package org.opentrafficsim.kpi.sampling;
   
   import java.util.LinkedHashMap;
   import java.util.LinkedHashSet;
   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.djutils.exceptions.Throw;
  import org.opentrafficsim.kpi.interfaces.GtuDataInterface;
  import org.opentrafficsim.kpi.sampling.data.ExtendedDataType;
  import org.opentrafficsim.kpi.sampling.meta.FilterDataType;
  import org.opentrafficsim.kpi.sampling.meta.MetaData;
  
  /**
   * Sampler is the highest level organizer for sampling.
   * <p>
   * Copyright (c) 2013-2020 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>
   * @param <G> gtu data type
   */
  public abstract class Sampler<G extends GtuDataInterface>
  {
  
      /** Sampler data. */
      private final SamplerData<G> samplerData;
  
      /** Registration of included extended data types. */
      private final Set<ExtendedDataType<?, ?, ?, G>> extendedDataTypes;
  
      /** Set of registered filter data types. */
      private final Set<FilterDataType<?>> filterDataTypes;
  
      /** Registration of current trajectories of each GTU per lane. */
      private final Map<String, Map<KpiLaneDirection, Trajectory<G>>> trajectoryPerGtu = new LinkedHashMap<>();
  
      /** End times of active samplings. */
      private final Map<KpiLaneDirection, Time> endTimes = new LinkedHashMap<>();
  
      /** Space time regions. */
      private Set<SpaceTimeRegion> spaceTimeRegions = new LinkedHashSet<>();
  
      /**
       * Constructor.
       * @param extendedDataTypes Set&lt;ExtendedDataType&lt;?, ?, ?, G&gt;&gt;; extended data types
       * @param filterDataTypes Set&lt;FilterDataType&lt;?&gt;&gt;; filter data types
       */
      @SuppressWarnings({"unchecked", "rawtypes"})
      public Sampler(final Set<ExtendedDataType<?, ?, ?, G>> extendedDataTypes, final Set<FilterDataType<?>> filterDataTypes)
      {
          this.extendedDataTypes = new LinkedHashSet<>(extendedDataTypes);
          this.filterDataTypes = new LinkedHashSet<>(filterDataTypes);
          Set<Column<?>> columns = new LinkedHashSet<>();
          // TODO: fixed columns!
          for (ExtendedDataType<?, ?, ?, G> extendedDataType : this.extendedDataTypes)
          {
              columns.add(new SimpleColumn(extendedDataType.getId(), extendedDataType.getId(), extendedDataType.getType()));
          }
          for (FilterDataType<?> filterDataType : this.filterDataTypes)
          {
              columns.add(new SimpleColumn(filterDataType.getId(), filterDataType.getId(), String.class));
          }
          this.samplerData = new SamplerData<>(columns);
      }
  
      /**
       * Underlying sampler data.
       * @return SamplerData&lt;G&gt;; underlying sampler data
       */
      public SamplerData<G> getSamplerData()
      {
          return this.samplerData;
      }
  
      /**
       * Whether this sampler has the given extended data type registered to it.
       * @param extendedDataType ExtendedDataType&lt;?,?,?,?&gt;; extended data type
       * @return whether this sampler has the given extended data type registered to it
       */
      public boolean contains(final ExtendedDataType<?, ?, ?, ?> extendedDataType)
      {
          return this.extendedDataTypes.contains(extendedDataType);
      }
  
      /**
       * Registers a space-time region. Data will be recorded across the entire length of a lane, but only during specified time
       * periods.
       * @param spaceTimeRegion 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.samplerData.contains(spaceTimeRegion.getLaneDirection()))
         {
             firstPossibleDataTime = this.samplerData.getTrajectoryGroup(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.samplerData.contains(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());
         this.spaceTimeRegions.add(spaceTimeRegion);
     }
 
     /**
      * 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; time to start recording
      * @param kpiLaneDirection KpiLaneDirection; lane-direction to start recording
      */
     public abstract void scheduleStartRecording(Time time, KpiLaneDirection kpiLaneDirection);
 
     /**
      * Schedules the stop of recording for a given lane-direction.
      * @param time Time; time to stop recording
      * @param kpiLaneDirection KpiLaneDirection; lane-direction to stop recording
      */
     public abstract void scheduleStopRecording(Time time, KpiLaneDirection kpiLaneDirection);
 
     /**
      * Start recording at the given time (which should be the current time) on the given lane direction.
      * @param kpiLaneDirection KpiLaneDirection; lane direction
      */
     public final void startRecording(final KpiLaneDirection kpiLaneDirection)
     {
         Throw.whenNull(kpiLaneDirection, "KpiLaneDirection may not be null.");
         if (this.samplerData.contains(kpiLaneDirection))
         {
             return;
         }
         this.samplerData.putTrajectoryGroup(kpiLaneDirection, new TrajectoryGroup<>(now(), kpiLaneDirection));
         initRecording(kpiLaneDirection);
     }
 
     /**
      * Adds listeners to start recording.
      * @param kpiLaneDirection KpiLaneDirection; lane direction to initialize recording for
      */
     public abstract void initRecording(KpiLaneDirection kpiLaneDirection);
 
     /**
      * Stop recording at given lane direction.
      * @param kpiLaneDirection KpiLaneDirection; lane direction
      */
     public final void stopRecording(final KpiLaneDirection kpiLaneDirection)
     {
         Throw.whenNull(kpiLaneDirection, "KpiLaneDirection may not be null.");
         if (!this.samplerData.contains(kpiLaneDirection) || this.endTimes.get(kpiLaneDirection).gt(now()))
         {
             return;
         }
         finalizeRecording(kpiLaneDirection);
     }
 
     /**
      * Remove listeners to stop recording.
      * @param kpiLaneDirection KpiLaneDirection; lane direction to finalize recording for
      */
     public abstract void finalizeRecording(KpiLaneDirection kpiLaneDirection);
 
     /**
      * Creates a trajectory with the current snapshot of a GTU.
      * @param kpiLaneDirection KpiLaneDirection; lane direction the gtu is at
      * @param position Length; position of the gtu on the lane
      * @param speed Speed; speed of the gtu
      * @param acceleration Acceleration; acceleration of the gtu
      * @param time Time; current time
      * @param gtu G; gtu
      */
     public final void processGtuAddEvent(final KpiLaneDirection kpiLaneDirection, final Length position, final Speed speed,
             final Acceleration acceleration, final Time time, final G 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.");
         if (kpiLaneDirection.getLaneData().getLength().lt(position))
         {
             // ignore event if beyond lane length (may happen during lane change)
             return;
         }
         String gtuId = gtu.getId();
         Trajectory<G> trajectory = new Trajectory<>(gtu, makeMetaData(gtu), this.extendedDataTypes, kpiLaneDirection);
         if (!this.trajectoryPerGtu.containsKey(gtuId))
         {
             Map<KpiLaneDirection, Trajectory<G>> map = new LinkedHashMap<>();
             this.trajectoryPerGtu.put(gtuId, map);
         }
         this.trajectoryPerGtu.get(gtuId).put(kpiLaneDirection, trajectory);
         this.samplerData.getTrajectoryGroup(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 KpiLaneDirection; lane direction the gtu is at
      * @param position Length; position of the gtu on the lane
      * @param speed Speed; speed of the gtu
      * @param acceleration Acceleration; acceleration of the gtu
      * @param time Time; current time
      * @param gtu G; gtu
      */
     public final void processGtuMoveEvent(final KpiLaneDirection kpiLaneDirection, final Length position, final Speed speed,
             final Acceleration acceleration, final Time time, final G 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 KpiLaneDirection; lane direction the gtu is at
      * @param position Length; position of the gtu on the lane
      * @param speed Speed; speed of the gtu
      * @param acceleration Acceleration; acceleration of the gtu
      * @param time Time; current time
      * @param gtu G; gtu
      */
     public final void processGtuRemoveEvent(final KpiLaneDirection kpiLaneDirection, final Length position, final Speed speed,
             final Acceleration acceleration, final Time time, final G gtu)
     {
         processGtuMoveEvent(kpiLaneDirection, position, speed, acceleration, time, gtu);
         processGtuRemoveEvent(kpiLaneDirection, gtu);
     }
 
     /**
      * Finalizes a trajectory.
      * @param kpiLaneDirection KpiLaneDirection; lane direction the gtu is at
      * @param gtu G; gtu
      */
     public final void processGtuRemoveEvent(final KpiLaneDirection kpiLaneDirection, final G 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 G; 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 G gtu)
     {
         MetaDatameta/MetaData.html#MetaData">MetaData metaData = new MetaData();
         for (FilterDataType<?> metaDataType : this.filterDataTypes)
         {
             T value = (T) metaDataType.getValue(gtu);
             if (value != null)
             {
                 metaData.put((FilterDataType<T>) metaDataType, value);
             }
         }
         return metaData;
     }
 
     // TODO: hashCode / equals
 
 }