/*
    Copyright (C) 2022 Nicola L.C. Talbot
    www.dickimaw-books.com

    This program 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 3 of the License, or
    (at your option) any later version.

    This program 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 program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/
package com.dickimawbooks.texparserlib.latex.etoolbox;

import java.io.IOException;

import com.dickimawbooks.texparserlib.*;
import com.dickimawbooks.texparserlib.latex.*;

public class IfUndef extends AbstractEtoolBoxCommand
{
   public IfUndef()
   {
      this("ifundef", false);
   }

   public IfUndef(String name, boolean isCsname)
   {
      super(name, isCsname);
   }

   @Override
   public Object clone()
   {
      return new IfUndef(getName(), isCsname);
   }

   @Override
   public TeXObjectList expandonce(TeXParser parser, TeXObjectList stack)
     throws IOException
   {
      ControlSequence cs = popCsArg(parser, stack);

      TeXObject truePart = popArg(parser, stack);
      TeXObject falsePart = popArg(parser, stack);

      if (parser.isUndefined(cs))
      {
         if (parser.isStack(truePart))
         {
            return (TeXObjectList)truePart;
         }
         else
         {
            TeXObjectList list = new TeXObjectList();
            list.add(truePart);
            return list;
         }
      }
      else
      {
         if (parser.isStack(falsePart))
         {
            return (TeXObjectList)falsePart;
         }
         else
         {
            TeXObjectList list = new TeXObjectList();
            list.add(falsePart);
            return list;
         }
      }
   }

   @Override
   public TeXObjectList expandonce(TeXParser parser)
     throws IOException
   {
      return expandonce(parser, parser);
   }

   @Override
   public TeXObjectList expandfully(TeXParser parser, TeXObjectList stack)
     throws IOException
   {
      return expandonce(parser, stack).expandfully(parser, stack);
   }

   @Override
   public TeXObjectList expandfully(TeXParser parser)
     throws IOException
   {
      return expandonce(parser).expandfully(parser);
   }

   @Override
   public void process(TeXParser parser, TeXObjectList stack)
     throws IOException
   {
      ControlSequence cs = popCsArg(parser, stack);

      TeXObject truePart = popArg(parser, stack);
      TeXObject falsePart = popArg(parser, stack);

      TeXObject doCode;

      if (parser.isUndefined(cs))
      {
         doCode = truePart;
      }
      else
      {
         doCode = falsePart;
      }

      TeXParserUtils.process(doCode, parser, stack);
   }

   @Override
   public void process(TeXParser parser)
     throws IOException
   {
      process(parser, parser);
   }

}
