content: /**
   * ﻿Copyright (C) 2007 - 2019 52°North Initiative for Geospatial Open Source
   * Software GmbH
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published
   * by the Free Software Foundation.
   *
   * If the program is linked with libraries which are licensed under one of
   * the following licenses, the combination of the program with the linked
   * library is not considered a "derivative work" of the program:
   *
   *       • Apache License, version 2.0
   *       • Apache Software License, version 1.0
   *       • GNU Lesser General Public License, version 3
   *       • Mozilla Public License, versions 1.0, 1.1 and 2.0
   *       • Common Development and Distribution License (CDDL), version 1.0
   *
   * Therefore the distribution of the program linked with libraries licensed
   * under the aforementioned licenses, is permitted by the copyright holders
   * if the distribution is compliant with both the GNU General Public
   * License version 2 and the aforementioned licenses.
   *
   * As an exception to the terms of the GPL, you may copy, modify,
   * propagate, and distribute a work formed by combining 52°North WPS
   * GeoTools Modules with the Eclipse Libraries, or a work derivative of
   * such a combination, even if such copying, modification, propagation, or
   * distribution would otherwise violate the terms of the GPL. Nothing in
   * this exception exempts you from complying with the GPL in all respects
   * for all of the code used other than the Eclipse Libraries. You may
   * include this exception and its grant of permissions when you distribute
   * 52°North WPS GeoTools Modules. Inclusion of this notice with such a
   * distribution constitutes a grant of such permissions. If you do not wish
   * to grant these permissions, remove this paragraph from your
   * distribution. "52°North WPS GeoTools Modules" means the 52°North WPS
   * modules using GeoTools functionality - software licensed under version 2
   * or any later version of the GPL, or a work based on such software and
   * licensed under the GPL. "Eclipse Libraries" means Eclipse Modeling
   * Framework Project and XML Schema Definition software distributed by the
   * Eclipse Foundation and licensed under the Eclipse Public License Version
   * 1.0 ("EPL"), or a work based on such software and licensed under the EPL.
   *
   * This program 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 General
   * Public License for more details.
   */
  package org.n52.wps.server.algorithm.simplify;
  
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  
  import org.geotools.feature.FeatureCollection;
  import org.geotools.feature.FeatureIterator;
  import org.geotools.feature.IllegalAttributeException;
  import org.n52.wps.io.data.IData;
  import org.n52.wps.io.data.binding.complex.GTVectorDataBinding;
  import org.n52.wps.io.data.binding.literal.LiteralDoubleBinding;
  import org.n52.wps.server.AbstractAlgorithm;
  import org.n52.wps.server.AbstractSelfDescribingAlgorithm;
  import org.opengis.feature.Feature;
  import org.opengis.feature.simple.SimpleFeature;
  
  import com.vividsolutions.jts.geom.Geometry;
  import com.vividsolutions.jts.geom.LineString;
  import com.vividsolutions.jts.geom.MultiLineString;
  import com.vividsolutions.jts.geom.MultiPolygon;
  import com.vividsolutions.jts.geom.Polygon;
  import com.vividsolutions.jts.simplify.TopologyPreservingSimplifier;
  
  /**
   * @author Theodor Foerster, ITC
   *
   */
  public class TopologyPreservingSimplificationAlgorithm extends
  AbstractSelfDescribingAlgorithm {
  
  	private List<String> errors = new ArrayList<String>();
  	
  	public Map<String, IData> run(Map<String, List<IData>> inputData) {
  		if(inputData==null || !inputData.containsKey("FEATURES")){
  			throw new RuntimeException("Error while allocating input parameters");
  		}
  		List<IData> dataList = inputData.get("FEATURES");
  		if(dataList == null || dataList.size() != 1){
  			throw new RuntimeException("Error while allocating input parameters");
  		}
  		IData firstInputData = dataList.get(0);
  				
  		FeatureCollection featureCollection = ((GTVectorDataBinding) firstInputData).getPayload();
  		FeatureIterator iter = featureCollection.features();
  		
  		if( !inputData.containsKey("width")){
  			throw new RuntimeException("Error while allocating input parameters");
  		}
  		List<IData> widthDataList = inputData.get("TOLERANCE");
  		if(widthDataList == null || widthDataList.size() != 1){
  			throw new RuntimeException("Error while allocating input parameters");
  		}
  		Double tolerance = ((LiteralDoubleBinding) widthDataList.get(0)).getPayload();
  		while(iter.hasNext()) {
  			SimpleFeature f = (SimpleFeature) iter.next();
  			Object userData = ((Geometry)f.getDefaultGeometry()).getUserData();
  			
  			try{
  				Geometry in = (Geometry)f.getDefaultGeometry();
  				Geometry out = TopologyPreservingSimplifier.simplify(in, tolerance);
                  /*
                   * THIS PASSAGE WAS CONTRIBUTED BY GOBE HOBONA.
                   *The simplification of MultiPolygons produces Polygon geometries. This becomes inconsistent with the original schema (which was of MultiPolygons).
                   *To ensure that the output geometries match that of the original schema we add the Polygon(from the simplication) to a MultiPolygon object
                   *
                   *This is issue is known to affect MultiPolygon geometries only, other geometries need to be tested to ensure conformance with the original (input) schema
                   */  
                  if(in.getGeometryType().equals("MultiPolygon") && out.getGeometryType().equals("Polygon"))
                  {                   
                      MultiPolygon mp = (MultiPolygon)in;                                               
                      Polygon[] p = {(Polygon)out};
                      mp = new MultiPolygon(p,mp.getFactory());                   
                      f.setDefaultGeometry(mp);
                  }
                  else if(in.getGeometryType().equals("MultiLineString") && out.getGeometryType().equals("LineString")) {
                  	MultiLineString ml = (MultiLineString)in;
                  	LineString[] l = {(LineString)out};
                      ml = new MultiLineString(l,ml.getFactory());                   
                      f.setDefaultGeometry(ml);
                  }
                  else
                  f.setDefaultGeometry(out);				
  				((Geometry)f.getDefaultGeometry()).setUserData(userData);
  			}
  			catch(IllegalAttributeException e) {
  				throw new RuntimeException("geometrytype of result is not matching", e);
  			}
  		}
  		HashMap<String, IData> result = new HashMap<String, IData>();
  		result.put("SIMPLIFIED_FEATURES", new GTVectorDataBinding(featureCollection));
  		return result;
  	}
  
  	public List<String> getErrors() {
  		return errors;
  	}
  
  	public Class getInputDataType(String id) {
  		if(id.equalsIgnoreCase("FEATURES")){
  			return GTVectorDataBinding.class;
  		}else if(id.equalsIgnoreCase("TOLERANCE")){
  			return LiteralDoubleBinding.class;
  		}
  		return null;
  	}
  
  	public Class getOutputDataType(String id) {
  		if(id.equalsIgnoreCase("result")){
  			return GTVectorDataBinding.class;
  		}
  		return null;
  	}
  
  
  	@Override
  	public List<String> getInputIdentifiers() {
  		List<String> identifierList =  new ArrayList<String>();
  		identifierList.add("FEATURES");
  		identifierList.add("TOLERANCE");
  		return identifierList;
  	}
  
  	@Override
  	public List<String> getOutputIdentifiers() {
  		List<String> identifierList =  new ArrayList<String>();
  		identifierList.add("result");
  		return identifierList;
  	}
  	
  
  }
  