#include "../config/pathan_config.h"
/*
 * Copyright (c) 2001, DecisionSoft Limited All rights reserved.
 * Please see LICENSE.TXT for more information.
 */

#include <assert.h>
#include <pathan/operators/UnaryMinus.hpp>
#include <pathan/operators/Multiply.hpp>
#include <pathan/dataItem/DataItemLiteral.hpp>
#include <pathan/ATDecimalOrDerived.hpp>
#include <pathan/exceptions/XPath2ErrorException.hpp>
#include <pathan/DynamicContext.hpp>
#include <pathan/internal/factory/DatatypeFactory.hpp>

/*static*/ const XMLCh UnaryMinus::name[]={ XERCES_CPP_NAMESPACE_QUALIFIER chLatin_u, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_m, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_i, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_n, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_u, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_s, XERCES_CPP_NAMESPACE_QUALIFIER chNull };

UnaryMinus::UnaryMinus(const VectorOfDataItems &args, XPath2MemoryManager* memMgr)
  : DataItemOperator(name, args, memMgr)
{
	assert(_args.size() == 1);
}

Sequence UnaryMinus::collapseTreeInternal(DynamicContext* context, int flags) const
{
  Sequence newArgs = getArithmeticOperatorArguments(context);
  XPath2MemoryManager* memMgr = context->getMemoryManager();
  if(newArgs.getLength() < 1)
    return Sequence(memMgr);
  const Item* arg1 = newArgs.first();

  assert(arg1->isAtomicValue());
  
  const AnyAtomicType* atom1 = (const AnyAtomicType*)arg1;  

  // only works on Numeric types
  if(atom1->isNumericValue()) {
    return Sequence(((const Numeric*)atom1)->invert(context), memMgr);
  } else {
    DSLthrow(XPath2ErrorException,X("UnaryMinus::collapseTreeInternal"), X("An attempt to apply unary minus a non numeric type has occurred"));
  }

}