// Copyright (c) 1997-2009 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 <apmrec.h>

#include <apmstd.h>

#include "RECTXT.H"

#include <ecom/implementationproxy.h>

const TUid KUidMimeTxtRecognizer={0x100012FB};

const TInt KMinBufferLength=42;  // minimum amount of file needed to determine a text file IF it's not called .TXT

const TInt KMaxBufferLength=1024; // maximum amount of buffer space we will ever use

_LIT8(KDataTypeTextPlain,"text/plain");

_LIT(KTextFileExt,".txt");

CApaTextRecognizer::CApaTextRecognizer()

	:CApaDataRecognizerType(KUidMimeTxtRecognizer,CApaDataRecognizerType::ELow)

	// Text files are low recognition - they don't have a clear signature

	{

	iCountDataTypes=1;

	}

TUint CApaTextRecognizer::PreferredBufSize()

	{

	return KMaxBufferLength;

	}

#if defined(_DEBUG)

TDataType CApaTextRecognizer::SupportedDataTypeL(TInt aIndex) const

#else

TDataType CApaTextRecognizer::SupportedDataTypeL(TInt /*aIndex*/) const

#endif

	{

	__ASSERT_DEBUG(aIndex==0,User::Invariant());

	return TDataType(KDataTypeTextPlain);

	}

void CApaTextRecognizer::DoRecognizeL(const TDesC& aName, const TDesC8& aBuffer)

	{

	TBool nameRecognized=EFalse;

	// check if the file has valid UIDs 

	if (aBuffer.Length() >= 16)

		{

		// if the first 3 bytes are valid UIDs,then this file is not a plain/text. 

		// Set iConfidence appropriately and exit.

		const TCheckedUid checkUid(aBuffer.Left(16));    

		if (checkUid.UidType().IsValid())

			{

			iConfidence=ENotRecognized;

			return;

			}

		}

	if (aName.Length()>4)

		{

		nameRecognized=(aName.Right(4).CompareF(KTextFileExt)==0);

		}

	const TInt length=Min(aBuffer.Length(), KMaxBufferLength);

	if (length<KMinBufferLength && !nameRecognized)

		return;

	TInt ii;

	for (ii=0; ii<length; ii++)

		{

		const TUint chr=aBuffer[ii];

		// these are guesses of what WON'T be in a text file

		if (chr<9 || chr==11 || chr==12 || (chr>13 && chr<32))

			{

			break;

			}

		if (chr>148)

			{

			break;

			}

		}

	const TBool validChars=(ii==length);

	if (nameRecognized)

		{

		iConfidence=validChars? EProbable : EUnlikely;

		}

	else

		{

		if (!validChars)

			{

			return;

			}

		iConfidence=EPossible;

		}

	iDataType=TDataType(KDataTypeTextPlain);

	}

CApaDataRecognizerType* CApaTextRecognizer::CreateRecognizerL()

	{

	return new (ELeave) CApaTextRecognizer();

	}

const TImplementationProxy ImplementationTable[] = 

    {

	IMPLEMENTATION_PROXY_ENTRY(0x101F7DA0,CApaTextRecognizer::CreateRecognizerL)

	};

EXPORT_C const TImplementationProxy* ImplementationGroupProxy(TInt& aTableCount)

    {

    aTableCount = sizeof(ImplementationTable) / sizeof(TImplementationProxy);

    return ImplementationTable;

    }