using HslCommunication.Core;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using HslCommunication.Core.Net;
using System.Net;
using System.Net.Sockets;

namespace HslCommunication.Enthernet
{

    /// <summary>
    /// 一个基于异步高性能的客户端网络类，支持主动接收服务器的消息
    /// </summary>
    /// <remarks>
    /// 详细的使用说明，请参照博客<a href="http://www.cnblogs.com/dathlin/p/7697782.html">http://www.cnblogs.com/dathlin/p/7697782.html</a>
    /// </remarks>
    /// <example>
    /// 此处贴上了Demo项目的服务器配置的示例代码
    /// <code lang="cs" source="TestProject\HslCommunicationDemo\FormComplexNet.cs" region="NetComplexClient" title="NetComplexClient示例" />
    /// </example>
    public class NetComplexClient : NetworkXBase
    {
        #region Constructor

        /// <summary>
        /// 实例化一个对象
        /// </summary>
        public NetComplexClient( )
        {
            session = new AppSession( );
            ServerTime = DateTime.Now;
            EndPointServer = new IPEndPoint( IPAddress.Any, 0 );
        }

        #endregion

        #region Private Member

        private AppSession session;                 // 客户端的核心连接对象
        private int isConnecting = 0;               // 指示客户端是否处于连接服务器中，0代表未连接，1代表连接中
        private bool IsQuie = false;                // 指示系统是否准备退出
        private Thread thread_heart_check  = null;  // 心跳线程

        #endregion

        #region Public Properties

        /// <summary>
        /// 客户端系统是否启动
        /// </summary>
        public bool IsClientStart { get; set; }

        /// <summary>
        /// 重连接失败的次数
        /// </summary>
        public int ConnectFailedCount { get; private set; }

        /// <summary>
        /// 客户端登录的标识名称，可以为ID号，也可以为登录名
        /// </summary>
        public string ClientAlias { get; set; } = string.Empty;

        /// <summary>
        /// 远程服务器的IP地址和端口
        /// </summary>
        public IPEndPoint EndPointServer { get; set; }

        /// <summary>
        /// 服务器的时间，自动实现和服务器同步
        /// </summary>
        public DateTime ServerTime { get; private set; }

        /// <summary>
        /// 系统与服务器的延时时间，单位毫秒
        /// </summary>
        public int DelayTime { get; private set; }


        #endregion

        #region Event Handle



        /// <summary>
        /// 客户端启动成功的事件，重连成功也将触发此事件
        /// </summary>
        public event Action LoginSuccess;

        /// <summary>
        /// 连接失败时触发的事件
        /// </summary>
        public event Action<int> LoginFailed;

        /// <summary>
        /// 服务器的异常，启动，等等一般消息产生的时候，出发此事件
        /// </summary>
        public event Action<string> MessageAlerts;

        /// <summary>
        /// 在客户端断开后并在重连服务器之前触发，用于清理系统资源
        /// </summary>
        public event Action BeforReConnected;

        /// <summary>
        /// 当接收到文本数据的时候,触发此事件
        /// </summary>
        public event Action<AppSession, NetHandle, string> AcceptString;

        /// <summary>
        /// 当接收到字节数据的时候,触发此事件
        /// </summary>
        public event Action<AppSession, NetHandle, byte[]> AcceptByte;


        #endregion

        #region Start Close Support


        /// <summary>
        /// 关闭该客户端引擎
        /// </summary>
        public void ClientClose( )
        {
            IsQuie = true;
            if (IsClientStart)
                SendBytes( session, HslProtocol.CommandBytes( HslProtocol.ProtocolClientQuit, 0, Token, null ) );

            IsClientStart = false;          // 关闭客户端
            thread_heart_check = null;

            LoginSuccess = null;            // 清空所有的事件
            LoginFailed = null;
            MessageAlerts = null;
            AcceptByte = null;
            AcceptString = null;
            try
            {
                session.WorkSocket?.Shutdown( SocketShutdown.Both );
                session.WorkSocket?.Close( );
            }
            catch
            {

            }
            LogNet?.WriteDebug( ToString( ), "Client Close." );
        }


        /// <summary>
        /// 启动客户端引擎，连接服务器系统
        /// </summary>
        public void ClientStart()
        {
            // 如果处于连接中就退出
            if (Interlocked.CompareExchange( ref isConnecting, 1, 0 ) != 0) return;

            // 启动后台线程连接
            new Thread( new ThreadStart( ThreadLogin ) ) { IsBackground = true }.Start( );

            // 启动心跳线程，在第一次Start的时候
            if (thread_heart_check == null)
            {
                thread_heart_check = new Thread( new ThreadStart( ThreadHeartCheck ) )
                {
                    Priority = ThreadPriority.AboveNormal,
                    IsBackground = true
                };
                thread_heart_check.Start( );
            }
        }

        /// <summary>
        /// 连接服务器之前的消息提示，如果是重连的话，就提示10秒等待信息
        /// </summary>
        private void AwaitToConnect( )
        {
            if (ConnectFailedCount == 0)
            {
                MessageAlerts?.Invoke( StringResources.Language.ConnectingServer );
            }
            else
            {
                int count = 10;
                while (count > 0)
                {
                    if (IsQuie) return;
                    count--;
                    MessageAlerts?.Invoke( string.Format( StringResources.Language.ConnectFailedAndWait, count ) );
                    Thread.Sleep( 1000 );
                }
                MessageAlerts?.Invoke( string.Format( StringResources.Language.AttemptConnectServer, ConnectFailedCount ) );
            }
        }

        private void ConnectFailed( )
        {
            ConnectFailedCount++;
            Interlocked.Exchange( ref isConnecting, 0 );
            LoginFailed?.Invoke( ConnectFailedCount );
            LogNet?.WriteDebug( ToString( ), "Connected Failed, Times: " + ConnectFailedCount );
        }

        private OperateResult<Socket> ConnectServer( )
        {
            OperateResult<Socket> connectResult = CreateSocketAndConnect( EndPointServer, 10000 );
            if (!connectResult.IsSuccess)
            {
                return connectResult;
            }
            
            // 连接成功，发送数据信息
            OperateResult sendResult = SendStringAndCheckReceive( connectResult.Content, 1, ClientAlias );
            if (!sendResult.IsSuccess)
            {
                return OperateResult.CreateFailedResult<Socket>( sendResult );
            }

            MessageAlerts?.Invoke( StringResources.Language.ConnectServerSuccess );
            return connectResult;
        }

        private void LoginSuccessMethod( Socket socket )
        {
            ConnectFailedCount = 0;
            try
            {
                session.IpEndPoint = (IPEndPoint)socket.RemoteEndPoint;
                session.LoginAlias = ClientAlias;
                session.WorkSocket = socket;
                session.HeartTime = DateTime.Now;
                IsClientStart = true;
                ReBeginReceiveHead( session, false );
            }
            catch(Exception ex)
            {
                LogNet?.WriteException( ToString( ), ex );
            }
        }


        private void ThreadLogin()
        {
            // 连接的消息等待
            AwaitToConnect( );
            
            OperateResult<Socket> connectResult = ConnectServer( );
            if (!connectResult.IsSuccess)
            {
                ConnectFailed( );
                // 连接失败，重新连接服务器
                ThreadPool.QueueUserWorkItem( new WaitCallback( ReconnectServer ), null );
                return;
            }

            // 登录成功
            LoginSuccessMethod( connectResult.Content );

            // 登录成功
            LoginSuccess?.Invoke( );
            Interlocked.Exchange( ref isConnecting, 0 );
            Thread.Sleep( 200 );
        }

        
        private void ReconnectServer(object obj = null)
        {
            // 是否连接服务器中，已经在连接的话，则不再连接
            if (isConnecting == 1) return;
            // 是否退出了系统，退出则不再重连
            if (IsQuie) return;
            // 触发连接失败，重连系统前错误
            BeforReConnected?.Invoke( );
            session?.WorkSocket?.Close( );
            // 重新启动客户端
            ClientStart( );
        }

        #endregion

        #region Send Message Support

        /// <summary>
        /// 通信出错后的处理
        /// </summary>
        /// <param name="receive">接收的会话</param>
        /// <param name="ex">异常</param>
        internal override void SocketReceiveException( AppSession receive, Exception ex )
        {
            if (ex.Message.Contains( StringResources.Language.SocketRemoteCloseException ))
            {
                // 异常掉线
                ReconnectServer( );
            }
            else
            {
                // MessageAlerts?.Invoke("数据接收出错：" + ex.Message);
            }

            LogNet?.WriteDebug( ToString( ), "Socket Excepiton Occured." );
        }


        /// <summary>
        /// 服务器端用于数据发送文本的方法
        /// </summary>
        /// <param name="customer">用户自定义的命令头</param>
        /// <param name="str">发送的文本</param>
        public void Send( NetHandle customer, string str )
        {
            if (IsClientStart)
            {
                SendBytes( session, HslProtocol.CommandBytes( customer, Token, str ) );
            }
        }

        /// <summary>
        /// 服务器端用于发送字节的方法
        /// </summary>
        /// <param name="customer">用户自定义的命令头</param>
        /// <param name="bytes">实际发送的数据</param>
        public void Send( NetHandle customer, byte[] bytes )
        {
            if (IsClientStart)
            {
                SendBytes( session, HslProtocol.CommandBytes( customer, Token, bytes ) );
            }
        }

        private void SendBytes( AppSession stateone, byte[] content )
        {
            SendBytesAsync( stateone, content );
        }

        #endregion

        #region Data Process Center

        /// <summary>
        /// 客户端的数据处理中心
        /// </summary>
        /// <param name="session">会话</param>
        /// <param name="protocol">消息暗号</param>
        /// <param name="customer">用户消息</param>
        /// <param name="content">数据内容</param>
        internal override void DataProcessingCenter( AppSession session, int protocol, int customer, byte[] content )
        {
            if (protocol == HslProtocol.ProtocolCheckSecends)
            {
                DateTime dt = new DateTime( BitConverter.ToInt64( content, 0 ) );
                ServerTime = new DateTime( BitConverter.ToInt64( content, 8 ) );
                DelayTime = (int)(DateTime.Now - dt).TotalMilliseconds;
                this.session.HeartTime = DateTime.Now;
                // MessageAlerts?.Invoke("心跳时间：" + DateTime.Now.ToString());
            }
            else if (protocol == HslProtocol.ProtocolClientQuit)
            {
                // 申请了退出
            }
            else if (protocol == HslProtocol.ProtocolUserBytes)
            {
                // 接收到字节数据
                AcceptByte?.Invoke( this.session, customer, content );
            }
            else if (protocol == HslProtocol.ProtocolUserString)
            {
                // 接收到文本数据
                string str = Encoding.Unicode.GetString( content );
                AcceptString?.Invoke( this.session, customer, str );
            }
        }

        #endregion

        #region Heart Check


        /// <summary>
        /// 心跳线程的方法
        /// </summary>
        private void ThreadHeartCheck()
        {
            Thread.Sleep( 2000 );
            while (true)
            {
                Thread.Sleep( 1000 );
                if (!IsQuie)
                {
                    byte[] send = new byte[16];
                    BitConverter.GetBytes( DateTime.Now.Ticks ).CopyTo( send, 0 );
                    SendBytes( session, HslProtocol.CommandBytes( HslProtocol.ProtocolCheckSecends, 0, Token, send ) );
                    double timeSpan = (DateTime.Now - session.HeartTime).TotalSeconds;
                    if (timeSpan > 1 * 8)//8次没有收到失去联系
                    {
                        if (isConnecting == 0)
                        {
                            LogNet?.WriteDebug( ToString( ), $"Heart Check Failed int {timeSpan} Seconds." );
                            ReconnectServer( );
                        }
                        if (!IsQuie) Thread.Sleep( 1000 );
                    }
                }
                else
                {
                    break;
                }
            }


        }


        #endregion

        #region Object Override

        /// <summary>
        /// 返回对象的字符串表示形式
        /// </summary>
        /// <returns></returns>
        public override string ToString()
        {
            return "NetComplexClient";
        }

        #endregion
    }
}