package org.djutils.stats.summarizers.event;
   
   import org.djutils.event.Event;
   import org.djutils.event.EventListener;
   import org.djutils.event.EventListenerMap;
   import org.djutils.event.EventProducer;
   import org.djutils.event.LocalEventProducer;
   import org.djutils.exceptions.Throw;
   import org.djutils.stats.summarizers.Tally;
  import org.djutils.stats.summarizers.quantileaccumulator.NoStorageAccumulator;
  import org.djutils.stats.summarizers.quantileaccumulator.QuantileAccumulator;
  
  /**
   * The EventBasedTally class registers a series of values and provides mean, standard deviation, etc. of the registered values.
   * It embeds an EventProducer so it can keep listeners informed about new observations, and it listens to external events to be
   * able to receive observations, in addition to the register(...) method.
   * <p>
   * Copyright (c) 2002-2025 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
   * for project information <a href="https://simulation.tudelft.nl/" target="_blank"> https://simulation.tudelft.nl</a>. The DSOL
   * project is distributed under a three-clause BSD-style license, which can be found at
   * <a href="https://simulation.tudelft.nl/dsol/3.0/license.html" target="_blank">
   * https://simulation.tudelft.nl/dsol/3.0/license.html</a>. <br>
   * @author <a href="https://www.tudelft.nl/averbraeck" target="_blank"> Alexander Verbraeck</a>
   * @author <a href="https://www.linkedin.com/in/peterhmjacobs">Peter Jacobs </a>
   * @author <a href="https://www.tudelft.nl/staff/p.knoppers/">Peter Knoppers</a>
   */
  public class EventBasedTally extends Tally implements EventProducer, EventListener
  {
      /** The embedded EventProducer. */
      private EventProducer eventProducer = null;
  
      /**
       * Constructs a new EventBasedTally.
       * @param description the description of this tally
       * @param quantileAccumulator the input series accumulator that can approximate or compute quantiles.
       */
      public EventBasedTally(final String description, final QuantileAccumulator quantileAccumulator)
      {
          this(description, quantileAccumulator, new LocalEventProducer());
      }
  
      /**
       * Convenience constructor that uses a NoStorageAccumulator to estimate quantiles.
       * @param description the description of this tally
       */
      public EventBasedTally(final String description)
      {
          this(description, new NoStorageAccumulator());
      }
  
      /**
       * Construct a new EventBasedCounter with a specific EventProducer, e.g. a remote one. The Tally uses uses a
       * NoStorageAccumulator to estimate quantiles.
       * @param description the description for this counter
       * @param eventProducer the EventProducer to embed and use in this statistic
       */
      public EventBasedTally(final String description, final EventProducer eventProducer)
      {
          this(description, new NoStorageAccumulator(), eventProducer);
      }
  
      /**
       * Construct a new EventBasedCounter with a specific EventProducer, e.g. a remote one.
       * @param description the description for this counter
       * @param quantileAccumulator the input series accumulator that can approximate or compute quantiles.
       * @param eventProducer the EventProducer to embed and use in this statistic
       */
      public EventBasedTally(final String description, final QuantileAccumulator quantileAccumulator,
              final EventProducer eventProducer)
      {
          super(description, quantileAccumulator);
          Throw.whenNull(eventProducer, "eventProducer cannot be null");
          this.eventProducer = eventProducer;
      }
  
      @Override
      public EventListenerMap getEventListenerMap()
      {
          return this.eventProducer.getEventListenerMap();
      }
  
      @Override
      public void initialize()
      {
          super.initialize();
          if (this.eventProducer != null)
          {
              this.eventProducer.fireEvent(StatisticsEvents.INITIALIZED_EVENT);
          }
      }
  
      @Override
      @SuppressWarnings("checkstyle:designforextension")
      public void notify(final Event event)
      {
          if (!(event.getContent() instanceof Number))
          {
              throw new IllegalArgumentException("Tally does not accept " + event);
          }
         double value = ((Number) event.getContent()).doubleValue();
         register(value);
     }
 
     @Override
     public double register(final double value)
     {
         super.register(value);
         if (hasListeners())
         {
             this.eventProducer.fireEvent(StatisticsEvents.OBSERVATION_ADDED_EVENT, value);
             fireEvents();
         }
         return value;
     }
 
     /**
      * Method that can be overridden to fire own events or additional events when registering an observation.
      */
     protected void fireEvents()
     {
         this.eventProducer.fireEvent(StatisticsEvents.N_EVENT, getN());
         this.eventProducer.fireEvent(StatisticsEvents.MIN_EVENT, getMin());
         this.eventProducer.fireEvent(StatisticsEvents.MAX_EVENT, getMax());
         this.eventProducer.fireEvent(StatisticsEvents.POPULATION_MEAN_EVENT, getPopulationMean());
         this.eventProducer.fireEvent(StatisticsEvents.POPULATION_VARIANCE_EVENT, getPopulationVariance());
         this.eventProducer.fireEvent(StatisticsEvents.POPULATION_SKEWNESS_EVENT, getPopulationSkewness());
         this.eventProducer.fireEvent(StatisticsEvents.POPULATION_KURTOSIS_EVENT, getPopulationKurtosis());
         this.eventProducer.fireEvent(StatisticsEvents.POPULATION_EXCESS_KURTOSIS_EVENT, getPopulationExcessKurtosis());
         this.eventProducer.fireEvent(StatisticsEvents.POPULATION_STDEV_EVENT, getPopulationStDev());
         this.eventProducer.fireEvent(StatisticsEvents.SUM_EVENT, getSum());
         this.eventProducer.fireEvent(StatisticsEvents.SAMPLE_MEAN_EVENT, getSampleMean());
         this.eventProducer.fireEvent(StatisticsEvents.SAMPLE_VARIANCE_EVENT, getSampleVariance());
         this.eventProducer.fireEvent(StatisticsEvents.SAMPLE_SKEWNESS_EVENT, getSampleSkewness());
         this.eventProducer.fireEvent(StatisticsEvents.SAMPLE_KURTOSIS_EVENT, getSampleKurtosis());
         this.eventProducer.fireEvent(StatisticsEvents.SAMPLE_EXCESS_KURTOSIS_EVENT, getSampleExcessKurtosis());
         this.eventProducer.fireEvent(StatisticsEvents.SAMPLE_STDEV_EVENT, getSampleStDev());
     }
 
     @Override
     @SuppressWarnings("checkstyle:designforextension")
     public String toString()
     {
         return "EventBasedTally" + super.toString().substring(5);
     }
 
 }