/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * 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.
 */
#include "FunctionDistinct.hpp"


#include <xalanc/Include/XalanSet.hpp>


#include <xalanc/XalanDOM/XalanDOMString.hpp>


#include <xalanc/PlatformSupport/XalanMessageLoader.hpp>
#include <xalanc/PlatformSupport/DOMStringHelper.hpp>


#include <xalanc/DOMSupport/DOMServices.hpp>


#include <xalanc/XPath/XPathExecutionContext.hpp>
#include <xalanc/XPath/XObjectFactory.hpp>


XALAN_CPP_NAMESPACE_BEGIN


FunctionDistinct::FunctionDistinct()
{
}


FunctionDistinct::~FunctionDistinct()
{
}


XObjectPtr
FunctionDistinct::execute(
			XPathExecutionContext&			executionContext,
			XalanNode*						context,
			const XObjectArgVectorType&		args,
			const LocatorType*				locator) const
{
	if (args.size() != 1)
	{
		executionContext.error(getError(), context, locator);
	}

	assert(args[0].null() == false);

	const NodeRefListBase&	nodeset = args[0]->nodeset();

	typedef XPathExecutionContext::BorrowReturnMutableNodeRefList	BorrowReturnMutableNodeRefList;

	BorrowReturnMutableNodeRefList	theResult(executionContext);

	const NodeRefListBase::size_type	theLength = nodeset.getLength();

	if (theLength == 1)
	{
		theResult->addNode(nodeset.item(0));
	}
	else if (theLength > 1)
	{
		typedef XPathExecutionContext::GetAndReleaseCachedString	GetAndReleaseCachedString;

		GetAndReleaseCachedString	theGuard(executionContext);

		XalanDOMString&				theCachedString = theGuard.get();


		typedef XalanSet<XalanDOMString>					SetType;

		SetType		theStrings;

		// Check to make sure each node has a unique
		// string value.
		for (NodeRefListBase::size_type i = 0; i < theLength; ++i)
		{
			XalanNode* const	theNode = nodeset.item(i);
			assert(theNode != 0);

			DOMServices::getNodeData(*theNode, theCachedString);

			if (theStrings.find(theCachedString) == theStrings.end())
			{
				theResult->addNodeInDocOrder(theNode, executionContext);

				theStrings.insert(theCachedString);
			}

			clear(theCachedString);
		}
	}

	theResult->setDocumentOrder();

	return executionContext.getXObjectFactory().createNodeSet(theResult);
}


#if defined(XALAN_NO_COVARIANT_RETURN_TYPE)
Function*
#else
FunctionDistinct*
#endif
FunctionDistinct::clone() const
{
	return new FunctionDistinct(*this);
}


const XalanDOMString
FunctionDistinct::getError() const
{

	return XalanMessageLoader::getMessage(XalanMessages::FunctionAcceptsOneArgument_1Param,"distinct()");

}


XALAN_CPP_NAMESPACE_END