package org.opentrafficsim.core.network;
   
   import java.io.Serializable;
   import java.rmi.RemoteException;
   import java.util.HashSet;
   import java.util.Set;
   
   import javax.media.j3d.BoundingSphere;
   import javax.media.j3d.Bounds;
  import javax.vecmath.Point3d;
  
  import nl.tudelft.simulation.dsol.animation.LocatableInterface;
  import nl.tudelft.simulation.language.d3.DirectedPoint;
  
  import org.opentrafficsim.core.unit.AnglePlaneUnit;
  import org.opentrafficsim.core.unit.AngleSlopeUnit;
  import org.opentrafficsim.core.value.vdouble.scalar.DoubleScalar;
  
  /**
   * The Node is a point with an id. It is used in the network to connect Links.
   * <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 Aug 19, 2014 <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.citg.tudelft.nl">Guus Tamminga</a>
   * @param <ID> the ID type.
   * @param <P> the point type, e.g., com.vividsolutions.jts.geom.Point, DirectedPoint.
   */
  public abstract class AbstractNode<ID, P> implements Node<ID, P>, LocatableInterface, Serializable
  {
      /** */
      private static final long serialVersionUID = 20140920L;
  
      /** the node id. */
      private final ID id;
  
      /** the point. */
      private final P point;
  
      /** the 3D direction. "East" is 0 degrees. "North" is 90 degrees (1/2 pi radians). */
      private final DoubleScalar.Abs<AnglePlaneUnit> direction;
  
      /** the slope as an angle. */
      private final DoubleScalar.Abs<AngleSlopeUnit> slope;
  
      /** the incoming links. */
      private final Set<Link<?, ? extends Node<ID, P>>> linksIn = new HashSet<Link<?, ? extends Node<ID, P>>>();
  
      /** the outgoing links. */
      private final Set<Link<?, ? extends Node<ID, P>>> linksOut = new HashSet<Link<?, ? extends Node<ID, P>>>();
  
      /**
       * Construction of a Node.
       * @param id the id of the Node.
       * @param point the point with usually an x and y setting.
       * @param direction the 3D direction. "East" is 0 degrees. "North" is 90 degrees (1/2 pi radians).
       * @param slope the slope as an angle.
       */
      public AbstractNode(final ID id, final P point, final DoubleScalar.Abs<AnglePlaneUnit> direction,
          final DoubleScalar.Abs<AngleSlopeUnit> slope)
      {
          this.id = id;
          this.point = point;
          this.direction = direction;
          this.slope = slope;
      }
  
      /**
       * Construction of a Node.
       * @param id the id of the Node.
       * @param point the point with usually an x and y setting.
       */
      public AbstractNode(final ID id, final P point)
      {
          this(id, point, new DoubleScalar.Abs<AnglePlaneUnit>(0.0, AnglePlaneUnit.SI), new DoubleScalar.Abs<AngleSlopeUnit>(
              0.0, AngleSlopeUnit.SI));
      }
  
      /**
       * @return node id.
       */
      public final ID getId()
      {
          return this.id;
      }
  
      /**
       * @return point.
       */
      public final P getPoint()
      {
          return this.point;
      }
  
      /**
       * @return the x-value of the point.
      */
     public abstract double getX();
 
     /**
      * @return the y-value of the point.
      */
     public abstract double getY();
 
     /**
      * @return the z-value of the point.
      */
     public abstract double getZ();
 
     /** {@inheritDoc} */
     @Override
     public final void addLinkIn(final Link<?, ? extends Node<ID, P>> linkIn)
     {
         this.linksIn.add(linkIn);
     }
 
     /** {@inheritDoc} */
     @Override
     public final void addLinkOut(final Link<?, ? extends Node<ID, P>> linkOut)
     {
         this.linksOut.add(linkOut);
     }
 
     /** {@inheritDoc} */
     @Override
     public final Set<Link<?, ? extends Node<ID, P>>> getLinksIn()
     {
         // XXX: should return a copy?
         return this.linksIn;
     }
 
     /** {@inheritDoc} */
     @Override
     public final Set<Link<?, ? extends Node<ID, P>>> getLinksOut()
     {
         // XXX: should return a copy?
         return this.linksOut;
     }
 
     /**
      * @return direction.
      */
     public final DoubleScalar.Abs<AnglePlaneUnit> getDirection()
     {
         return this.direction;
     }
 
     /**
      * @return slope.
      */
     public final DoubleScalar.Abs<AngleSlopeUnit> getSlope()
     {
         return this.slope;
     }
 
     /** {@inheritDoc} */
     @Override
     public final DirectedPoint getLocation() throws RemoteException
     {
         return new DirectedPoint(new double[] {getX(), getY(), getZ()});
     }
 
     /** {@inheritDoc} */
     @Override
     public final Bounds getBounds() throws RemoteException
     {
         return new BoundingSphere(new Point3d(0.0d, 0.0d, 0.0d), 10.0d);
     }
 
     /** {@inheritDoc} */
     public final String toString()
     {
         return "Node " + this.id;
     }
 
     /** {@inheritDoc} */
     @Override
     @SuppressWarnings("checkstyle:designforextension")
     public int hashCode()
     {
         final int prime = 31;
         int result = 1;
         result = prime * result + ((this.id == null) ? 0 : this.id.hashCode());
         return result;
     }
 
     /** {@inheritDoc} */
     @Override
     @SuppressWarnings({"checkstyle:designforextension", "checkstyle:needbraces"})
     public boolean equals(final Object obj)
     {
         if (this == obj)
             return true;
         if (obj == null)
             return false;
         if (getClass() != obj.getClass())
             return false;
         @SuppressWarnings("unchecked")
         AbstractNode<ID, P> other = (AbstractNode<ID, P>) obj;
         if (this.id == null)
         {
             if (other.id != null)
                 return false;
         }
         else if (!this.id.equals(other.id))
             return false;
         return true;
     }
 
 }