/*
 * Copyright (C) 2012 eXo Platform SAS.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.crsh.cli.completers;

import org.crsh.cli.descriptor.ParameterDescriptor;
import org.crsh.cli.spi.Completer;
import org.crsh.cli.spi.Completion;

import java.util.Enumeration;

/**
 * A completer for system property names.
 *
 * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
 */
public class SystemPropertyNameCompleter implements Completer {

  public Completion complete(ParameterDescriptor parameter, String prefix) throws Exception {
    Completion.Builder b = new Completion.Builder(prefix);
    for (Enumeration<Object> e = System.getProperties().keys();e.hasMoreElements();) {
      Object key = e.nextElement();
      if (key instanceof String) {
        String s = (String)key;
        if (s.startsWith(prefix)) {
          b.add(s.substring(prefix.length()), true);
        }
      }
    }
    return b.build();
  }
}