package org.opentrafficsim.draw.graphs;
   
   import java.awt.BasicStroke;
   import java.awt.Color;
   import java.awt.Paint;
   import java.awt.Shape;
   import java.awt.Stroke;
   import java.awt.geom.CubicCurve2D;
   import java.awt.geom.Line2D;
  import java.util.ArrayList;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.djunits.value.vdouble.scalar.Duration;
  import org.djunits.value.vdouble.scalar.Length;
  import org.djunits.value.vdouble.scalar.Time;
  import org.djutils.exceptions.Try;
  import org.jfree.chart.JFreeChart;
  import org.jfree.chart.LegendItem;
  import org.jfree.chart.LegendItemCollection;
  import org.jfree.chart.axis.NumberAxis;
  import org.jfree.chart.entity.EntityCollection;
  import org.jfree.chart.entity.XYItemEntity;
  import org.jfree.chart.labels.XYToolTipGenerator;
  import org.jfree.chart.plot.XYPlot;
  import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
  import org.jfree.data.DomainOrder;
  import org.jfree.data.xy.XYDataset;
  import org.opentrafficsim.core.animation.gtu.colorer.IDGTUColorer;
  import org.opentrafficsim.core.dsol.OTSSimulatorInterface;
  import org.opentrafficsim.draw.core.BoundsPaintScale;
  import org.opentrafficsim.draw.graphs.GraphPath.Section;
  import org.opentrafficsim.kpi.sampling.KpiLaneDirection;
  import org.opentrafficsim.kpi.sampling.Sampler;
  import org.opentrafficsim.kpi.sampling.SamplingException;
  import org.opentrafficsim.kpi.sampling.Trajectory;
  import org.opentrafficsim.kpi.sampling.TrajectoryGroup;
  
  /**
   * Plot of trajectories along a path.
   * <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 13 okt. 2018 <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 class TrajectoryPlot extends AbstractSamplerPlot implements XYDataset
  {
      /** Single shape to provide due to non-null requirement, but actually not used. */
      private static final Shape NO_SHAPE = new Line2D.Float(0, 0, 0, 0);
  
      /** Color map. */
      private static final Color[] COLORMAP;
  
      /** Strokes. */
      private static final BasicStroke[] STROKES;
  
      /** Shape for the legend entries to draw the line over. */
      private static final Shape LEGEND_LINE = new CubicCurve2D.Float(-20, 7, -10, -7, 0, 7, 20, -7);
  
      /** Updater for update times. */
      private final GraphUpdater<Time> graphUpdater;
  
      /** Counter of the number of trajectories imported per lane. */
      private final Map<KpiLaneDirection, Integer> knownTrajectories = new LinkedHashMap<>();
  
      /** Per lane, mapping from series rank number to trajectory. */
      private List<List<OffsetTrajectory>> curves = new ArrayList<>();
  
      /** Stroke per series. */
      private List<List<Stroke>> strokes = new ArrayList<>();
  
      /** Number of curves per lane. This may be less than the length of {@code List<OffsetTrajectory>} due to concurrency. */
      private List<Integer> curvesPerLane = new ArrayList<>();
  
      /** Legend to change text color to indicate visibility. */
      private LegendItemCollection legend;
  
      /** Whether each lane is visible or not. */
      private final List<Boolean> laneVisible = new ArrayList<>();
  
      static
      {
          Color[] c = BoundsPaintScale.hue(6);
          COLORMAP = new Color[] {c[0], c[4], c[2], c[1], c[3], c[5]};
          float lw = 0.4f;
          STROKES = new BasicStroke[] {new BasicStroke(lw, BasicStroke.CAP_SQUARE, BasicStroke.JOIN_MITER, 10.0f, null, 0.0f),
                  new BasicStroke(lw, BasicStroke.CAP_SQUARE, BasicStroke.JOIN_MITER, 1.0f, new float[] {13f, 4f}, 0.0f),
                  new BasicStroke(lw, BasicStroke.CAP_SQUARE, BasicStroke.JOIN_MITER, 1.0f, new float[] {11f, 3f, 2f, 3f}, 0.0f)};
      }
  
      /**
       * Constructor.
       * @param caption String; caption
       * @param updateInterval Duration; regular update interval (simulation time)
      * @param simulator OTSSimulatorInterface; simulator
      * @param sampler Sampler&lt;?&gt;; road sampler
      * @param path GraphPath&lt;KpiLaneDirection&gt;; path
      */
     public TrajectoryPlot(final String caption, final Duration updateInterval, final OTSSimulatorInterface simulator,
             final Sampler<?> sampler, final GraphPath<KpiLaneDirection> path)
     {
         super(caption, updateInterval, simulator, sampler, path, Duration.ZERO);
         for (int i = 0; i < path.getNumberOfSeries(); i++)
         {
             this.curves.add(new ArrayList<>());
             this.strokes.add(new ArrayList<>());
             this.curvesPerLane.add(0);
             this.laneVisible.add(true);
         }
         setChart(createChart());
 
         // setup updater to do the actual work in another thread
         this.graphUpdater = new GraphUpdater<>("Trajectories worker", Thread.currentThread(), (t) ->
         {
             for (Section<KpiLaneDirection> section : path.getSections())
             {
                 Length startDistance = path.getStartDistance(section);
                 for (int i = 0; i < path.getNumberOfSeries(); i++)
                 {
                     KpiLaneDirection lane = section.getSource(i);
                     TrajectoryGroup<?> trajectoryGroup = getSampler().getTrajectoryGroup(lane);
                     int from = this.knownTrajectories.getOrDefault(lane, 0);
                     int to = trajectoryGroup.size();
                     double scaleFactor = section.getLength().si / lane.getLaneData().getLength().si;
                     for (Trajectory<?> trajectory : trajectoryGroup.getTrajectories().subList(from, to))
                     {
                         if (getPath().getNumberOfSeries() > 1)
                         {
                             // assign a stroke with random offset, otherwise it will look artificial
                             BasicStroke stroke = STROKES[i % STROKES.length];
                             if (stroke.getDashArray() != null)
                             {
                                 float dashLength = 0.0f;
                                 for (float d : stroke.getDashArray())
                                 {
                                     dashLength += d;
                                 }
                                 stroke = new BasicStroke(stroke.getLineWidth(), stroke.getEndCap(), stroke.getLineJoin(),
                                         stroke.getMiterLimit(), stroke.getDashArray(), (float) (Math.random() * dashLength));
                             }
                             this.strokes.get(i).add(stroke);
                         }
                         this.curves.get(i).add(
                                 new OffsetTrajectory(trajectory, startDistance, scaleFactor, lane.getLaneData().getLength()));
                     }
                     this.knownTrajectories.put(lane, to);
                 }
             }
         });
     }
 
     /**
      * Create a chart.
      * @return JFreeChart; chart
      */
     private JFreeChart createChart()
     {
         NumberAxis xAxis = new NumberAxis("Time [s] \u2192");
         NumberAxis yAxis = new NumberAxis("Distance [m] \u2192");
         XYLineAndShapeRendererID renderer = new XYLineAndShapeRendererID();
         XYPlot plot = new XYPlot(this, xAxis, yAxis, renderer);
         boolean showLegend;
         if (getPath().getNumberOfSeries() < 2)
         {
             plot.setFixedLegendItems(null);
             showLegend = false;
         }
         else
         {
             this.legend = new LegendItemCollection();
             for (int i = 0; i < getPath().getNumberOfSeries(); i++)
             {
                 LegendItem li = new LegendItem(getPath().getName(i));
                 li.setSeriesKey(i); // lane series, not curve series
                 li.setShape(STROKES[i & STROKES.length].createStrokedShape(LEGEND_LINE));
                 li.setFillPaint(COLORMAP[i % COLORMAP.length]);
                 this.legend.add(li);
             }
             plot.setFixedLegendItems(this.legend);
             showLegend = true;
         }
         return new JFreeChart(getCaption(), JFreeChart.DEFAULT_TITLE_FONT, plot, showLegend);
     }
 
     /** {@inheritDoc} */
     @Override
     public GraphType getGraphType()
     {
         return GraphType.TRAJECTORY;
     }
 
     /** {@inheritDoc} */
     @Override
     public String getStatusLabel(final double domainValue, final double rangeValue)
     {
         return String.format("time %.0fs, distance %.0fm", domainValue, rangeValue);
     }
 
     /** {@inheritDoc} */
     @Override
     protected void increaseTime(final Time time)
     {
         if (this.graphUpdater != null) // null during construction
         {
             this.graphUpdater.offer(time);
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public int getSeriesCount()
     {
         int n = 0;
         for (int i = 0; i < this.curves.size(); i++)
         {
             List<OffsetTrajectory> list = this.curves.get(i);
             int m = list.size();
             this.curvesPerLane.set(i, m);
             n += m;
         }
         return n;
     }
 
     /** {@inheritDoc} */
     @Override
     public Comparable<Integer> getSeriesKey(final int series)
     {
         return series;
     }
 
     /** {@inheritDoc} */
     @SuppressWarnings("rawtypes")
     @Override
     public int indexOf(final Comparable seriesKey)
     {
         return 0;
     }
 
     /** {@inheritDoc} */
     @Override
     public DomainOrder getDomainOrder()
     {
         return DomainOrder.ASCENDING;
     }
 
     /** {@inheritDoc} */
     @Override
     public int getItemCount(final int series)
     {
         OffsetTrajectory trajectory = getTrajectory(series);
         return trajectory == null ? 0 : trajectory.size();
     }
 
     /** {@inheritDoc} */
     @Override
     public Number getX(final int series, final int item)
     {
         return getXValue(series, item);
     }
 
     /** {@inheritDoc} */
     @Override
     public double getXValue(final int series, final int item)
     {
         return getTrajectory(series).getT(item);
     }
 
     /** {@inheritDoc} */
     @Override
     public Number getY(final int series, final int item)
     {
         return getYValue(series, item);
     }
 
     /** {@inheritDoc} */
     @Override
     public double getYValue(final int series, final int item)
     {
         return getTrajectory(series).getX(item);
     }
 
     /**
      * Get the trajectory of the series number.
      * @param series int; series
      * @return OffsetTrajectory; trajectory of the series number
      */
     private OffsetTrajectory getTrajectory(final int series)
     {
         int[] n = getLaneAndSeriesNumber(series);
         return this.curves.get(n[0]).get(n[1]);
     }
 
     /**
      * Returns the lane number, and series number within the lane data.
      * @param series int; overall series number
      * @return int[]; lane number, and series number within the lane data
      */
     private int[] getLaneAndSeriesNumber(final int series)
     {
         int n = series;
         for (int i = 0; i < this.curves.size(); i++)
         {
             int m = this.curvesPerLane.get(i);
             if (n < m)
             {
                 return new int[] {i, n};
             }
             n -= m;
         }
         throw new RuntimeException("Discrepancy between series number and available data.");
     }
 
     /**
      * Extension of a line renderer to select a color based on GTU ID, and to overrule an unused shape to save memory.
      * <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 14 okt. 2018 <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>
      */
     private final class XYLineAndShapeRendererID extends XYLineAndShapeRenderer
     {
         /** */
         private static final long serialVersionUID = 20181014L;
 
         /**
          * Constructor.
          */
         XYLineAndShapeRendererID()
         {
             super(false, true);
             setDefaultLinesVisible(true);
             setDefaultShapesVisible(false);
             setDrawSeriesLineAsPath(true);
         }
 
         /** {@inheritDoc} */
         @SuppressWarnings("synthetic-access")
         @Override
         public boolean isSeriesVisible(final int series)
         {
             int[] n = getLaneAndSeriesNumber(series);
             return TrajectoryPlot.this.laneVisible.get(n[0]);
         }
 
         /** {@inheritDoc} */
         @SuppressWarnings("synthetic-access")
         @Override
         public Stroke getSeriesStroke(final int series)
         {
             if (TrajectoryPlot.this.curves.size() == 1)
             {
                 return STROKES[0];
             }
             int[] n = getLaneAndSeriesNumber(series);
             return TrajectoryPlot.this.strokes.get(n[0]).get(n[1]);
         }
 
         /** {@inheritDoc} */
         @SuppressWarnings("synthetic-access")
         @Override
         public Paint getSeriesPaint(final int series)
         {
             if (TrajectoryPlot.this.curves.size() == 1)
             {
                 String gtuId = getTrajectory(series).getGtuId();
                 for (int pos = gtuId.length(); --pos >= 0;)
                 {
                     Character c = gtuId.charAt(pos);
                     if (Character.isDigit(c))
                     {
                         return IDGTUColorer.LEGEND.get(c - '0').getColor();
                     }
                 }
             }
             int[] n = getLaneAndSeriesNumber(series);
             return COLORMAP[n[0] % COLORMAP.length];
         }
 
         /**
          * {@inheritDoc} Largely based on the super implementation, but returns a dummy shape for markers to save memory and as
          * markers are not used.
          */
         @SuppressWarnings("synthetic-access")
         @Override
         protected void addEntity(final EntityCollection entities, final Shape hotspot, final XYDataset dataset,
                 final int series, final int item, final double entityX, final double entityY)
         {
 
             if (!getItemCreateEntity(series, item))
             {
                 return;
             }
 
             // if not hotspot is provided, we create a default based on the
             // provided data coordinates (which are already in Java2D space)
             Shape hotspot2 = hotspot == null ? NO_SHAPE : hotspot;
             String tip = null;
             XYToolTipGenerator generator = getToolTipGenerator(series, item);
             if (generator != null)
             {
                 tip = generator.generateToolTip(dataset, series, item);
             }
             String url = null;
             if (getURLGenerator() != null)
             {
                 url = getURLGenerator().generateURL(dataset, series, item);
             }
             XYItemEntity entity = new XYItemEntity(hotspot2, dataset, series, item, tip, url);
             entities.add(entity);
         }
 
         /** {@inheritDoc} */
         @Override
         public String toString()
         {
             return "XYLineAndShapeRendererID []";
         }
 
     }
 
     /**
      * Class containing a trajectory with an offset. Takes care of bits that are before and beyond the lane without affecting
      * the trajectory itself.
      * <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 14 okt. 2018 <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>
      */
     private class OffsetTrajectory
     {
         /** The trajectory. */
         private final Trajectory<?> trajectory;
 
         /** The offset. */
         private final double offset;
 
         /** Scale factor for space dimension. */
         private final double scaleFactor;
 
         /** First index of the trajectory to include, possibly cutting some measurements before the lane. */
         private int first;
 
         /** Size of the trajectory to consider starting at first, possibly cutting some measurements beyond the lane. */
         private int size;
 
         /** Length of the lane to determine {@code size}. */
         private final Length laneLength;
 
         /**
          * Construct a new TrajectoryAndLengthOffset object.
          * @param trajectory Trajectory&lt;?&gt;; the trajectory
          * @param offset Length; the length from the beginning of the sampled path to the start of the lane to which the
          *            trajectory belongs
          * @param scaleFactor double; scale factor for space dimension
          * @param laneLength Length; length of the lane
          */
         OffsetTrajectory(final Trajectory<?> trajectory, final Length offset, final double scaleFactor, final Length laneLength)
         {
             this.trajectory = trajectory;
             this.offset = offset.si;
             this.scaleFactor = scaleFactor;
             this.laneLength = laneLength;
         }
 
         /**
          * Returns the number of measurements in the trajectory.
          * @return int; number of measurements in the trajectory
          */
         public final int size()
         {
             // as trajectories grow, this calculation needs to be done on each request
             try
             {
                 /*
                  * Note on overlap:
                  * 
                  * Suppose a GTU crosses a lane boundary producing the following events, where distance e->| is the front, and
                  * |->l is the tail, relative to the reference point of the GTU.
                  * @formatter:off
                  * -------------------------------------------  o) regular move event
                  *  o     e   o         o |  l    o         o   e) lane enter event on next lane
                  * -------------------------------------------  l) lane leave event on previous lane
                  *  o         o         o   (l)                 measurements on previous lane
                  *       (e) (o)       (o)        o         o   measurements on next lane
                  * @formatter:on
                  * Trajectories of a particular GTU are not explicitly tied together. Not only would this involve quite some
                  * work, it is also impossible to distinguish a lane change near the start or end of a lane, from moving
                  * longitudinally on to the next lane. The basic idea to minimize overlap is to remove all positions on the
                  * previous lane beyond the lane length, and all negative positions on the next lane, i.e. all between ( ). This
                  * would however create a gap at the lane boundary '|'. Allowing one event beyond the lane length may still
                  * result in a gap, l->o in this case. Allowing one event before the lane would work in this case, but 'e' could
                  * also fall between an 'o' and '|'. At one trajectory it is thus not known whether the other trajectory
                  * continues from, or is continued from, the extra point. Hence we require an extra point before the lane and
                  * one beyond the lane to assure there is no gap. The resulting overlap can be as large as a move, but this is
                  * better than occasional gaps.
                  */
                 int f = 0;
                 while (f < this.trajectory.size() - 1 && this.trajectory.getX(f + 1) < 0.0)
                 {
                     f++;
                 }
                 this.first = f;
                 int s = this.trajectory.size() - 1;
                 while (s > 1 && this.trajectory.getX(s - 1) > this.laneLength.si)
                 {
                     s--;
                 }
                 this.size = s - f + 1;
             }
             catch (SamplingException exception)
             {
                 throw new RuntimeException("Unexpected exception while obtaining location value from trajectory for plotting.",
                         exception);
             }
             return this.size;
         }
 
         /**
          * Returns the location, including offset, of an item.
          * @param item int; item (sample) number
          * @return double; location, including offset, of an item
          */
         public final double getX(final int item)
         {
             return Try.assign(() -> this.offset + this.trajectory.getX(this.first + item) * this.scaleFactor,
                     "Unexpected exception while obtaining location value from trajectory for plotting.");
         }
 
         /**
          * Returns the time of an item.
          * @param item int; item (sample) number
          * @return double; time of an item
          */
         public final double getT(final int item)
         {
             return Try.assign(() -> (double) this.trajectory.getT(this.first + item),
                     "Unexpected exception while obtaining time value from trajectory for plotting.");
         }
 
         /**
          * Returns the ID of the GTU of this trajectory.
          * @return String; the ID of the GTU of this trajectory
          */
         public final String getGtuId()
         {
             return this.trajectory.getGtuId();
         }
 
         /** {@inheritDoc} */
         @Override
         public final String toString()
         {
             return "OffsetTrajectory [trajectory=" + this.trajectory + ", offset=" + this.offset + "]";
         }
 
     }
 
     /** {@inheritDoc} */
     @Override
     public String toString()
     {
         return "TrajectoryPlot [graphUpdater=" + this.graphUpdater + ", knownTrajectories=" + this.knownTrajectories
                 + ", curves=" + this.curves + ", strokes=" + this.strokes + ", curvesPerLane=" + this.curvesPerLane
                 + ", legend=" + this.legend + ", laneVisible=" + this.laneVisible + "]";
     }
 
     /**
      * Retrieve the legend.
      * @return LegendItemCollection; the legend
      */
     public LegendItemCollection getLegend()
     {
         return legend;
     }
 
     /**
      * Retrieve the lane visibility flags.
      * @return List&lt;Boolean&gt;; the lane visibility flags
      */
     public List<Boolean> getLaneVisible()
     {
         return laneVisible;
     }
 
 }