/*
 * The JTS Topology Suite is a collection of Java classes that
 * implement the fundamental operations required to validate a given
 * geo-spatial data set to a known topological specification.
 *
 * Copyright (C) 2001 Vivid Solutions
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * For more information, contact:
 *
 *     Vivid Solutions
 *     Suite #1A
 *     2328 Government Street
 *     Victoria BC  V8T 5G5
 *     Canada
 *
 *     (250)385-6040
 *     www.vividsolutions.com
 */

package com.revolsys.geometry.operation.overlay.snap;

import com.revolsys.geometry.model.Geometry;
import com.revolsys.geometry.model.TopologyException;
import com.revolsys.geometry.operation.overlay.OverlayOp;

/**
 * Performs an overlay operation using snapping and enhanced precision
 * to improve the robustness of the result.
 * This class only uses snapping
 * if an error is detected when running the standard JTS overlay code.
 * Errors detected include thrown exceptions
 * (in particular, {@link TopologyException})
 * and invalid overlay computations.
 *
 * @author Martin Davis
 * @version 1.7
 */
public class SnapIfNeededOverlayOp {
  public static Geometry difference(final Geometry g0, final Geometry geometry1) {
    return overlayOp(g0, geometry1, OverlayOp.DIFFERENCE);
  }

  public static Geometry intersection(final Geometry g0, final Geometry geometry1) {
    return overlayOp(g0, geometry1, OverlayOp.INTERSECTION);
  }

  public static Geometry overlayOp(final Geometry g0, final Geometry geometry1, final int opCode) {
    final SnapIfNeededOverlayOp op = new SnapIfNeededOverlayOp(g0, geometry1);
    return op.getResultGeometry(opCode);
  }

  public static Geometry symDifference(final Geometry g0, final Geometry geometry1) {
    return overlayOp(g0, geometry1, OverlayOp.SYMDIFFERENCE);
  }

  public static Geometry union(final Geometry g0, final Geometry geometry1) {
    return overlayOp(g0, geometry1, OverlayOp.UNION);
  }

  private final Geometry geometry1;

  private final Geometry geometry2;

  public SnapIfNeededOverlayOp(final Geometry geometry1, final Geometry geometry2) {
    this.geometry1 = geometry1;
    this.geometry2 = geometry2;
  }

  public Geometry getResultGeometry(final int opCode) {
    Geometry result = null;
    boolean isSuccess = false;
    RuntimeException savedException = null;
    try {
      // try basic operation with input geometries
      result = OverlayOp.overlayOp(this.geometry1, this.geometry2, opCode);
      final boolean isValid = true;
      // not needed if noding validation is used
      // boolean isValid = OverlayResultValidator.isValid(geometry1, geometry2,
      // OverlayOp.INTERSECTION, result);
      if (isValid) {
        isSuccess = true;
      }
    } catch (final RuntimeException ex) {
      savedException = ex;
      // ignore this exception, since the operation will be rerun
      // System.out.println(ex.getMessage());
      // ex.printStackTrace();
      // System.out.println(ex.getMessage());
      // System.out.println("Geom 0: " + geometry1);
      // System.out.println("Geom 1: " + geometry2);
    }
    if (!isSuccess) {
      // this may still throw an exception
      // if so, throw the original exception since it has the input coordinates

      try {
        result = SnapOverlayOp.overlayOp(this.geometry1, this.geometry2, opCode);
      } catch (final RuntimeException ex) {
        throw savedException;
      }
    }
    return result;
  }
}