VACLibrary.h

/***************************************************************************
 *   Copyright (C) 2024-2025 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 <QAbstractListModel>
#include <QFile>
#include <QProperty>
#include <QStandardPaths>
#include <QTimer>
 
#include "geomaps/VAC.h"
 
 
namespace GeoMaps
{

 
class VACLibrary : public QAbstractListModel
{
    Q_OBJECT
    QML_ELEMENT
    QML_SINGLETON
 
public:
    VACLibrary(QObject *parent = nullptr);

    ~VACLibrary() override;

    enum Role : int {
        VacRole = Qt::UserRole + 1,

        NameRole,

        SectionRole,

        CenterRole
    };
 
    //
    // Properties
    //

    Q_PROPERTY(bool hasManuallyImported READ hasManuallyImported BINDABLE bindableHasManuallyImported NOTIFY hasManuallyImportedChanged)
 
    
    Q_PROPERTY(bool isEmpty READ isEmpty BINDABLE bindableIsEmpty NOTIFY isEmptyChanged)

    Q_PROPERTY(QList<GeoMaps::VAC> vacs READ vacs NOTIFY vacsChanged)
 
 
    //
    // Getter Methods
    //

    [[nodiscard]] bool hasManuallyImported() const { return m_hasManuallyImported.value(); }

    [[nodiscard]] QBindable<bool> bindableHasManuallyImported() const { return &m_hasManuallyImported; }

    [[nodiscard]] bool isEmpty() const { return m_isEmpty.value(); }

    [[nodiscard]] QBindable<bool> bindableIsEmpty() const { return &m_isEmpty; }

    [[nodiscard]] QList<GeoMaps::VAC> vacs() const { return m_rows; }
 
 
    //
    // Model API
    //

    [[nodiscard]] int rowCount(const QModelIndex& parent = QModelIndex()) const override;

    [[nodiscard]] QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const override;

    [[nodiscard]] QHash<int, QByteArray> roleNames() const override;
 
 
    //
    // Methods
    //

    Q_INVOKABLE void clear();

    [[nodiscard]] Q_INVOKABLE GeoMaps::VAC get(const QString& name);

    [[nodiscard]] Q_INVOKABLE QString importTripKit(const QString& fileName);

    [[nodiscard]] Q_INVOKABLE GeoMaps::VAC materialize(const GeoMaps::VAC& vac);

    [[nodiscard]] Q_INVOKABLE QString importVAC(GeoMaps::VAC vac);

    Q_INVOKABLE void remove(const QString& name);

    [[nodiscard]] Q_INVOKABLE QString rename(const QString& oldName, const QString& newName);

    [[nodiscard]] Q_INVOKABLE QVector<GeoMaps::VAC> vacs4Point(const QGeoCoordinate& position);
 
signals:
    void hasManuallyImportedChanged();

    void isEmptyChanged();

    void vacsChanged();

    void importTripKitStatus(double percent);
 
private:
    Q_DISABLE_COPY_MOVE(VACLibrary)
 
    // This method cleans the VAC directory. It deletes all VAC from m_vacs that
    // have no raster image files. It looks for unmanaged raster image files and
    // either imports them or moves them to the subdirectory "unrecognised".
    void janitor();
 
    // This method re-reads the chart index from all VAC collection files
    // managed by DataManagement::DataManager, rebuilds m_collectionVacs and
    // deletes stale entries from the extraction cache.
    void updateCollections();
 
    // This method saves m_vacs to m_dataFileName, atomically.
    void save();
 
    // This method returns the absolute path of a given VAC. Needed for iOS
    // after App Update. See GeoMaps::VACLibrary::janitor
    QString absolutePathForVac(const GeoMaps::VAC&);
    QString absolutePathForVac(const QString& name);
 
    // Replaces the manually imported charts and rebuilds the model rows
    void setManualVacs(const QVector<GeoMaps::VAC>& vacs);
 
    // Replaces the charts from VAC collections and rebuilds the model rows
    void setCollectionVacs(const QVector<GeoMaps::VAC>& vacs);
 
    // Recomputes m_rows from m_vacs and m_collectionVacs, announces the
    // difference with row-granular model signals, updates the derived
    // properties and emits vacsChanged() if anything changed.
    void rebuildRows();
 
    // Sort order of the model rows: by section, then by name, then by file
    // name, so that distinct charts never compare equal
    static bool lessThan(const GeoMaps::VAC& first, const GeoMaps::VAC& second);
 
    // Source data: manually imported charts and charts from VAC collections.
    // Mutations go through setManualVacs() and setCollectionVacs(): modify a
    // local copy, then assign it back in a single call.
    QVector<GeoMaps::VAC> m_vacs;
    QVector<GeoMaps::VAC> m_collectionVacs;
 
    // Model rows: m_vacs and m_collectionVacs together, sorted with lessThan()
    QVector<GeoMaps::VAC> m_rows;
 
    // Derived properties, updated by rebuildRows()
    Q_OBJECT_BINDABLE_PROPERTY(GeoMaps::VACLibrary, bool, m_isEmpty, &GeoMaps::VACLibrary::isEmptyChanged)
    Q_OBJECT_BINDABLE_PROPERTY(GeoMaps::VACLibrary, bool, m_hasManuallyImported, &GeoMaps::VACLibrary::hasManuallyImportedChanged)
 
    QString m_vacDirectory {QStandardPaths::writableLocation(QStandardPaths::AppDataLocation) + u"/VAC"_s};
    QString m_cacheDirectory {QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + u"/VAC"_s};
    QString m_dataFileName {QStandardPaths::writableLocation(QStandardPaths::AppDataLocation) + u"/VAC.data"_s};
 
    // Compresses multiple change notifications from DataManager into a single
    // call to updateCollections()
    QTimer m_updateCollectionsTimer;
 
};
 
} // namespace GeoMaps