/*
    qgpgmekeylistjob.cpp

    This file is part of libkleopatra, the KDE keymanagement library
    Copyright (c) 2004 Klarälvdalens Datakonsult AB

    Libkleopatra is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.

    Libkleopatra 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
    General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

    In addition, as a special exception, the copyright holders give
    permission to link the code of this program with any edition of
    the TQt library by Trolltech AS, Norway (or with modified versions
    of TQt that use the same license as TQt), and distribute linked
    combinations including the two.  You must obey the GNU General
    Public License in all respects for all of the code used other than
    TQt.  If you modify this file, you may extend this exception to
    your version of the file, but you are not obligated to do so.  If
    you do not wish to do so, delete this exception statement from
    your version.
*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "qgpgmekeylistjob.h"

#include <qgpgme/eventloopinteractor.h>

#include <gpgmepp/key.h>
#include <gpgmepp/context.h>
#include <gpgmepp/keylistresult.h>
#include <gpg-error.h>

#include <tdemessagebox.h>
#include <tdelocale.h>
#include <kdebug.h>

#include <tqstringlist.h>
#include <tqtimer.h>

#include <algorithm>

#include <stdlib.h>
#include <string.h>
#include <assert.h>

Kleo::QGpgMEKeyListJob::QGpgMEKeyListJob( GpgME::Context * context )
  : KeyListJob( QGpgME::EventLoopInteractor::instance(), "Kleo::QGpgMEKeyListJob" ),
    QGpgMEJob( this, context ),
    mResult(), mSecretOnly( false )
{
  assert( context );
}

Kleo::QGpgMEKeyListJob::~QGpgMEKeyListJob() {
}

void Kleo::QGpgMEKeyListJob::setup( const TQStringList & pats, bool secretOnly ) {
  assert( !patterns() );

  mSecretOnly = secretOnly;
  setPatterns( pats );
}

GpgME::Error Kleo::QGpgMEKeyListJob::start( const TQStringList & pats, bool secretOnly ) {
  setup( pats, secretOnly );

  hookupContextToEventLoopInteractor();
  connect( QGpgME::EventLoopInteractor::instance(),
	   TQ_SIGNAL(nextKeyEventSignal(GpgME::Context*,const GpgME::Key&)),
	   TQ_SLOT(slotNextKeyEvent(GpgME::Context*,const GpgME::Key&)) );

  // The communication channel between gpgme and gpgsm is limited in
  // the number of patterns that can be transported, but they won't
  // say to how much, so we need to find out ourselves if we get a
  // LINE_TOO_LONG error back...

  // We could of course just feed them single patterns, and that would
  // probably be easier, but the performance penalty would currently
  // be noticable.

  while ( const GpgME::Error err = mCtx->startKeyListing( patterns(), mSecretOnly ) ) {
    if ( err.code() == GPG_ERR_LINE_TOO_LONG ) {
      setChunkSize( chunkSize()/2 );
      if ( chunkSize() >= 1 ) {
	kdDebug(5150) << "QGpgMEKeyListJob::start(): retrying keylisting with chunksize " << chunkSize() << endl;
	continue;
      }
    } else if ( err.code() == GPG_ERR_EOF ) {
        kdDebug(5150) << "QGpgMEKeyListJob::start(): early end of keylisting, trying to fake an empty result" << endl;
        TQTimer::singleShot( 10, this, TQ_SLOT(slotFakeOperationDoneEvent()) );
        return GpgME::Error();
    }
    deleteLater();
    mResult = GpgME::KeyListResult( 0, err );
    return err;
  }
  mResult = GpgME::KeyListResult( 0, 0 );
  return 0;
}

GpgME::KeyListResult Kleo::QGpgMEKeyListJob::exec( const TQStringList & pats, bool secretOnly, std::vector<GpgME::Key> & keys ) {
  setup( pats, secretOnly );

  // The communication channel between gpgme and gpgsm is limited in
  // the number of patterns that can be transported, but they won't
  // say to how much, so we need to find out ourselves if we get a
  // LINE_TOO_LONG error back...

  // We could of course just feed them single patterns, and that would
  // probably be easier, but the performance penalty would currently
  // be noticable.

  for (;;) {
    keys.clear();
    mResult = attemptSyncKeyListing( keys );
    if ( !mResult.error() || mResult.error().code() != GPG_ERR_LINE_TOO_LONG )
      return mResult;
    // got LINE_TOO_LONG, try a smaller chunksize:
    setChunkSize( chunkSize()/2 );
    if ( chunkSize() < 1 )
      // chunks smaller than one can't be -> return the error.
      return mResult;
    kdDebug(5150) << "QGpgMEKeyListJob::exec(): retrying keylisting with chunksize " << chunkSize() << endl;
  }
  kdFatal(5150) << "QGpgMEKeyListJob::exec(): Oops, this is not supposed to happen!" << endl;
  return GpgME::KeyListResult();
}

GpgME::KeyListResult Kleo::QGpgMEKeyListJob::attemptSyncKeyListing( std::vector<GpgME::Key> & keys ) {
  GpgME::KeyListResult result;
  for ( const char* * chunk = patterns() ; chunk ; chunk = nextChunk() ) {

    if ( const GpgME::Error err = mCtx->startKeyListing( chunk, mSecretOnly ) )
      return GpgME::KeyListResult( 0, err );

    GpgME::Error err;
    do
      keys.push_back( mCtx->nextKey( err ) );
    while ( !err );
    keys.pop_back();
    result.mergeWith( mCtx->endKeyListing() );
    if ( result.error() )
      break;
  }
  return result;
}

void Kleo::QGpgMEKeyListJob::slotNextKeyEvent( GpgME::Context * context, const GpgME::Key & key ) {
  if ( context == mCtx )
    emit nextKey( key );
}

void Kleo::QGpgMEKeyListJob::slotFakeOperationDoneEvent() {
  const GpgME::KeyListResult res = mCtx->keyListResult();
  if ( res.error().code() != GPG_ERR_EOF )
    kdDebug(5150) << "QGpgMEKeyListJob::slotFakeOperationDoneEvent: expected EOF, got "
                  << res.error().asString() << endl;
  mResult = GpgME::KeyListResult();
  emit done();
  emit result( mResult );
  deleteLater();
}

void Kleo::QGpgMEKeyListJob::slotOperationDoneEvent( GpgME::Context * context, const GpgME::Error & ) {
  if ( context != mCtx )
    return;
  mResult.mergeWith( mCtx->keyListResult() );
  if ( !mResult.error() )
    if ( const char* * chunk = nextChunk() ) {
      if ( const GpgME::Error err = mCtx->startKeyListing( chunk, mSecretOnly ) )
	mResult.mergeWith( GpgME::KeyListResult( 0, err ) );
      else
	return;
    }
  emit done();
  emit result( mResult );
  deleteLater();
}

void Kleo::QGpgMEKeyListJob::showErrorDialog( TQWidget * parent, const TQString & caption ) const {
  if ( !mResult.error() || mResult.error().isCanceled() )
    return;
  const TQString msg = i18n( "<qt><p>An error occurred while fetching "
			    "the keys from the backend:</p>"
			    "<p><b>%1</b></p></qt>" )
    .arg( TQString::fromLocal8Bit( mResult.error().asString() ) );
  KMessageBox::error( parent, msg, caption );
}

#include "qgpgmekeylistjob.moc"
