/*
 * MessageSetTokenizer.java
 * Copyright (C) 2005 The Free Software Foundation
 * 
 * This file is part of GNU inetlib, a library.
 * 
 * GNU inetlib is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * GNU inetlib 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.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linking this library statically or dynamically with other modules is
 * making a combined work based on this library.  Thus, the terms and
 * conditions of the GNU General Public License cover the whole
 * combination.
 *
 * As a special exception, the copyright holders of this library give you
 * permission to link this library with independent modules to produce an
 * executable, regardless of the license terms of these independent
 * modules, and to copy and distribute the resulting executable under
 * terms of your choice, provided that you also meet, for each linked
 * independent module, the terms and conditions of the license of that
 * module.  An independent module is a module which is not derived from
 * or based on this library.  If you modify this library, you may extend
 * this exception to your version of the library, but you are not
 * obliged to do so.  If you do not wish to do so, delete this
 * exception statement from your version.
 */

package gnu.inet.imap;

import java.util.Iterator;
import java.util.LinkedList;

/**
 * Tokenizer for an IMAP UID message-set.
 * This iterates over the UIDs specified in the set.
 *
 * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
 */
class MessageSetTokenizer
  implements Iterator
{

  private Iterator iterator;

  MessageSetTokenizer(String spec)
  {
    LinkedList acc = new LinkedList();
    for (int ci = spec.indexOf(','); ci != -1; ci = spec.indexOf(','))
      {
        addToken(acc, spec.substring(0, ci));
        spec = spec.substring(ci + 1);
      }
    addToken(acc, spec);
    iterator = acc.iterator();
  }

  private void addToken(LinkedList acc, String token)
  {
    int ci = token.indexOf(':');
    if (ci == -1)
      {
        acc.add(new Long(token));
      }
    else
      {
        long start = Long.parseLong(token.substring(0, ci));
        long end = Long.parseLong(token.substring(ci + 1));
        while (start <= end)
          {
            acc.add(new Long(start++));
          }
      }
  }

  public boolean hasNext()
  {
    return iterator.hasNext();
  }

  public Object next()
  {
    return iterator.next();
  }

  public void remove()
  {
    iterator.remove();
  }
  
}