
                    break;

                case TELE_CMD_RD_MON_ON:
                    monitoring.isMonitor = 1;
                    sendVoidAnswer(TELE_CMD_RD_MON_ON);
                    break;

                case TELE_CMD_RD_MON_OFF:
                    monitoring.isMonitor = 0;
                    sendVoidAnswer(TELE_CMD_RD_MON_OFF);
                    break;

                case TELE_CMD_RD_MON_ADD:
                    int id = monitoring.monitorPut(slot, offset, 4);
                    sendIntAnswer(TELE_CMD_RD_MON_ADD, id);
                    monitoring.isMonitor = 1;
                    break;

                case TELE_CMD_RD_MON_REMOVE:
                    id = monitoring.monitorRemove(offset);//in this case offset == id
                    if(monitoring.monitorFillLevel == 0)monitoring.isMonitor = 0;//if monitor_fill_level == 0 there is no item to monitor
                    if (monitoring.isMonitor > 0) sendIntAnswer(TELE_CMD_RD_MON_REMOVE, id);
                    else sendVoidAnswer(TELE_CMD_RD_MON_REMOVEALL);
                    break;
            }
        }

        private void setData(byte[] load, int slot, int offset, int len)
        {
            telemetry.setSlot(slot, load, offset, len);
        }

        private void sendVoidAnswer(int command)
        {
            putRequest(prepareTelegram(command, 0, new byte[0], 0));
        }

        private void sendIntAnswer(int command, int param)
        {
            putRequest(prepareTelegram(command, 0, new byte[0], param));
        }

        protected override void sendData(byte[] data)
        {
            sendQueue.Enqueue(data);
        }

        public override void setCommParams(iCommParams commParams)
        {
            if (commParams.GetType() == typeof(TCPCommParams))
            {
                var comm = (TCPCommParams)commParams;
                IP = comm.IP;
                Port = comm.Port;
            }
        }

        private void HandleDisconnectedClient(TcpClient client)
        {
            isClientConnected = false;
            StrikeOnTeleClientDisconnected();
        }

        private bool IsNetworkError(Exception ex)
        {
            // Проверяем типичные сетевые ошибки при разрыве соединения
            return ex is IOException
                   || ex is SocketException
                   || ex.InnerException is SocketException;
        }

        public void StrikeOnTeleClientConnected()
        {
            OnTeleClientConnected?.Invoke(this, EventArgs.Empty);
        }

        public void StrikeOnTeleClientDisconnected()
        {
            OnTeleClientDisconnected?.Invoke(this, EventArgs.Empty);
        }
    }
}