package org.opentrafficsim.core.perception;
   
   import org.djunits.value.vdouble.scalar.Time;
   import org.opentrafficsim.base.parameters.ParameterException;
   import org.opentrafficsim.base.parameters.ParameterSet;
   import org.opentrafficsim.base.parameters.ParameterType;
   import org.opentrafficsim.base.parameters.Parameters;
   import org.opentrafficsim.core.perception.HistoricalParameters.ParameterEvent;
   import org.opentrafficsim.core.perception.HistoricalParameters.ParameterValueSet;
  
  /**
   * Historical representation of {@code Parameters}.
   * <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 19 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 HistoricalParameters extends AbstractHistorical<ParameterValueSet, ParameterEvent> implements Parameters
  {
  
      /** Current parameter set. */
      private final Parameters params;
  
      /**
       * Constructor.
       * @param manager HistoryManager; history manager
       * @param parameters Parameters; initial parameter set
       */
      public HistoricalParameters(final HistoryManager manager, final Parameters parameters)
      {
          super(manager);
          this.params = parameters;
      }
  
      /**
       * Get the parameters at the current simulation time.
       * @return Parameters; parameters at the current simulation time
       */
      public Parameters getParameters()
      {
          return new ParameterSet(this.params);
      }
  
      /**
       * Get the parameters at the given simulation time.
       * @param time Time; simulation time
       * @return Parameters; parameters at the given simulation time
       */
      public Parameters getParameters(final Time time)
      {
          Parameters parameters = getParameters();
          for (ParameterEvent event : getEvents(time))
          {
              event.resetEvent(parameters);
          }
          return parameters;
      }
  
      /** {@inheritDoc} */
      @Override
      public <T> void setParameter(final ParameterType<T> parameterType, final T value) throws ParameterException
      {
          addEvent(new ParameterEvent(now().si, parameterType, this.params));
          this.params.setParameter(parameterType, value);
      }
  
      /** {@inheritDoc} */
      @Override
      public <T> void setParameterResettable(final ParameterType<T> parameterType, final T value) throws ParameterException
      {
          addEvent(new ParameterEvent(now().si, parameterType, this.params));
          this.params.setParameterResettable(parameterType, value);
      }
  
      /** {@inheritDoc} */
      @Override
      public void resetParameter(final ParameterType<?> parameterType) throws ParameterException
      {
          addEvent(new ParameterEvent(now().si, parameterType, this.params));
          this.params.resetParameter(parameterType);
      }
  
      /** {@inheritDoc} */
      @Override
      public <T> T getParameter(final ParameterType<T> parameterType) throws ParameterException
      {
          return this.params.getParameter(parameterType);
      }
  
      /** {@inheritDoc} */
      @Override
      public <T> T getParameterOrNull(final ParameterType<T> parameterType)
      {
          return this.params.getParameterOrNull(parameterType);
      }
 
     /** {@inheritDoc} */
     @Override
     public boolean contains(final ParameterType<?> parameterType)
     {
         return this.params.contains(parameterType);
     }
 
     /** {@inheritDoc} */
     @Override
     public void setAllIn(final Parameters parameters)
     {
         this.params.setAllIn(parameters);
     }
 
     /**
      * Value for a parameter event, which contains a parameter type and (the previous) value.
      * <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 19 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 static class ParameterValueSet
     {
 
         /** Parameter type. */
         private final ParameterType<?> parameter;
 
         /** Previous parameter value. */
         private final Object value;
 
         /**
          * @param parameter ParameterType&lt;T&gt;; parameter
          * @param value T; parameter value
          * @param <T> parameter value type
          */
         public <T> ParameterValueSet(final ParameterType<T> parameter, final T value)
         {
             this.value = value;
             this.parameter = parameter;
         }
 
         /**
          * @return value.
          */
         public Object getValue()
         {
             return this.value;
         }
 
         /**
          * @return parameter.
          */
         public ParameterType<?> getParameter()
         {
             return this.parameter;
         }
 
         /** {@inheritDoc} */
         @Override
         public String toString()
         {
             return "ParameterValueSet [parameter=" + this.parameter + ", value=" + this.value + "]";
         }
 
     }
 
     /**
      * Parameter event, which will restore the previous value.
      * <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 19 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 static class ParameterEvent extends AbstractHistorical.EventValue<ParameterValueSet> // import is removed
     {
 
         /**
          * Constructor. New value is not required, as it's not required to restore the state from before the change.
          * @param time double; time of event
          * @param parameterType ParameterType&lt;T&gt;; parameter type
          * @param parameters Parameters; parameters
          * @param <T> parameter value type
          */
         public <T> ParameterEvent(final double time, final ParameterType<T> parameterType, final Parameters parameters)
         {
             super(time, new ParameterValueSet(parameterType, parameters.getParameterOrNull(parameterType)));
         }
 
         /**
          * Resets the parameter type to it's value before the change.
          * @param parameters Parameters; parameters
          * @param <T> parameter value type
          */
         @SuppressWarnings("unchecked")
         public final <T> void resetEvent(final Parameters parameters)
         {
             try
             {
                 parameters.setParameter((ParameterType<T>) getValue().getParameter(), (T) getValue().getValue());
             }
             catch (ParameterException exception)
             {
                 // should not happen
                 throw new RuntimeException(exception);
             }
         }
 
         /** {@inheritDoc} */
         @Override
         public String toString()
         {
             return "ParameterEvent []";
         }
 
     }
 
     /** {@inheritDoc} */
     @Override
     public String toString()
     {
         return "HistoricalParameters [params=" + this.params + "]";
     }
 
 }