using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Houdar.PLC.Driver.Simenss.Protocol.Iso;
using ByteBuffer = Houdar.Core.Communication.Transport.ByteBuffer;

namespace Houdar.PLC.Driver.Simenss.Communication
{
    /// <summary>
    /// 采用同步通信机制
    /// </summary>
    public class IsoSocket : IIsoSender
    {
        private Socket _socket;
        public bool Connected
        {
            get
            {
                try
                {
                    if (_socket == null)
                        return false;
                    return !((_socket.Poll(1000, SelectMode.SelectRead) && (_socket.Available == 0)) || !_socket.Connected);
                }
                catch { return false; }
            }
        }


        private Action<MessageEvent> _messageAction;

        public void RegisterMessage(Action<MessageEvent> messageAction)
        {
            if (messageAction == null) throw new ArgumentNullException("messageAction");
            _messageAction = messageAction;
        }

        private void OnMessage(string methode, string message)
        {
            if (_messageAction != null)
                _messageAction.Invoke(new MessageEvent(methode, message));
        }
        private static bool _isConnectionSuccessful = false;
        private int _connecting;//连接中
        public bool Connect(string ip, int port)
        {
            try
            {
                if (Interlocked.CompareExchange(ref _connecting, 1, 0) != 0)
                {
                    OnMessage("Connect", "连接正在处理中");
                    return false;
                }

                _socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                _socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, 1000);
                _socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.SendTimeout, 1000);
                IPEndPoint server = new IPEndPoint(IPAddress.Parse(ip), 102);

                #region 添加的代码 20170801 
                timeoutObject = new ManualResetEvent(false);
                _socket.BeginConnect(server, new AsyncCallback(CallBackMethod), _socket);
                if (timeoutObject.WaitOne(1000, false))
                {
                    if (_isConnectionSuccessful)
                    {
                    }
                    else
                    {
                        _socket.Close();
                        throw new Exception("连接超时");
                    } 
                }
                #endregion;

                #region 被注释的代码 
                //_socket.Connect(server);
                #endregion;
                return true;
            }
            catch (Exception ex)
            {
                OnMessage("Connect", "连接异常:{ex.Message}");
                return false;
            }
            finally
            {
                Interlocked.CompareExchange(ref _connecting, 0, 1);
            }
        }

        #region 添加的代码 20170801
        private ManualResetEvent timeoutObject;//通知一个或多个正在等待的线程已发生事件
        /// <summary>
        /// 连接过程中的异步回调
        /// </summary>
        /// <param name="asyncresult"></param>
        private void CallBackMethod(IAsyncResult asyncresult)
        {
            try
            {
                _isConnectionSuccessful = false;
                _socket = asyncresult.AsyncState as Socket;
                if (_socket != null)
                {
                    _socket.EndConnect(asyncresult);
                    _isConnectionSuccessful = true;
                }
            }
            catch (Exception ex)
            {
                _isConnectionSuccessful = false;
            }
            finally
            {
                timeoutObject.Set();//解除被阻塞的连接线程
            }
        }
        #endregion;

        private bool IsActive()
        {
            if (!Connected)
            {
                OnMessage("SendRecive", "未连接到PLC设备");
                return false;
            }
            if (Interlocked.CompareExchange(ref _sending, 1, 0) != 0)
            {
                OnMessage("SendRecive", "正在处理中");
                return false;
            }

            return true;
        }

        private int _sending;//发送中
        public byte[] SendRecive(byte[] sendBytes, int length)
        {
            try
            {
                if (!IsActive()) return null;

                var sendStr = BitConverter.ToString(sendBytes, 0, length);
                //Console.WriteLine($"{DateTime.Now.ToString("HH:mm:ss ffff")}[Send]({length}):{sendStr}");

                _socket.Send(sendBytes, length, SocketFlags.None);

                byte[] bReceive = new byte[1024 * 4 * 8];
                var resLength = _socket.Receive(bReceive, SocketFlags.None);

                var recvStr = BitConverter.ToString(bReceive, 0, resLength);
                //Console.WriteLine($"{DateTime.Now.ToString("HH:mm:ss ffff")}[Recv]({resLength}):{recvStr}");

                var receiveBytes = new byte[resLength];
                Array.Copy(bReceive, 0, receiveBytes, 0, resLength);

                return receiveBytes;
            }
            catch (Exception ex)
            {
                OnMessage("Send", "发送异常:{ex.Message}");
                return null;
            }
            finally
            {
                Interlocked.CompareExchange(ref _sending, 0, 1);
            }
        }
        
        private TResponse GetResponse<TResponse>(byte[] resBytes, bool isContainHeader = true)
            where TResponse : IBuildResponse, new()
        {
            ByteBuffer buffer= ByteBuffer.Allocate();
            buffer.Push(resBytes);

            if(isContainHeader)
            {
                IsoDataPdu pdu = new IsoDataPdu();
                pdu.Build(buffer);

                if (resBytes.Length != pdu.Length)
                    return default(TResponse);
            }

            TResponse response = new TResponse();
            response.Build(buffer);

            return response;
        }

        private ByteBuffer GetByteBuffer<TRequest>(TRequest request, bool isContainHeader=true)
            where TRequest : IBuildRequest, new()
        {
            if(request==null) throw  new ArgumentNullException("request");

            request.Build();
            var bufferData = request.GetBuffer();
            ByteBuffer buffer = ByteBuffer.Allocate();

            if(isContainHeader)
            {
                //构建ISO头部
                IsoDataPdu pdu = new IsoDataPdu { Length = (ushort)bufferData.WriteIndex };
                pdu.Build();
                pdu.GetBuffer(buffer);
            }

            buffer.Push(bufferData.Buffer, bufferData.WriteIndex);

            return buffer;
        }

        /// <summary>
        /// 不含ISO头的请求
        /// </summary>
        /// <typeparam name="TRequest"></typeparam>
        /// <typeparam name="TResponse"></typeparam>
        /// <param name="request"></param>
        /// <returns></returns>
        public TResponse Send<TRequest, TResponse>(TRequest request) where TRequest : IBuildRequest, new() where TResponse : IBuildResponse, new()
        {
            var buffer = GetByteBuffer(request, false);
            var resByte = SendRecive(buffer.Buffer, buffer.WriteIndex);

            if (resByte == null || resByte.Length == 0) return default(TResponse);


            return GetResponse<TResponse>(resByte, false);
        }

        /// <summary>
        /// 包含ISO头的请求
        /// </summary>
        /// <typeparam name="TRequest"></typeparam>
        /// <typeparam name="TResponse"></typeparam>
        /// <param name="request"></param>
        /// <returns></returns>
        public TResponse IsoSend<TRequest, TResponse>(TRequest request) where TRequest : IBuildRequest, new() where TResponse : IBuildResponse, new()
        {
            try
            {
                var buffer = GetByteBuffer(request);

                var resByte = SendRecive(buffer.Buffer, buffer.WriteIndex);

                if (resByte == null) return default(TResponse);

                return GetResponse<TResponse>(resByte);
            }
            catch (Exception ex)
            {
                return default(TResponse);
            }
        }
    }
}