WeatherDataProvider.h

/***************************************************************************
 *   Copyright (C) 2019-2025 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 <QGeoRectangle>
#include <QProperty>
#include <QTimer>
 
#include "GlobalObject.h"
#include "geomaps/Waypoint.h"
#include "navigation/Atmosphere.h"
#include "weather/METAR.h"
#include "weather/TAF.h"
 
class QNetworkReply;
 
 
namespace Weather {

class WeatherDataProvider : public QObject {
    Q_OBJECT
    QML_ELEMENT
    QML_SINGLETON
 
    class updateLogEntry;
    friend QDataStream& operator<<(QDataStream& stream, const updateLogEntry& ule);
    friend QDataStream& operator>>(QDataStream& stream, updateLogEntry& ule);
 
public:
    explicit WeatherDataProvider(QObject *parent = nullptr);
 
    // No default constructor, important for QML singleton
    explicit WeatherDataProvider() = delete;
 
    // factory function for QML singleton
    static Weather::WeatherDataProvider* create(QQmlEngine* /*unused*/, QJSEngine* /*unused*/)
    {
        return GlobalObject::weatherDataProvider();
    }
 
 
    //
    // Properties
    //

    Q_PROPERTY(bool downloading READ downloading NOTIFY downloadingChanged)
 
    
    Q_PROPERTY(Units::Pressure QNH READ QNH NOTIFY QNHInfoChanged)

    Q_PROPERTY(Units::Distance QNHPressureAltitude READ QNHPressureAltitude NOTIFY QNHInfoChanged)

    Q_PROPERTY(QString QNHInfo READ QNHInfo NOTIFY QNHInfoChanged)

    Q_PROPERTY(QString sunInfo READ sunInfo NOTIFY sunInfoChanged)

    Q_PROPERTY(QMap<QString,Weather::METAR> METARs READ METARs BINDABLE bindableMETARs)

    Q_PROPERTY(QMap<QString,Weather::TAF> TAFs READ TAFs BINDABLE bindableTAFs)
 
 
    //
    // Getter Methods
    //

    [[nodiscard]] bool downloading() const;

    QMap<QString, Weather::METAR> METARs() {return m_METARs.value();}

    QBindable<QMap<QString, Weather::METAR>> bindableMETARs() {return &m_METARs;}

    [[nodiscard]] Units::Pressure QNH() const;

    [[nodiscard]] Units::Distance QNHPressureAltitude() const { return Navigation::Atmosphere::height(QNH()); }

    [[nodiscard]] QString QNHInfo() const;

    static QString sunInfo();

    QMap<QString, Weather::TAF> TAFs() {return m_TAFs.value();}

    QBindable<QMap<QString, Weather::TAF>> bindableTAFs() {return &m_TAFs;}
 
 
    //
    // Methods
    //

    Q_INVOKABLE void requestUpdate();

    Q_INVOKABLE void requestUpdate4Waypoint(const GeoMaps::Waypoint& wp);
 
signals:
    void downloadingChanged();

    void error(QString message);

    void QNHInfoChanged();

    void sunInfoChanged();
 
private slots:
    // Called when a download is finished
    void downloadFinished();
 
    // Check for expired METARs and TAFs and delete them. This also deletes
    // weather stations if they are no longer in use.
    void deleteExpiredMesages();
 
    // Name says it all. This method is called from the constructor, but with a
    // little lag to avoid conflicts in the initialisation of static objects.
    void deferredInitialization();
 
    // This method is called by requestUpdate and requestUpdate4Waypoint. It
    // does the actual network request.
    void startDownload(const QGeoRectangle& bBox);
 
private:
    Q_DISABLE_COPY_MOVE(WeatherDataProvider)
 
    // Update interval is 30 mins, or 5 mins if update failed
    static const int updateIntervalNormal_ms  = 30*60*1000;
    static const int updateIntervalOnError_ms =  5*60*1000;
 
    // This method loads METAR/TAFs from a file "weather.dat" in
    // QStandardPaths::AppDataLocation.  There is locking to ensure that no two
    // processes access the file. The method will fail silently on error.
    // Returns true on success and false on failure.
    bool load();
 
    // This method saves all METAR/TAFs that are valid and not yet expired to a
    // file "weather.dat" in QStandardPaths::AppDataLocation.  There is locking
    // to ensure that no two processes access the file. The method will fail
    // silently on error.
    void save();
 
    // List of replies from aviationweather.com
    QList<QPointer<QNetworkReply>> m_networkReplies;
 
    // A timer used for auto-updating the weather reports every 30 minutes
    QTimer m_updateTimer;
 
    // A timer used for deleting expired weather reports ever 11 minutes
    QTimer m_deleteExiredMessagesTimer;
 
    // METARs and TAFs by ICAO Code
    QProperty<QMap<QString, Weather::METAR>> m_METARs;
    QProperty<QMap<QString, Weather::TAF>> m_TAFs;
 
    // Time and BBox of the last succesful METAR update for the current region and flight route
    struct updateLogEntry
    {
        QDateTime m_time;
        QGeoRectangle m_bBox;
    };
    QList<updateLogEntry> updateLog;
};
 
QDataStream& operator<<(QDataStream& stream, const WeatherDataProvider::updateLogEntry& ule);
 
QDataStream& operator>>(QDataStream& stream, WeatherDataProvider::updateLogEntry& ule);
 
} // namespace Weather