using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Timers;
using System.Windows;

namespace LaOlaWelle
{
   /// <summary>
   /// Interaktionslogik für ServerGUI.xaml
   /// </summary>
   public partial class ServerGUI : Window
   {

      IPEndPoint remoteep;
      UdpClient udpclient;

      int client = 0;
      double intervallTime = 0.5;
      int clientsCnt = 0;

      Timer timer;

      bool initialized = false;

      public ServerGUI()
      {
         InitializeComponent();

         initialized = true;
         udpclient = new UdpClient();

         IPAddress multicastaddress = IPAddress.Parse("239.0.0.222");
         udpclient.JoinMulticastGroup(multicastaddress);
         remoteep = new IPEndPoint(multicastaddress, 2222);
      }

      private void clients_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
      {
         if (!initialized) return;
         clientsCnt = (int)clients.Value;
         clientsCNT.Content = clientsCnt;
      }

      private void intervall_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
      {
         if (!initialized) return;
         intervallCNT.Content = intervall.Value;
         intervallTime = intervall.Value;
      }

      private void start_CheckChanged(object sender, RoutedEventArgs e)
      {
         if (!initialized) return;
         if ((bool)start.IsChecked)
         {
            timer = new Timer(intervallTime * 1000);
            timer.Elapsed += Timer_Elapsed;
            timer.Enabled = true;
            timer.AutoReset = true;
         } else
         {
            if (timer == null) return;
            timer.Enabled = false;
         }
      }

      private void Timer_Elapsed(object sender, ElapsedEventArgs e)
      {
         if (!initialized) return;
         var message = new Message();
         message.ID = client;
         message.State = state.close;

         WriteMessage(message);

         client++;

         if (client > clientsCnt) client = 1;

         message = new Message();
         message.ID = client;
         message.State = state.open;
         WriteMessage(message);
      }

      private void WriteMessage(Message message)
      {
         using (var stream = new MemoryStream())
         {
            using (var writer = new BinaryWriter(stream))
            {
               writer.Write(message.Valid);
               writer.Write(message.ID);
               writer.Write((int)message.State);

               writer.Flush();

               stream.Position = 0;

               byte[] data = stream.ToArray();

               udpclient.Send(data, data.Length, remoteep);
            }
         }
      }
   }
}