public class UdpNetMgr : MonoBehaviour
{
    private static UdpNetMgr instance;
    public static UdpNetMgr Instance => instance;
    
    private EndPoint serverIpPoint;

    private Socket socket;
    
    private bool isClosed;
    //两个容器
    //接收和发送消息的队列 主要用于多线程
    private Queue<BaseMsg> sendQueue = new Queue<BaseMsg>();
    private Queue<BaseMsg> ReceiveQueue = new Queue<BaseMsg>();
    
    private byte[] cacheBytes = new byte[512];
    private void Awake()
    {
        instance = this;
        DontDestroyOnLoad(this);
    }
    private void Update()
    {
        if (ReceiveQueue.Count > 0)
        {
            BaseMsg msg = ReceiveQueue.Dequeue();
            switch (msg)
            {
                case PlayerMsg playerMsg:
                    print(playerMsg.playerID);
                    print(playerMsg.playerData.name);
                    print(playerMsg.playerData.atk);
                    print(playerMsg.playerData.lev);
                    break;
            }
        }
    }

    /// <summary>
    /// 启动客户端socket相关的方法
    /// </summary>
    /// <param name="ip">远端服务器的IP</param>
    /// <param name="port">远端服务器的端口</param>
    public void StartClient(string ip, int port)
    {
        //不重复开启
        if (isClosed)
            return;
        
        //先记录服务器地址，一会发消息使用
        serverIpPoint = new IPEndPoint(IPAddress.Parse(ip),port);
        IPEndPoint clientIpPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 8081);
        try
        {
            socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            socket.Bind(clientIpPoint);
            isClosed = false;
            ThreadPool.QueueUserWorkItem(ReceiveMsg);
            ThreadPool.QueueUserWorkItem(SendMsg);
        }
        catch (Exception e)
        {
            Console.WriteLine("启动Socket出问题"+e.Message);
            throw;
        }
    }
    //多线程发送消息
    private void SendMsg(object obj)
    {
        while (socket!=null&&!isClosed)
        {
            if (sendQueue.Count > 0)
            {
                try
                {
                    socket.SendTo(sendQueue.Dequeue().Writing(),serverIpPoint);
                }
                catch (SocketException e)
                {
                    print("发送消息出错"+e.ErrorCode+e.Message);
                }
            }
        }
    }
    /// <summary>
    /// 发送消息
    /// </summary>
    /// <param name="msg">消息内容</param>
    public void Send(BaseMsg msg)
    {
        sendQueue.Enqueue(msg);
    }
    //多线程接收消息
    private void ReceiveMsg(object obj)
    {
        EndPoint tmpIpPoint = new IPEndPoint(IPAddress.Any, 0);
        int nowIndex;
        int msgID;
        int msgLength;
        while (socket!=null&&!isClosed)
        {
            if (socket.Available>0)
            {
                try
                {
                    socket.ReceiveFrom(cacheBytes, ref tmpIpPoint);
                    //为了避免非服务器发来的 骚扰消息
                    //如果发现不是服务器 就不处理
                    if (!tmpIpPoint.Equals(serverIpPoint))
                        continue;
                    //处理服务器发来的消息
                    nowIndex = 0;
                    //解析ID
                    msgID = BitConverter.ToInt32(cacheBytes, nowIndex);
                    nowIndex += 4;
                    //解析长度
                    msgLength = BitConverter.ToInt32(cacheBytes, nowIndex);
                    nowIndex += 4;
                    //解析消息体
                    BaseMsg msg = null;
                    switch (msgID)
                    {
                        case 1001:
                            msg = new PlayerMsg();
                            //反序列化消息体
                            msg.Reading(cacheBytes, nowIndex);
                            break;
                    }
                    if (msg != null)
                        ReceiveQueue.Enqueue(msg);
                }
                catch (SocketException e)
                {
                    print("接收消息出问题" + e.ErrorCode + e.Message);
                }
                catch (Exception e)
                {
                    print("接收消息出问题（非网络）" + e.Message);
                }
            }
        }
    }
    
    /// <summary>
    /// 关闭socket
    /// </summary>
    public void Close()
    {
        if (socket != null)
        {
            isClosed = true;
            socket.Shutdown(SocketShutdown.Both);
            socket.Close();
            socket = null;
        }
    }

    private void OnDestroy()
    {
        Close();
    }
}