/*
 * RiskScape™ Copyright New Zealand Institute for Earth Science Limited
 * (Earth Sciences New Zealand) is distributed for research purposes only
 * under the terms of AGPLv3.
 *
 * RiskScape™ Copyright 2026 New Zealand Institute for Earth Science
 * Limited (Earth Sciences New Zealand). All rights reserved. Source code
 * available under the AGPLv3.
 * 
 * This program is free software: you can redistribute it and/or modify it under
 *  the terms of the GNU Affero General Public License as published by the Free
 *  Software Foundation, either version 3 of the License, or (at your option) any
 *  later version.
 * 
 * This program is distributed for RESEARCH PURPOSES ONLY, in the hope that it will
 * be useful for research and education initiatives.
 * 
 * If you are not a researcher, or you are a researcher who wishes to use this
 * program on terms other than AGPLv3 (including those who wish to restrict the
 * distribution of any source code created using this program), please contact:
 * https://riskscape.org.nz
 * 
 * This program is distributed WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Affero General Public License for more details.  You should have received a copy
 * of the GNU Affero General Public License along with this program.  If not, see
 * <http://www.gnu.org/licenses/>.
 * 
 * By way of summary only, under the AGPLv3:
 *     • Permissions of this strongest copyleft license are conditioned
 *       on making available complete source code of licensed works and
 *       modifications, which include larger works using a licensed work,
 *       under the same license.
 *     • Copyright and license notices must be preserved.
 *     • Contributors provide an express grant of patent rights.
 *     • When a modified version is used to provide a service over a
 *       network, the complete source code of the modified version must be made
 *       available.
 */

package nz.org.riskscape.engine.i18n;

import java.io.IOException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Arrays;
import java.util.Enumeration;

/**
 * A {@link ClassLoader} for loading resources from the supplied {@link URL}s only.
 *
 * In effect this class loader has no parent, prevent them from being found rather than the resources
 * found in the URLs.
 */
public class ResourceClassLoader extends URLClassLoader {

  public static final String DEFAULT_SUB_PATH = "i18n/";

  private String subPath;

  public ResourceClassLoader(URL... urls) {
    this(DEFAULT_SUB_PATH, urls);
  }

  public ResourceClassLoader(String subPath, URL... urls) {
    super(urls);
    this.subPath = subPath;
  }

  @Override
  public URL getResource(String name) {
    return findResource(adjustName(name));
  }

  @Override
  public Enumeration<URL> getResources(String name) throws IOException {
    return findResources(adjustName(name));
  }

  @Override
  public Class<?> loadClass(String name) throws ClassNotFoundException {
    // NB - we could enable this again in case we wanted java class style bundles to be loadable - but given this
    // is a potential remote code exploit path, it's shut down for now
    throw new UnsupportedOperationException("This class loader is meant for resource loading only");
  }

  private String adjustName(String name) {
    return subPath + name;
  }

  @Override
  public String toString() {
    return String.format("ResourceClassLoader(prefix=%s, urls=%s)", subPath, Arrays.asList(getURLs()));
  }
}
