package org.opentrafficsim.kpi.sampling;
   
   import java.util.ArrayList;
   import java.util.Iterator;
   import java.util.LinkedHashMap;
   import java.util.LinkedHashSet;
   import java.util.List;
   import java.util.Map;
   import java.util.Map.Entry;
  import java.util.Set;
  import java.util.UUID;
  
  import org.djunits.value.vdouble.scalar.Duration;
  import org.djunits.value.vdouble.scalar.Frequency;
  import org.djunits.value.vdouble.scalar.Length;
  import org.djutils.base.Identifiable;
  import org.djutils.exceptions.Throw;
  import org.djutils.immutablecollections.ImmutableIterator;
  import org.opentrafficsim.kpi.interfaces.GtuData;
  import org.opentrafficsim.kpi.interfaces.LaneData;
  import org.opentrafficsim.kpi.interfaces.LinkData;
  import org.opentrafficsim.kpi.sampling.filter.FilterDataSet;
  import org.opentrafficsim.kpi.sampling.filter.FilterDataType;
  
  /**
   * A query defines which subset of trajectory information should be included. This is in terms of space-time regions, and in
   * terms of filter data of trajectories, e.g. only include trajectories of trucks.
   * <p>
   * Copyright (c) 2013-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
   * </p>
   * @author <a href="https://github.com/averbraeck">Alexander Verbraeck</a>
   * @author <a href="https://github.com/peter-knoppers">Peter Knoppers</a>
   * @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
   * @param <G> GTU data type
   * @param <L> lane data type
   */
  public final class Query<G extends GtuData, L extends LaneData<L>> implements Identifiable
  {
  
      /** unique id. */
      private final String id;
  
      /** Sampling. */
      private final Sampler<G, L> sampler;
  
      /** Description. */
      private final String description;
  
      /** Filter data set. */
      private final FilterDataSet filterDataSet;
  
      /** Update frequency. */
      private final Frequency updateFrequency;
  
      /** Interval to gather statistics over. */
      private final Duration interval;
  
      /** List of space-time regions of this query. */
      private final List<SpaceTimeRegion<? extends L>> spaceTimeRegions = new ArrayList<>();
  
      /**
       * Constructor.
       * @param sampler sampler
       * @param id id
       * @param description description
       * @param filterDataSet filter data
       * @throws NullPointerException if sampling, description or filterDataSet is null
       */
      public Query(final Sampler<G, L> sampler, final String id, final String description, final FilterDataSet filterDataSet)
      {
          this(sampler, id, description, filterDataSet, null, null);
      }
  
      /**
       * Constructor with time interval and update frequency.
       * @param sampler sampler
       * @param id id, may be {@code null}
       * @param description description
       * @param filterDataSet filter data
       * @param updateFrequency update frequency, used by external controller, may be {@code null}
       * @param interval interval to gather statistics over, used by external controller, may be {@code null}
       * @throws NullPointerException if sampling, description or filterDataSet is {@code null}
       */
      public Query(final Sampler<G, L> sampler, final String id, final String description, final FilterDataSet filterDataSet,
              final Frequency updateFrequency, final Duration interval)
      {
          Throw.whenNull(sampler, "Sampling may not be null.");
          Throw.whenNull(description, "Description may not be null.");
          Throw.whenNull(filterDataSet, "Meta data may not be null.");
          this.sampler = sampler;
          this.filterDataSet = new FilterDataSet(filterDataSet);
          this.id = id == null ? UUID.randomUUID().toString() : id;
          this.description = description;
          this.updateFrequency = updateFrequency;
          this.interval = interval;
      }
  
      @Override
     public String getId()
     {
         return this.id.toString();
     }
 
     /**
      * Returns the description.
      * @return description
      */
     public String getDescription()
     {
         return this.description;
     }
 
     /**
      * Returns the update frequency.
      * @return updateFrequency.
      */
     public Frequency getUpdateFrequency()
     {
         return this.updateFrequency;
     }
 
     /**
      * Returns the time interval.
      * @return interval.
      */
     public Duration getInterval()
     {
         return this.interval;
     }
 
     /**
      * Returns the number of filter datas.
      * @return number of filter data entries
      */
     public int filterSize()
     {
         return this.filterDataSet.size();
     }
 
     /**
      * Returns an iterator over the filter datas and the related data sets.
      * @return iterator over filter data entries, removal is not allowed
      */
     public Iterator<Entry<FilterDataType<?, ?>, Set<?>>> getFilterDataSetIterator()
     {
         return this.filterDataSet.getFilterDataSetIterator();
     }
 
     /**
      * Defines a region in space and time for which this query is valid. All lanes in the link are included.
      * @param link link
      * @param startPosition start position
      * @param endPosition end position
      * @param startTime start time
      * @param endTime end time
      */
     public void addSpaceTimeRegionLink(final LinkData<? extends L> link, final Length startPosition, final Length endPosition,
             final Duration startTime, final Duration endTime)
     {
         Throw.whenNull(link, "Link may not be null.");
         Throw.whenNull(startPosition, "Start position may not be null.");
         Throw.whenNull(endPosition, "End position may not be null.");
         Throw.whenNull(startTime, "Start time may not be null.");
         Throw.whenNull(endTime, "End time may not be null.");
         Throw.when(endPosition.lt(startPosition), IllegalArgumentException.class,
                 "End position should be greater than start position.");
         Throw.when(endTime.lt(startTime), IllegalArgumentException.class, "End time should be greater than start time.");
         double fStart = startPosition.si / link.getLength().si;
         double fEnd = endPosition.si / link.getLength().si;
         for (L lane : link.getLanes())
         {
             Length x0 = lane.getLength().times(fStart);
             Length x1 = lane.getLength().times(fEnd);
             addSpaceTimeRegion(lane, x0, x1, startTime, endTime);
         }
     }
 
     /**
      * Defines a region in space and time for which this query is valid.
      * @param lane lane
      * @param startPosition start position
      * @param endPosition end position
      * @param startTime start time
      * @param endTime end time
      */
     public void addSpaceTimeRegion(final L lane, final Length startPosition, final Length endPosition, final Duration startTime,
             final Duration endTime)
     {
         Throw.whenNull(lane, "Lane direction may not be null.");
         Throw.whenNull(startPosition, "Start position may not be null.");
         Throw.whenNull(endPosition, "End position may not be null.");
         Throw.whenNull(startTime, "Start time may not be null.");
         Throw.whenNull(endTime, "End time may not be null.");
         Throw.when(endPosition.lt(startPosition), IllegalArgumentException.class,
                 "End position should be greater than start position.");
         Throw.when(endTime.lt(startTime), IllegalArgumentException.class, "End time should be greater than start time.");
         SpaceTimeRegion<L> spaceTimeRegion = new SpaceTimeRegion<>(lane, startPosition, endPosition, startTime, endTime);
         this.sampler.registerSpaceTimeRegion(spaceTimeRegion);
         this.spaceTimeRegions.add(spaceTimeRegion);
     }
 
     /**
      * Returns the number of space-time regions.
      * @return number of space-time regions
      */
     public int spaceTimeRegionSize()
     {
         return this.spaceTimeRegions.size();
     }
 
     /**
      * Returns an iterator over the space-time regions.
      * @return iterator over space-time regions, removal is not allowed
      */
     public Iterator<SpaceTimeRegion<? extends L>> getSpaceTimeIterator()
     {
         return new ImmutableIterator<>(this.spaceTimeRegions.iterator());
     }
 
     /**
      * Returns a list of TrajectoryGroups in accordance with the query. Each {@code TrajectoryGroup} contains {@code Trajectory}
      * objects pertaining to a {@code SpaceTimeRegion} from the query. A {@code Trajectory} is only included if all the filter
      * data of this query accepts the trajectory. This method uses {@code Time.ZERO} as start.
      * @param endTime end time of interval to get trajectory groups for
      * @param <T> underlying class of filter data type and its value
      * @return list of trajectory groups in accordance with the query
      */
     public <T> List<TrajectoryGroup<G>> getTrajectoryGroups(final Duration endTime)
     {
         return getTrajectoryGroups(Duration.ZERO, endTime);
     }
 
     /**
      * Returns a list of TrajectoryGroups in accordance with the query. Each {@code TrajectoryGroup} contains {@code Trajectory}
      * objects pertaining to a {@code SpaceTimeRegion} from the query. A {@code Trajectory} is only included if all the filter
      * data of this query accepts the trajectory.
      * @param startTime start time of interval to get trajectory groups for
      * @param endTime start time of interval to get trajectory groups for
      * @param <T> underlying class of filter data type and its value
      * @return list of trajectory groups in accordance with the query
      */
     @SuppressWarnings("unchecked")
     public <T> List<TrajectoryGroup<G>> getTrajectoryGroups(final Duration startTime, final Duration endTime)
     {
         Throw.whenNull(startTime, "Start t may not be null.");
         Throw.whenNull(endTime, "End t may not be null.");
         // Step 1) gather trajectories per GTU, truncated over space and time
         Map<String, TrajectoryAcceptList> trajectoryAcceptLists = new LinkedHashMap<>();
         List<TrajectoryGroup<G>> trajectoryGroupList = new ArrayList<>();
         for (SpaceTimeRegion<? extends L> spaceTimeRegion : this.spaceTimeRegions)
         {
             Duration start = startTime.gt(spaceTimeRegion.startTime()) ? startTime : spaceTimeRegion.startTime();
             Duration end = endTime.lt(spaceTimeRegion.endTime()) ? endTime : spaceTimeRegion.endTime();
             TrajectoryGroup<G> trajectoryGroup;
             if (this.sampler.getSamplerData().getTrajectoryGroup(spaceTimeRegion.lane()).isEmpty())
             {
                 trajectoryGroup = new TrajectoryGroup<>(start, spaceTimeRegion.lane());
             }
             else
             {
                 trajectoryGroup = this.sampler.getSamplerData().getTrajectoryGroup(spaceTimeRegion.lane()).get()
                         .getTrajectoryGroup(spaceTimeRegion.startPosition(), spaceTimeRegion.endPosition(), start, end);
             }
             for (Trajectory<G> trajectory : trajectoryGroup.getTrajectories())
             {
                 if (!trajectoryAcceptLists.containsKey(trajectory.getGtuId()))
                 {
                     trajectoryAcceptLists.put(trajectory.getGtuId(), new TrajectoryAcceptList());
                 }
                 trajectoryAcceptLists.get(trajectory.getGtuId()).addTrajectory(trajectory, trajectoryGroup);
             }
             trajectoryGroupList.add(trajectoryGroup);
         }
         // Step 2) accept per GTU
         Iterator<String> iterator = trajectoryAcceptLists.keySet().iterator();
         while (iterator.hasNext())
         {
             String gtuId = iterator.next();
             TrajectoryAcceptList trajectoryAcceptListCombined = trajectoryAcceptLists.get(gtuId);
             trajectoryAcceptListCombined.acceptAll(); // refuse only if any filter data type refuses
             for (FilterDataType<?, ?> filterDataType : this.filterDataSet.getFilterDataTypes())
             {
                 // create safe copy per filter data type, with defaults accepts = false
                 TrajectoryAcceptList trajectoryAcceptListCopy = copyTrajectoryAcceptList(trajectoryAcceptLists.get(gtuId));
                 // request filter data type to accept or reject
                 ((FilterDataType<T, ?>) filterDataType).accept(trajectoryAcceptListCopy,
                         (Set<T>) new LinkedHashSet<>(this.filterDataSet.get(filterDataType)));
                 // combine acceptance/rejection of filter data types so far
                 for (int i = 0; i < trajectoryAcceptListCopy.size(); i++)
                 {
                     Trajectory<?> trajectory = trajectoryAcceptListCopy.getTrajectory(i);
                     trajectoryAcceptListCombined.acceptTrajectory(trajectory,
                             trajectoryAcceptListCombined.isAccepted(trajectory)
                                     && trajectoryAcceptListCopy.isAccepted(trajectory));
                 }
             }
         }
         // Step 3) filter trajectories
         List<TrajectoryGroup<G>> out = new ArrayList<>();
         for (TrajectoryGroup<G> full : trajectoryGroupList)
         {
             TrajectoryGroup<G> filtered = new TrajectoryGroup<>(full.getStartTime(), full.getLane());
             for (Trajectory<G> trajectory : full.getTrajectories())
             {
                 String gtuId = trajectory.getGtuId();
                 if (trajectory.size() > 0 && trajectoryAcceptLists.get(gtuId).isAccepted(trajectory))
                 {
                     filtered.addTrajectory(trajectory);
                 }
             }
             out.add(filtered);
         }
         return out;
     }
 
     /**
      * Returns a copy of the trajectory accept list, with all assumed not accepted.
      * @param trajectoryAcceptList trajectory accept list to copy
      * @return copy of the trajectory accept list, with all assumed not accepted
      */
     private TrajectoryAcceptList copyTrajectoryAcceptList(final TrajectoryAcceptList trajectoryAcceptList)
     {
         TrajectoryAcceptList trajectoryAcceptListCopy = new TrajectoryAcceptList();
         for (int i = 0; i < trajectoryAcceptList.size(); i++)
         {
             trajectoryAcceptListCopy.addTrajectory(trajectoryAcceptList.getTrajectory(i),
                     trajectoryAcceptList.getTrajectoryGroup(i));
         }
         return trajectoryAcceptListCopy;
     }
 
     /**
      * Returns the sampler.
      * @return sampler.
      */
     public Sampler<G, L> getSampler()
     {
         return this.sampler;
     }
 
     @Override
     public int hashCode()
     {
         final int prime = 31;
         int result = 1;
         result = prime * result + this.description.hashCode();
         result = prime * result + ((this.interval == null) ? 0 : this.interval.hashCode());
         result = prime * result + this.filterDataSet.hashCode();
         result = prime * result + this.sampler.hashCode();
         result = prime * result + this.spaceTimeRegions.hashCode();
         result = prime * result + this.id.hashCode();
         result = prime * result + ((this.updateFrequency == null) ? 0 : this.updateFrequency.hashCode());
         return result;
     }
 
     @Override
     public boolean equals(final Object obj)
     {
         if (this == obj)
         {
             return true;
         }
         if (obj == null)
         {
             return false;
         }
         if (getClass() != obj.getClass())
         {
             return false;
         }
         Query<?, ?> other = (Query<?, ?>) obj;
         if (!this.description.equals(other.description))
         {
             return false;
         }
         if (this.interval == null)
         {
             if (other.interval != null)
             {
                 return false;
             }
         }
         else if (!this.interval.equals(other.interval))
         {
             return false;
         }
         if (!this.filterDataSet.equals(other.filterDataSet))
         {
             return false;
         }
         if (!this.sampler.equals(other.sampler))
         {
             return false;
         }
         if (!this.spaceTimeRegions.equals(other.spaceTimeRegions))
         {
             return false;
         }
         if (!this.id.equals(other.id))
         {
             return false;
         }
         if (this.updateFrequency == null)
         {
             if (other.updateFrequency != null)
             {
                 return false;
             }
         }
         else if (!this.updateFrequency.equals(other.updateFrequency))
         {
             return false;
         }
         return true;
     }
 
     @Override
     public String toString()
     {
         return "Query (" + this.description + ")";
     }
 
 }