/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

*/

#include "CdlCompilerToolkit/CdlTkProcess.h"

#include <algorithm>

using namespace std;

namespace CdlCompilerToolkit {

//

// CCdlTkApiListComparator

//

class CCdlTkApiListComparator

	{

public:

	CCdlTkApiListComparator(CCdlTkApiList::const_iterator& aIter) : iIter(aIter) {}

	bool operator()(const CCdlTkApi* aApi) { return *aApi == **iIter; }

	CCdlTkApiList::const_iterator& iIter;

	};

//

// CCdlTkApiChecker

//

CCdlTkApiChecker::CCdlTkApiChecker(const CCdlTkInterface& aLeft, 

								   const CCdlTkInterface& aRight, 

								   MCdlTkApiCheckObserver& aObserver)

: iLeft(aLeft), iRight(aRight), iObserver(aObserver)

	{

	}

CCdlTkApiChecker::~CCdlTkApiChecker()

	{

	}

void CCdlTkApiChecker::Process()

	{

	iObserver.StartCheck();

	const CCdlTkApiList& leftList = iLeft.ApiList();

	const CCdlTkApiList& rightList = iRight.ApiList();

	CApiListIter posLeft = leftList.begin();

	CApiListIter posRight = rightList.begin();

	CApiListIter leftEnd = leftList.end();

	CApiListIter rightEnd = rightList.end();

	while (posLeft!=leftEnd && posRight!=rightEnd)

		{

		// if left and right APIs don't match, 

		// move the iterators till they do, or they hit the end

		if (**posLeft != **posRight)

			ReSync(posLeft, posRight, leftEnd, rightEnd);

		if (posLeft == leftEnd || posRight == rightEnd)

			{

			// if either iterator hits the end, fail everything remaining

			FailLeft(posLeft, leftEnd);

			FailRight(posRight, rightEnd);

			}

		else

			{

			// the APIs match, so tell the observer and move on

			iObserver.ApiInBoth(**posLeft);

			++posLeft;

			++posRight;

			}

		}

	iObserver.CheckComplete();

	}

// This function moves the iterators posLeft and posRight onwards till they

// match APIs again, or they hit the ends.

void CCdlTkApiChecker::ReSync(CApiListIter& posLeft, CApiListIter& posRight, 

							  const CApiListIter& leftEnd, const CApiListIter& rightEnd) const

	{

	// lookaheadLeft and lookaheadRight are how far we are looking ahead for a match

	CApiListIter lookaheadLeft = posLeft;

	CApiListIter lookaheadRight = posRight;

	// predicates for finding an API in a range

	CCdlTkApiListComparator chkContainsLeft(lookaheadLeft);

	CCdlTkApiListComparator chkContainsRight(lookaheadRight);

	// keep going till we get a match or reach the end

	for (;;) 

		{

		// move lookahead iterators on one step

		++lookaheadLeft;

		++lookaheadRight;

		// stop and fail if we've hit the end on the left

		if (lookaheadLeft == leftEnd)

			{

			FailLeft(posLeft, leftEnd);

			break;

			}

		// stop and fail if we've hit the end on the right

		if (lookaheadRight == rightEnd)

			{

			FailRight(posRight, rightEnd);

			break;

			}

		// look through LHS lookahead range for the RHS API at the lookahead position

		CApiListIter foundLeft = find_if(posLeft, lookaheadLeft+1, chkContainsRight);

		if (foundLeft != lookaheadLeft+1)

			{

			// found a match, fail everything up till the match position and stop

			FailLeft(posLeft, foundLeft);

			FailRight(posRight, lookaheadRight);

			break;

			}

		// look through RHS lookahead range for the LHS API at the lookahead position

		CApiListIter foundRight = find_if(posRight, lookaheadRight+1, chkContainsLeft);

		if (foundRight != lookaheadRight+1)

			{

			// found a match, fail everything up till the match position and stop

			FailLeft(posLeft, lookaheadLeft);

			FailRight(posRight, foundRight);

			break;

			}

		}

	}

void CCdlTkApiChecker::FailLeft(CApiListIter& aFrom, const CApiListIter& aTo) const

	{

	while (aFrom != aTo)

		{

		iObserver.ApiNotInRight(**aFrom);

		++aFrom;

		}

	}

void CCdlTkApiChecker::FailRight(CApiListIter& aFrom, const CApiListIter& aTo) const

	{

	while (aFrom != aTo)

		{

		iObserver.ApiNotInLeft(**aFrom);

		++aFrom;

		}

	}

}	// end of namespace CdlCompilerToolkit