package org.opentrafficsim.road.gtu.lane.perception.categories;
   
   import org.djunits.value.vdouble.scalar.Length;
   import org.opentrafficsim.core.gtu.GTUException;
   import org.opentrafficsim.road.gtu.lane.LaneBasedGTU;
   import org.opentrafficsim.road.gtu.lane.perception.headway.GTUStatus;
   import org.opentrafficsim.road.gtu.lane.perception.headway.HeadwayGTU;
   import org.opentrafficsim.road.gtu.lane.perception.headway.HeadwayGTUReal;
   import org.opentrafficsim.road.gtu.lane.perception.headway.HeadwayGTURealCopy;
  
  /**
   * Whether a GTU needs to be wrapped, or information should be copied for later and unaltered use.
   * <p>
   * Copyright (c) 2013-2017 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 24 mrt. 2017 <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 enum HeadwayGtuType
  {
  
      /** The GTU is wrapped, and info is taken directly from it. */
      WRAP
      {
          @Override
          public HeadwayGTU createHeadwayGtu(final LaneBasedGTU gtu, final Length distance) throws GTUException
          {
              return new HeadwayGTUReal(gtu, distance, true);
          }
  
          @Override
          public HeadwayGTU createHeadwayGtu(final LaneBasedGTU gtu, final Length overlapFront, final Length overlap,
                  final Length overlapRear) throws GTUException
          {
              return new HeadwayGTUReal(gtu, overlapFront, overlap, overlapRear, true);
          }
      },
  
      /** Info regarding the GTU is copied. */
      COPY
      {
          @Override
          public HeadwayGTU createHeadwayGtu(final LaneBasedGTU gtu, final Length distance) throws GTUException
          {
              // TODO more GTU statuses
              if (gtu.getTurnIndicatorStatus().isLeft())
              {
                  return new HeadwayGTURealCopy(gtu, distance, GTUStatus.LEFT_TURNINDICATOR);
              }
              else if (gtu.getTurnIndicatorStatus().isRight())
              {
                  return new HeadwayGTURealCopy(gtu, distance, GTUStatus.RIGHT_TURNINDICATOR);
              }
              else if (gtu.getTurnIndicatorStatus().isHazard())
              {
                  return new HeadwayGTURealCopy(gtu, distance, GTUStatus.EMERGENCY_LIGHTS);
              }
              return new HeadwayGTURealCopy(gtu, distance);
          }
  
          @Override
          public HeadwayGTU createHeadwayGtu(final LaneBasedGTU gtu, final Length overlapFront, final Length overlap,
                  final Length overlapRear) throws GTUException
          {
              return new HeadwayGTURealCopy(gtu, overlapFront, overlap, overlapRear);
          }
      };
  
      /**
       * Creates a headway object from a GTU, downstream or upstream.
       * @param gtu gtu
       * @param distance distance
       * @return headway object from a gtu
       * @throws GTUException when headway object cannot be created
       */
      public abstract HeadwayGTU createHeadwayGtu(LaneBasedGTU gtu, Length distance) throws GTUException;
  
      /**
       * Creates a headway object from a GTU, parallel.
       * @param gtu gtu
       * @param overlapFront front overlap
       * @param overlap overlap
       * @param overlapRear rear overlap
       * @return headway object from a gtu
       * @throws GTUException when headway object cannot be created
       */
      public abstract HeadwayGTU createHeadwayGtu(LaneBasedGTU gtu, Length overlapFront, Length overlap, Length overlapRear)
              throws GTUException;
  
  }