/*
  This file is part of the KDE Kontact Plugin Interface Library.

  Copyright (c) 2003,2008 David Faure <faure@kde.org>

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

  This library 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
  Library General Public License for more details.

  You should have received a copy of the GNU Library General Public License
  along with this library; see the file COPYING.LIB.  If not, write to
  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  Boston, MA 02110-1301, USA.
*/

#include "uniqueapphandler.h"
#include <qdbusabstractadaptor.h>
#include "core.h"

#include <kpimutils/processes.h>

#include <kapplication.h>
#include <kcmdlineargs.h>
#include <kdebug.h>
#include <kstartupinfo.h>
#include <kuniqueapplication.h>
#include <kwindowsystem.h>

#include <QDBusConnection>
#include <QDBusConnectionInterface>

#ifdef Q_WS_WIN
#  include <process.h>
#endif

/*
 Test plan for the various cases of interaction between standalone apps and kontact:

 1) start kontact, select "Mail".
 1a) type "korganizer" -> it switches to korganizer
 1b) type "kmail" -> it switches to kmail
 1c) type "kaddressbook" -> it switches to kaddressbook
 1d) type "kmail foo@kde.org" -> it opens a kmail composer, without switching
 1e) type "knode" -> it switches to knode [unless configured to be external]
 1f) type "kaddressbook --new-contact" -> it opens a kaddressbook contact window
 1g) type "knode news://foobar/group" -> it pops up "can't resolve hostname"

 2) close kontact. Launch kmail. Launch kontact again.
 2a) click "Mail" icon -> kontact doesn't load a part, but activates the kmail window
 2b) type "kmail foo@kde.org" -> standalone kmail opens composer.
 2c) close kmail, click "Mail" icon -> kontact loads the kmail part.
 2d) type "kmail" -> kontact is brought to front

 3) close kontact. Launch korganizer, then kontact.
 3a) both Todo and Calendar activate the running korganizer.
 3b) type "korganizer" -> standalone korganizer is brought to front
 3c) close korganizer, click Calendar or Todo -> kontact loads part.
 3d) type "korganizer" -> kontact is brought to front

 4) close kontact. Launch kaddressbook, then kontact.
 4a) "Contacts" icon activate the running kaddressbook.
 4b) type "kaddressbook" -> standalone kaddressbook is brought to front
 4c) close kaddressbook, type "kaddressbook -a foo@kde.org" -> kontact loads part and opens editor
 4d) type "kaddressbook" -> kontact is brought to front

 5) close kontact. Launch knode, then kontact.
 5a) "News" icon activate the running knode.
 5b) type "knode" -> standalone knode is brought to front
 5c) close knode, type "knode news://foobar/group" -> kontact loads knode and pops up msgbox
 5d) type "knode" -> kontact is brought to front

 6) start "kontact --module summaryplugin"
 6a) type "qdbus org.kde.kmail /kmail_PimApplication newInstance '' ''" ->
     kontact switches to kmail (#103775)
 6b) type "kmail" -> kontact is brought to front
 6c) type "kontact" -> kontact is brought to front
 6d) type "kontact --module summaryplugin" -> kontact switches to summary

*/

using namespace KontactInterface;

//@cond PRIVATE
class UniqueAppHandler::Private
{
  public:
    Plugin *mPlugin;
};
//@endcond

UniqueAppHandler::UniqueAppHandler( Plugin *plugin )
 : QObject( plugin ), d( new Private )
{
  //kDebug() << "plugin->objectName():" << plugin->objectName();

  d->mPlugin = plugin;
  QDBusConnection session = QDBusConnection::sessionBus();
  const QString appName = plugin->objectName();
  session.registerService( QLatin1String("org.kde.") + appName );
  const QString objectName = QLatin1Char( '/' ) + appName + QLatin1String("_PimApplication");
  session.registerObject( objectName, this, QDBusConnection::ExportAllSlots );
}

UniqueAppHandler::~UniqueAppHandler()
{
  QDBusConnection session = QDBusConnection::sessionBus();
  const QString appName = parent()->objectName();
  session.unregisterService( QLatin1String("org.kde.") + appName );
  delete d;
}

// DBUS call
int UniqueAppHandler::newInstance( const QByteArray &asn_id, const QByteArray &args )
{
  if ( !asn_id.isEmpty() ) {
    kapp->setStartupId( asn_id );
  }

  KCmdLineArgs::reset(); // forget options defined by other "applications"
  loadCommandLineOptions(); // implemented by plugin

  // This bit is duplicated from KUniqueApplicationAdaptor::newInstance()
  QDataStream ds( args );
  KCmdLineArgs::loadAppArgs( ds );

  return newInstance();
}

static QWidget *s_mainWidget = 0;

// Plugin-specific newInstance implementation, called by above method
int KontactInterface::UniqueAppHandler::newInstance()
{
  if ( s_mainWidget ) {
    s_mainWidget->show();
    KWindowSystem::forceActiveWindow( s_mainWidget->winId() );
    KStartupInfo::appStarted();
  }

  // Then ensure the part appears in kontact
  d->mPlugin->core()->selectPlugin( d->mPlugin );
  return 0;
}

Plugin *UniqueAppHandler::plugin() const
{
  return d->mPlugin;
}

bool KontactInterface::UniqueAppHandler::load()
{
  (void)d->mPlugin->part(); // load the part without bringing it to front
  return true;
}

//@cond PRIVATE
class UniqueAppWatcher::Private
{
  public:
    UniqueAppHandlerFactoryBase *mFactory;
    Plugin *mPlugin;
    bool mRunningStandalone;
};
//@endcond

UniqueAppWatcher::UniqueAppWatcher( UniqueAppHandlerFactoryBase *factory, Plugin *plugin )
  : QObject( plugin ), d( new Private )
{
  d->mFactory = factory;
  d->mPlugin = plugin;

  // The app is running standalone if 1) that name is known to D-Bus
  const QString serviceName = QLatin1String("org.kde.") + plugin->objectName();
  //Needed for wince build
  #undef interface
  d->mRunningStandalone =
    QDBusConnection::sessionBus().interface()->isServiceRegistered( serviceName );
#ifdef Q_WS_WIN
  if ( d->mRunningStandalone ) {
    QList<int> pids;
    KPIMUtils::getProcessesIdForName( plugin->objectName(), pids );
    const int mypid = getpid();
    bool processExits = false;
    foreach ( int pid, pids ) {
      if ( mypid != pid ) {
        processExits = true;
        break;
      }
    }
    if ( !processExits ) {
      d->mRunningStandalone = false;
    }
  }
#endif

  QString owner = QDBusConnection::sessionBus().interface()->serviceOwner( serviceName );
  if ( d->mRunningStandalone && ( owner == QDBusConnection::sessionBus().baseService() ) ) {
    d->mRunningStandalone = false;
  }
  //kDebug() << " plugin->objectName()=" << plugin->objectName()
  //         << " running standalone:" << d->mRunningStandalone;

  if ( d->mRunningStandalone ) {
    QObject::connect( QDBusConnection::sessionBus().interface(),
                      SIGNAL(serviceOwnerChanged(QString,QString,QString)),
                      this, SLOT(slotApplicationRemoved(QString,QString,QString)) );
  } else {
    d->mFactory->createHandler( d->mPlugin );
  }
}

UniqueAppWatcher::~UniqueAppWatcher()
{
  delete d->mFactory;
  delete d;
}

bool UniqueAppWatcher::isRunningStandalone() const
{
  return d->mRunningStandalone;
}

void KontactInterface::UniqueAppWatcher::slotApplicationRemoved( const QString &name,
                                                                 const QString &oldOwner,
                                                                 const QString &newOwner )
{
  if ( oldOwner.isEmpty() || !newOwner.isEmpty() ) {
    return;
  }

  const QString serviceName = QLatin1String("org.kde.") + d->mPlugin->objectName();
  if ( name == serviceName && d->mRunningStandalone ) {
    d->mFactory->createHandler( d->mPlugin );
    d->mRunningStandalone = false;
  }
}

void KontactInterface::UniqueAppHandler::setMainWidget( QWidget *widget )
{
  s_mainWidget = widget;
}

QWidget *KontactInterface::UniqueAppHandler::mainWidget()
{
  return s_mainWidget;
}