#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/dataItem/DataItemSequence.hpp>
#include <pathan/dataItem/DataItem.hpp>

#ifdef WIN32
#define snprintf _snprintf
#endif

#include <pathan/Sequence.hpp>
#include <pathan/DynamicContext.hpp>
#include <pathan/Item.hpp>
#include <pathan/dataItem/StaticResolutionContext.hpp>

DataItemSequence::DataItemSequence(const Sequence & s, XPath2MemoryManager* memMgr)
	: DataItemImpl(memMgr), _sequence(s, memMgr)
{
  setType(DataItem::SEQUENCE);
}

DataItemSequence::DataItemSequence(const Item* b, XPath2MemoryManager* memMgr)
	: DataItemImpl(memMgr), _sequence(b, memMgr)
{
  setType(DataItem::SEQUENCE);
}

DataItemSequence::DataItemSequence(XPath2MemoryManager* memMgr)
	: DataItemImpl(memMgr), _sequence(memMgr)
{
  setType(DataItem::SEQUENCE);
}

DataItemSequence::~DataItemSequence()
{
  //no-op
}

DataItemImpl *DataItemSequence::resolvePredicate(VectorOfDataItems::reverse_iterator it, VectorOfDataItems &newPreds, DynamicContext *context, StaticResolutionContext *src)
{
  if(it != _predList.rend()) {
    StaticResolutionContext newSrc(context->getMemoryManager());
    resolvePredicate(it + 1, newPreds, context, &newSrc);

    if(_sequence.isEmpty()) {
      newPreds.clear();
    }
    else {
      DataItem *pred = (*it)->staticResolution(context, &newSrc);

      // Remove context item usage
      newSrc.contextItemUsed(false);
      newSrc.contextPositionUsed(false);
      newSrc.contextSizeUsed(false);

      if(newSrc.isUsed()) {
        // We can't constant fold, so just return
        newPreds.push_back(pred);
        src->add(&newSrc);
      }
      else {
        // Constant fold
        _sequence = checkPredicate(_sequence, pred, context);
      }
    }
  }

  return this;
}

DataItem* DataItemSequence::staticResolution(StaticContext *context, StaticResolutionContext *src)
{
  return resolvePredicates(context, src);
}

Sequence DataItemSequence::collapseTreeInternal(DynamicContext* context, int flags) const
{
	return _sequence;
}