/*
 * Copyright (c) 2001-2008
 *     DecisionSoft Limited. All rights reserved.
 * Copyright (c) 2004-2008
 *     Oracle. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * $Id$
 */

#include "../config/xqilla_config.h"
#include <xqilla/functions/FunctionRoundHalfToEven.hpp>
#include <xqilla/items/ATDecimalOrDerived.hpp>
#include <xqilla/context/DynamicContext.hpp>
#include <xqilla/items/DatatypeFactory.hpp>

const XMLCh FunctionRoundHalfToEven::name[] = { 
  XERCES_CPP_NAMESPACE_QUALIFIER chLatin_r, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_o, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_u, 
  XERCES_CPP_NAMESPACE_QUALIFIER chLatin_n, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_d, XERCES_CPP_NAMESPACE_QUALIFIER chDash, 
  XERCES_CPP_NAMESPACE_QUALIFIER chLatin_h, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_a, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_l, 
  XERCES_CPP_NAMESPACE_QUALIFIER chLatin_f, XERCES_CPP_NAMESPACE_QUALIFIER chDash,    XERCES_CPP_NAMESPACE_QUALIFIER chLatin_t, 
  XERCES_CPP_NAMESPACE_QUALIFIER chLatin_o, XERCES_CPP_NAMESPACE_QUALIFIER chDash,    XERCES_CPP_NAMESPACE_QUALIFIER chLatin_e, 
  XERCES_CPP_NAMESPACE_QUALIFIER chLatin_v, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_e, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_n, 
  XERCES_CPP_NAMESPACE_QUALIFIER chNull 
};
const unsigned int FunctionRoundHalfToEven::minArgs = 1;
const unsigned int FunctionRoundHalfToEven::maxArgs = 2;

/*
 * fn:round-half-to-even($arg as numeric?) as numeric?
 * fn:round-half-to-even($arg as numeric?, $precision as xs:integer) as numeric?
 */

FunctionRoundHalfToEven::FunctionRoundHalfToEven(const VectorOfASTNodes &args, XPath2MemoryManager* memMgr)
  : NumericFunction(name, minArgs, maxArgs, "anyAtomicType?, integer", args, memMgr)
{
  _src.getStaticType() = StaticType(StaticType::NUMERIC_TYPE, 0, 1);
}

Sequence FunctionRoundHalfToEven::createSequence(DynamicContext* context, int flags) const
{
  XPath2MemoryManager* memMgr = context->getMemoryManager();

  Numeric::Ptr numericArg = getNumericParam(1, context);
    
  //If the argument is the empty sequence, the empty sequence is returned.
  if(numericArg.isNull()) {
    return Sequence(memMgr);
  }

  if(numericArg->isNaN() || numericArg->isInfinite())
    return Sequence(numericArg, memMgr);
  ATDecimalOrDerived::Ptr precision = NULL;
  if(getNumArgs() > 1) {
    Sequence precisionArg = getParamNumber(2,context)->toSequence(context);
    precision = (const ATDecimalOrDerived::Ptr )precisionArg.first();
  }
  else
    precision = context->getItemFactory()->createInteger(0, context);
  
  return Sequence(numericArg->roundHalfToEven(precision, context), memMgr);
}
