package org.opentrafficsim.road.network;
   
   import static org.junit.Assert.assertEquals;
   
   import org.djunits.unit.util.UNITS;
   import org.djunits.value.vdouble.scalar.Direction;
   import org.djunits.value.vdouble.scalar.Length;
   import org.junit.Test;
   import org.opentrafficsim.core.definitions.DefaultsNl;
  import org.opentrafficsim.core.dsol.OtsSimulatorInterface;
  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.NetworkException;
  import org.opentrafficsim.core.network.Node;
  import org.opentrafficsim.road.mock.MockSimulator;
  import org.opentrafficsim.road.network.lane.CrossSectionLink;
  import org.opentrafficsim.road.network.lane.changing.LaneKeepingPolicy;
  
  /**
   * Test the LinkLocation class.
   * <p>
   * Copyright (c) 2013-2023 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://tudelft.nl/staff/p.knoppers-1">Peter Knoppers</a>
   */
  public class LinkLocationTest implements UNITS
  {
      /**
       * Test constructor and verify all getters.
       * @throws OtsGeometryException if that happens this test has failed
       * @throws NetworkException if that happens this test has failed
       */
      @Test
      public final void linkLocationTest() throws OtsGeometryException, NetworkException
      {
          // Preparations
          OtsSimulatorInterface simulator = MockSimulator.createMock();
          RoadNetwork network = new RoadNetwork("link location test network", simulator);
          Node nodeFrom = new Node(network, "From", new OtsPoint3d(0, 0, 0), Direction.ZERO);
          Node nodeTo = new Node(network, "To", new OtsPoint3d(1000, 0, 0), Direction.ZERO);
          OtsLine3d line = new OtsLine3d(new OtsPoint3d[] {new OtsPoint3d(0, 0, 0), new OtsPoint3d(1000, 0, 0)});
          CrossSectionLink link =
                  new CrossSectionLink(network, "Link", nodeFrom, nodeTo, DefaultsNl.ROAD, line, LaneKeepingPolicy.KEEPRIGHT);
          Length linkLength = line.getLength();
          // Now we can make a LinkLocation.
          Length referenceLocationDistance = new Length(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(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)
          }
      }
  }