package org.djutils.draw.line;
   
   import java.util.ArrayList;
   import java.util.Arrays;
   import java.util.Iterator;
   import java.util.List;
   
   import org.djutils.draw.DrawRuntimeException;
   import org.djutils.draw.point.Point3d;
  import org.djutils.exceptions.Throw;
  
  /**
   * Polygon3d.java. Closed PolyLine3d. The actual closing point (which is the same as the starting point) is NOT included in the
   * super PolyLine3d. The constructors automatically remove the last point if it is a at the same location as the first point.
   * <p>
   * Copyright (c) 2020-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="https://djutils.org/docs/current/djutils/licenses.html">DJUTILS License</a>.
   * </p>
   * @author <a href="https://www.tudelft.nl/averbraeck">Alexander Verbraeck</a>
   * @author <a href="https://www.tudelft.nl/pknoppers">Peter Knoppers</a>
   */
  public class Polygon3d extends PolyLine3d
  {
      /** */
      private static final long serialVersionUID = 20209999L;
  
      /**
       * Construct a new Polygon3d.
       * @param x double[]; the x coordinates of the points
       * @param y double[]; the y coordinates of the points
       * @param z double[]; the z coordinates of the points
       * @throws DrawRuntimeException when any two successive points are equal, or when there are too few points
       */
      public Polygon3d(final double[] x, final double[] y, final double[] z) throws DrawRuntimeException
      {
          super(fixClosingPointX(Throw.whenNull(x, "x"), Throw.whenNull(y, "y"), Throw.whenNull(z, "z")),
                  fixClosingPointY(x, y, z), fixClosingPointZ(x, y, z));
      }
  
      /**
       * Ensure that the last point is not equal to the first. Remove the last point if necessary.
       * @param x double[]; the x coordinates of the points
       * @param y double[]; the y coordinates of the points
       * @param z double[]; the z coordinates of the points
       * @return double[]; the y coordinates of the points (possibly a copy with the last element removed)
       */
      static double[] fixClosingPointX(final double[] x, final double[] y, final double[] z)
      {
          if (x.length > 1 && y.length == x.length && z.length == x.length && x[0] == x[x.length - 1] && y[0] == y[x.length - 1]
                  && z[0] == z[z.length - 1])
          {
              return Arrays.copyOf(x, x.length - 1);
          }
          return x;
      }
  
      /**
       * Ensure that the last point is not equal to the first. Remove the last point if necessary.
       * @param x double[]; the x coordinates of the points
       * @param y double[]; the y coordinates of the points
       * @param z double[]; the z coordinates of the points
       * @return double[]; the y coordinates of the points (possibly a copy with the last element removed)
       */
      static double[] fixClosingPointY(final double[] x, final double[] y, final double[] z)
      {
          if (x.length > 1 && y.length == x.length && z.length == x.length && x[0] == x[x.length - 1] && y[0] == y[x.length - 1]
                  && z[0] == z[z.length - 1])
          {
              return Arrays.copyOf(y, x.length - 1);
          }
          return y;
      }
  
      /**
       * Ensure that the last point is not equal to the first. Remove the last point if necessary.
       * @param x double[]; the x coordinates of the points
       * @param y double[]; the y coordinates of the points
       * @param z double[]; the z coordinates of the points
       * @return double[]; the y coordinates of the points (possibly a copy with the last element removed)
       */
      static double[] fixClosingPointZ(final double[] x, final double[] y, final double[] z)
      {
          if (x.length > 1 && y.length == x.length && z.length == x.length && x[0] == x[x.length - 1] && y[0] == y[x.length - 1]
                  && z[0] == z[z.length - 1])
          {
              return Arrays.copyOf(z, x.length - 1);
          }
          return z;
      }
  
      /**
       * Construct a new Polygon3d.
       * @param points Point3d[]; array of Point3d objects.
       * @throws NullPointerException when points is null
       * @throws DrawRuntimeException when points is too short, or contains successive duplicate points
       */
      public Polygon3d(final Point3d[] points) throws NullPointerException, DrawRuntimeException
      {
          this(PolyLine3d.makeArray(Throw.whenNull(points, "points"), p -> p.x), PolyLine3d.makeArray(points, p -> p.y),
                 PolyLine3d.makeArray(points, p -> p.z));
     }
 
     /**
      * Construct a new Polygon3d.
      * @param point1 Point3d; the first point of the new Polygon3d
      * @param point2 Point3d; the second point of the new Polygon3d
      * @param otherPoints Point3d[]; all remaining points of the new Polygon3d (may be null)
      * @throws NullPointerException when point1 or point2 is null
      * @throws DrawRuntimeException when point1 is equal to the last point of otherPoints, or any two successive points are
      *             equal
      */
     public Polygon3d(final Point3d point1, final Point3d point2, final Point3d... otherPoints)
             throws NullPointerException, DrawRuntimeException
     {
         super(Throw.whenNull(point1, "point1"), Throw.whenNull(point2, "point2"), fixClosingPoint(point1, otherPoints));
     }
 
     /**
      * Ensure that the last point of otherPoints is not equal to point1. Remove the last point if necessary.
      * @param point1 Point3d; the first point of a new Polygon3d
      * @param otherPoints Point3d[]; the remaining points of a new Polygon3d (may be null)
      * @return Point3d[]; otherPoints (possibly a copy thereof with the last entry removed)
      */
     private static Point3d[] fixClosingPoint(final Point3d point1, final Point3d[] otherPoints)
     {
         if (otherPoints == null || otherPoints.length == 0)
         {
             return otherPoints;
         }
         Point3d[] result = otherPoints;
         Point3d lastPoint = result[result.length - 1];
         if (point1.x == lastPoint.x && point1.y == lastPoint.y)
         {
             result = Arrays.copyOf(otherPoints, result.length - 1);
             lastPoint = result[result.length - 1];
         }
         Throw.when(point1.x == lastPoint.x && point1.y == lastPoint.y, DrawRuntimeException.class,
                 "Before last point and last point are at same location");
         return result;
     }
 
     /**
      * Construct a new Polygon3d from a list of Point3d objects.
      * @param points List&lt;Point3d&gt;; the list of points
      * @throws NullPointerException when points is null
      * @throws DrawRuntimeException when points is too short, or the last two points are at the same location
      */
     public Polygon3d(final List<Point3d> points) throws NullPointerException, DrawRuntimeException
     {
         super(fixClosingPoint(true, Throw.whenNull(points, "points")));
 
     }
 
     /**
      * Ensure that the last point in the list is different from the first point by possibly removing the last point.
      * @param doNotModifyList boolean; if true; the list of points will not be modified (if the last point is to be removed; the
      *            entire list up to the last point is duplicated)
      * @param points List&lt;Point3d&gt;; the list of points
      * @return List&lt;Point3d&gt;; the fixed list
      * @throws DrawRuntimeException when the (resulting) list is too short, or the before last and last point of points have the
      *             same coordinates
      */
     private static List<Point3d> fixClosingPoint(final boolean doNotModifyList, final List<Point3d> points)
             throws DrawRuntimeException
     {
         Throw.when(points.size() < 2, DrawRuntimeException.class, "Need at least two points");
         Point3d firstPoint = points.get(0);
         Point3d lastPoint = points.get(points.size() - 1);
         List<Point3d> result = points;
         if (firstPoint.x == lastPoint.x && firstPoint.y == lastPoint.y && firstPoint.z == lastPoint.z)
         {
             if (doNotModifyList)
             {
                 result = new ArrayList<>(points.size() - 1);
                 for (int i = 0; i < points.size() - 1; i++)
                 {
                     result.add(points.get(i));
                 }
             }
             else
             {
                 result.remove(points.size() - 1);
             }
             lastPoint = result.get(result.size() - 1);
         }
         Throw.when(firstPoint.x == lastPoint.x && firstPoint.y == lastPoint.y && firstPoint.z == lastPoint.z,
                 DrawRuntimeException.class, "Before last point and last point are at same location");
         return result;
     }
 
     /**
      * Construct a new Polygon3d from an iterator that yields Point3d.
      * @param iterator Iterator&lt;Point3d&gt;; the iterator
      */
     public Polygon3d(final Iterator<Point3d> iterator)
     {
         this(fixClosingPoint(false, iteratorToList(Throw.whenNull(iterator, "iterator"))));
     }
 
     /**
      * Create a new Polygon3d, optionally filtering out repeating successive points.
      * @param filterDuplicates boolean; if true; filter out successive repeated points; otherwise do not filter
      * @param points Point3d...; the coordinates of the polygon as Point3d
      * @throws DrawRuntimeException when number of points &lt; 2
      */
     public Polygon3d(final boolean filterDuplicates, final Point3d... points) throws DrawRuntimeException
     {
         this(PolyLine3d.cleanPoints(filterDuplicates, Arrays.stream(points).iterator()));
     }
 
     /**
      * Create a new Polygon3d, optionally filtering out repeating successive points.
      * @param filterDuplicates boolean; if true; filter out successive repeated points; otherwise do not filter
      * @param pointList List&lt;Point3d&gt;; list of the coordinates of the line as Point3d; any duplicate points in this list
      *            are removed (this method may modify the provided list)
      * @throws DrawRuntimeException when number of non-equal points &lt; 2
      */
     public Polygon3d(final boolean filterDuplicates, final List<Point3d> pointList) throws DrawRuntimeException
     {
         this(PolyLine3d.cleanPoints(filterDuplicates, pointList.iterator()));
     }
 
     /**
      * Construct a new Polygon3d from an existing one. This constructor is primarily intended for use in extending classes.
      * @param polygon Polygon3d; the existing Polygon3d
      */
     public Polygon3d(final Polygon3d polygon)
     {
         super(polygon);
     }
 
     @Override
     public double getLength()
     {
         // Length a polygon is computed by taking the length of the PolyLine and adding the length of the closing segment
         return super.getLength()
                 + Math.hypot(Math.hypot(getX(size() - 1) - getX(0), getY(size() - 1) - getY(0)), getZ(size() - 1) - getZ(0));
     }
 
     @Override
     public LineSegment3d getSegment(final int index)
     {
         if (index < size() - 1)
         {
             return super.getSegment(index);
         }
         Throw.when(index != size() - 1, DrawRuntimeException.class, "index must be in range 0..size() - 1");
         return new LineSegment3d(getX(index), getY(index), getZ(index), getX(0), getY(0), getZ(0));
     }
 
     @Override
     public Polygon2d project() throws DrawRuntimeException
     {
         double[] projectedX = new double[this.size()];
         double[] projectedY = new double[this.size()];
 
         int nextIndex = 0;
         for (int i = 0; i < this.size(); i++)
         {
             if (i > 0 && getX(i) == getX(i - 1) && getY(i) == getY(i - 1))
             {
                 continue;
             }
             projectedX[nextIndex] = getX(i);
             projectedY[nextIndex] = getY(i);
             nextIndex++;
         }
         if (nextIndex < projectedX.length)
         {
             return new Polygon2d(Arrays.copyOf(projectedX, nextIndex), Arrays.copyOf(projectedY, nextIndex));
         }
         return new Polygon2d(projectedX, projectedY);
     }
 
     @Override
     public Polygon3d reverse()
     {
         return new Polygon3d(super.reverse().getPoints());
     }
 
     @Override
     public final String toString()
     {
         return toString("%f", false);
     }
 
     @Override
     public String toString(final String doubleFormat, final boolean doNotIncludeClassName)
     {
         StringBuilder result = new StringBuilder();
         if (!doNotIncludeClassName)
         {
             result.append("Polygon3d ");
         }
         result.append("[super=");
         result.append(super.toString(doubleFormat, false));
         result.append("]");
         return result.toString();
     }
 
 }