package fr.in2p3.jsaga.engine.descriptors;
   
   import fr.in2p3.jsaga.engine.config.ConfigurationException;
   
   import java.net.URL;
   import java.util.*;
   
   /* ***************************************************
   * *** Centre de Calcul de l'IN2P3 - Lyon (France) ***
  * ***             http://cc.in2p3.fr/             ***
  * ***************************************************
  * File:   AdaptorLoader
  * Author: Sylvain Reynaud (sreynaud@in2p3.fr)
  * Date:   20 juin 2007
  * ***************************************************
  * Description:                                      */
  /**
   *
   */
  public class AdaptorLoader {
      private static final String ADAPTOR_PROPERTIES = "META-INF/adaptor.properties";
      private Class[] m_adaptorClasses;
  
      public AdaptorLoader() throws ConfigurationException {
      	String clazzName=null;
          try {
              List list = new ArrayList();
              Enumeration e = AdaptorLoader.class.getClassLoader().getResources(ADAPTOR_PROPERTIES);
              while (e.hasMoreElements()) {
                  URL url = (URL) e.nextElement();
                  Properties prop = new Properties();
                  prop.load(url.openStream());
                  for (Enumeration e2=prop.propertyNames(); e2.hasMoreElements(); ) {
                      clazzName = (String) e2.nextElement();
                      Class clazz = Class.forName(clazzName);
                      list.add(clazz);
                  }
              }
              m_adaptorClasses = (Class[]) list.toArray(new Class[list.size()]);
          } catch(Exception e) {
              throw new ConfigurationException("Failed to load class " + clazzName, e);
          }
      }
  
      public Class[] getClasses(Class itf) {
          List list = new ArrayList();
          for (int i=0; i<m_adaptorClasses.length; i++) {
              Class current = m_adaptorClasses[i];
              if (hasInterface(current, itf)) {
                  list.add(current);
              }
          }
          return (Class[]) list.toArray(new Class[list.size()]);
      }
  
      private static boolean hasInterface(Class clazz, Class itf) {
          Set itfSet = new HashSet();
          listInterfaces(clazz, itfSet);
          return itfSet.contains(itf);
      }
      
      private static void listInterfaces(Class clazz, Set set) {
          // list interfaces of implemented interfaces
          Class[] interfaces = clazz.getInterfaces();
          for (int i=0; i<interfaces.length; i++) {
              set.add(interfaces[i]);
              listInterfaces(interfaces[i], set);
          }
          // list interfaces of extended class
          Class extended = clazz.getSuperclass();
          if (extended != null) {
              listInterfaces(extended, set);
          }
      }
  }