using DotNetty.Buffers;
using DotNetty.Codecs;
using DotNetty.Common.Internal.Logging;
using DotNetty.Handlers.Logging;
using DotNetty.Handlers.Tls;
using DotNetty.Transport.Bootstrapping;
using DotNetty.Transport.Channels;
using DotNetty.Transport.Channels.Sockets;
using DotNetty.Transport.Libuv;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Console;
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Net;
using System.Net.Http.Headers;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Threading.Tasks;

namespace TcpEventBus
{
    public class NettyServerManger: ISocket
    {
        [AllowNull]
        private IEventLoopGroup bossGroup;
        [AllowNull]
        private IEventLoopGroup workerGroup;
        [AllowNull]
        private IChannel boundChannel;
        [AllowNull]
        private ServerBootstrap bootstrap;
        public string IP { get; }
        public int MaxFrameLength { get; }
        public int Port { get; }
        public bool IsService => true;
        public bool IsConnect => handler == null ? false:handler.IsConnect;

        public int ReceiveTimeout { get; }
        [AllowNull]

        public Action OnConnected { get; set; }
        [AllowNull]
        public Action<ArraySegment<byte>> OnData { get; set; }
        [AllowNull]
        public Action OnDisconnected { get; set; }
        private NettyHandler handler = new NettyHandler();

        public NettyServerManger(string ip,int port,int timeout=1000,int maxFrameLength=204800)
        {
            if (maxFrameLength <= 0) throw new ArgumentOutOfRangeException($"{nameof(maxFrameLength)} must be greater than 0");
            MaxFrameLength = maxFrameLength;
            this.IP = ip;
            this.Port = port;
            ReceiveTimeout = timeout;
            RunServer();
        }

       private void RunServer()
        {
#if DEBUG
            InternalLoggerFactory.DefaultFactory = LoggerFactory.Create(builder => builder.AddConsole());
#endif
            if (true)
            {
                var dispatcher = new DispatcherEventLoopGroup();
                bossGroup = dispatcher;
                workerGroup = new WorkerEventLoopGroup(dispatcher);
            }
            else
            {
                bossGroup = new MultithreadEventLoopGroup(1);
                workerGroup = new MultithreadEventLoopGroup();
            }


            try
            {
                bootstrap = new ServerBootstrap();
                bootstrap.Group(bossGroup, workerGroup);

                if (true)
                {
                    bootstrap.Channel<TcpServerChannel>();
                }
                else
                {
                    bootstrap.Channel<TcpServerSocketChannel>();
                }
                handler = new NettyHandler();
                handler.OnData = (data)=>OnData?.Invoke(data);
                handler.OnConnected = ()=>OnConnected?.Invoke();
                handler.OnDisconnected = ()=>OnDisconnected?.Invoke();
                bootstrap
                    .Option(ChannelOption.SoBacklog, 10)
                    .ChildOption(ChannelOption.SoLinger, 0)
                    .Handler(new LoggingHandler("SRV-LSTN"))
                    .ChildHandler(new ActionChannelInitializer<IChannel>(channel =>
                    {
                        IChannelPipeline pipeline = channel.Pipeline;
                        pipeline.AddLast(new LoggingHandler("SRV-CONN"));
                        pipeline.AddLast("framing-enc", new LengthFieldPrepender(3));
                        pipeline.AddLast("framing-dec", new LengthFieldBasedFrameDecoder(MaxFrameLength + 3, 0, 3, 0, 3));

                        pipeline.AddLast("echo", handler);
                    }));
            }
            finally
            {
            }
        }
        public async void Disconnect()
        {
            Console.WriteLine(nameof(Disconnect));
            await boundChannel.CloseAsync();
            await Task.WhenAll(
                bossGroup.ShutdownGracefullyAsync(TimeSpan.FromMilliseconds(100), TimeSpan.FromSeconds(1)),
                workerGroup.ShutdownGracefullyAsync(TimeSpan.FromMilliseconds(100), TimeSpan.FromSeconds(1)));
        }

        public async void Start()
        {
            boundChannel = await bootstrap.BindAsync(Port);
        }

        public void Send(byte[] data)
        {
            if (!IsConnect || data ==null|| data.Length ==0 || handler ==null) return;
            handler.SendData(data);
        }
    }

    public class NettyHandler: ChannelHandlerAdapter
    {
        [AllowNull]
        public Action OnConnected { get; set; }
        [AllowNull]
        public Action<ArraySegment<byte>> OnData { get; set; }
        [AllowNull]
        public Action OnDisconnected { get; set; }
        public bool IsConnect { get; private set; }
        [AllowNull]
        private IChannelHandlerContext _Context;
        public NettyHandler()
        {
            IsConnect = false;
        }
        public override bool IsSharable => true;
        public override void ChannelRead(IChannelHandlerContext context, object message)
        {            
            if(message is IByteBuffer buffer)
            {
                OnData?.Invoke(buffer.GetIoBuffer());
                buffer.Release();
            }
        }
        public override void ChannelReadComplete(IChannelHandlerContext context)
        {
            context.Flush();
        }
        public override void ChannelRegistered(IChannelHandlerContext context)
        {
            base.ChannelRegistered(context);
            Console.WriteLine(nameof(ChannelRegistered));
            OnConnected?.Invoke();
            IsConnect = true;
            
            _Context = context;
        }
        public override async void ChannelUnregistered(IChannelHandlerContext context)
        {
            base.ChannelUnregistered(context);
            Console.WriteLine(nameof(ChannelUnregistered));
            OnDisconnected?.Invoke();
            IsConnect = false;
            if (_Context != null)
            {
                _Context.Allocator.HeapBuffer().Clear();
                _Context.Allocator.DirectBuffer().Clear();
                _Context.Allocator.Buffer().Clear();
                _Context.Allocator.CompositeBuffer().Clear();
                _Context.Allocator.CompositeDirectBuffer().Clear();
                _Context.Allocator.CompositeHeapBuffer().Clear();
                _Context.Channel.Allocator.HeapBuffer().Clear();
                await _Context.CloseAsync();
                _Context.Channel.Pipeline.Remove(_Context.Handler);
            }
            _Context = null;
        }
        public void SendData(byte[] data)
        {
            if (_Context == null || data == null || data.Length == 0 || !IsConnect) return;
           var buffer =  _Context.Allocator.Buffer(data.Length);
            buffer.WriteBytes(data);
            _Context?.WriteAndFlushAsync(buffer);
        }
    }

    public class NettyClientManger :  ISocket
    {
        [AllowNull]
        private Bootstrap bootstrap;
        [AllowNull]
        private MultithreadEventLoopGroup group;
        [AllowNull]
        private IChannel clientChannel;
        public string IP { get; }
        public int Port { get; }
        public bool IsService => true;
        public bool IsConnect => handler == null ? false : handler.IsConnect;

        public int ReceiveTimeout { get; }
        [AllowNull]

        public Action OnConnected { get; set; }
        public int MaxFrameLength { get; }
        [AllowNull]
        public Action<ArraySegment<byte>> OnData { get; set; }
        [AllowNull]
        public Action OnDisconnected { get; set; }
        private NettyHandler handler = new NettyHandler();

        public NettyClientManger(string ip, int port,int timeout = 1000,int maxFrameLength=204800)
        {
            if(maxFrameLength<=0) throw new ArgumentOutOfRangeException($"{nameof(maxFrameLength)} must be greater than 0");
            this.IP = ip;
            this.Port = port;
            ReceiveTimeout = timeout;
            MaxFrameLength = maxFrameLength;
            RunClientAsync();
        }
        private void RunClientAsync()
        {
#if DEBUG
            InternalLoggerFactory.DefaultFactory = LoggerFactory.Create(builder => builder.AddConsole());
#endif
            group = new MultithreadEventLoopGroup();

            try
            {
                handler = new NettyHandler();
                handler.OnConnected =()=>OnConnected?.Invoke();
                handler.OnData = (data) => OnData?.Invoke(data);
                handler.OnDisconnected = ()=>OnDisconnected?.Invoke();
                bootstrap = new Bootstrap();
                bootstrap
                    .Group(group)
                    .Channel<TcpSocketChannel>()
                    .Option(ChannelOption.TcpNodelay, true)
                    .Handler(new ActionChannelInitializer<ISocketChannel>(channel =>
                    {
                        IChannelPipeline pipeline = channel.Pipeline;

                        pipeline.AddLast(new LoggingHandler());
                        pipeline.AddLast("framing-enc", new LengthFieldPrepender(3));
                        pipeline.AddLast("framing-dec", new LengthFieldBasedFrameDecoder(MaxFrameLength + 3, 0, 3, 0, 3));

                        pipeline.AddLast("echo", handler);
                    }));
            }
            finally
            {
            }
        }
        public async void Disconnect()
        {
            if (clientChannel == null) return;
            await clientChannel.CloseAsync();
            Console.WriteLine($"{DateTime.Now}:{nameof(Disconnect)}");
        }
        public void Start()
        {
            try
            {
               Task.Run(()=>  clientChannel = bootstrap.ConnectAsync(new IPEndPoint(IPAddress.Parse(IP), Port)).Result);
               Thread.Sleep(100);
            }
            catch
            {
            }
        }


        public void Send(byte[] data)
        {
            if (!IsConnect || data == null || data.Length == 0 || clientChannel ==null) return;
            var buffer = clientChannel.Allocator.Buffer(data.Length);
            buffer.WriteBytes(data);
            clientChannel.WriteAndFlushAsync(buffer);
        }
    }
}