/**
 * $Id$
 * $Date$
 *
 */

package org.xmlsh.builtin.commands;

import java.util.List;
import org.xmlsh.core.BuiltinCommand;
import org.xmlsh.core.InvalidArgumentException;
import org.xmlsh.core.XValue;
import org.xmlsh.core.XVariable;
import org.xmlsh.util.Util;

public class shift extends BuiltinCommand {

  @Override
  public int run(List<XValue> args) throws Exception {

    if(args.size() == 0) {
      return mShell.shift(1) ? 0 : 1;

    }

    if(args.size() == 1) {
      String a1 = args.get(0).toString();
      if(Util.isInt(a1, false))
        return mShell.shift(Util.parseInt(a1, 1)) ? 0 : 1;
      else
        return shiftvar(a1, 1) ? 0 : 1;
    }

    if(args.size() == 2)
      return shiftvar(args.get(0).toString(), Util.parseInt(args.get(1), 1)) ? 0
          : 1;
    usage();
    return -1;

  }

  private boolean shiftvar(String name, int n) throws InvalidArgumentException {
    XVariable var = mShell.getEnv().getVar(name);
    if(var != null)
      return var.shift(n);
    else {
      // Try positional params
      // shift 1 2
      if(Util.isInt(name, false)) {
        int np = Util.parseInt(name, -1);
        // Only shift params 1..
        List<XValue> args = mShell.getArgs();
        if(np > 1 && np < args.size()) {
          XValue val = args.get(np - 1);
          val = val.shift(n);
          args.set(np - 1, val);
          return true;
        }

      }
      return false;
    }
  }

}
//
//
// Copyright (C) 2008-2014 David A. Lee.
//
// The contents of this file are subject to the "Simplified BSD License" (the
// "License");
// you may not use this file except in compliance with the License. You may
// obtain a copy of the
// License at http://www.opensource.org/licenses/bsd-license.php
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations
// under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is David A. Lee
//
// Portions created by (your name) are Copyright (C) (your legal entity). All
// Rights Reserved.
//
// Contributor(s): none.
//