/*
    Copyright (c) 2010 Volker Krause <vkrause@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 "agentserver.h"

#include "agentthread.h"
#include "libs/xdgbasedirs_p.h"
#include "libs/protocol_p.h"
#include "shared/akdebug.h"

#include <QtCore/QCoreApplication>
#include <QtCore/QDebug>
#include <QtCore/QPluginLoader>
#include <QtCore/QTimer>
#include <QtDBus/QDBusConnection>

using namespace Akonadi;

AgentServer::AgentServer( QObject *parent )
  : QObject( parent )
  , m_processingConfigureRequests( false )
  , m_quiting( false )
{
  QDBusConnection::sessionBus().registerObject( QLatin1String( AKONADI_DBUS_AGENTSERVER_PATH ),
                                                this, QDBusConnection::ExportScriptableSlots );
}

AgentServer::~AgentServer()
{
  qDebug() << Q_FUNC_INFO;
  if ( !m_quiting ) {
    quit();
  }
}

void AgentServer::agentInstanceConfigure( const QString &identifier, qlonglong windowId )
{
  m_configureQueue.enqueue( ConfigureInfo( identifier, windowId ) );
  if ( !m_processingConfigureRequests ) { // Start processing the requests if needed.
    QTimer::singleShot( 0, this, SLOT(processConfigureRequest()) );
  }
}

bool AgentServer::started( const QString &identifier ) const
{
  return m_agents.contains( identifier );
}

void AgentServer::startAgent( const QString &identifier, const QString &typeIdentifier, const QString &fileName )
{
  akDebug() << Q_FUNC_INFO << identifier << typeIdentifier << fileName;

  //First try to load it staticly
  Q_FOREACH ( QObject *plugin, QPluginLoader::staticInstances() ) {
    if ( plugin->objectName() == fileName ) {
      AgentThread *thread = new AgentThread( identifier, plugin, this );
      m_agents.insert( identifier, thread );
      thread->start();
      return;
    }
  }

  QPluginLoader *loader = m_agentLoader.load( fileName );
  if ( loader == 0 ) {
    return; // No plugin found, debug output in AgentLoader.
  }

  Q_ASSERT( loader->isLoaded() );

  AgentThread *thread = new AgentThread( identifier, loader->instance(), this );
  m_agents.insert( identifier, thread );
  thread->start();
}

void AgentServer::stopAgent( const QString &identifier )
{
  if ( !m_agents.contains( identifier ) ) {
    return;
  }

  AgentThread *thread = m_agents.take( identifier );
  thread->quit();
  thread->wait();
  delete thread;
}

void AgentServer::quit()
{
  Q_ASSERT( !m_quiting );
  m_quiting = true;

  QMutableHashIterator<QString, AgentThread *> it( m_agents );
  while ( it.hasNext() ) {
    it.next();
    stopAgent( it.key() );
  }

  QCoreApplication::instance()->quit();
}

void AgentServer::processConfigureRequest()
{
  if ( m_processingConfigureRequests ) {
    return; // Protect against reentrancy
  }

  m_processingConfigureRequests = true;

  while ( !m_configureQueue.empty() ) {
    const ConfigureInfo info = m_configureQueue.dequeue();
    // call configure on the agent with id info.first for windowId info.second.
    Q_ASSERT( m_agents.contains( info.first ) );
    AgentThread *thread = m_agents.value( info.first );
    thread->configure( info.second );
  }

  m_processingConfigureRequests = false;
}