using System.ComponentModel;
using System.Net;
using System.Net.Sockets;

namespace JiLinApp.Docking.FenceAlarm;

public class Udp
{
    #region Fields

    private BackgroundWorker BackWorker { get; }

    /// <summary>
    /// 用于UDP接收的网络服务类
    /// </summary>
    private UdpClient RecvUdp { get; }

    /// <summary>
    /// 用于UDP发送的网络服务类
    /// </summary>
    private UdpClient SendUdp { get; }

    #endregion Fields

    #region Ctors

    public Udp(int port) : this("0.0.0.0", port)
    {
    }

    public Udp(string ip, int port)
    {
        RecvUdp = new(new IPEndPoint(IPAddress.Parse(ip), port));
        SendUdp = new(new IPEndPoint(IPAddress.Any, 0));
        BackWorker = new BackgroundWorker
        {
            WorkerSupportsCancellation = true
        };
        BackWorker.DoWork += Back_DoWork;
        BackWorker.RunWorkerAsync();
    }

    ~Udp()
    {
        Stop();
    }

    #endregion Ctors

    #region Server

    public void Stop()
    {
        BackWorker?.CancelAsync();
        RecvUdp?.Close();
        SendUdp?.Close();
    }

    #endregion Server

    #region Receive

    public delegate void UDPReceive(IPEndPoint ipep, byte[] str);

    public event UDPReceive DatagramReceived;

    private void RaiseDatagramReceived(IPEndPoint ipep, byte[] datagram)
    {
        DatagramReceived?.Invoke(ipep, datagram);
    }

    #endregion Receive

    #region Send

    public bool SendMessage(string ip, int port, byte[] byteMsg)
    {
        IPEndPoint ipep = new(IPAddress.Parse(ip), port); // 发送到的IP地址和端口号
        int result = SendUdp.Send(byteMsg, byteMsg.Length, ipep);
        bool flag = result >= byteMsg.Length;
        Console.WriteLine("Send ok: {0}", flag);
        return flag;
    }

    public bool SendMessage(IPEndPoint ipep, byte[] byteMsg)
    {
        int result = SendUdp.Send(byteMsg, byteMsg.Length, ipep);
        return result >= byteMsg.Length;
    }

    #endregion Send

    private void Back_DoWork(object? sender, DoWorkEventArgs e)
    {
        IPEndPoint remoteIpep = new(IPAddress.Any, 0);
        while (BackWorker != null && !BackWorker.CancellationPending)
        {
            try
            {
                byte[] bytRecv = RecvUdp.Receive(ref remoteIpep);
                DatagramReceived(remoteIpep, bytRecv);
            }
            catch
            {
                throw;
            }
        }
    }
}