FlightRecorder.h

/***************************************************************************
 *   Copyright (C) 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 <QGeoPath>
#include <QStandardPaths>
 
#include "flightlog/Flight.h"
#include "flightlog/FlightDetector.h"
#include "flightlog/TrackPoint.h"
#include "positioning/PositionInfo.h"
#include "units/Distance.h"
 
using namespace Qt::Literals::StringLiterals;
 
namespace Flightlog {

class FlightRecorder : public QObject
{
    Q_OBJECT
 
public:
    explicit FlightRecorder(QObject* parent = nullptr);

    ~FlightRecorder() override = default;

    void processPositionUpdate(FlightDetector::DetectionState state,
                               const Positioning::PositionInfo& info,
                               Units::Distance pressureAltitude = {});

    bool saveTrack(Flight& flight);

    void clearTrack();

    [[nodiscard]] auto loadTrackPath(const Flight& flight) const -> QList<QGeoCoordinate>;

    [[nodiscard]] QByteArray exportToIGC(const Flight& flight) const;

    void removeTrack(Flight& flight);

    [[nodiscard]] auto trackGeoPath() const -> QGeoPath;

    static auto toIGC(const Flight& flight, const QList<TrackPoint>& track) -> QByteArray;

    static auto trackFromIGC(const QByteArray& igcData, const QDate& date = {}) -> QList<TrackPoint>;
 
signals:
    void trackGeoPathChanged();
 
private:
    Q_DISABLE_COPY_MOVE(FlightRecorder)
 
    // Build a TrackPoint from position info and optional pressure altitude
    static auto makeTrackPoint(const Positioning::PositionInfo& info, Units::Distance pressureAltitude) -> TrackPoint;
 
    // Check if a point should be recorded based on distance/time thresholds
    [[nodiscard]] auto shouldRecord(const Positioning::PositionInfo& info) const -> bool;
 
    // Record a point if thresholds are met
    void recordFiltered(const Positioning::PositionInfo& info, Units::Distance pressureAltitude);
 
    // Last recorded point for distance/time filtering
    QGeoCoordinate m_lastCoordinate;
    QDateTime m_lastTimestamp;
 
    // Previous detection state for transition detection
    FlightDetector::DetectionState m_previousState {FlightDetector::Idle};
 
    // Accumulated track points
    QList<TrackPoint> m_track;
 
    // Cached geo path kept in sync with m_track for O(1) reads
    QGeoPath m_geoPath;
 
    // Recording thresholds
    static constexpr auto minDistance = Units::Distance::fromM(300.0);
    static constexpr auto minTimeInterval = Units::Timespan::fromS(10);
    static constexpr int maxTrackPoints = 100'000; 
 
    // Tracks directory
    const QString m_trackDir {QStandardPaths::writableLocation(QStandardPaths::AppDataLocation) + u"/tracks"_s};
};
 
} // namespace Flightlog