"""Sample CardConnectionDecorator that provides exclusive transmit()

__author__ = "http://www.gemalto.com"

Copyright 2001-2010 gemalto
Author: Jean-Daniel Aussel, mailto:jean-daniel.aussel@gemalto.com

This file is part of pyscard.

pyscard is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

pyscard is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with pyscard; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
"""
from smartcard.CardConnection import CardConnection
from smartcard.CardConnectionDecorator import CardConnectionDecorator
from smartcard.Exceptions import CardConnectionException
from smartcard.scard import SCardBeginTransaction, SCardEndTransaction, SCARD_LEAVE_CARD
from smartcard.scard import SCardGetErrorMessage
from smartcard.pcsc import PCSCCardConnection
import smartcard.pcsc

class ExclusiveTransmitCardConnection( CardConnectionDecorator ):
    '''This decorator uses SCardBeginTransaction/SCardEndTransaction
    to preserve other processes of threads to access the card during transmit().'''
    def __init__( self, cardconnection ):
        CardConnectionDecorator.__init__( self, cardconnection )

    def lock( self ):
        '''Lock card with SCardBeginTransaction.'''

        component=self.component
        while True:
            if isinstance( component, smartcard.pcsc.PCSCCardConnection.PCSCCardConnection ):
                hresult = SCardBeginTransaction( component.hcard )
                if 0!=hresult:
                    raise CardConnectionException( 'Failed to lock with SCardBeginTransaction' + SCardGetErrorMessage(hresult) )
                else:
                    #print 'locked'
                    pass
                break
            if hasattr( component, 'component' ):
                component=component.component
            else:
                break

    def unlock( self ):
        '''Unlock card with SCardEndTransaction.'''
        component=self.component
        while True:
            if isinstance( component, smartcard.pcsc.PCSCCardConnection.PCSCCardConnection ):
                hresult = SCardEndTransaction( component.hcard, SCARD_LEAVE_CARD )
                if 0!=hresult:
                    raise CardConnectionException( 'Failed to unlock with SCardEndTransaction' + SCardGetErrorMessage(hresult) )
                else:
                    #print 'unlocked'
                    pass
                break
            if hasattr( component, 'component' ):
                component=component.component
            else:
                break


    def transmit( self, bytes, protocol=None ):
        '''Gain exclusive access to card during APDU transmission for if this
        decorator decorates a PCSCCardConnection.'''
        data, sw1, sw2 = CardConnectionDecorator.transmit( self, bytes, protocol )
        return data, sw1, sw2