package org.opentrafficsim.road.gtu.lane.tactical.lmrs;
   
   import org.djunits.value.vdouble.scalar.Speed;
   import org.opentrafficsim.base.parameters.ParameterException;
   import org.opentrafficsim.base.parameters.ParameterTypeDouble;
   import org.opentrafficsim.base.parameters.ParameterTypeSpeed;
   import org.opentrafficsim.base.parameters.Parameters;
   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.neighbors.NeighborsPerception;
  import org.opentrafficsim.road.gtu.lane.perception.headway.HeadwayGTU;
  import org.opentrafficsim.road.gtu.lane.tactical.following.DesiredSpeedModel;
  import org.opentrafficsim.road.gtu.lane.tactical.following.Initialisable;
  import org.opentrafficsim.road.gtu.lane.tactical.util.lmrs.LmrsParameters;
  import org.opentrafficsim.road.gtu.lane.tactical.util.lmrs.Tailgating;
  import org.opentrafficsim.road.network.speed.SpeedLimitInfo;
  
  /**
   * Wrapper of a base-desired speed model. The speed may be increased due to social pressure from the follower.
   * <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 7 mrt. 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 SocioDesiredSpeed implements DesiredSpeedModel, Initialisable
  {
  
      /** Social pressure applied to the leader. */
      protected static final ParameterTypeDouble RHO = Tailgating.RHO;
  
      /** Socio-speed sensitivity parameter. */
      protected static final ParameterTypeDouble SOCIO = LmrsParameters.SOCIO;
  
      /** Vgain parameter; ego-speed sensitivity. */
      protected static final ParameterTypeSpeed VGAIN = LmrsParameters.VGAIN;
  
      /** GTU. */
      private LaneBasedGTU gtu;
  
      /** Base model for desired speed. */
      private final DesiredSpeedModel baseModel;
  
      /**
       * Constructor.
       * @param baseModel DesiredSpeedModel; base model for desired speed
       */
      public SocioDesiredSpeed(final DesiredSpeedModel baseModel)
      {
          this.baseModel = baseModel;
      }
  
      /** {@inheritDoc} */
      @Override
      public Speed desiredSpeed(final Parameters parameters, final SpeedLimitInfo speedInfo) throws ParameterException
      {
          Speed desiredSpeed = this.baseModel.desiredSpeed(parameters, speedInfo);
          if (this.gtu == null)
          {
              return desiredSpeed;
          }
          PerceptionCollectable<HeadwayGTU, LaneBasedGTU> followers;
          LanePerception perception = this.gtu.getTacticalPlanner().getPerception();
          NeighborsPerception neighbors = perception.getPerceptionCategoryOrNull(NeighborsPerception.class);
          if (neighbors != null)
          {
              followers = neighbors.getFollowers(RelativeLane.CURRENT);
              if (!followers.isEmpty())
              {
                  double sigma = parameters.getParameter(SOCIO);
                  Speed vGain = parameters.getParameter(VGAIN);
                  HeadwayGTU follower = followers.first();
                  double rhoFollower = follower.getParameters().getParameter(RHO);
                  desiredSpeed = Speed.createSI(desiredSpeed.si + rhoFollower * sigma * vGain.si);
              }
          }
          return desiredSpeed;
      }
  
      /** {@inheritDoc} */
      @Override
      public void init(final LaneBasedGTU laneBasedGtu)
      {
          this.gtu = laneBasedGtu;
      }
  
  }