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

#include <pathan/functions/FunctionNormalizeSpace.hpp>
#include <pathan/functions/FunctionString.hpp>
#include <pathan/XPath2Utils.hpp>
#include <pathan/DynamicContext.hpp>
#include <pathan/ATStringOrDerived.hpp>
#include <pathan/internal/factory/DatatypeFactory.hpp>
#include <xercesc/util/XMLUni.hpp>
#include <xercesc/util/XMLString.hpp>
#include <pathan/dataItem/DataItemSequence.hpp>
#include <pathan/dataItem/StaticResolutionContext.hpp>

const XMLCh FunctionNormalizeSpace::name[] = {
XERCES_CPP_NAMESPACE_QUALIFIER chLatin_n, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_o, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_r, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_m, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_a, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_l, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_i, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_z, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_e, XERCES_CPP_NAMESPACE_QUALIFIER chDash, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_s, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_p, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_a, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_c, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_e, XERCES_CPP_NAMESPACE_QUALIFIER chNull };

/**
 * fn:normalize-space() as xs:string
 * fn:normalize-space($arg as xs:string?) as xs:string
**/

FunctionNormalizeSpace::FunctionNormalizeSpace(const VectorOfDataItems &args, XPath2MemoryManager* memMgr)
  : DataItemFunction(name,0, 1, "string?", args, memMgr)
{
}

const XMLCh* FunctionNormalizeSpace::getString(DynamicContext* context) const {
  XPath2MemoryManager* memMgr = context->getMemoryManager();
  //setup xf:string with empty args
  VectorOfDataItems args=VectorOfDataItems(PathanAllocator<DataItem*>(memMgr));
  FunctionString stringGrabber(args, memMgr);
  //call xf:string and extract result
  return ((const ATStringOrDerived*)stringGrabber.collapseTree(context).first())->asString(context);
}

DataItem* FunctionNormalizeSpace::staticResolution(StaticContext *context, StaticResolutionContext *src) {
  if(_args.empty()) {
    src->contextItemUsed(true);
  }
  return resolveDataItems(_args, context, src, !_args.empty());
}

Sequence FunctionNormalizeSpace::collapseTreeInternal(DynamicContext* context, int flags) const
{
  XPath2MemoryManager* memMgr = context->getMemoryManager();
  const XMLCh* str;
  if (getNumArgs() == 0) {
    str = getString(context);
  } else {
    Sequence strParm=getParamNumber(1,context);
    if(strParm.isEmpty())
      return Sequence(DatatypeFactory::STR2AT::createString(memMgr, XERCES_CPP_NAMESPACE_QUALIFIER XMLUni::fgZeroLenString, context), memMgr);
   
     str = ((const ATStringOrDerived*)strParm.first())->asString(context);
  }
	const XMLCh* result = NULL;

	int whitespace = 0; 
	for(unsigned int i = 0; i < XERCES_CPP_NAMESPACE_QUALIFIER XMLString::stringLen(str); i++) 
	{
		XMLCh ch = str[i];

		if((ch == 0x9) || (ch == 0xA) || (ch == 0xD) || (ch == 0x20))
		{
			whitespace++;
			ch = 0x20;
		}
		else
		{
			whitespace = 0;
		}
		if(whitespace < 2)
		{
			result = XPath2Utils::concatStrings(result, ch, memMgr);
		}
	}

	if(XERCES_CPP_NAMESPACE_QUALIFIER XMLString::stringLen(result)>0)
	{
		XMLCh first = result[0];
		if((first == 0x9) || (first == 0xA) || (first == 0xD) || (first == 0x20)) {
			result = XPath2Utils::deleteData(result, 0, 1, memMgr); 
		}
	}
	if(XERCES_CPP_NAMESPACE_QUALIFIER XMLString::stringLen(result)>0)
	{
		XMLCh last = result[XERCES_CPP_NAMESPACE_QUALIFIER XMLString::stringLen(result) - 1];
		if((last == 0x9) || (last == 0xA) || (last == 0xD) || (last == 0x20)) {
			result = XPath2Utils::deleteData(result, XERCES_CPP_NAMESPACE_QUALIFIER XMLString::stringLen(result) -1, 1, memMgr);
		}
	}
	return Sequence(DatatypeFactory::STR2AT::createString(memMgr, result, context), memMgr);
}