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

#include <pathan/functions/FunctionResolveQName.hpp>

#include <pathan/XPath2Utils.hpp>
#include <pathan/XPath2NSUtils.hpp>
#include <pathan/DynamicContext.hpp>
#include <pathan/functions/FunctionNormalizeSpace.hpp>
#include <pathan/Sequence.hpp>
#include <pathan/ATQNameOrDerived.hpp>
#include <pathan/Node.hpp>
#include <pathan/ATStringOrDerived.hpp>
#include <xercesc/dom/DOMDocument.hpp>
#include <pathan/exceptions/FunctionException.hpp>
#include <pathan/internal/factory/DatatypeFactory.hpp>
#include <xercesc/util/XMLString.hpp>

const XMLCh FunctionResolveQName::name[] = { XERCES_CPP_NAMESPACE_QUALIFIER chLatin_r, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_e, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_s, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_o, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_l, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_v, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_e, XERCES_CPP_NAMESPACE_QUALIFIER chDash, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_Q, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_N, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_a, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_m, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_e, XERCES_CPP_NAMESPACE_QUALIFIER chNull };

/**
 * fn:resolve-QName($qname as xs:string?, $element as element()?) as xs:QName?
**/

/** Returns an QName with the lexical form given in the first argument. The 
 *  prefix is resolved using the in-scope namespaces for a given element. **/
FunctionResolveQName::FunctionResolveQName(const VectorOfDataItems &args, XPath2MemoryManager* memMgr)
  : ConstantFoldingFunction(name,2, 2, "string?, element()?", args, memMgr)
{
}

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

  Sequence arg1=getParamNumber(1, context);
  if(arg1.isEmpty())
    return Sequence(memMgr);
    
  const XMLCh* paramQName = ((const ATStringOrDerived*)arg1.first())->asString(context);
  const XMLCh* prefix = XPath2NSUtils::getPrefix(paramQName, memMgr);
  const XMLCh* localName = XPath2NSUtils::getLocalName(paramQName);

  Sequence arg2=getParamNumber(2, context);
  if(arg2.isEmpty())
    DSLthrow(FunctionException, X("FunctionResolveQName::collapseTreeInternal"),X("An element must be specified"));
  const XERCES_CPP_NAMESPACE_QUALIFIER DOMNode* node = ((const Node*)arg2.first())->getDOMNode();

  bool noPrefix = XERCES_CPP_NAMESPACE_QUALIFIER XMLString::equals(prefix, XERCES_CPP_NAMESPACE_QUALIFIER XMLUni::fgZeroLenString);
  const XMLCh* namespaceURI = 0;
  
  // If $qname has no prefix
  if(noPrefix) { 
    namespaceURI = node->lookupNamespaceURI(0);
  } 
  // If $qname has a prefix
  else {
    namespaceURI = node->lookupNamespaceURI(prefix);
    if (namespaceURI == 0) {
       DSLthrow(FunctionException, X("FunctionResolveQName::collapseTreeInternal"),X("no namespace found for prefix"));
    }
  }

  Sequence result(DatatypeFactory::STR2AT::createQName(memMgr, namespaceURI, localName, context), memMgr);

  return result; 
}