/*

* Copyright (c) 2007 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:  Parses Skype id from UUI message.

*

*/

#include "tcspskypeidparser.h"

const TInt KMinSkypeIdUUILength = 3;

const TInt KMaxSkypeIdUUILength = 33;

const TInt KMaxSkypeIdLength = 32;

const TInt KStartOf31To32EncodingByte = 26;

const TInt KUUIMTDicriminator = 0x44;

// ======== MEMBER FUNCTIONS ========

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

// Constructor

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

//

TCSPSkypeIdParser::TCSPSkypeIdParser() 

    {

    }

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

// Creates buffer to be used by client with parse method.

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

//  

HBufC* TCSPSkypeIdParser::CreateSkypeIdBufferL()

    {

    return HBufC::NewL( KMaxSkypeIdLength );

    }

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

// Parses skype id.

// SkypeID format:

// byte 0: Protocol discriminator: Always 0x00

// byte 1: User-User Information Discriminator.

//         For MT call this has to be 0x44

// Byte 2: First skype id character a.k.a payload. MSB bit is zero.

// Byte 26-33 May have MSB bit set, which are bits of the last character.

// The 26 byte's MSB is the last characters MSB bit.

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

//

TInt TCSPSkypeIdParser::Parse( 

    const TDesC& aUUIMessage, 

    TDes& aSkypeId )

    {

    const TInt messageLength( aUUIMessage.Length() );

    TInt error = KErrNone;

    const TBool messageSizeOk = (messageLength >= KMinSkypeIdUUILength &&

    							 messageLength <= KMaxSkypeIdUUILength);

    if( messageSizeOk &&

       ( aUUIMessage[1] ) == KUUIMTDicriminator ) // address type

        {

        TUint lastChar = 0;

        // skypeId payload starts from the second byte.

        TInt i = 2;

        for( ; i < messageLength; i++ )

            {

            TUint byte = aUUIMessage[i];

            if( i >= KStartOf31To32EncodingByte )

                {

                // 31 to 32 encoding: last character is build from

                // 7 last bytes.

                lastChar = lastChar << 1;

                lastChar |= (byte>>7)&0x01;

                }

            // MSB bit is not part of the character.

            aSkypeId.Append( byte & 0x7F ); 

            }

        // Append the last char only if the aUUIMessage size was the maximum and there

        // is content in the last char.

        if( messageLength == KMaxSkypeIdUUILength && lastChar != 0 )

            {

            aSkypeId.Append(lastChar);

            }

        }

    else

        {

        error = KErrNotSupported;

        }

    return error;

    }