// Copyright (c) 1998-2009 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:

// f32\sfat\inc\sl_scandrv.h

// 

//

/**

 @file

 @internalTechnology

*/

#ifndef SL_SCANDRV_H

#define SL_SCANDRV_H

//---------------------------------------------------------------------------------------------------------------------------------

const TInt KMaxMatchingEntries		= 2;        ///< Maximum number of matching directory entries scan drive can fix. Any more indicates a fault in the file system

const TInt KMaxArrayDepth			= 6;        ///< Maximum array depth for cluster storage when KMaxScanDepth is reached

//---------------------------------------------------------------------------------------------------------------------------------

/**

Data structure used to store the location of a partial VFat entry

*/

struct TPartVFatEntry

	{

	TEntryPos    iEntryPos; ///< The position of the partial VFat entry

	TFatDirEntry iEntry;    ///< The Dos entry The VFat entries belong with

	};

//---------------------------------------------------------------------------------------------------------------------------------

/**

Data structure used to store the locations of entries with matching

start cluster numbers. 

*/

struct TMatchingStartCluster

	{

	TEntryPos   iEntries[KMaxMatchingEntries]; ///< The positions of the matching entries

	TInt        iCount;         ///< Count of matching entries

	TInt        iStartCluster;  ///< The matching cluster number found in more than one entry

	};

//---------------------------------------------------------------------------------------------------------------------------------

class CCheckFatTable : public CBase

	{

public:

	static CCheckFatTable* NewL(CFatMountCB* aOwner);

	CCheckFatTable(CFatMountCB* aOwner);

	~CCheckFatTable();

	void InitializeL();

	TBool FlushL();

	TBool GetNextClusterL(TInt& aCluster) const;

	void WriteFatEntryEofFL(TInt aCluster);

	TInt ReadL(TInt aFatIndex) const;

	void WriteL(TInt aFatIndex,TInt aValue);

private:

	void WriteMediaDescriptor();

	TInt PosInBytes(TInt aFatIndex) const;

	TInt PosInIndex(TInt aBytePos) const;

	inline TBool IsEof16Bit(TInt aCluster) const;

	inline TBool IsEof12Bit(TInt aCluster) const;

    inline TInt MaxFatIndex() const;

protected:

    TInt iMaxFatIndex;

	TUint8* iCheckFat;

	CFatMountCB* iOwner;

	};

//---------------------------------------------------------------------------------------------------------------------------------

/**

Scan drive class performs scan drive functionality on all types

of fat volume.

*/

class CScanDrive : public CBase

	{

public:

	enum TDirError{EScanMatchingEntry=1,EScanPartEntry};

public:

	CScanDrive();

	~CScanDrive();

	static CScanDrive* NewL(CFatMountCB* aMount);

	void ConstructL(CFatMountCB* aMount);

	TInt StartL();

    TBool ProblemsDiscovered() const;  

private:

#if defined(DEBUG_SCANDRIVE)

	void PrintErrors();

	void CompareFatsL() const;

#endif

	void FixupDirErrorL();

	void FindSameStartClusterL();

	TInt FindStartClusterL(TInt aDirCluster);

	void CheckDirStructureL();

	void CheckDirL(TInt aCluster);

	void ProcessEntryL(const TFatDirEntry& aEntry);

	TInt CheckEntryClusterL(const TFatDirEntry& aEntry, const TEntryPos& aEntryPos);

	void WriteClusterChainL(TInt aCluster,TInt aSizeInBytes);

	TBool MoveToVFatEndL(TEntryPos& aPos,TFatDirEntry& aEntry,TInt& aDirLength);

	TBool IsValidVFatEntry(const TFatDirEntry& aEntry,TInt prevNum)const;

	TBool IsDosEntry(const TFatDirEntry& aEntry)const;

	void AddPartialVFatL(const TEntryPos& aStartPos, const TFatDirEntry& aEntry);

	TBool AddMatchingEntryL(const TEntryPos& aEntryPos);

	TInt GetReservedidL(const TEntryPos aVFatPos);

	void WriteNewFatsL();

	void FixPartEntryL();

	void FixMatchingEntryL();

	void MovePastEntriesL(TEntryPos& aEntryPos,TFatDirEntry& aEntry,TInt aToMove,TInt& aDirEntries);

	void AddToClusterListL(TInt aCluster);

	inline TBool AlreadyExistsL(TInt aCluster)const;

	inline TBool IsEndOfRootDir(const TEntryPos& aPos)const;

	inline TBool IsEofF(TInt aVal)const;

	inline TBool IsDirError()const;

    void IndicateErrorsFound();

private:

	CFatMountCB*        iMount;

	CCheckFatTable*     iNewFat;

	TPartVFatEntry      iPartEntry;

	TMatchingStartCluster iMatching;

	TDirError           iDirError;

	TInt                iDirsChecked;

	TInt                iRecursiveDepth;

	RArray<TInt>*       iClusterListArray[KMaxArrayDepth];

	TInt                iListArrayIndex;

    TBool               iFoundProblems; ///< if ETrue after finish, it means that there where some problems FS structure and they were probably fixed;

	};

#endif //SL_SCANDRV_H