/*
* Copyright (c) 2002-2009 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:  Symbian recognizer for DRM protected files
*
*/


// INCLUDE FILES
#include <apmrec.h>
#include <apmstd.h>
#include <ecom/ecom.h>
#include <ecom/implementationproxy.h>

#include "recdrm.h"

#define RECOGNIZE_KEY_CHAIN

// CONSTANTS
const TUid KUidDRMRecognizer={ 0x101F51F4 };

// Version must be 1 so that it conforms to OMA DRM 1.0 specification
const TInt KDCFVersionSupported( 1 );

// minimum size of supported mime-type
const TInt KMinContentTypeLen( 3 );

// maximum amount of buffer space we will ever use
const TInt KMaxBufferLength=256;

const TInt KDCFHeaderLength=3;
const TInt KLengthBoxSize = 4;
const TInt KLengthBoxType = 4;
const TInt KLengthBoxSize64 = 8;
const TInt KLengthVersion = 1;
const TInt KLengthFlags = 3;

_LIT8(KFTypPrefix, "ftyp");
_LIT8(KODFPrefix, "odcf");
_LIT8(KRoapTriggerElement, "roap-trigger:roapTrigger"); // before OMA spec CR, ROAP Trigger namespace prefix was roap-trigger 
_LIT8(KRoapTriggerElement2, "roap:roapTrigger");
_LIT8(KRoapTriggerType, "application/vnd.oma.drm.roap-trigger+xml");

const TImplementationProxy ImplementationTable[] = 
	    {
	    IMPLEMENTATION_PROXY_ENTRY(0x101F6DB8, CApaDRMRecognizer::CreateRecognizerL)
	    };

#ifdef DRM_OMA2_ENABLED
TUint32 ReadUint32FromBlock(const TDesC8& aBlock, TInt aOffset)
    {
    return (aBlock[aOffset] << 24) +
        (aBlock[aOffset + 1] << 16) +
        (aBlock[aOffset + 2] << 8) +
        aBlock[aOffset + 3];
    }

TInt ReadIntFromBlock(const TDesC8& aBlock, TInt aOffset)
    {
    return (aBlock[aOffset] << 24) +
        (aBlock[aOffset + 1] << 16) +
        (aBlock[aOffset + 2] << 8) +
        aBlock[aOffset + 3];
    }

TUint16 ReadUint16FromBlock(const TDesC8& aBlock, TInt aOffset)
    {
    return ((aBlock[aOffset] << 8) + aBlock[aOffset + 1]);
    }
#endif

CApaDRMRecognizer::CApaDRMRecognizer():
	CApaDataRecognizerType( KUidDRMRecognizer,CApaDataRecognizerType::ENormal )
{
	
	iCountDataTypes = 0;
	return;
}

CApaDRMRecognizer::~CApaDRMRecognizer()
{
}


CApaDataRecognizerType* CApaDRMRecognizer::CreateRecognizerL()
{
	return new (ELeave) CApaDRMRecognizer ();
}
	

TUint CApaDRMRecognizer::PreferredBufSize()
{
	return KMaxBufferLength;
}

#ifdef _DEBUG
TDataType CApaDRMRecognizer::SupportedDataTypeL( TInt aIndex ) const
#else
TDataType CApaDRMRecognizer::SupportedDataTypeL( TInt /*aIndex*/ ) const
#endif
{
__ASSERT_DEBUG( aIndex >= 0 && aIndex < iCountDataTypes, User::Invariant() );
	return TDataType( _L8("application/vdn.omd.drm.content") ); // this should never be run
}

void CApaDRMRecognizer::DoRecognizeL( const TDesC& aName, const TDesC8& aBuffer )
{
	if ( aBuffer.Size() < 3) 
        {
        return;
        }
	
#ifdef RECOGNIZE_KEY_CHAIN	
	// Recognize device key chain
	if ( aName.Length() > 3 && aName.Right(4).CompareF(_L(".dkc")) == 0)
        {
        iConfidence = ECertain;
        iDataType = TDataType( _L8("application/x-device-key-chain") );
        return;
        }
#endif        
	
#ifdef DRM_OMA2_ENABLED
	// Recognize ROAP Trigger
	if ( RecognizeRoapTrigger( aBuffer ) )
        {
        return;
        }
	
	// Recognize DCFv2    
	if ( RecognizeODF( aBuffer ) )
        {
        return;
        }   
#endif	
	// Recognize DCFv1
	TUint8 version = aBuffer[0];
	TUint8 contentTypeLen = aBuffer[1];
	TUint8 contentURILen = aBuffer[2];

	if ( contentTypeLen < KMinContentTypeLen || contentURILen == 0 ) 
	{
		return;
	}
	if ( version != KDCFVersionSupported ) 
	{
		return;
	}

	// Too little data received
	if ( aBuffer.Size() < ( contentTypeLen + KDCFHeaderLength ) ) 
	{
		return;
	}

	TPtrC8 mimeType = aBuffer.Mid( KDCFHeaderLength, contentTypeLen );
	if ( mimeType.Locate( '/' ) != KErrNotFound )
	{
		iConfidence = ECertain;
		iDataType=TDataType( mimeType );	
	}
	
	
	return;
}

#ifdef DRM_OMA2_ENABLED
TBool CApaDRMRecognizer::RecognizeRoapTrigger( const TDesC8& aBuffer )
{
        if ( aBuffer.FindF( KRoapTriggerElement() ) != KErrNotFound
             || aBuffer.FindF( KRoapTriggerElement2() ) != KErrNotFound )
        {
            iConfidence = ECertain;
            iDataType=TDataType( KRoapTriggerType() );
            return ETrue;
        }
	return EFalse;
}

TBool CApaDRMRecognizer::RecognizeODF( const TDesC8& aBuffer )
{
	if ( aBuffer.Size() < 24 ) return EFalse;
	TPtrC8 ftypPrefix = aBuffer.Mid( 4, KFTypPrefix().Length() );
	if ( KFTypPrefix().CompareF( ftypPrefix ) == KErrNone )
	{
		TPtrC8 odfPrefix = aBuffer.Mid( 8, KODFPrefix().Length() );
		if ( KODFPrefix().CompareF( odfPrefix ) == KErrNone )
		{
			TBuf8<4> buffer;
    		TUint32 size;
    		TPtr8 ptr(NULL, 0);
    		TUint32 offset(20);
    
    		// ODRM box header
    		buffer.Zero();
    		buffer.Copy( aBuffer.Mid( offset, 4 ));
    		size = ReadUint32FromBlock( buffer, 0 );
    		offset += KLengthBoxSize + KLengthBoxType + KLengthVersion + KLengthFlags;
    		
    		if (size == 1)
        	{
        		offset += KLengthBoxSize64;
        	}
    		if ( aBuffer.Size() < offset+4 ) return EFalse;
    		
    		// Discrete headers box header
    		buffer.Zero();
    		buffer.Copy( aBuffer.Mid( offset, 4 ));
    		size = ReadUint32FromBlock( buffer, 0 );
    		offset += KLengthBoxSize + KLengthBoxType + KLengthVersion + KLengthFlags;
    		if ( size == 1 )
        	{
        		offset += KLengthBoxSize64;
        	}
    		if ( aBuffer.Size() < offset+1 ) return EFalse;
    		
    		// Content type
    		buffer.Zero();
    		buffer.Copy( aBuffer.Mid( offset, 1 ));
    		if ( aBuffer.Size() < offset + 1 + buffer[0] ) return EFalse;
    		TPtrC8 mimeType = aBuffer.Mid( offset+1, buffer[0] );
   			
   			iConfidence = ECertain;
			iDataType=TDataType( mimeType );
			return ETrue;
		}
		
	}
	return EFalse;
}
#endif

EXPORT_C const TImplementationProxy* ImplementationGroupProxy(TInt& aTableCount)
    {
    aTableCount = sizeof(ImplementationTable) / sizeof(TImplementationProxy);
    return ImplementationTable;
    }