package org.opentrafficsim.road.gtu.lane.perception.mental;
   
   import static org.opentrafficsim.base.parameters.constraint.NumericConstraint.POSITIVEZERO;
   
   import java.util.LinkedHashSet;
   import java.util.Optional;
   import java.util.Set;
   
   import org.djutils.exceptions.Throw;
  import org.djutils.immutablecollections.Immutable;
  import org.djutils.immutablecollections.ImmutableLinkedHashSet;
  import org.djutils.immutablecollections.ImmutableSet;
  import org.opentrafficsim.base.parameters.ParameterException;
  import org.opentrafficsim.base.parameters.ParameterTypeDouble;
  import org.opentrafficsim.base.parameters.Parameters;
  import org.opentrafficsim.road.gtu.lane.perception.LanePerception;
  
  /**
   * Task-capability interface in accordance to Fuller (2011). Task demand is the sum of demands described by individual
   * {@code Task}s. These take exogenous information to describe the workload in fundamental relations. Task demand is divided by
   * task capability to arrive at a task saturation. Task saturation is input to {@code BehavioralAdaptation}s which alter
   * parameters describing personal traits, such as desired headway and desired speed. In this way, task demand is kept at an
   * equilibrium as described by Fuller.
   * <p>
   * A {@code BehavioralAdaptation} may also determine what the level of situational awareness is, which includes determining
   * reaction time. Both situational awareness and reaction time parameters can be used in perception to model deteriorated
   * perception due to a task demand imbalance.
   * <p>
   * Fuller, R., Driver control theory: From task difficulty homeostasis to risk allostasis, in Handbook of Traffic Psychology.
   * 2011. p. 13-26
   * <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>
   * @param <T> task type
   */
  public class SumFuller<T extends Task> extends Fuller
  {
  
      /** Critical task saturation. */
      public static final ParameterTypeDouble TS_CRIT =
              new ParameterTypeDouble("TScrit", "Critical task saturation", 0.8, POSITIVEZERO)
              {
                  @Override
                  public void check(final Double value, final Parameters params) throws ParameterException
                  {
                      Optional<Double> tsMax = params.getOptionalParameter(TS_MAX);
                      Throw.when(tsMax.isPresent() && value > tsMax.get(), ParameterException.class,
                              "Value for TS_CRIT should not be larger than TS_MAX.");
                  }
              };
  
      /** Maximum task saturation, pertaining to maximum deterioration. */
      public static final ParameterTypeDouble TS_MAX =
              new ParameterTypeDouble("TSmax", "Maximum task saturation", 2.0, POSITIVEZERO)
              {
                  @Override
                  public void check(final Double value, final Parameters params) throws ParameterException
                  {
                      Optional<Double> tsCrit = params.getOptionalParameter(TS_CRIT);
                      Throw.when(tsCrit.isPresent() && value < tsCrit.get(), ParameterException.class,
                              "Value for TS_MAX should not be smaller than TS_CRIT.");
                  }
              };
  
      /** Tasks causing task demand. */
      private final Set<T> tasks;
  
      /**
       * Constructor with custom situational awareness.
       * @param tasks tasks
       * @param behavioralAdapatations behavioralAdapatations
       */
      public SumFuller(final Set<T> tasks, final Set<BehavioralAdaptation> behavioralAdapatations)
      {
          super(behavioralAdapatations);
          Throw.whenNull(tasks, "Tasks may not be null.");
          this.tasks = new LinkedHashSet<>();
          this.tasks.addAll(tasks);
      }
  
      @Override
      protected double getTotalTaskDemand(final LanePerception perception) throws ParameterException
      {
          double taskDemand = 0.0;
          for (T task : this.tasks)
          {
              taskDemand += task.getTaskDemand(perception);
          }
          return taskDemand;
      }
  
      /**
       * Adds a task.
       * @param task task to add
       */
     public void addTask(final T task)
     {
         this.tasks.add(task);
     }
 
     /**
      * Removes a task.
      * @param task task to remove
      */
     public void removeTask(final T task)
     {
         this.tasks.remove(task);
     }
 
     @Override
     public ImmutableSet<T> getTasks()
     {
         return new ImmutableLinkedHashSet<>(this.tasks, Immutable.WRAP);
     }
 
     @Override
     public String toString()
     {
         return "SumFuller [tasks=" + this.tasks + "]";
     }
 
 }