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
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   *
   * 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.convexhull;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.UUID;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.geotools.feature.DefaultFeatureCollections;
  import org.geotools.feature.FeatureCollection;
  import org.geotools.feature.FeatureIterator;
  import org.n52.wps.io.GTHelper;
  import org.n52.wps.io.data.IData;
  import org.n52.wps.io.data.binding.complex.GTVectorDataBinding;
  import org.n52.wps.server.AbstractSelfDescribingAlgorithm;
  import org.opengis.feature.Feature;
  import org.opengis.feature.simple.SimpleFeature;
  import org.opengis.feature.simple.SimpleFeatureType;
  import org.opengis.referencing.crs.CoordinateReferenceSystem;
  
  import com.vividsolutions.jts.algorithm.ConvexHull;
  import com.vividsolutions.jts.geom.Coordinate;
  import com.vividsolutions.jts.geom.Geometry;
  import com.vividsolutions.jts.geom.GeometryFactory;
  
  /**
   * @author Benjamin Pross (bpross-52n) 
   *
   */
  public class ConvexHullAlgorithm extends AbstractSelfDescribingAlgorithm {
  
  	Logger LOGGER = LoggerFactory.getLogger(ConvexHullAlgorithm.class);
  	private List<String> errors = new ArrayList<String>();
  
  	public List<String> getErrors() {
  		return errors;
  	}
  
  	public Class getInputDataType(String id) {
  		if (id.equalsIgnoreCase("FEATURES")) {
  			return GTVectorDataBinding.class;
  		}
  		return null;
  	}
  
  	public Class getOutputDataType(String id) {
  		return GTVectorDataBinding.class;
  	}
  	
  	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();
  
  		List<Coordinate> coordinateList = new ArrayList<Coordinate>();
  		
  		int counter = 0;
  		
  		Geometry unifiedGeometry = null;
  		
  		while (iter.hasNext()) {
  			SimpleFeature  feature = (SimpleFeature) iter.next();
  
  			if (feature.getDefaultGeometry() == null) {
  				throw new NullPointerException(
  						"defaultGeometry is null in feature id: "
  								+ feature.getID());
  			}
  			
  			Geometry geom = (Geometry) feature.getDefaultGeometry();
  			
  			Coordinate[] coordinateArray = geom.getCoordinates();
  			for(Coordinate coordinate : coordinateArray){
  				coordinateList.add(coordinate);
  			}
  			
  		}	
  		
  		Coordinate[] coordinateArray = new Coordinate[coordinateList.size()];
  		
  		for(int i = 0; i<coordinateList.size(); i++){
  			coordinateArray[i] = coordinateList.get(i);
  		}
  		ConvexHull convexHull = new ConvexHull(coordinateArray, new GeometryFactory());		
  		
  		Geometry out = convexHull.getConvexHull();
  
  		Feature feature = createFeature(out, featureCollection.getSchema().getCoordinateReferenceSystem());
  		
  		FeatureCollection fOut = DefaultFeatureCollections.newCollection();
  		
  		fOut.add(feature);
  
  		HashMap<String, IData> result = new HashMap<String, IData>();
  
  		result.put("RESULT",
  				new GTVectorDataBinding(fOut));
  		return result;
  	}
  	
  	private Feature createFeature(Geometry geometry, CoordinateReferenceSystem crs) {
  		String uuid = UUID.randomUUID().toString();
  		SimpleFeatureType featureType = GTHelper.createFeatureType(geometry, uuid, crs);
  		GTHelper.createGML3SchemaForFeatureType(featureType);
  		
  		Feature feature = GTHelper.createFeature("0", geometry, featureType);
  		
  		return feature;
  	}	
  	
  	@Override
  	public List<String> getInputIdentifiers() {
  		List<String> identifierList =  new ArrayList<String>();
  		identifierList.add("FEATURES");
  		return identifierList;
  	}
  
  	@Override
  	public List<String> getOutputIdentifiers() {
  		List<String> identifierList =  new ArrayList<String>();
  		identifierList.add("RESULT");
  		return identifierList;
  	}
  }
  