/*
 * 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 "FunctionSubstringAfter.hpp"


#include <xalanc/PlatformSupport/XalanMessageLoader.hpp>


#include "XObjectFactory.hpp"


XALAN_CPP_NAMESPACE_BEGIN


FunctionSubstringAfter::FunctionSubstringAfter()
{
}


FunctionSubstringAfter::~FunctionSubstringAfter()
{
}


static const XalanDOMString		theEmptyString;


inline XObjectPtr
createEmptyString(XPathExecutionContext&	executionContext)
{
	return executionContext.getXObjectFactory().createStringReference(theEmptyString);
}


XObjectPtr
FunctionSubstringAfter::execute(
			XPathExecutionContext&	executionContext,
			XalanNode*				/* context */,
			const XObjectPtr		arg1,
			const XObjectPtr		arg2,
			const LocatorType*		/* locator */) const
{
	assert(arg1.null() == false && arg2.null() == false);

	const XalanDOMString&				theFirstString = arg1->str();

	const XalanDOMString::size_type		theFirstStringLength = length(theFirstString);

	if (theFirstStringLength == 0)
	{
		return createEmptyString(executionContext);
	}
	else
	{
		const XalanDOMString&	theSecondString = arg2->str();

		const XalanDOMString::size_type		theSecondStringLength = length(theSecondString);

		if (theSecondStringLength == 0)
		{
			return arg1;
		}
		else
		{
			const XalanDOMString::size_type		theIndex = indexOf(theFirstString,
													   theSecondString);

			if (theIndex == theFirstStringLength)
			{
				return createEmptyString(executionContext);
			}
			else
			{
				const XalanDOMString::size_type		theSecondStringLength = length(theSecondString);

				// Find the first character, which will be the offset of the index of the
				// beginning of the second string, plus the length of the second string.
				const XalanDOMChar* const	theFirstCharacter =
					toCharArray(theFirstString) + theIndex + theSecondStringLength;

				// The remaining length is just the opposite -- the length of the string,
				// minus the index, minus the length of the second string.
				const XalanDOMString::size_type		theSubstringLength =
					theFirstStringLength  - theIndex - theSecondStringLength;

				XPathExecutionContext::GetAndReleaseCachedString	theResult(executionContext);

				XalanDOMString&		theString = theResult.get();

				assign(
						theString,
						theFirstCharacter,
						theSubstringLength);

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


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


const XalanDOMString
FunctionSubstringAfter::getError() const
{

	return XalanMessageLoader::getMessage(XalanMessages::FunctionTakesTwoArguments_1Param, "substring-after()");

}


XALAN_CPP_NAMESPACE_END