code: /*
   * citygml-tools - Collection of tools for processing CityGML files
   * https://github.com/citygml4j/citygml-tools
   *
   * citygml-tools is part of the citygml4j project
   *
   * Copyright 2018-2023 Claus Nagel <claus.nagel@gmail.com>
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.citygml4j.tools.util;
  
  import org.citygml4j.tools.ExecutionException;
  import org.geotools.referencing.CRS;
  import org.opengis.referencing.FactoryException;
  import org.opengis.referencing.crs.CoordinateReferenceSystem;
  
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  public class ReferenceSystem {
      public static final Pattern CRS_URL = Pattern.compile("^https?://www.opengis.net/def/crs/(.+?)/(.*?)/(\\d+)$");
      public static final Pattern CRS_URN = Pattern.compile("^urn:ogc:def:crs(?:,crs)?:(.+?):(.*?):(\\d+).*");
      public static final Pattern CRS_SHORT = Pattern.compile("^(?:([^:]+):)?(\\d+)$");
      public static final Pattern CRS_WKT = Pattern.compile("^.+?((CRS)|(CS))\\s*\\[.+", Pattern.DOTALL);
  
      private CoordinateReferenceSystem crs;
      private String authority = "EPSG";
      private String version = "0";
      private int code;
  
      private ReferenceSystem() {
      }
  
      public static ReferenceSystem of(String name) throws ExecutionException {
          return of(name, false);
      }
  
      public static ReferenceSystem of(String name, boolean forceLongitudeFirst) throws ExecutionException {
          try {
              ReferenceSystem referenceSystem = new ReferenceSystem();
              Matcher matcher = CRS_WKT.matcher(name);
              if (matcher.matches()) {
                  referenceSystem.setCRS(CRS.parseWKT(name));
              } else {
                  if (matcher.usePattern(CRS_SHORT).matches()) {
                      referenceSystem.setAuthority(matcher.group(1));
                      referenceSystem.setCode(Integer.parseInt(matcher.group(2)));
                  } else if (matcher.usePattern(CRS_URL).matches() || matcher.usePattern(CRS_URN).matches()) {
                      referenceSystem.setAuthority(matcher.group(1));
                      referenceSystem.setVersion(matcher.group(2));
                      referenceSystem.setCode(Integer.parseInt(matcher.group(3)));
                  }
  
                  try {
                      referenceSystem.setCRS(CRS.decode(name, forceLongitudeFirst));
                  } catch (FactoryException e) {
                      //
                  }
  
                  if (referenceSystem.getCRS() == null) {
                      if (referenceSystem.getCode() > 0) {
                          referenceSystem.setCRS(CRS.decode(referenceSystem.toShortNotation(), forceLongitudeFirst));
                      } else {
                          throw new ExecutionException("Failed to interpret CRS string '" + name + "'.");
                      }
                  }
              }
  
              return referenceSystem;
          } catch (FactoryException e) {
              throw new ExecutionException("Failed to create CRS from '" + name + "'.", e);
          }
      }
  
      public CoordinateReferenceSystem getCRS() {
          return crs;
      }
  
      void setCRS(CoordinateReferenceSystem crs) {
          this.crs = crs;
      }
  
      public String getAuthority() {
          return authority;
      }
  
      void setAuthority(String authority) {
          this.authority = authority != null && !authority.isEmpty() ? authority : "EPSG";
      }
  
      public String getVersion() {
          return version;
      }
  
      public void setVersion(String version) {
          this.version = version != null && !version.isEmpty() ? version : "0";
      }
  
      public int getCode() {
          return code;
      }
  
      public void setCode(int code) {
          this.code = Math.max(code, 0);
      }
  
      public String toShortNotation() {
          return authority + ":" + code;
      }
  
  
      public String toURL() {
          return "http://www.opengis.net/def/crs/" + authority + "/" + version + "/" + code;
      }
  
      public String toURN() {
          return "urn:ogc:def:crs:" + authority + ":" + (!version.equals("0") ? version : "") + ":" + code;
      }
  }
  