TerrainQuery.h

/****************************************************************************
 *
 *   (c) 2017 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
 *
 * QGroundControl is licensed according to the terms in the file
 * COPYING.md in the root of the source code directory.
 *
 ****************************************************************************/

#pragma once

#include "TerrainTile.h"
#include "QGCMapEngineData.h"
#include "QGCLoggingCategory.h"

#include <QObject>
#include <QGeoCoordinate>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QTimer>
#include <QtLocation/private/qgeotiledmapreply_p.h>

Q_DECLARE_LOGGING_CATEGORY(TerrainQueryLog)
Q_DECLARE_LOGGING_CATEGORY(TerrainQueryVerboseLog)

class TerrainAtCoordinateQuery;

/// Base class for offline/online terrain queries
class TerrainQueryInterface : public QObject
{
    Q_OBJECT

public:
    TerrainQueryInterface(QObject* parent) : QObject(parent) { }

    /// Request terrain heights for specified coodinates.
    /// Signals: coordinateHeights when data is available
    virtual void requestCoordinateHeights(const QList<QGeoCoordinate>& coordinates) = 0;

    /// Requests terrain heights along the path specified by the two coordinates.
    /// Signals: pathHeights
    ///     @param coordinates to query
    virtual void requestPathHeights(const QGeoCoordinate& fromCoord, const QGeoCoordinate& toCoord) = 0;

    /// Request terrain heights for the rectangular area specified.
    /// Signals: carpetHeights when data is available
    ///     @param swCoord South-West bound of rectangular area to query
    ///     @param neCoord North-East bound of rectangular area to query
    ///     @param statsOnly true: Return only stats, no carpet data
    virtual void requestCarpetHeights(const QGeoCoordinate& swCoord, const QGeoCoordinate& neCoord, bool statsOnly) = 0;

signals:
    void coordinateHeightsReceived(bool success, QList<double> heights);
    void pathHeightsReceived(bool success, double latStep, double lonStep, const QList<double>& heights);
    void carpetHeightsReceived(bool success, double minHeight, double maxHeight, const QList<QList<double>>& carpet);
};

/// AirMap online implementation of terrain queries
class TerrainAirMapQuery : public TerrainQueryInterface {
    Q_OBJECT

public:
    TerrainAirMapQuery(QObject* parent = nullptr);

    // Overrides from TerrainQueryInterface
    void requestCoordinateHeights   (const QList<QGeoCoordinate>& coordinates) final;
    void requestPathHeights         (const QGeoCoordinate& fromCoord, const QGeoCoordinate& toCoord) final;
    void requestCarpetHeights       (const QGeoCoordinate& swCoord, const QGeoCoordinate& neCoord, bool statsOnly) final;

private slots:
    void _requestError              (QNetworkReply::NetworkError code);
    void _requestFinished           (void);
    void _sslErrors                 (const QList<QSslError> &errors);

private:
    void _sendQuery                 (const QString& path, const QUrlQuery& urlQuery);
    void _requestFailed             (void);
    void _parseCoordinateData       (const QJsonValue& coordinateJson);
    void _parsePathData             (const QJsonValue& pathJson);
    void _parseCarpetData           (const QJsonValue& carpetJson);

    enum QueryMode {
        QueryModeCoordinates,
        QueryModePath,
        QueryModeCarpet
    };

    QNetworkAccessManager   _networkManager;
    QueryMode               _queryMode;
    bool                    _carpetStatsOnly;
};

/// AirMap offline cachable implementation of terrain queries
class TerrainOfflineAirMapQuery : public TerrainQueryInterface {
    Q_OBJECT

public:
    TerrainOfflineAirMapQuery(QObject* parent = nullptr);

    // Overrides from TerrainQueryInterface
    void requestCoordinateHeights(const QList<QGeoCoordinate>& coordinates) final;
    void requestPathHeights(const QGeoCoordinate& fromCoord, const QGeoCoordinate& toCoord) final;
    void requestCarpetHeights(const QGeoCoordinate& swCoord, const QGeoCoordinate& neCoord, bool statsOnly) final;

    // Internal methods
    void _signalCoordinateHeights(bool success, QList<double> heights);
    void _signalPathHeights(bool success, double latStep, double lonStep, const QList<double>& heights);
    void _signalCarpetHeights(bool success, double minHeight, double maxHeight, const QList<QList<double>>& carpet);
};

/// Used internally by TerrainOfflineAirMapQuery to manage terrain tiles
class TerrainTileManager : public QObject {
    Q_OBJECT

public:
    TerrainTileManager(void);

    void addCoordinateQuery (TerrainOfflineAirMapQuery* terrainQueryInterface, const QList<QGeoCoordinate>& coordinates);
    void addPathQuery       (TerrainOfflineAirMapQuery* terrainQueryInterface, const QGeoCoordinate& startPoint, const QGeoCoordinate& endPoint);