package org.opentrafficsim.core.network;
   
   import static org.junit.Assert.assertEquals;
   
   import org.junit.Test;
   import org.opentrafficsim.core.network.geotools.NodeGeotools;
   import org.opentrafficsim.core.network.lane.CrossSectionLink;
   import org.opentrafficsim.core.unit.LengthUnit;
   import org.opentrafficsim.core.value.vdouble.scalar.DoubleScalar;
  
  import com.vividsolutions.jts.geom.Coordinate;
  
  /**
   * Test the LinkLocation class.
   * <p>
   * Copyright (c) 2013-2014 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 20 jan. 2015 <br>
   * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
   */
  public class LinkLocationTest
  {
      /**
       * Test constructor and verify all getters.
       */
      @Test
      public void linkLocationTest()
      {
          // Preparations
          NodeGeotools.STR nodeFrom = new NodeGeotools.STR("From", new Coordinate(0, 0, 0));
          NodeGeotools.STR nodeTo = new NodeGeotools.STR("To", new Coordinate(1000, 0, 0));
          DoubleScalar.Rel<LengthUnit> linkLength = new DoubleScalar.Rel<LengthUnit>(1000, LengthUnit.METER);
          CrossSectionLink<?, ?> link = new CrossSectionLink<String, String>("Link", nodeFrom, nodeTo, linkLength);
          // Now we can make a LinkLocation.
          DoubleScalar.Rel<LengthUnit> referenceLocationDistance =
                  new DoubleScalar.Rel<LengthUnit>(123, LengthUnit.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 DoubleScalar.Rel<LengthUnit>(position, LengthUnit.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)
          }
      }
  }