package org.opentrafficsim.draw.graphs;
   
   import java.util.ArrayList;
   import java.util.List;
   
   import org.djunits.value.vdouble.scalar.Duration;
   import org.djunits.value.vdouble.scalar.Length;
   import org.opentrafficsim.draw.graphs.GraphPath.Section;
   import org.opentrafficsim.kpi.interfaces.LaneData;
  import org.opentrafficsim.kpi.sampling.SamplerData;
  import org.opentrafficsim.kpi.sampling.TrajectoryGroup;
  
  /**
   * Super class for plots that use sampler data. Sub classes may obtain trajectories using {@code getTrajectories()}, or
   * alternatively maintain some other -possibly more efficient- connection to the sampler. This class also connects the plot to a
   * path, consisting of a list of lanes. Start distance along the path for each lane is provided to sub classes using
   * {@code getStartDistance(LaneData)}. Total length is obtained using {@code getEndLocation()}.
   * <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>
   */
  public abstract class AbstractSamplerPlot extends AbstractSpaceTimePlot
  {
  
      /** Sampler data. */
      private final SamplerData<?> samplerData;
  
      /** KPI lane directions registered in the sampler. */
      private final GraphPath<? extends LaneData<?>> path;
  
      /** Time when trajectories were last updated per series in the path. */
      private List<Duration> lastUpdateTime = new ArrayList<>();
  
      /** Cached trajectories per series in the path. */
      private List<List<TrajectoryGroup<?>>> trajectoriesCache = new ArrayList<>();
  
      /**
       * Constructor.
       * @param caption caption
       * @param updateInterval regular update interval (simulation time)
       * @param scheduler scheduler.
       * @param samplerData sampler data
       * @param path path
       * @param delay amount of time that chart runs behind simulation to prevent gaps in the charted data
       */
      public AbstractSamplerPlot(final String caption, final Duration updateInterval, final PlotScheduler scheduler,
              final SamplerData<?> samplerData, final GraphPath<? extends LaneData<?>> path, final Duration delay)
      {
          super(caption, updateInterval, scheduler, delay, DEFAULT_INITIAL_UPPER_TIME_BOUND);
          this.samplerData = samplerData;
          this.path = path;
          for (int i = 0; i < path.getNumberOfSeries(); i++)
          {
              this.trajectoriesCache.add(new ArrayList<>());
              this.lastUpdateTime.add(null);
          }
      }
  
      /**
       * Returns all trajectories for the series, in order of the path.
       * @param series series number
       * @return the trajectories
       */
      protected List<TrajectoryGroup<?>> getTrajectories(final int series)
      {
          if (this.lastUpdateTime.get(series) == null || this.lastUpdateTime.get(series).lt(getUpdateTime()))
          {
              List<TrajectoryGroup<?>> cache = new ArrayList<>();
              for (Section<? extends LaneData<?>> section : getPath().getSections())
              {
                  TrajectoryGroup<?> trajectories = this.samplerData.getTrajectoryGroup(section.getSource(series)).orElse(null);
                  if (trajectories != null)
                  {
                      cache.add(trajectories);
                  }
              }
              this.trajectoriesCache.set(series, cache);
              this.lastUpdateTime.set(series, getUpdateTime());
          }
          return this.trajectoriesCache.get(series);
      }
  
      /**
       * Returns the path.
       * @return the path
       */
      public final GraphPath<? extends LaneData<?>> getPath()
      {
          return this.path;
      }
  
      @Override
      protected final Length getEndLocation()
      {
          return getPath().getTotalLength();
     }
 
     /**
      * Returns the sampler data.
      * @return sampler.
      */
     protected final SamplerData<?> getSamplerData()
     {
         return this.samplerData;
     }
 
 }