package org.opentrafficsim.core.perception;
   
   import java.rmi.RemoteException;
   
   import org.djunits.value.vdouble.scalar.Duration;
   import org.djunits.value.vdouble.scalar.Time;
   import org.djutils.exceptions.Try;
   
   import nl.tudelft.simulation.dsol.SimRuntimeException;
  import nl.tudelft.simulation.dsol.simulators.DEVSSimulatorInterface;
  import nl.tudelft.simulation.dsol.simulators.SimulatorInterface;
  import nl.tudelft.simulation.event.EventInterface;
  import nl.tudelft.simulation.event.EventListenerInterface;
  
  /**
   * History manager that uses an {@code DEVSSimulatorInterface.TimeDoubleUnit}.
   * <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 5 jan. 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 HistoryManagerDEVS extends HistoryManager implements EventListenerInterface
  {
  
      /** Simulator. */
      private final DEVSSimulatorInterface.TimeDoubleUnit simulator;
  
      /** Time over which history is guaranteed. */
      private final Duration history;
  
      /** Clean-up interval. */
      private final Duration cleanUpInterval;
  
      /** Event input, can be the same as it's nothing. */
      private final Object[] none = new Object[0];
  
      /**
       * Constructor.
       * @param simulator DEVSSimulatorInterface.TimeDoubleUnit; simulator
       * @param history Duration; time over which history is guaranteed
       * @param cleanUpInterval Duration; clean-up interval
       */
      public HistoryManagerDEVS(final DEVSSimulatorInterface.TimeDoubleUnit simulator, final Duration history,
              final Duration cleanUpInterval)
      {
          this.simulator = simulator;
          this.history = history;
          this.cleanUpInterval = cleanUpInterval;
          cleanUpHistory(); // start clean-up event chain
          Try.execute(() -> this.simulator.addListener(this, SimulatorInterface.END_REPLICATION_EVENT),
                  "Unable to add listener.");
      }
  
      /** {@inheritDoc} */
      @Override
      public Time now()
      {
          return this.simulator.getSimulatorTime();
      }
  
      /**
       * Cleans up the history of all registered {@code Historicals}.
       */
      protected final void cleanUpHistory()
      {
          for (HistoricalElement historical : getHistoricals())
          {
              historical.cleanUpHistory(this.history);
          }
          try
          {
              this.simulator.scheduleEventRel(this.cleanUpInterval, this, this, "cleanUpHistory", this.none);
          }
          catch (SimRuntimeException exception)
          {
              throw new RuntimeException(exception);
          }
      }
  
      /** {@inheritDoc} */
      @Override
      public void notify(final EventInterface event) throws RemoteException
      {
          if (event.getType().equals(SimulatorInterface.END_REPLICATION_EVENT))
          {
              endOfSimulation();
          }
      }
  
      /** {@inheritDoc} */
      @Override
      public String toString()
      {
          return "HistoryManagerDEVS [history=" + this.history + ", cleanUpInterval=" + this.cleanUpInterval + "]";
      }
 
 }