TrafficDataSource_Ogn.h

/***************************************************************************
 *   Copyright (C) 2021-2026 by Stefan Kebekus                             *
 *   stefan.kebekus@gmail.com                                              *
 *                                                                         *
 *   This program 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 3 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program 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.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
 
#pragma once
 
#include <QElapsedTimer>
#include <QPointer>
#include <QTcpSocket>
#include <string>
#include <vector>
 
#include "traffic/TrafficDataSource_AbstractSocket.h"
#include "OgnFilter.h"  // From enrouteOGN library
#include "OgnParser.h"  // From enrouteOGN library
 
using namespace Qt::Literals::StringLiterals;
 
namespace Traffic {

 
class TrafficDataSource_Ogn : public TrafficDataSource_AbstractSocket {
    Q_OBJECT
 
public:
    TrafficDataSource_Ogn(bool isCanonical, QString hostName, quint16 port, QObject *parent = nullptr);
 
    // Standard destructor
    ~TrafficDataSource_Ogn() override;
 
    //
    // Properties
    //

    Q_PROPERTY(QString host READ host CONSTANT)
 
    
    Q_PROPERTY(quint16 port READ port CONSTANT)
 
    //
    // Getter Methods
    //

    [[nodiscard]] QString dataFormat() const override { return u"APRS-IS"_s; }

    [[nodiscard]] QString host() const
    {
        return m_hostName;
    }

    [[nodiscard]] QString icon() const override { return u"/icons/material/ic_wifi.svg"_s; }

    [[nodiscard]] auto sourceName() const -> QString override
    {
        return tr("Open Glider Network-Connection");
    }

    [[nodiscard]] quint16 port() const
    {
        return m_port;
    }
 
public slots:
    void connectToTrafficReceiver() override;

    void disconnectFromTrafficReceiver() override;
 
private slots:
 
    // Read lines from the socket's text stream and passes the string on to
    // processAprsisMessage.
    void onReadyRead();
 
private:
    Q_DISABLE_COPY_MOVE(TrafficDataSource_Ogn)
 
    QTcpSocket m_socket;
    QTextStream m_textStream;
    QString m_hostName;
    quint16 m_port;
 
    // True while a connection is wanted. The socket's "disconnected" signal only
    // triggers an automatic reconnect while this is true, so that
    // disconnectFromTrafficReceiver() can actually stop the connection — abort()
    // emits "disconnected", which would otherwise reconnect immediately.
    bool m_connectionDesired = false;
 
    // Time of the last connection attempt. Automatic reconnects (from the
    // "disconnected" signal and from the watchdog verifyConnection()) wait at
    // least reconnectBackoff after an attempt before they try again, so that a
    // slow host lookup or handshake is not aborted and an unreachable server is
    // not hammered once per second.
    QElapsedTimer m_lastConnectionAttempt;
    static constexpr qint64 reconnectBackoffMs = 10'000;
 
    QString m_lineBuffer;         // Reusable buffer for reading lines
    Ogn::OgnMessage m_ognMessage; // Reusable message structure
    Ogn::OgnFilter m_ognFilter;   // Deduplication and out-of-order packet filter
 
    // our own OGN APRS CallSign, like "ENR12345"
    QString m_callSign;
 
    // Radius around the approximate position for which traffic data is requested.
    static constexpr Units::Distance m_receiveRadius = Units::Distance::fromNM(20.0);
 
    // Current coordinate and GPS usage
    QGeoCoordinate m_currentPosition;
    bool m_usingGps = true;
 
    // Cached ownship filter data (updated when aircraft settings change)
    std::u16string m_ownAircraftName;
    std::vector<std::string> m_ownTransponderCodes;
 
    // Throttling for filter updates
    QGeoCoordinate m_lastFilterPosition;     // Last coordinate actually sent to OGN server
    qint64 m_lastFilterUpdateTime = 0;
    static constexpr qint64 MIN_FILTER_UPDATE_INTERVAL_MS = 1000; // 1 second
    static constexpr double MIN_FILTER_UPDATE_DISTANCE_KM = 5.0;  // 5 km
 
    // Update filter with throttling logic
    void setFilter(const QGeoCoordinate& coordinate);
 
    // Update current coordinate based on GPS and map center availability
    void updateCurrentCoordinate();
 
    // Update cached ownship filter data from aircraft settings
    void updateOwnshipFilterData();
 
    // Periodic update function called once per minute
    void periodicUpdate();
 
    // Process OGN message and emit factorWithPosition signal
    void processOgnMessage(const QString& data);
 
    // Send a keep-alive message to the APRS-IS server
    void sendKeepAlive();
 
    // Verify the connection to the APRS-IS server and reconnect if necessary
    void verifyConnection();
};
 
} // namespace Traffic