package org.opentrafficsim.graphs;
   
   import java.rmi.RemoteException;
   import java.util.HashSet;
   import java.util.List;
   import java.util.Set;
   
   import org.opentrafficsim.core.gtu.GTU;
   import org.opentrafficsim.core.network.Network;
  import org.opentrafficsim.core.network.OTSNetwork;
  import org.opentrafficsim.road.gtu.lane.LaneBasedGTU;
  import org.opentrafficsim.road.network.lane.Lane;
  
  import nl.tudelft.simulation.event.EventInterface;
  import nl.tudelft.simulation.event.EventListenerInterface;
  
  /**
   * <p>
   * Copyright (c) 2013-2018 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="http://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
   * </p>
   * $LastChangedDate: 2015-07-24 02:58:59 +0200 (Fri, 24 Jul 2015) $, @version $Revision: 1147 $, by $Author: averbraeck $,
   * initial version Aug 26, 2016 <br>
   * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
   * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
   * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
   */
  public class DataSampler implements EventListenerInterface
  {
      /** The (ordered) set of observed lanes. */
      private final List<Lane> lanes;
  
      /** The OTS Network that knows about all the GTUs and Lanes. */
      private final OTSNetwork network;
  
      /** The GTUs currently in the network. */
      private final Set<String> gtus = new HashSet<>();
  
      /**
       * Construct the data sampler demo.
       * @param network OTSNetwork; the network
       * @param lanes List&lt;Lane&gt;; the lanes to sample on
       */
      public DataSampler(final OTSNetwork network, final List<Lane> lanes)
      {
          this.lanes = lanes;
          this.network = network;
          network.addListener(this, Network.GTU_ADD_EVENT);
          network.addListener(this, Network.GTU_REMOVE_EVENT);
      }
  
      /** {@inheritDoc} */
      @Override
      public final void notify(final EventInterface event) throws RemoteException
      {
          if (event.getType().equals(Network.GTU_ADD_EVENT))
          {
              Object[] addInfo = (Object[]) event.getContent();
              this.gtus.add(addInfo[0].toString());
              GTU gtu = this.network.getGTU(addInfo[0].toString());
              gtu.addListener(this, LaneBasedGTU.LANEBASED_MOVE_EVENT);
          }
          else if (event.getType().equals(Network.GTU_REMOVE_EVENT))
          {
              Object[] removeInfo = (Object[]) event.getContent();
              this.gtus.remove(removeInfo[0].toString());
              GTU gtu = this.network.getGTU(removeInfo[0].toString());
              gtu.removeListener(this, LaneBasedGTU.LANEBASED_MOVE_EVENT);
          }
          else if (event.getType().equals(LaneBasedGTU.LANEBASED_MOVE_EVENT))
          {
              // Ignored.
          }
      }
  
      /** {@inheritDoc} */
      @Override
      public final String toString()
      {
          return "DataSampler [lanes=" + this.lanes + ", network=" + this.network + ", #gtus=" + this.gtus.size() + "]";
      }
  
  }