using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;

namespace BITKit.Net.LAN
{
	/// <summary>
	/// 基于UDP的LAN广播
	/// </summary>
	public class UdpBasedLanBroadcaster : ILANBroadcaster
	{
		public int Port { get; set; }
		public byte[] Buffer { get; set; } = StringHelper.GetBytes("Hello World");
		private bool _isBroadcasting;
		private bool _isListening;

		public UdpBasedLanBroadcaster()
		{

		}

		public event Action<EndPoint, string> OnReceive;

		public void StartBroadcast()
		{
			_isBroadcasting = true;
			Thread thread = new(Process)
			{
				IsBackground = true
			};
			thread.Start();
			BIT4Log.Log<ILANBroadcaster>($"开始广播端口{Port}");
		}

		public void StopBroadcast()
		{
			_isBroadcasting = false;
			BIT4Log.Log<ILANBroadcaster>($"停止广播端口 {Port}");
		}

		public void StartListen()
		{
			_isListening = true;
			var thread = new Thread(ReceiveThread)
			{
				IsBackground = true
			};
			thread.Start();
			BIT4Log.Log<ILANBroadcaster>($"开始监听端口:{Port}");
		}

		public void StopListen()
		{
			_isListening = false;
			BIT4Log.Log<ILANBroadcaster>($"停止监听端口{Port}");
		}


		private void Process()
		{
			var udpClient = new UdpClient(new IPEndPoint(IPAddress.Any, 0));
			
			var endpoint = new IPEndPoint(IPAddress.Broadcast, Port);
			//其实 IPAddress.Broadcast 就是 255.255.255.255
			//下面代码与上面有相同的作用
			//IPEndPoint endpoint = new IPEndPoint(IPAddress.Parse("255.255.255.255"), 8080);
			try
			{
				while (_isBroadcasting)
				{
					udpClient.Send(Buffer, Buffer.Length, endpoint);
					Thread.Sleep(1000);
				}
			}
			catch (Exception e)
			{
				BIT4Log.LogException(e);
			}
			udpClient.Dispose();
		}

		private void ReceiveThread()
		{
			try
			{
				var udpClient = new UdpClient(new IPEndPoint(IPAddress.Any, Port));
				var endpoint = new IPEndPoint(IPAddress.Any, 0);
				while (_isListening)
				{
					var buf = udpClient.Receive(ref endpoint);
					var msg = Encoding.Default.GetString(buf);
					if (OnReceive is not null)
						OnReceive(endpoint, msg);
					else
						BIT4Log.Log<ILANBroadcaster>($"Receive From {endpoint}:\t{msg}");
					Thread.Sleep(500);
				}
			}
			catch (Exception e)
			{
				BIT4Log.LogException(e);
			}
		
		}
	}
}