/**
 * @file Common/eventqueue.h
 * @brief Event queue interface implementation
 * @author Enar Vaikene
 *
 * Copyright (c) 2011-2019 Enar Vaikene
 *
 * This file is part of the eVaf C++ cross-platform application development framework.
 *
 * This file can be used under the terms of the GNU General Public License
 * version 3.0 as published by the Free Software Foundation and appearing in
 * the file LICENSE included in the packaging of this file. Please review the
 * the following information to ensure the GNU General Public License version
 * 3.0 requirements will be met: http://www.gnu.org/copyleft/gpl.html.
 *
 * Alternatively, this file may be used in accordance with the Commercial License
 * Agreement provided with the Software.
 */

#ifndef __COMMON_EVENTQUEUE_H
#define __COMMON_EVENTQUEUE_H

#include "ieventqueue.h"

#include <QObject>
#include <QString>
#include <QHash>
#include <QVector>


namespace eVaf {
namespace Common {
namespace Internal {

/**
 * iEventQueue interface implementation
 */
class EventQueue : public iEventQueue
{
    Q_OBJECT

public:

    EventQueue();

    virtual ~EventQueue();

    /// Qt event handler
    virtual bool event(QEvent * e);

    /*
        iEventQueue interface
    */

    virtual uint registerEvent(QString const & name);

    virtual uint queryEvent(QString const & name) const;

    virtual void unregisterEvent(uint id);

    virtual uint subscribeEvent(uint id, QObject * obj);

    virtual void unsubscribeEvent(uint id, QObject * obj);

    virtual void broadcastEvent(Event * event);


private: // Members

    /// ID of the next event
    uint mNextEventId;

    /// List of registered events
    typedef QHash<uint, QString> Events;
    Events mEvents;

    /// List of subscribers
    typedef QHash<uint, QVector<QObject *> > Subscribers;
    Subscribers mSubscribers;


private slots:

    /// One of the subscribers is destroyed
    /// We need to remove it from the list of subscribers.
    void subscriberDestroyed(QObject * obj = nullptr);

};

} // namespace evaf::Common::Internal
} // namespace eVaf::Common
} // namespace eVaf

#endif // eventqueue.h