/**

Copyright (c) 1999 by Robert J Colquhoun, All Rights Reserved


This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

This library 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA 
 
*/

package org.maverickdbms.database.localdb;

import org.maverickdbms.basic.mvConstantString;
import org.maverickdbms.basic.mvException;
import org.maverickdbms.basic.List;
import org.maverickdbms.basic.mvString;
import java.io.*;

public class ldbList implements List {

   private File fdir;
   private String[] selkeys;
   private int maxkeys;
   private int keyctr;
   private String iname;
   static final char[] ESCAPED_CHARS = {
        '/','?','"','%','*',':','<','|','>','\\'
    };
    static final String MANGLE_CHARS =  new String(ESCAPED_CHARS);
    static final String REP_CHARS    = "SQD%ACLVGB";    
 
    ldbList() {
        fdir = null;
        selkeys = null;
        maxkeys = 0;
        keyctr = 0;
    }

    public void close() {
      selkeys = null;
      maxkeys = 0;
      keyctr = 0;
    }

    mvConstantString select(File pdir) {
      
      fdir = pdir;
      selkeys = fdir.list();
      maxkeys = selkeys.length;
      keyctr = 0;
      return RETURN_SUCCESS;
    }

    public boolean isAfterLast() {
        return (keyctr < maxkeys);
    }

    public mvConstantString READLIST(mvString result) throws mvException {
      throw new mvException(0, "Sorry READLIST is not yet implemented");
    }
 
    public mvConstantString READNEXT(mvString id, mvString val, mvString subval) {

      while (keyctr < maxkeys) {
         String temp = selkeys[keyctr++];
         demangle(temp);
	 id.set(iname);
         return RETURN_SUCCESS;
      }
      return RETURN_ELSE;
   }

   public void demangle (String mname) {

        int len = mname.length();
        StringBuffer sb = new StringBuffer();
        for (int i = 1; i < len; i++) {
            char c = mname.charAt(i - 1);
            if (c == '%') {
               char c2 = mname.charAt(i);
               int tpos = REP_CHARS.indexOf(c2);
               if (tpos > -1) {
                  sb.append(MANGLE_CHARS.charAt(tpos));
                  i++;
               }
            } else {
              sb.append(c);
            }
         }
         sb.append(mname.charAt(len - 1));
         iname = sb.toString();
   }  
}