package org.opentrafficsim.graphs;
   
   import java.awt.BorderLayout;
   import java.awt.event.ActionEvent;
   import java.awt.event.ActionListener;
   import java.util.ArrayList;
   
   import javax.swing.ButtonGroup;
   import javax.swing.JFrame;
  import javax.swing.JLabel;
  import javax.swing.JMenu;
  import javax.swing.JPopupMenu;
  import javax.swing.JRadioButtonMenuItem;
  import javax.swing.SwingConstants;
  import javax.swing.event.EventListenerList;
  
  import nl.tudelft.simulation.dsol.SimRuntimeException;
  
  import org.djunits.unit.LinearDensityUnit;
  import org.djunits.value.vdouble.scalar.DoubleScalar;
  import org.jfree.chart.ChartFactory;
  import org.jfree.chart.ChartPanel;
  import org.jfree.chart.JFreeChart;
  import org.jfree.chart.StandardChartTheme;
  import org.jfree.chart.axis.NumberAxis;
  import org.jfree.chart.axis.ValueAxis;
  import org.jfree.chart.event.AxisChangeEvent;
  import org.jfree.chart.plot.PlotOrientation;
  import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
  import org.jfree.data.DomainOrder;
  import org.jfree.data.general.DatasetChangeEvent;
  import org.jfree.data.general.DatasetChangeListener;
  import org.jfree.data.general.DatasetGroup;
  import org.jfree.data.xy.XYDataset;
  import org.opentrafficsim.core.OTS_SCALAR;
  import org.opentrafficsim.core.dsol.OTSDEVSSimulatorInterface;
  import org.opentrafficsim.core.gtu.RelativePosition;
  import org.opentrafficsim.core.network.NetworkException;
  import org.opentrafficsim.road.gtu.lane.LaneBasedGTU;
  import org.opentrafficsim.road.network.lane.AbstractSensor;
  import org.opentrafficsim.road.network.lane.Lane;
  
  /**
   * The Fundamental Diagram Graph; see <a href="http://en.wikipedia.org/wiki/Fundamental_diagram_of_traffic_flow"> Wikipedia:
   * http://en.wikipedia.org/wiki/Fundamental_diagram_of_traffic_flow</a>.
   * <p>
   * Copyright (c) 2013-2015 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/docs/license.html">OpenTrafficSim License</a>.
   * <p>
   * $LastChangedDate: 2015-09-14 01:33:02 +0200 (Mon, 14 Sep 2015) $, @version $Revision: 1401 $, by $Author: averbraeck $,
   * initial version Jul 31, 2014 <br>
   * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
   */
  public class FundamentalDiagramLane extends JFrame implements XYDataset, ActionListener, OTS_SCALAR
  {
      /** */
      private static final long serialVersionUID = 20140701L;
  
      /** The ChartPanel for this Fundamental Diagram. */
      private JFreeChart chartPanel;
  
      /** Caption for this Fundamental Diagram. */
      private final String caption;
  
      /** Area to show status information. */
      private final JLabel statusLabel;
  
      /** Sample duration of the detector that generates this Fundamental Diagram. */
      private final Time.Rel aggregationTime;
  
      /** Storage for the Samples. */
      private ArrayList<Sample> samples = new ArrayList<Sample>();
  
      /** Definition of the density axis. */
      private Axis densityAxis = new Axis(new DoubleScalar.Abs<LinearDensityUnit>(0, PER_KILOMETER),
          new DoubleScalar.Abs<LinearDensityUnit>(200, PER_KILOMETER), null, 0d, "Density [veh/km]", "Density",
          "density %.1f veh/km");
  
      /**
       * @return densityAxis
       */
      public final Axis getDensityAxis()
      {
          return this.densityAxis;
      }
  
      /** Definition of the speed axis. */
      private Axis speedAxis = new Axis(new Speed.Abs(0, KM_PER_HOUR), new Speed.Abs(120, KM_PER_HOUR), null, 0d,
          "Speed [km/h]", "Speed", "speed %.0f km/h");
  
      /**
       * @return speedAxis
       */
      public final Axis getSpeedAxis()
      {
          return this.speedAxis;
      }
  
      /**
      * @return flowAxis
      */
     public final Axis getFlowAxis()
     {
         return this.flowAxis;
     }
 
     /** Definition of the flow axis. */
     private Axis flowAxis = new Axis(new Frequency.Abs(0, PER_HOUR), new Frequency.Abs(3000d, HERTZ), null, 0d,
         "Flow [veh/h]", "Flow", "flow %.0f veh/h");
 
     /** The currently shown X-axis. */
     private Axis xAxis;
 
     /** The currently shown Y-axis. */
     private Axis yAxis;
 
     /** List of parties interested in changes of this ContourPlot. */
     private transient EventListenerList listenerList = new EventListenerList();
 
     /** Not used internally. */
     private DatasetGroup datasetGroup = null;
 
     /** the lane for which data is gathered. */
     private final Lane lane;
 
     /** the simulator to schedule sampling. */
     private final OTSDEVSSimulatorInterface simulator;
     
     /** flow counter. */
     
     int flow = 0;
 
     /**
      * Retrieve the format string for the Y axis.
      * @return format string
      */
     public final String getYAxisFormat()
     {
         return this.yAxis.getFormat();
     }
 
     /**
      * Retrieve the format string for the X axis.
      * @return format string
      */
     public final String getXAxisFormat()
     {
         return this.xAxis.getFormat();
     }
 
     /**
      * Graph a Fundamental Diagram.
      * @param caption String; the caption shown above the graphing area.
      * @param aggregationTime DoubleScalarRel&lt;TimeUnit&gt;; the aggregation of the detector that generates the data for this
      *            Fundamental diagram
      * @param lane Lane; the Lane on which the traffic will be sampled
      * @param simulator the simulator to schedule the sampling on
      * @throws NetworkException on network inconsistency
      * @throws SimRuntimeException in case scheduling of the sampler fails
      */
     public FundamentalDiagramLane(final String caption, final Time.Rel aggregationTime, final Lane lane,
         final OTSDEVSSimulatorInterface simulator) throws NetworkException, SimRuntimeException
     {
         if (aggregationTime.getSI() <= 0)
         {
             throw new Error("Aggregation time must be > 0 (got " + aggregationTime + ")");
         }
         this.aggregationTime = aggregationTime;
         this.caption = caption;
         this.lane = lane;
         this.simulator = simulator;
         ChartFactory.setChartTheme(new StandardChartTheme("JFree/Shadow", false));
         this.chartPanel =
             ChartFactory.createXYLineChart(this.caption, "", "", this, PlotOrientation.VERTICAL, false, false, false);
         FixCaption.fixCaption(this.chartPanel);
         final XYLineAndShapeRenderer renderer = (XYLineAndShapeRenderer) this.chartPanel.getXYPlot().getRenderer();
         renderer.setBaseShapesVisible(true);
 
         final ChartPanel cp = new ChartPanel(this.chartPanel);
         PointerHandler ph = new PointerHandler()
         {
             /** {@inheritDoc} */
             @Override
             void updateHint(final double domainValue, final double rangeValue)
             {
                 if (Double.isNaN(domainValue))
                 {
                     setStatusText(" ");
                     return;
                 }
                 String s1 = String.format(getXAxisFormat(), domainValue);
                 String s2 = String.format(getYAxisFormat(), rangeValue);
                 setStatusText(s1 + ", " + s2);
             }
 
         };
         cp.addMouseMotionListener(ph);
         cp.addMouseListener(ph);
         cp.setMouseWheelEnabled(true);
         final JMenu subMenu = new JMenu("Set layout");
         final ButtonGroup group = new ButtonGroup();
         final JRadioButtonMenuItem defaultItem = addMenuItem(subMenu, group, getDensityAxis(), this.flowAxis, true);
         addMenuItem(subMenu, group, this.flowAxis, this.speedAxis, false);
         addMenuItem(subMenu, group, this.densityAxis, this.speedAxis, false);
         actionPerformed(new ActionEvent(this, 0, defaultItem.getActionCommand()));
         final JPopupMenu popupMenu = cp.getPopupMenu();
         popupMenu.insert(subMenu, 0);
         this.add(cp, BorderLayout.CENTER);
         this.statusLabel = new JLabel(" ", SwingConstants.CENTER);
         this.add(this.statusLabel, BorderLayout.SOUTH);
         simulator.scheduleEventRel(this.aggregationTime, this, this, "addData", null);
         new FlowSensor(lane);
     }
 
     /**
      * Update the status text.
      * @param newText String; the new text to show
      */
     public final void setStatusText(final String newText)
     {
         this.statusLabel.setText(newText);
     }
 
     /**
      * @return aggregationTime
      */
     public final Time.Rel getAggregationTime()
     {
         return this.aggregationTime;
     }
 
     /**
      * Build one JRadioButtonMenuItem for the sub menu of the context menu.
      * @param subMenu JMenu; the menu to which the new JRadioButtonMenuItem is added
      * @param group ButtonGroup; the buttonGroup for the new JRadioButtonMenuItem
      * @param xAxisToSelect Axis; the Axis that will become X-axis when this item is clicked
      * @param yAxisToSelect Axis; the Axis that will become Y-axis when this item is clicked
      * @param selected Boolean; if true, the new JRadioButtonMenuItem will be selected; if false, the new JRadioButtonMenuItem
      *            will <b>not</b> be selected
      * @return JRatioButtonMenuItem; the newly added item
      */
     private JRadioButtonMenuItem addMenuItem(final JMenu subMenu, final ButtonGroup group, final Axis xAxisToSelect,
         final Axis yAxisToSelect, final boolean selected)
     {
         final JRadioButtonMenuItem item =
             new JRadioButtonMenuItem(yAxisToSelect.getShortName() + " / " + xAxisToSelect.getShortName());
         item.setSelected(selected);
         item.setActionCommand(yAxisToSelect.getShortName() + "/" + xAxisToSelect.getShortName());
         item.addActionListener(this);
         subMenu.add(item);
         group.add(item);
         return item;
     }
 
     /**
      * Add the density and average speed on the lane to this Fundamental Diagram.
      * @throws SimRuntimeException when scheduling of next sampling time fails
      */
     public final void addData() throws SimRuntimeException
     {
         // collect (harmonic) mean speed and number of vehicles per meter on the lane
         double n = this.lane.getGtuList().size();
         double density = n / this.lane.getLength().si;
         if (density > 0.0)
         {
             double meanSpeed = 0.0;
             for (LaneBasedGTU gtu : this.lane.getGtuList())
             {
                 meanSpeed += 1 / gtu.getVelocity().si;
             }
             meanSpeed = n / meanSpeed;
             this.samples.add(new Sample(meanSpeed, density, this.flow / this.aggregationTime.si));
             this.flow = 0;
         }
         this.simulator.scheduleEventRel(this.aggregationTime, this, this, "addData", null);
     }
 
     /**
      * Set up a JFreeChart axis.
      * @param valueAxis ValueAxis; the axis to set up
      * @param axis Axis; the Axis that provides the data to setup the ValueAxis
      */
     private static void configureAxis(final ValueAxis valueAxis, final Axis axis)
     {
         valueAxis.setLabel("\u2192 " + axis.getName());
         valueAxis.setRange(axis.getMinimumValue().getInUnit(), axis.getMaximumValue().getInUnit());
     }
 
     /**
      * Redraw this TrajectoryGraph (after the underlying data has been changed, or to change axes).
      */
     public final void reGraph()
     {
         NumberAxis numberAxis = new NumberAxis();
         configureAxis(numberAxis, this.xAxis);
         this.chartPanel.getXYPlot().setDomainAxis(numberAxis);
         this.chartPanel.getPlot().axisChanged(new AxisChangeEvent(numberAxis));
         numberAxis = new NumberAxis();
         configureAxis(numberAxis, this.yAxis);
         this.chartPanel.getXYPlot().setRangeAxis(numberAxis);
         this.chartPanel.getPlot().axisChanged(new AxisChangeEvent(numberAxis));
         notifyListeners(new DatasetChangeEvent(this, null)); // This guess work actually works!
     }
 
     /**
      * Notify interested parties of an event affecting this TrajectoryPlot.
      * @param event DatasetChangedEvent
      */
     private void notifyListeners(final DatasetChangeEvent event)
     {
         for (DatasetChangeListener dcl : this.listenerList.getListeners(DatasetChangeListener.class))
         {
             dcl.datasetChanged(event);
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public final int getSeriesCount()
     {
         return 1;
     }
 
     /** {@inheritDoc} */
     @Override
     public final Comparable<Integer> getSeriesKey(final int series)
     {
         return series;
     }
 
     /** {@inheritDoc} */
     @SuppressWarnings("rawtypes")
     @Override
     public final int indexOf(final Comparable seriesKey)
     {
         if (seriesKey instanceof Integer)
         {
             return (Integer) seriesKey;
         }
         return -1;
     }
 
     /** {@inheritDoc} */
     @Override
     public final void addChangeListener(final DatasetChangeListener listener)
     {
         this.listenerList.add(DatasetChangeListener.class, listener);
     }
 
     /** {@inheritDoc} */
     @Override
     public final void removeChangeListener(final DatasetChangeListener listener)
     {
         this.listenerList.remove(DatasetChangeListener.class, listener);
     }
 
     /** {@inheritDoc} */
     @Override
     public final DatasetGroup getGroup()
     {
         return this.datasetGroup;
     }
 
     /** {@inheritDoc} */
     @Override
     public final void setGroup(final DatasetGroup group)
     {
         this.datasetGroup = group;
     }
 
     /** {@inheritDoc} */
     @Override
     public final DomainOrder getDomainOrder()
     {
         return DomainOrder.ASCENDING;
     }
 
     /** {@inheritDoc} */
     @Override
     public final int getItemCount(final int series)
     {
         return this.samples.size();
     }
 
     /**
      * Retrieve a value from the recorded samples.
      * @param item Integer; the rank number of the sample
      * @param axis Axis; the axis that determines which quantity to retrieve
      * @return Double; the requested value, or Double.NaN if the sample does not (yet) exist
      */
     private Double getSample(final int item, final Axis axis)
     {
         if (item >= this.samples.size())
         {
             return Double.NaN;
         }
         double result = this.samples.get(item).getValue(axis);
         return result;
     }
 
     /** {@inheritDoc} */
     @Override
     public final Number getX(final int series, final int item)
     {
         return getXValue(series, item);
     }
 
     /** {@inheritDoc} */
     @Override
     public final double getXValue(final int series, final int item)
     {
         return getSample(item, this.xAxis);
     }
 
     /** {@inheritDoc} */
     @Override
     public final Number getY(final int series, final int item)
     {
         return getYValue(series, item);
     }
 
     /** {@inheritDoc} */
     @Override
     public final double getYValue(final int series, final int item)
     {
         return getSample(item, this.yAxis);
     }
 
     /** {@inheritDoc} */
     @Override
     public final void actionPerformed(final ActionEvent actionEvent)
     {
         final String command = actionEvent.getActionCommand();
         // System.out.println("command is \"" + command + "\"");
         final String[] fields = command.split("[/]");
         if (fields.length == 2)
         {
             for (String field : fields)
             {
                 if (field.equalsIgnoreCase(this.densityAxis.getShortName()))
                 {
                     if (field == fields[0])
                     {
                         this.yAxis = this.densityAxis;
                     }
                     else
                     {
                         this.xAxis = this.densityAxis;
                     }
                 }
                 else if (field.equalsIgnoreCase(this.flowAxis.getShortName()))
                 {
                     if (field == fields[0])
                     {
                         this.yAxis = this.flowAxis;
                     }
                     else
                     {
                         this.xAxis = this.flowAxis;
                     }
                 }
                 else if (field.equalsIgnoreCase(this.speedAxis.getShortName()))
                 {
                     if (field == fields[0])
                     {
                         this.yAxis = this.speedAxis;
                     }
                     else
                     {
                         this.xAxis = this.speedAxis;
                     }
                 }
                 else
                 {
                     throw new Error("Cannot find axis name: " + field);
                 }
             }
             reGraph();
         }
         else
         {
             throw new Error("Unknown ActionEvent");
         }
     }
 
     /**
      * Storage for one sample of data collected with mean speed [m/s] and number of vehicles per km. Flow per second can be calculated
      * from these two numbers as  
      * <p>
      * Copyright (c) 2013-2015 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
      * </p>
      * $LastChangedDate: 2015-07-15 11:18:39 +0200 (Wed, 15 Jul 2015) $, @version $Revision: 1401 $, by $Author: averbraeck $,
      * initial versionJul 31, 2014 <br>
      * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
      */
     class Sample
     {
         /** mean speed observed during this sample [m/s]. */
         private final double meanSpeed;
 
         /** density [veh/m]. */
         private final double density;
         
         /** flow [veh/s]. */
         private final double flow;
 
         /**
          * @param meanSpeed mean speed observed during this sample [m/s]
          * @param density density [veh/m]
          * @param flow [veh/s]
          */
         public Sample(final double meanSpeed, final double density, final double flow)
         {
             super();
             this.meanSpeed = meanSpeed;
             this.density = density;
             this.flow = flow;
         }
 
         /**
          * Retrieve a value stored in this Sample.
          * @param axis Axis; the axis along which the data is requested
          * @return double; the retrieved value
          */
         public double getValue(final Axis axis)
         {
             if (axis == getDensityAxis())
             {
                 return 1000.0 * this.density; // [veh/km]
             }
             else if (axis == getFlowAxis())
             {
                 return 3600.0 * this.meanSpeed * this.density; // [veh/h]
             }
             else if (axis == getSpeedAxis())
             {
                 return 3.6 * this.meanSpeed; // [km / h]
             }
             else
             {
                 throw new Error("Sample.getValue: Can not identify axis");
             }
         }
     }
 
     /** */
     private class FlowSensor extends AbstractSensor
     {
         /** */
         private static final long serialVersionUID = 1L;
 
         /**
          * @param lane the lane for which to build the flowSensor
          */
         public FlowSensor(final Lane lane)
         {
             super(lane, lane.getLength().divideBy(2.0), RelativePosition.FRONT, "FLOW", null);
         }
 
         /** {@inheritDoc} */
         @Override
         public void trigger(final LaneBasedGTU gtu)
         {
             FundamentalDiagramLane.this.flow += 1;
         }
         
     }
 }