package org.opentrafficsim.road.gtu.lane.tactical.lmrs;
   
   import org.djunits.value.vdouble.scalar.Acceleration;
   import org.djunits.value.vdouble.scalar.Length;
   import org.djutils.exceptions.Try;
   import org.opentrafficsim.base.parameters.ParameterException;
   import org.opentrafficsim.base.parameters.ParameterTypes;
   import org.opentrafficsim.base.parameters.Parameters;
   import org.opentrafficsim.core.gtu.Stateless;
  import org.opentrafficsim.core.gtu.perception.EgoPerception;
  import org.opentrafficsim.core.gtu.plan.operational.OperationalPlanException;
  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.categories.IntersectionPerception;
  import org.opentrafficsim.road.gtu.lane.perception.categories.neighbors.NeighborsPerception;
  import org.opentrafficsim.road.gtu.lane.perception.object.PerceivedConflict;
  import org.opentrafficsim.road.gtu.lane.perception.object.PerceivedGtu;
  import org.opentrafficsim.road.gtu.lane.perception.object.PerceivedTrafficLight;
  import org.opentrafficsim.road.gtu.lane.tactical.following.CarFollowingModel;
  import org.opentrafficsim.road.gtu.lane.tactical.util.CarFollowingUtil;
  import org.opentrafficsim.road.gtu.lane.tactical.util.lmrs.Desire;
  import org.opentrafficsim.road.gtu.lane.tactical.util.lmrs.VoluntaryIncentive;
  import org.opentrafficsim.road.network.lane.conflict.Conflict;
  import org.opentrafficsim.road.network.lane.object.trafficlight.TrafficLight;
  import org.opentrafficsim.road.network.speed.SpeedLimitInfo;
  
  /**
   * Incentive to join the shortest queue near intersection.
   * <p>
   * Copyright (c) 2013-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
   * </p>
   * @author <a href="https://github.com/averbraeck">Alexander Verbraeck</a>
   * @author <a href="https://github.com/peter-knoppers">Peter Knoppers</a>
   * @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
   */
  public final class IncentiveQueue implements VoluntaryIncentive, Stateless<IncentiveQueue>
  {
  
      /** Singleton instance. */
      public static final IncentiveQueue SINGLETON = new IncentiveQueue();
  
      @Override
      public IncentiveQueue get()
      {
          return SINGLETON;
      }
  
      /**
       * Constructor.
       */
      private IncentiveQueue()
      {
          //
      }
  
      @Override
      public Desire determineDesire(final Parameters parameters, final LanePerception perception,
              final CarFollowingModel carFollowingModel, final Desire mandatoryDesire, final Desire voluntaryDesire)
              throws ParameterException, OperationalPlanException
      {
          if (!perception.contains(IntersectionPerception.class))
          {
              return Desire.ZERO;
          }
          EgoPerception<?, ?> ego = perception.getPerceptionCategory(EgoPerception.class);
          double aCur = Try.assign(() -> perception.getGtu().getCarFollowingAcceleration().si, OperationalPlanException.class,
                  "Could not obtain the car-following acceleration.");
          if (aCur <= 0.0 && ego.getSpeed().eq0())
          {
              return Desire.ZERO;
          }
          IntersectionPerception inter = perception.getPerceptionCategoryOrNull(IntersectionPerception.class);
          PerceptionCollectable<PerceivedConflict, Conflict> conflicts = inter.getConflicts(RelativeLane.CURRENT);
          PerceptionCollectable<PerceivedTrafficLight, TrafficLight> lights = inter.getTrafficLights(RelativeLane.CURRENT);
          // TODO: a ramp-metering traffic light triggers this incentive with possible cooperation from the main line
          if (conflicts.isEmpty() && lights.isEmpty())
          {
              return Desire.ZERO;
          }
          Acceleration a = parameters.getParameter(ParameterTypes.A);
          NeighborsPerception neigbors = perception.getPerceptionCategory(NeighborsPerception.class);
          InfrastructurePerception infra = perception.getPerceptionCategory(InfrastructurePerception.class);
  
          SpeedLimitInfo sli = infra.getSpeedLimitProspect(RelativeLane.CURRENT).getSpeedLimitInfo(Length.ZERO);
  
          double dLeft = 0.0;
          if (infra.getCrossSection().contains(RelativeLane.LEFT))
          {
              PerceptionCollectable<PerceivedGtu, LaneBasedGtu> leaders = neigbors.getLeaders(RelativeLane.LEFT);
              if (!leaders.isEmpty())
              {
                  Acceleration acc = CarFollowingUtil.followSingleLeader(carFollowingModel, parameters, ego.getSpeed(), sli,
                          leaders.first());
                  dLeft = (acc.si - aCur) / a.si;
              }
         }
         double dRight = 0.0;
         if (infra.getCrossSection().contains(RelativeLane.RIGHT))
         {
             PerceptionCollectable<PerceivedGtu, LaneBasedGtu> leaders = neigbors.getLeaders(RelativeLane.RIGHT);
             if (!leaders.isEmpty())
             {
                 Acceleration acc = CarFollowingUtil.followSingleLeader(carFollowingModel, parameters, ego.getSpeed(), sli,
                         leaders.first());
                 dRight = (acc.si - aCur) / a.si;
             }
         }
         return new Desire(dLeft, dRight);
     }
 
     @Override
     public String toString()
     {
         return "IncentiveQueue";
     }
 
 }