package org.opentrafficsim.kpi.sampling;
   
   import java.util.HashMap;
   import java.util.HashSet;
   import java.util.Map;
   import java.util.Set;
   
   import org.djunits.value.vdouble.scalar.Acceleration;
   import org.djunits.value.vdouble.scalar.Length;
  import org.djunits.value.vdouble.scalar.Speed;
  import org.djunits.value.vdouble.scalar.Time;
  import org.opentrafficsim.kpi.interfaces.GtuDataInterface;
  import org.opentrafficsim.kpi.sampling.data.ExtendedDataType;
  import org.opentrafficsim.kpi.sampling.meta.MetaData;
  import org.opentrafficsim.kpi.sampling.meta.MetaDataType;
  
  import nl.tudelft.simulation.language.Throw;
  
  /**
   * Sampler is the highest level organizer for sampling.
   * <p>
   * Copyright (c) 2013-2016 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 Sep 22, 2016 <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 Sampler
  {
  
      /** Map with all sampling data. */
      private final Map<KpiLaneDirection, TrajectoryGroup> trajectories = new HashMap<>();
  
      /** End times of active samplings. */
      private final Map<KpiLaneDirection, Time> endTimes = new HashMap<>();
  
      /** Registration of current trajectories of each GTU per lane. */
      private final Map<String, Map<KpiLaneDirection, Trajectory>> trajectoryPerGtu = new HashMap<>();
  
      /** Registration of included extended data types. */
      private final Set<ExtendedDataType<?>> extendedDataTypes = new HashSet<>();
  
      /** Set of registered meta data types. */
      private Set<MetaDataType<?>> registeredMetaDataTypes = new HashSet<>();
  
      /**
       * @param spaceTimeRegion space-time region
       * @throws IllegalStateException if data is not available from the requested start time
       */
      public final void registerSpaceTimeRegion(final SpaceTimeRegion spaceTimeRegion)
      {
          Throw.whenNull(spaceTimeRegion, "SpaceTimeRegion may not be null.");
          Time firstPossibleDataTime;
          if (this.trajectories.containsKey(spaceTimeRegion.getLaneDirection()))
          {
              firstPossibleDataTime = this.trajectories.get(spaceTimeRegion.getLaneDirection()).getStartTime();
          }
          else
          {
              firstPossibleDataTime = now();
          }
          Throw.when(spaceTimeRegion.getStartTime().lt(firstPossibleDataTime), IllegalStateException.class,
                  "Space time region with start time %s is defined while data is available from %s onwards.",
                  spaceTimeRegion.getStartTime(), firstPossibleDataTime);
          if (this.trajectories.containsKey(spaceTimeRegion.getLaneDirection()))
          {
              this.endTimes.put(spaceTimeRegion.getLaneDirection(),
                      Time.max(this.endTimes.get(spaceTimeRegion.getLaneDirection()), spaceTimeRegion.getEndTime()));
          }
          else
          {
              this.endTimes.put(spaceTimeRegion.getLaneDirection(), spaceTimeRegion.getEndTime());
              scheduleStartRecording(spaceTimeRegion.getStartTime(), spaceTimeRegion.getLaneDirection());
          }
          scheduleStopRecording(this.endTimes.get(spaceTimeRegion.getLaneDirection()), spaceTimeRegion.getLaneDirection());
      }
  
      /**
       * Returns the current simulation time.
       * @return current simulation time
       */
      public abstract Time now();
  
      /**
       * Schedules the start of recording for a given lane-direction.
       * @param time time to start recording
       * @param kpiLaneDirection lane-direction to start recording
       */
      public abstract void scheduleStartRecording(final Time time, final KpiLaneDirection kpiLaneDirection);
  
      /**
       * Schedules the stop of recording for a given lane-direction.
       * @param time time to stop recording
       * @param kpiLaneDirection lane-direction to stop recording
       */
      public abstract void scheduleStopRecording(final Time time, final KpiLaneDirection kpiLaneDirection);
  
     /**
      * Registers meta data types that will be stored with the trajectories.
      * @param metaDataTypes meta data types to register
      */
     public final void registerMetaDataTypes(final Set<MetaDataType<?>> metaDataTypes)
     {
         Throw.whenNull(metaDataTypes, "MetaDataTypes may not be null.");
         this.registeredMetaDataTypes.addAll(metaDataTypes);
     }
 
     /**
      * Registers extended data type that will be stored with the trajectories.
      * @param extendedDataType extended data type to register
      */
     public final void registerExtendedDataType(final ExtendedDataType<?> extendedDataType)
     {
         Throw.whenNull(extendedDataType, "ExtendedDataType may not be null.");
         this.extendedDataTypes.add(extendedDataType);
     }
 
     /**
      * Start recording at the given time (which should be the current time) on the given lane direction.
      * @param kpiLaneDirection lane direction
      */
     public final void startRecording(final KpiLaneDirection kpiLaneDirection)
     {
         Throw.whenNull(kpiLaneDirection, "KpiLaneDirection may not be null.");
         if (this.trajectories.containsKey(kpiLaneDirection))
         {
             return;
         }
         this.trajectories.put(kpiLaneDirection, new TrajectoryGroup(now(), kpiLaneDirection));
         initRecording(kpiLaneDirection);
     }
 
     /**
      * Adds listeners to start recording.
      * @param kpiLaneDirection lane direction to initialize recording for
      */
     public abstract void initRecording(final KpiLaneDirection kpiLaneDirection);
 
     /**
      * Stop recording at given lane direction.
      * @param kpiLaneDirection lane direction
      */
     public final void stopRecording(final KpiLaneDirection kpiLaneDirection)
     {
         Throw.whenNull(kpiLaneDirection, "KpiLaneDirection may not be null.");
         if (!this.trajectories.containsKey(kpiLaneDirection) || this.endTimes.get(kpiLaneDirection).gt(now()))
         {
             return;
         }
         finalizeRecording(kpiLaneDirection);
     }
 
     /**
      * Remove listeners to stop recording.
      * @param kpiLaneDirection lane direction to finalize recording for
      */
     public abstract void finalizeRecording(final KpiLaneDirection kpiLaneDirection);
 
     /**
      * Creates a trajectory with the current snapshot of a GTU.
      * @param kpiLaneDirection lane direction the gtu is at
      * @param position position of the gtu on the lane
      * @param speed speed of the gtu
      * @param acceleration acceleration of the gtu
      * @param time current time
      * @param gtu gtu
      */
     public final void processGtuAddEvent(final KpiLaneDirection kpiLaneDirection, final Length position, final Speed speed,
             final Acceleration acceleration, final Time time, final GtuDataInterface gtu)
     {
         Throw.whenNull(kpiLaneDirection, "KpiLaneDirection may not be null.");
         Throw.whenNull(position, "Position may not be null.");
         Throw.whenNull(speed, "Speed may not be null.");
         Throw.whenNull(acceleration, "Acceleration may not be null.");
         Throw.whenNull(time, "Time may not be null.");
         Throw.whenNull(gtu, "GtuDataInterface may not be null.");
         String gtuId = gtu.getId();
         Trajectory trajectory = new Trajectory(gtu, makeMetaData(gtu), this.extendedDataTypes, kpiLaneDirection);
         if (!this.trajectoryPerGtu.containsKey(gtuId))
         {
             Map<KpiLaneDirection, Trajectory> map = new HashMap<>();
             this.trajectoryPerGtu.put(gtuId, map);
         }
         this.trajectoryPerGtu.get(gtuId).put(kpiLaneDirection, trajectory);
         this.trajectories.get(kpiLaneDirection).addTrajectory(trajectory);
         processGtuMoveEvent(kpiLaneDirection, position, speed, acceleration, time, gtu);
     }
 
     /**
      * Adds a new snapshot of a GTU to its recording trajectory, if recorded. This method may be invoked on GTU that are not
      * being recorded; the event will then be ignored.
      * @param kpiLaneDirection lane direction the gtu is at
      * @param position position of the gtu on the lane
      * @param speed speed of the gtu
      * @param acceleration acceleration of the gtu
      * @param time current time
      * @param gtu gtu
      */
     public final void processGtuMoveEvent(final KpiLaneDirection kpiLaneDirection, final Length position, final Speed speed,
             final Acceleration acceleration, final Time time, final GtuDataInterface gtu)
     {
         Throw.whenNull(kpiLaneDirection, "KpiLaneDirection may not be null.");
         Throw.whenNull(position, "Position may not be null.");
         Throw.whenNull(speed, "Speed may not be null.");
         Throw.whenNull(acceleration, "Acceleration may not be null.");
         Throw.whenNull(time, "Time may not be null.");
         Throw.whenNull(gtu, "GtuDataInterface may not be null.");
         String gtuId = gtu.getId();
         if (this.trajectoryPerGtu.containsKey(gtuId) && this.trajectoryPerGtu.get(gtuId).containsKey(kpiLaneDirection))
         {
             this.trajectoryPerGtu.get(gtuId).get(kpiLaneDirection).add(position, speed, acceleration, time, gtu);
         }
     }
 
     /**
      * Finalizes a trajectory with the current snapshot of a GTU.
      * @param kpiLaneDirection lane direction the gtu is at
      * @param position position of the gtu on the lane
      * @param speed speed of the gtu
      * @param acceleration acceleration of the gtu
      * @param time current time
      * @param gtu gtu
      */
     public final void processGtuRemoveEvent(final KpiLaneDirection kpiLaneDirection, final Length position, final Speed speed,
             final Acceleration acceleration, final Time time, final GtuDataInterface gtu)
     {
         processGtuMoveEvent(kpiLaneDirection, position, speed, acceleration, time, gtu);
         processGtuRemoveEvent(kpiLaneDirection, gtu);
     }
     
     /**
      * Finalizes a trajectory.
      * @param kpiLaneDirection lane direction the gtu is at
      * @param gtu gtu
      */
     public final void processGtuRemoveEvent(final KpiLaneDirection kpiLaneDirection, final GtuDataInterface gtu)
     {
         Throw.whenNull(kpiLaneDirection, "KpiLaneDirection may not be null.");
         Throw.whenNull(gtu, "GtuDataInterface may not be null.");
         String gtuId = gtu.getId();
         if (this.trajectoryPerGtu.containsKey(gtuId))
         {
             this.trajectoryPerGtu.get(gtuId).remove(kpiLaneDirection);
             if (this.trajectoryPerGtu.get(gtuId).isEmpty())
             {
                 this.trajectoryPerGtu.remove(gtuId);
             }
         }
     }
 
     /**
      * @param gtu gtu to return meta data for
      * @param <T> underlying type of a meta data type
      * @return meta data for the given gtu
      */
     @SuppressWarnings("unchecked")
     private <T> MetaData makeMetaData(final GtuDataInterface gtu)
     {
         MetaData metaData = new MetaData();
         for (MetaDataType<?> metaDataType : this.registeredMetaDataTypes)
         {
             T value = (T) metaDataType.getValue(gtu);
             if (value != null)
             {
                 metaData.put((MetaDataType<T>) metaDataType, value);
             }
         }
         return metaData;
     }
 
     /**
      * Returns whether there is data for the give lane direction.
      * @param kpiLaneDirection lane direction
      * @return whether there is data for the give lane direction
      */
     public final boolean contains(final KpiLaneDirection kpiLaneDirection)
     {
         return this.trajectories.containsKey(kpiLaneDirection);
     }
 
     /**
      * Returns the trajectory group of given lane direction.
      * @param kpiLaneDirection lane direction
      * @return trajectory group of given lane direction, {@code null} if none
      */
     public final TrajectoryGroup getTrajectoryGroup(final KpiLaneDirection kpiLaneDirection)
     {
         return this.trajectories.get(kpiLaneDirection);
     }
 
     /** {@inheritDoc} */
     @Override
     public int hashCode()
     {
         final int prime = 31;
         int result = 1;
         result = prime * result + ((this.endTimes == null) ? 0 : this.endTimes.hashCode());
         result = prime * result + ((this.extendedDataTypes == null) ? 0 : this.extendedDataTypes.hashCode());
         result = prime * result + ((this.registeredMetaDataTypes == null) ? 0 : this.registeredMetaDataTypes.hashCode());
         result = prime * result + ((this.trajectories == null) ? 0 : this.trajectories.hashCode());
         result = prime * result + ((this.trajectoryPerGtu == null) ? 0 : this.trajectoryPerGtu.hashCode());
         return result;
     }
 
     /** {@inheritDoc} */
     @Override
     public boolean equals(final Object obj)
     {
         if (this == obj)
         {
             return true;
         }
         if (obj == null)
         {
             return false;
         }
         if (getClass() != obj.getClass())
         {
             return false;
         }
         Sampler other = (Sampler) obj;
         if (this.endTimes == null)
         {
             if (other.endTimes != null)
             {
                 return false;
             }
         }
         else if (!this.endTimes.equals(other.endTimes))
         {
             return false;
         }
         if (this.extendedDataTypes == null)
         {
             if (other.extendedDataTypes != null)
             {
                 return false;
             }
         }
         else if (!this.extendedDataTypes.equals(other.extendedDataTypes))
         {
             return false;
         }
         if (this.registeredMetaDataTypes == null)
         {
             if (other.registeredMetaDataTypes != null)
             {
                 return false;
             }
         }
         else if (!this.registeredMetaDataTypes.equals(other.registeredMetaDataTypes))
         {
             return false;
         }
         if (this.trajectories == null)
         {
             if (other.trajectories != null)
             {
                 return false;
             }
         }
         else if (!this.trajectories.equals(other.trajectories))
         {
             return false;
         }
         if (this.trajectoryPerGtu == null)
         {
             if (other.trajectoryPerGtu != null)
             {
                 return false;
             }
         }
         else if (!this.trajectoryPerGtu.equals(other.trajectoryPerGtu))
         {
             return false;
         }
         return true;
     }
 
 }