package org.opentrafficsim.road.network;
   
   import static org.junit.Assert.assertEquals;
   
   import org.djunits.unit.UNITS;
   import org.djunits.value.vdouble.scalar.Length;
   import org.junit.Test;
   import org.opentrafficsim.core.geometry.OTSGeometryException;
   import org.opentrafficsim.core.geometry.OTSLine3D;
  import org.opentrafficsim.core.geometry.OTSPoint3D;
  import org.opentrafficsim.core.network.LinkLocation;
  import org.opentrafficsim.core.network.LinkType;
  import org.opentrafficsim.core.network.LongitudinalDirectionality;
  import org.opentrafficsim.core.network.OTSNode;
  import org.opentrafficsim.road.network.lane.CrossSectionLink;
  import org.opentrafficsim.road.network.lane.changing.LaneKeepingPolicy;
  
  /**
   * Test the LinkLocation class.
   * <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: 2015-09-16 19:20:07 +0200 (Wed, 16 Sep 2015) $, @version $Revision: 1405 $, by $Author: averbraeck $,
   * initial version 20 jan. 2015 <br>
   * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
   */
  public class LinkLocationTest implements UNITS
  {
      /**
       * Test constructor and verify all getters.
       * @throws OTSGeometryException
       */
      @Test
      public void linkLocationTest() throws OTSGeometryException
      {
          // Preparations
          OTSNode nodeFrom = new OTSNode("From", new OTSPoint3D(0, 0, 0));
          OTSNode nodeTo = new OTSNode("To", new OTSPoint3D(1000, 0, 0));
          OTSLine3D line = new OTSLine3D(new OTSPoint3D[]{new OTSPoint3D(0, 0, 0), new OTSPoint3D(1000, 0, 0)});
          CrossSectionLink link =
              new CrossSectionLink("Link", nodeFrom, nodeTo, LinkType.ALL, line, LongitudinalDirectionality.DIR_PLUS,
                  LaneKeepingPolicy.KEEP_RIGHT);
          Length.Rel linkLength = line.getLength();
          // Now we can make a LinkLocation.
          Length.Rel referenceLocationDistance = new Length.Rel(123, METER);
          LinkLocation referenceLocation = new LinkLocation(link, referenceLocationDistance);
          assertEquals("link should be the provided Link", link, referenceLocation.getLink());
          assertEquals("longitudinalPosition should be " + referenceLocationDistance, referenceLocationDistance.getSI(),
              referenceLocation.getLongitudinalPosition().getSI(), 0.0001);
          for (int position = 0; position < 1000; position += 100)
          {
              final double fraction = position / linkLength.getSI();
              LinkLocation linkLocation = new LinkLocation(link, fraction);
              assertEquals("link should be the provided Link", link, linkLocation.getLink());
              assertEquals("fractionalLongitudinalPosition should be " + fraction, fraction, linkLocation
                  .getFractionalLongitudinalPosition(), 0.000001);
              assertEquals("longitudinalPosition should be " + position, position, linkLocation.getLongitudinalPosition()
                  .getSI(), 0.0001);
              // Repeat with the other constructor
              linkLocation = new LinkLocation(link, new Length.Rel(position, METER));
              assertEquals("link should be the provided Link", link, linkLocation.getLink());
              assertEquals("fractionalLongitudinalPosition should be " + fraction, fraction, linkLocation
                  .getFractionalLongitudinalPosition(), 0.000001);
              assertEquals("longitudinalPosition should be " + position, position, linkLocation.getLongitudinalPosition()
                  .getSI(), 0.0001);
              double delta = referenceLocationDistance.getSI() - position;
              assertEquals("distance from reference should be " + delta, delta, linkLocation.distance(referenceLocation)
                  .getSI(), 0.0001);
              // TODO distance to location on another link (not yet possible; currently ALWAYS returns null)
          }
      }
  }