package org.opentrafficsim.road.gtu.lane.perception.categories;
   
   import java.util.ArrayList;
   import java.util.HashMap;
   import java.util.List;
   
   import org.djunits.value.vdouble.scalar.Duration;
   import org.djunits.value.vdouble.scalar.Time;
   import org.opentrafficsim.base.TimeStampedObject;
  import org.opentrafficsim.base.Type;
  import org.opentrafficsim.core.gtu.GTUException;
  import org.opentrafficsim.core.gtu.behavioralcharacteristics.BehavioralCharacteristics;
  import org.opentrafficsim.core.gtu.behavioralcharacteristics.ParameterException;
  import org.opentrafficsim.core.gtu.behavioralcharacteristics.ParameterTypeDuration;
  import org.opentrafficsim.core.gtu.perception.PerceptionCategory;
  import org.opentrafficsim.core.gtu.perception.PerceptionException;
  import org.opentrafficsim.core.network.LateralDirectionality;
  import org.opentrafficsim.road.gtu.lane.perception.LanePerception;
  import org.opentrafficsim.road.gtu.lane.perception.RelativeLane;
  
  import nl.tudelft.simulation.language.Throw;
  
  /**
   * Utility superclass for perception categories with single delayed snapshots.
   * <p>
   * Copyright (c) 2013-2017 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 14 feb. 2017 <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 abstract class AbstractDelayedPerceptionCategory extends LaneBasedAbstractPerceptionCategory
          implements PerceptionCategory
  {
  
      /** Margin of 1 millisecond. */
      private static final Duration MARGIN = Duration.createSI(0.001);
  
      /** */
      private static final long serialVersionUID = 20170217L;
  
      /**
       * @param perception perception
       */
      public AbstractDelayedPerceptionCategory(final LanePerception perception)
      {
          super(perception);
      }
  
      /** Map of info type and list of time stamped data of that info type. */
      private final HashMap<DelayedInfoType<?>, HashMap<RelativeLane, List<TimeStampedObject<?>>>> map = new HashMap<>();
  
      /**
       * Set info of given delayed info type, not pertaining to any lane.
       * @param delayedInfoType info type
       * @param info info
       * @param <T> data type of delayed info
       */
      public <T> void setInfo(final DelayedInfoType<T> delayedInfoType, final TimeStampedObject<T> info)
      {
          setInfo(delayedInfoType, null, info);
      }
  
      /**
       * Set info of given delayed info type, pertaining to a lane.
       * @param delayedInfoType info type
       * @param lane lane, may be {@code null}
       * @param info info
       * @param <T> data type of delayed info
       */
      public <T> void setInfo(final DelayedInfoType<T> delayedInfoType, final RelativeLane lane, final TimeStampedObject<T> info)
      {
          Throw.whenNull(delayedInfoType, "Delayed info type may not be null.");
          Throw.whenNull(info, "Info may not be null.");
          if (!this.map.containsKey(delayedInfoType))
          {
              this.map.put(delayedInfoType, new HashMap<>());
          }
          if (!this.map.get(delayedInfoType).containsKey(lane))
          {
              this.map.get(delayedInfoType).put(lane, new ArrayList<TimeStampedObject<?>>());
          }
          List<TimeStampedObject<?>> list = this.map.get(delayedInfoType).get(lane);
          if (!list.isEmpty())
          {
              Throw.when(!list.isEmpty() && info.getTimestamp().le(list.get(list.size() - 1).getTimestamp()),
                      RuntimeException.class,
                      "Setting delayed info for type %s with timestamp %s while info with timestamp %s is already present.",
                      delayedInfoType, info.getTimestamp(), list.get(list.size() - 1).getTimestamp());
          }
  
          // append data at end
          list.add(info);
      }
  
      /**
       * Returns the most recent info of the given type, that is older than the delay. If all data is more recent than the delay,
      * the oldest data is returned. If no data is present, an exception is thrown.
      * @param delayedInfoType info type
      * @param <T> data type of the info type
      * @return info of the given type
      * @throws PerceptionException if info was not perceived
      */
     public <T> TimeStampedObject<T> getInfo(final DelayedInfoType<T> delayedInfoType) throws PerceptionException
     {
         return getInfo(delayedInfoType, null);
     }
 
     /**
      * Returns the most recent info of the given type, that is older than the delay. If all data is more recent than the delay,
      * the oldest data is returned. If no data is present, an exception is thrown.
      * @param delayedInfoType info type
      * @param lane lane the data pertains to, may be {@code null}
      * @param <T> data type of the info type
      * @return info of the given type
      * @throws PerceptionException if info was not perceived
      */
     @SuppressWarnings("unchecked")
     public <T> TimeStampedObject<T> getInfo(final DelayedInfoType<T> delayedInfoType, final RelativeLane lane)
             throws PerceptionException
     {
         Throw.whenNull(delayedInfoType, "Delayed info type may not be null.");
         Throw.when(!this.map.containsKey(delayedInfoType), PerceptionException.class,
                 "Perception does not contain any data for info type %s.", delayedInfoType);
         Throw.when(!this.map.get(delayedInfoType).containsKey(lane), PerceptionException.class,
                 "Perception does not contain any data for info type %s for lane %s.", delayedInfoType, lane);
         List<TimeStampedObject<?>> list = this.map.get(delayedInfoType).get(lane);
         Throw.when(list.isEmpty(), RuntimeException.class, "Perception does not contain any data for info type %s.",
                 delayedInfoType);
 
         // remove old data if required
         BehavioralCharacteristics bc;
         Time now;
         try
         {
             bc = getPerception().getGtu().getBehavioralCharacteristics();
             now = getPerception().getGtu().getSimulator().getSimulatorTime().getTime();
         }
         catch (GTUException exception)
         {
             throw new RuntimeException("GTU not yet initialized.", exception);
         }
         Time delayedTime;
         try
         {
             delayedTime = now.minus(bc.getParameter(delayedInfoType.getDelayParameter())).plus(MARGIN);
         }
         catch (ParameterException exception)
         {
             throw new RuntimeException("Delay parameter not found.", exception);
         }
         while (list.size() > 1 && list.get(1).getTimestamp().le(delayedTime))
         {
             list.remove(0);
         }
 
         return (TimeStampedObject<T>) list.get(0);
     }
 
     /**
      * Move data coupled to a lane to another lane to account for a lane change. The tactical planner needs to call this exactly
      * when it flips logic concerning the origin and target lane.
      * @param dir direction of lane change
      */
     public void changeLane(final LateralDirectionality dir)
     {
         for (DelayedInfoType<?> delayedInfoType : this.map.keySet())
         {
             HashMap<RelativeLane, List<TimeStampedObject<?>>> newMap = new HashMap<>();
             for (RelativeLane lane : this.map.get(delayedInfoType).keySet())
             {
                 if (lane != null)
                 {
                     newMap.put(dir.isLeft() ? lane.getRight() : lane.getLeft(), this.map.get(delayedInfoType).get(lane));
                 }
                 else
                 {
                     newMap.put(lane, this.map.get(delayedInfoType).get(lane));
                 }
             }
             this.map.put(delayedInfoType, newMap);
         }
     }
 
     /**
      * Superclass for delayed info.
      * <p>
      * Copyright (c) 2013-2017 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 14 feb. 2017 <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>
      * @param <T> type of information.
      */
     public static class DelayedInfoType<T> extends Type<DelayedInfoType<T>>
     {
 
         /** Id. */
         private final String id;
 
         /** Parameter for delay. */
         private final ParameterTypeDuration delayParameter;
 
         /**
          * Constructor.
          * @param id id
          * @param delayParameter delay parameter type
          */
         public DelayedInfoType(final String id, final ParameterTypeDuration delayParameter)
         {
             this.id = id;
             this.delayParameter = delayParameter;
         }
 
         /**
          * Returns the id.
          * @return id
          */
         public final String getId()
         {
             return this.getId();
         }
 
         /**
          * Returns the delay parameter type.
          * @return delayParameter
          */
         public ParameterTypeDuration getDelayParameter()
         {
             return this.delayParameter;
         }
 
         /** {@inheritDoc} */
         @Override
         public final int hashCode()
         {
             final int prime = 31;
             int result = 1;
             result = prime * result + ((this.id == null) ? 0 : this.id.hashCode());
             return result;
         }
 
         /** {@inheritDoc} */
         @Override
         public final boolean equals(final Object obj)
         {
             if (this == obj)
             {
                 return true;
             }
             if (obj == null)
             {
                 return false;
             }
             if (getClass() != obj.getClass())
             {
                 return false;
             }
             DelayedInfoType<?> other = (DelayedInfoType<?>) obj;
             if (this.id == null)
             {
                 if (other.id != null)
                 {
                     return false;
                 }
             }
             else if (!this.id.equals(other.id))
             {
                 return false;
             }
             return true;
         }
 
         /** {@inheritDoc} */
         @Override
         public String toString()
         {
             return "DelayedInfoType [id=" + this.id + ", delayParameter=" + this.delayParameter + "]";
         }
 
     }
 
 }