/*

* Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "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: 

* Definition of the Swi::Sis::CParser

*

*/

#include <apadef.h>

#include "sisinstallerrors.h"

#include "sisdataprovider.h"

#include "sisparser.h"

#include "siscontents.h"

#include "swicommon.h"

using namespace Swi;

using namespace Swi::Sis;

EXPORT_C /*static*/ CContents* Parser::ContentsL(MSisDataProvider& aDataProvider)

	{

	TInt32 uid1;

	TInt32 uid2;

	TInt32 uid3;

	TUint32 uidCrc;

	// Check Uids and header Crc	

	ReadSymbianHeaderL(aDataProvider, uid1, uid2, uid3, uidCrc);

	// Create CContents (delegate the parsing to CContents)

	TInt64 bytesRead=0;

	CContents* ret = CContents::NewL(aDataProvider, bytesRead);

	return ret;

	}

void Parser::ReadSymbianHeaderL(MSisDataProvider& aDataProvider, TInt32& aUid1, TInt32& aUid2, TInt32& aUid3, TUint32& aUidCrc)

	{

	// Parse the SISX header, that's 4*4 bytes (UID1, UID2, UID3, UID Checksum)

	TPckg<TInt32> uid1pkg(aUid1);

	TInt err = aDataProvider.Read(uid1pkg, sizeof(TInt32));           // UID1

	if ((err != KErrNone) || (uid1pkg.Length() != sizeof(TInt32)))

		{

		User::Leave(KErrSISFieldBufferTooShort);

		}

	if (aUid1 != KUidSisxFile.iUid) // The first UID *must* be KUidSisxFile

		{

		// We could have errored out here because we

		// have a legacy SIS file, check that.

		// consume UID 2 and 3 to do the check.

		// ignore error here, we'll just leave 

		// with KErrCorrupt.

		TPckg<TInt32> uid2pkg(aUid2);

		aDataProvider.Read(uid2pkg, sizeof(TInt32));

		TPckg<TInt32> uid3pkg(aUid3);

		aDataProvider.Read(uid3pkg, sizeof(TInt32));

		if (aUid3 == KUidLegacySisFile.iUid)

			{

			User::Leave(KErrLegacySisFile);

			}

		else

			{

			User::Leave(KErrCorrupt);

			}

		}

	TPckg<TInt32> uid2pkg(aUid2);

	err = aDataProvider.Read(uid2pkg, sizeof(TInt32));                // UID2

	if ((err != KErrNone) || (uid2pkg.Length() != sizeof(TInt32)))

		{

		User::Leave(KErrSISFieldBufferTooShort);

		}

	TPckg<TInt32> uid3pkg(aUid3);

	err = aDataProvider.Read(uid3pkg, sizeof(TInt32));                // UID3

	if ((err != KErrNone) || (uid3pkg.Length() != sizeof(TInt32)))

		{

		User::Leave(KErrSISFieldBufferTooShort);

		}

	TPckg<TUint32> uidcrcpkg(aUidCrc);

	err = aDataProvider.Read(uidcrcpkg, sizeof(TInt32));                // Checksum

	if ((err != KErrNone) || (uidcrcpkg.Length() != sizeof(TInt32)))

		{

		User::Leave(KErrSISFieldBufferTooShort);

		}

	User::LeaveIfError(Parser::CheckUidCrc(aUidCrc, uid1pkg, uid2pkg, uid3pkg));

	}

TInt Parser::CheckUidCrc(TUint32 aCrc, const TDesC8& aUid1, const TDesC8& aUid2, const TDesC8& aUid3)

	{

/*	_LIT8(KCrcTest, "123456789");

	TBuf8 <12> buffer(KCrcTest);

	TUint16 tcrc=0;

	Mem::Crc(tcrc, buffer.PtrZ(), 9);

*/	

	TBuf8<12> uidBits;

	uidBits.Append(aUid1);

	uidBits.Append(aUid2);

	uidBits.Append(aUid3);

	TBuf8<7> evenBits;        // 1 more byte for zero terminator

	TBuf8<7> oddBits;		  // 1 more byte for zero terminator

	evenBits.SetLength(6);

	oddBits.SetLength(6);

	for (TInt k = 0; k < 6; k++)

		{

		evenBits[k] = uidBits[k*2]; 		

		oddBits[k] = uidBits[(k*2)+1]; 		

		}

	TUint16 crcHigh(0);

	TUint16 crcLow(0);

	Mem::Crc(crcHigh, oddBits.PtrZ(), 6);

	Mem::Crc(crcLow, evenBits.PtrZ(), 6);

	TUint32 crc = (crcHigh << 16) + crcLow;

	if (aCrc != crc) 

		{

		return KErrCorrupt;

		}

	return KErrNone;

	}

EXPORT_C void Parser::CreateSisStubL(RFile& aFile, MSisDataProvider& aDataProvider)

	{

	TInt32 uid1;

	TInt32 uid2;

	TInt32 uid3;

	TUint32 uidCrc;

	// Read the SisX header from the data provider and write it to the file

	ReadSymbianHeaderL(aDataProvider, uid1, uid2, uid3, uidCrc);

	WriteSymbianHeaderL(aFile, uid1, uid2, uid3, uidCrc);

	// Write the rest of the stub (SISX format) to the file

	CContents::WriteStubFieldsL(aFile, aDataProvider);

	}

void Parser::WriteSymbianHeaderL(RFile& aFile, TInt32& aUid1, TInt32& aUid2, TInt32& aUid3, TUint32& aUidCrc)

	{

	TPckg<TInt32> uid1Pckg(aUid1);

	User::LeaveIfError(aFile.Write(uid1Pckg));

	TPckg<TInt32> uid2Pckg(aUid2);

	User::LeaveIfError(aFile.Write(uid2Pckg));

	TPckg<TInt32> uid3Pckg(aUid3);

	User::LeaveIfError(aFile.Write(uid3Pckg));

	TPckg<TUint32> uidCrcPckg(aUidCrc);

	User::LeaveIfError(aFile.Write(uidCrcPckg));

	}