/*
 * Copyright (c) 2019 Martin Davis.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
 * and the Eclipse Distribution License is available at
 *
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */
package org.locationtech.jts.operation.overlayng;

import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.LineString;
import org.locationtech.jts.geom.PrecisionModel;
import org.locationtech.jts.geom.TopologyException;

/**
 * Functions to reduce the precision of a geometry
 * by rounding it to a given precision model.
 * <p>
 * This class handles only polygonal and linear inputs.
 * For full functionality see {@link GeometryPrecisionReducer}.
 * 
 * @see GeometryPrecisionReducer
 * @author Martin Davis
 *
 */
public class PrecisionReducer {

  /**
   * Reduces the precision of a geometry by rounding and snapping it to the
   * supplied {@link PrecisionModel}.
   * The input geometry must be polygonal or linear.
   * <p> 
   * The output is always a valid geometry.  This implies that input components
   * may be merged if they are closer than the grid precision.
   * if merging is not desired, then the individual geometry components
   * should be processed separately.
   * <p>
   * The output is fully noded
   * (i.e. coincident lines are merged and noded).  
   * This provides an effective way to node / snap-round a collection of {@link LineString}s.
   * 
   * @param geom the geometry to reduce
   * @param pm the precision model to use
   * @return the precision-reduced geometry
   * 
   * @throws IllegalArgumentException if the reduction fails due to invalid input geometry is invalid
   */
  public static Geometry reducePrecision(Geometry geom, PrecisionModel pm) {
    OverlayNG ov = new OverlayNG(geom, pm);
    /**
     * Ensure reducing a area only produces polygonal result.
     * (I.e. collapse lines are not output)
     */
    if (geom.getDimension() == 2) {
      ov.setAreaResultOnly(true);
    }
    try {
      Geometry reduced = ov.getResult();
      return reduced;
    }
    catch (TopologyException ex) {
      throw new IllegalArgumentException("Reduction failed, possible invalid input");
    }
  }

  private PrecisionReducer() {
    // no instantiation for now
  }
}
