package org.opentrafficsim.road.gtu.lane.perception.mental.channel;
   
   import java.util.Set;
   import java.util.function.Function;
   
   import org.opentrafficsim.base.parameters.ParameterException;
   import org.opentrafficsim.base.parameters.ParameterTypeDouble;
   import org.opentrafficsim.road.gtu.lane.perception.LanePerception;
   import org.opentrafficsim.road.gtu.lane.perception.mental.AbstractTask;
  import org.opentrafficsim.road.gtu.lane.tactical.util.lmrs.LmrsParameters;
  
  /**
   * Task demand for lane changing left and right. This is defined as the level of lane change desire if the lane change desire in
   * the relevant direction is equal or larger to the other direction. Otherwise it is 0.
   * <p>
   * Copyright (c) 2024-2024 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/wjschakel">Wouter Schakel</a>
   */
  public final class ChannelTaskLaneChange extends AbstractTask implements ChannelTask
  {
  
      /** Current left lane change desire. */
      private static final ParameterTypeDouble DLEFT = LmrsParameters.DLEFT;
  
      /** Current right lane change desire. */
      private static final ParameterTypeDouble DRIGHT = LmrsParameters.DRIGHT;
  
      /** Standard set of left and right lane-change task. */
      private static final Set<ChannelTask> SET = Set.of(new ChannelTaskLaneChange(true), new ChannelTaskLaneChange(false));
  
      /** Standard supplier that supplies instances for left and right lane-change task. */
      public static final Function<LanePerception, Set<ChannelTask>> SUPPLIER = (p) -> SET;
  
      /** Whether this task instance regards the left side. */
      private final boolean left;
  
      /**
       * Constructor.
       * @param left whether this task instance regards the left side.
       */
      private ChannelTaskLaneChange(final boolean left)
      {
          super("lane-changing");
          this.left = left;
      }
  
      @Override
      public String getId()
      {
          return String.format("lane-changing (%s)", this.left ? "left" : "right");
      }
  
      @Override
      public Object getChannel()
      {
          return this.left ? LEFT : RIGHT;
      }
  
      @Override
      public double calculateTaskDemand(final LanePerception perception) throws ParameterException
      {
          double dLeft = perception.getGtu().getParameters().getParameter(DLEFT);
          double dRight = perception.getGtu().getParameters().getParameter(DRIGHT);
          return Math.min(0.999,
                  this.left ? (dLeft >= dRight && dLeft > 0.0 ? dLeft : 0.0) : (dRight >= dLeft && dRight > 0.0 ? dRight : 0.0));
      }
  
  }