/*
    Copyright (c) 2007 Tobias Koenig <tokoe@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.
*/

#ifndef AKONADI_MONITOR_P_H
#define AKONADI_MONITOR_P_H

#include "akonadiprivate_export.h"
#include "monitor.h"
#include "collection.h"
#include "collectionstatisticsjob.h"
#include "collectionfetchscope.h"
#include "item.h"
#include "itemfetchscope.h"
#include "job.h"
#include <akonadi/private/notificationmessage_p.h>
#include "notificationsourceinterface.h"
#include "entitycache_p.h"
#include "servermanager.h"
#include "changenotificationdependenciesfactory_p.h"

#include <kmimetype.h>

#include <QtCore/QObject>
#include <QtCore/QTimer>

namespace Akonadi {

class Monitor;

/**
 * @internal
 */
class AKONADI_TESTS_EXPORT MonitorPrivate
{
  public:
    MonitorPrivate( ChangeNotificationDependenciesFactory *dependenciesFactory_, Monitor *parent );
    virtual ~MonitorPrivate() {
      delete dependenciesFactory;
      delete collectionCache;
      delete itemCache;
    }
    void init();

    Monitor *q_ptr;
    Q_DECLARE_PUBLIC( Monitor )
    ChangeNotificationDependenciesFactory *dependenciesFactory;
    QObject* notificationSource;
    Collection::List collections;
    QSet<QByteArray> resources;
    QSet<Item::Id> items;
    QSet<QString> mimetypes;
    bool monitorAll;
    QList<QByteArray> sessions;
    ItemFetchScope mItemFetchScope;
    CollectionFetchScope mCollectionFetchScope;
    bool mFetchChangedOnly;
    Session *session;
    CollectionCache *collectionCache;
    ItemCache *itemCache;
    QQueue<NotificationMessage> pendingNotifications;
    QQueue<NotificationMessage> pipeline;
    bool fetchCollection;
    bool fetchCollectionStatistics;

    // Virtual so it can be overridden in FakeMonitor.
    virtual bool connectToNotificationManager();
    bool acceptNotification( const NotificationMessage &msg );
    void dispatchNotifications();
    void flushPipeline();

    // Called when the monitored item/collection changes, checks if the queued messages
    // are still accepted, if not they are removed
    void cleanOldNotifications();

    bool ensureDataAvailable( const NotificationMessage &msg );
    /**
     * Sends out the change notification @p msg.
     * @return @c true if the notification was actually send to someone, @c false if no one was listening.
     */
    virtual bool emitNotification( const NotificationMessage &msg );
    void updatePendingStatistics( const NotificationMessage &msg );
    void invalidateCaches( const NotificationMessage &msg );

    /** Used by ResourceBase to inform us about collection changes before the notifications are emitted,
        needed to avoid the missing RID race on change replay.
    */
    void invalidateCache( const Collection &col );

    virtual int pipelineSize() const;

    // private slots
    void dataAvailable();
    void slotSessionDestroyed( QObject* );
    void slotStatisticsChangedFinished( KJob* );
    void slotFlushRecentlyChangedCollections();

    /**
      Returns whether a message was appended to @p notificationQueue
    */
    bool translateAndCompress( QQueue<NotificationMessage> &notificationQueue, const NotificationMessage &msg  );

    virtual void slotNotify( const NotificationMessage::List &msgs );

    /**
     * Sends out a change notification for an item.
     * @return @c true if the notification was actually send to someone, @c false if no one was listening.
     */
    bool emitItemNotification( const NotificationMessage &msg, const Item &item = Item(),
                               const Collection &collection = Collection(), const Collection &collectionDest = Collection() );
    /**
     * Sends out a change notification for a collection.
     * @return @c true if the notification was actually send to someone, @c false if no one was listening.
     */
    bool emitCollectionNotification( const NotificationMessage &msg, const Collection &col = Collection(),
                                     const Collection &par = Collection(), const Collection &dest = Collection() );

    void serverStateChanged( Akonadi::ServerManager::State state );

    /**
     * This method is called by the ChangeMediator to enforce an invalidation of the passed collection.
     */
    void invalidateCollectionCache( qint64 collectionId );

    /**
     * This method is called by the ChangeMediator to enforce an invalidation of the passed item.
     */
    void invalidateItemCache( qint64 itemId );

    /**
      @brief Class used to determine when to purge items in a Collection

      The buffer method can be used to buffer a Collection. This may cause another Collection
      to be purged if it is removed from the buffer.

      The purge method is used to purge a Collection from the buffer, but not the model.
      This is used for example, to not buffer Collections anymore if they get referenced,
      and to ensure that one Collection does not appear twice in the buffer.

      Check whether a Collection is buffered using the isBuffered method.
    */
    class PurgeBuffer
    {
      // Buffer the most recent 10 unreferenced Collections
      static const int MAXBUFFERSIZE = 10;
    public:
      explicit PurgeBuffer()
        : m_index( 0 ),
          m_bufferSize( MAXBUFFERSIZE )
      {
      }

      /**
        Adds @p id to the Collections to be buffered

        @returns The collection id which was removed form the buffer or -1 if none.
      */
      Collection::Id buffer( Collection::Id id );

      /**
      Removes @p id from the Collections being buffered
      */
      void purge( Collection::Id id );

      bool isBuffered( Collection::Id id ) const
      {
        return m_buffer.contains( id );
      }

    private:
      QVector<Collection::Id> m_buffer;
      int m_index;
      int m_bufferSize;
    } m_buffer;


    QHash<Collection::Id, int> refCountMap;
    bool useRefCounting;
    void ref( Collection::Id id );
    Collection::Id deref( Collection::Id id );

  private:
    // collections that need a statistics update
    QSet<Collection::Id> recentlyChangedCollections;
    QTimer statisticsCompressionTimer;

    /**
      @returns True if @p msg should be ignored. Otherwise appropriate signals are emitted for it.
    */
    bool isLazilyIgnored( const NotificationMessage & msg ) const;

    bool isCollectionMonitored( Collection::Id collection ) const
    {
      if (collection < 0)
        return false;
      if ( collections.contains( Collection( collection ) ) )
        return true;
      if ( collections.contains( Collection::root() ) )
        return true;
      return false;
    }

    bool isMimeTypeMonitored( const QString& mimetype ) const
    {
      if ( mimetypes.contains( mimetype ) )
        return true;

      KMimeType::Ptr mimeType = KMimeType::mimeType( mimetype, KMimeType::ResolveAliases );
      if ( mimeType.isNull() )
        return false;

      foreach ( const QString &mt, mimetypes ) {
        if ( mimeType->is( mt ) )
          return true;
      }

      return false;
    }

    bool isMoveDestinationResourceMonitored( const NotificationMessage &msg )
    {
      if ( msg.operation() != NotificationMessage::Move )
        return false;
      return resources.contains( msg.destinationResource() );
    }

    void fetchStatistics( Collection::Id colId )
    {
      CollectionStatisticsJob *job = new CollectionStatisticsJob( Collection( colId ), session );
      QObject::connect( job, SIGNAL( result( KJob* ) ), q_ptr, SLOT( slotStatisticsChangedFinished( KJob* ) ) );
    }

    void notifyCollectionStatisticsWatchers( Collection::Id collection, const QByteArray &resource );
};

}

#endif
