package org.opentrafficsim.road.gtu.lane.perception.categories.neighbors;
   
   import java.io.Serializable;
   import java.util.HashMap;
   import java.util.Map;
   import java.util.Set;
   import java.util.SortedSet;
   
   import org.djutils.exceptions.Try;
  import org.opentrafficsim.base.TimeStampedObject;
  import org.opentrafficsim.base.parameters.ParameterException;
  import org.opentrafficsim.core.gtu.GTUException;
  import org.opentrafficsim.core.gtu.perception.AbstractPerceptionCategory;
  import org.opentrafficsim.core.network.LateralDirectionality;
  import org.opentrafficsim.core.network.NetworkException;
  import org.opentrafficsim.road.gtu.lane.LaneBasedGTU;
  import org.opentrafficsim.road.gtu.lane.perception.LanePerception;
  import org.opentrafficsim.road.gtu.lane.perception.PerceptionCollectable;
  import org.opentrafficsim.road.gtu.lane.perception.RelativeLane;
  import org.opentrafficsim.road.gtu.lane.perception.categories.InfrastructurePerception;
  import org.opentrafficsim.road.gtu.lane.perception.headway.HeadwayGTU;
  
  /**
   * <p>
   * Copyright (c) 2013-2019 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/node/13">OpenTrafficSim License</a>.
   * <p>
   * @version $Revision$, $LastChangedDate$, by $Author$, initial version 31 jan. 2018 <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 HistoricalNeighborsPerception extends AbstractPerceptionCategory<LaneBasedGTU, LanePerception>
          implements NeighborsPerception, Serializable
  {
  
      /** */
      private static final long serialVersionUID = 20180131L;
  
      /** Number of followers. */
      private final int nFollowers;
  
      /** Number of leaders. */
      private final int nLeaders;
  
      /** Set of followers per relative lane. */
      private final Map<RelativeLane, TimeStampedObject<SortedSet<HeadwayGTU>>> followers = new HashMap<>();
  
      /** Set of leaders per relative lane. */
      private final Map<RelativeLane, TimeStampedObject<SortedSet<HeadwayGTU>>> leaders = new HashMap<>();
  
      /** Set of first followers per lane upstream of merge per lateral direction, i.e. in the left or right lane. */
      private final Map<LateralDirectionality, TimeStampedObject<SortedSet<HeadwayGTU>>> firstFollowers = new HashMap<>();
  
      /** Set of first leaders per lane downstream of split per lateral direction, i.e. in the left or right lane. */
      private final Map<LateralDirectionality, TimeStampedObject<SortedSet<HeadwayGTU>>> firstLeaders = new HashMap<>();
  
      /** Whether a GTU is alongside per lateral direction, i.e. in the left or right lane. */
      private final Map<LateralDirectionality, TimeStampedObject<Boolean>> gtuAlongside = new HashMap<>();
  
      /** Headway GTU type that should be used. */
      private final HeadwayGtuType headwayGtuType;
  
      public HistoricalNeighborsPerception(final LanePerception perception, final HeadwayGtuType headwayGtuType)
      {
          this(perception, Integer.MAX_VALUE, Integer.MAX_VALUE, headwayGtuType);
      }
  
      public HistoricalNeighborsPerception(final LanePerception perception, final int nFollowers, final int nLeaders,
              final HeadwayGtuType headwayGtuType)
      {
          super(perception);
          this.nFollowers = nFollowers;
          this.nLeaders = nLeaders;
          this.headwayGtuType = headwayGtuType;
      }
  
      /** {@inheritDoc} */
      @Override
      public void updateAll() throws GTUException, NetworkException, ParameterException
      {
          this.followers.clear();
          this.leaders.clear();
          this.firstFollowers.clear();
          this.firstLeaders.clear();
          this.gtuAlongside.clear();
          // TODO how to get a specific String to getCrossSection???
          Set<RelativeLane> crossSection =
                  Try.assign(() -> getPerception().getPerceptionCategory(InfrastructurePerception.class).getCrossSection(),
                          GTUException.class, "HistoricalNeighborsPerception requires InfrastructurePerception");
          for (RelativeLane lane : crossSection)
          {
  
          }
      }
  
      /** {@inheritDoc} */
      @Override
      public void updateFirstLeaders(final LateralDirectionality lat) throws ParameterException, GTUException, NetworkException
     {
         updateAll();
     }
 
     /** {@inheritDoc} */
     @Override
     public void updateFirstFollowers(final LateralDirectionality lat) throws GTUException, ParameterException, NetworkException
     {
         updateAll();
     }
 
     /** {@inheritDoc} */
     @Override
     public void updateGtuAlongside(final LateralDirectionality lat) throws GTUException, ParameterException, NetworkException
     {
         updateAll();
     }
 
     /** {@inheritDoc} */
     @Override
     public void updateLeaders(final RelativeLane lane) throws ParameterException, GTUException, NetworkException
     {
         updateAll();
     }
 
     /** {@inheritDoc} */
     @Override
     public void updateFollowers(final RelativeLane lane) throws GTUException, NetworkException, ParameterException
     {
         updateAll();
     }
 
     /** {@inheritDoc} */
     @Override
     public SortedSet<HeadwayGTU> getFirstLeaders(final LateralDirectionality lat)
             throws ParameterException, NullPointerException, IllegalArgumentException
     {
         return null;
     }
 
     /** {@inheritDoc} */
     @Override
     public SortedSet<HeadwayGTU> getFirstFollowers(final LateralDirectionality lat)
             throws ParameterException, NullPointerException, IllegalArgumentException
     {
         return null;
     }
 
     /** {@inheritDoc} */
     @Override
     public boolean isGtuAlongside(final LateralDirectionality lat)
             throws ParameterException, NullPointerException, IllegalArgumentException
     {
         return false;
     }
 
     /** {@inheritDoc} */
     @Override
     public PerceptionCollectable<HeadwayGTU, LaneBasedGTU> getLeaders(final RelativeLane lane)
     {
         return null;
     }
 
     /** {@inheritDoc} */
     @Override
     public PerceptionCollectable<HeadwayGTU, LaneBasedGTU> getFollowers(final RelativeLane lane)
     {
         return null;
     }
 
 }