qtdoc/examples/demos/osmbuildings/request.cpp

// Copyright (C) 2023 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

#include "request.h"

#include <QFileInfo>
#include <QGeoPolygon>
#include <QJsonDocument>
#include <QJsonObject>
#include <QNetworkReply>

QGeoCoordinate importPosition(const QVariant &position)
{
    QGeoCoordinate returnedCoordinates;
    const QVariantList positionList = position.value<QVariantList>();
    for (qsizetype i  = 0; i < positionList.size(); ++i) { // Iterating Point coordinates arrays
        double value = positionList.at(i).toDouble();
        switch (i) {
        case 0:
            returnedCoordinates.setLongitude(value);
            break;
        case 1:
            returnedCoordinates.setLatitude(value);
            break;
        case 2:
            returnedCoordinates.setAltitude(value);
            break;
        default:
            break;
        }
    }
    return returnedCoordinates;
}

QList<QGeoCoordinate> importArrayOfPositions(const QVariant &arrayOfPositions)
{
    QList<QGeoCoordinate> returnedCoordinates;
    const QVariantList positionsList = arrayOfPositions.value<QVariantList>();
    for (const auto &position : positionsList) // Iterating the LineString coordinates nested arrays
    {
        QGeoCoordinate coordinate = importPosition(position);
        if ( coordinate.isValid() )
            returnedCoordinates.append(coordinate); // Populating the QList of coordinates
    }
    return returnedCoordinates;
}

QList<QList<QGeoCoordinate>> importArrayOfArrayOfPositions(const QVariant &arrayOfArrayofPositions)
{
    QList<QList<QGeoCoordinate>> returnedCoordinates;
    const QVariantList positionsList = arrayOfArrayofPositions.value<QVariantList>();
    for (const QVariant &position : positionsList) // Iterating the Polygon coordinates nested arrays
        returnedCoordinates << importArrayOfPositions(position);
    return returnedCoordinates;
}


QGeoPolygon importPolygon(const QVariantMap &inputMap)
{
    QGeoPolygon returnedObject;
    const QVariant valueCoordinates = inputMap.value(QStringLiteral("coordinates"));
    const QList<QList<QGeoCoordinate>> perimeters = importArrayOfArrayOfPositions(valueCoordinates);
    for (qsizetype i  = 0; i < perimeters.size(); ++i) { // Import an array of QList<QGeocoordinates>
        if (i == 0)
            returnedObject.setPerimeter(perimeters.at(i)); // External perimeter
        else
            returnedObject.addHole(perimeters.at(i)); // Inner perimeters
    }
    return returnedObject;
}

QVariantMap importGeometry(const QVariantMap &inputMap)
{
    QVariantMap returnedObject;

    const int geometryTypesLen = 1;
    QString geometryTypes[] = {
        QStringLiteral("Polygon"),
    };
    enum geoTypeSwitch {
        Polygon,
    };
    for (int i = 0; i < geometryTypesLen; ++i) {
    if (inputMap.value(QStringLiteral("type")).value<QString>() == geometryTypes[i]) {
        switch (i) {
        case Polygon: {
            returnedObject.insert(QStringLiteral("type"), QStringLiteral("Polygon"));
            returnedObject.insert(QStringLiteral("data"), QVariant::fromValue(importPolygon(inputMap)));
            break;
        }
        default:
            break;
        }
    }
    }
    return returnedObject;
}

static QVariantList importFeatureCollection(const QVariantMap &inputMap)
{
    QVariantList returnedObject;
    const QVariantList featuresList = inputMap.value(QStringLiteral("features")).value<QVariantList>();
    for (const QVariant &inputfeature : featuresList) {
        QVariantMap inputFeatureMap = inputfeature.value<QVariantMap>();
        QVariantMap singleFeatureMap = importGeometry(inputFeatureMap.value(QStringLiteral("geometry")).value<QVariantMap>());
        const QVariantMap importedProperties = inputFeatureMap.value(QStringLiteral("properties")).value<QVariantMap>();
        singleFeatureMap.insert(QStringLiteral("properties"), importedProperties);
        if (inputFeatureMap.contains(QStringLiteral("id"))) {
            QVariant importedId = inputFeatureMap.value(QStringLiteral("id")).value<QVariant>();
            singleFeatureMap.insert(QStringLiteral("id"), importedId);
        }
        returnedObject.append(singleFeatureMap);
    }
    return returnedObject;
}

static QVariantList importGeoJson(const QJsonDocument &geoJson)
{
    QVariantList returnedList;
    QJsonObject object = geoJson.object(); // Read json object from imported doc
    QVariantMap rootGeoJsonObject = object.toVariantMap(); // Extraced map using Qt's API

    const int geometryTypesLen = 3;
    QString geoType[] = {
        QStringLiteral("Polygon"),
        QStringLiteral("Feature"),
        QStringLiteral("FeatureCollection")
    };
    enum geoTypeSwitch {
        Polygon,
        Feature,
        FeatureCollection
    };
    QVariantMap parsedGeoJsonMap;

    // Checking whether the JSON object has a "type" member
    const QVariant keyVariant = rootGeoJsonObject.value(QStringLiteral("type"));
    QString valueType = keyVariant.value<QString>();

    // Checking whether the "type" member has a GeoJSON admitted value
    for (int i = 0; i < geometryTypesLen; ++i) {
        if (valueType == geoType[i]) {
            switch (i) {
            case Polygon: {
                QGeoPolygon poly = importPolygon(rootGeoJsonObject);
                QVariant dataNodeValue = QVariant::fromValue(poly);
                parsedGeoJsonMap.insert(QStringLiteral("type"), QStringLiteral("Polygon"));
                parsedGeoJsonMap.insert(QStringLiteral("data"), dataNodeValue);
                break;
            }
            // Single GeoJson geometry object with properties
            case Feature: {
                parsedGeoJsonMap = importGeometry(rootGeoJsonObject.value(QStringLiteral("geometry")).value<QVariantMap>());
                QVariantMap importedProperties = rootGeoJsonObject.value(QStringLiteral("properties")).value<QVariantMap>();
                parsedGeoJsonMap.insert(QStringLiteral("properties"), importedProperties);
                if (rootGeoJsonObject.contains(QStringLiteral("id"))){
                    QVariant importedId = rootGeoJsonObject.value(QStringLiteral("id")).value<QVariant>();
                    parsedGeoJsonMap.insert(QStringLiteral("id"), importedId);
                }
                break;
            }
            // Heterogeneous list of GeoJSON geometries with properties
            case FeatureCollection: {
                QVariantList featCollection = importFeatureCollection(rootGeoJsonObject);
                QVariant dataNodeValue = QVariant::fromValue(featCollection);
                parsedGeoJsonMap.insert(QStringLiteral("type"), QStringLiteral("FeatureCollection"));
                parsedGeoJsonMap.insert(QStringLiteral("data"), dataNodeValue);
                break;
            }
            default:
                break;
            }
            QVariant bboxNodeValue = rootGeoJsonObject.value(QStringLiteral("bbox"));
            if (bboxNodeValue.isValid()) {
                parsedGeoJsonMap.insert(QStringLiteral("bbox"), bboxNodeValue);
            }
            returnedList.append(parsedGeoJsonMap);
        } else if (i >= 9) {
            // Error
            break;
        }
    }
    return returnedList;
}


OSMRequest::OSMRequest(QObject *parent)
    : QObject{parent}
{
    connect( &m_queuesTimer, &QTimer::timeout, this, [this](){
        if ( m_buildingsQueue.isEmpty() && m_mapsQueue.isEmpty() ) {
            m_queuesTimer.stop();
        }
        else {

#ifdef QT_DEBUG
            const int numConcurrentRequests = 1;
#else
            const int numConcurrentRequests = 6;
#endif
            if ( !m_buildingsQueue.isEmpty() && m_buildingsNumberOfRequestsInFlight < numConcurrentRequests )
            {
                getBuildingsDataRequest(m_buildingsQueue.dequeue());
                ++m_buildingsNumberOfRequestsInFlight;
            }

            if ( !m_mapsQueue.isEmpty() && m_mapsNumberOfRequestsInFlight < numConcurrentRequests )
            {
                getMapsDataRequest(m_mapsQueue.dequeue());
                ++m_mapsNumberOfRequestsInFlight;
            }
        }
    });
    m_queuesTimer.setInterval(0);
}

void OSMRequest::getBuildingsData(const QQueue<OSMTileData> &buildingsQueue) {

    if ( buildingsQueue.isEmpty() )
        return;
    m_buildingsQueue = buildingsQueue;
    if ( !m_queuesTimer.isActive() )
        m_queuesTimer.start();
}

void OSMRequest::getBuildingsDataRequest(const OSMTileData &tile)
{
    QString fileName = "data/" + QString::number(tile.ZoomLevel) + "," + QString::number(tile.TileX) + ","
                       + QString::number(tile.TileY) + ".json";
    QFileInfo file(fileName);
    if ( file.size() )
    {
        QFile file(fileName);
        if (file.open(QFile::ReadOnly)){
            QByteArray data = file.readAll();
            file.close();
            emit buildingsDataReady( importGeoJson(QJsonDocument::fromJson( data )), tile.TileX, tile.TileY, tile.ZoomLevel );
            --m_buildingsNumberOfRequestsInFlight;
            return;
        }
    }

    QUrl url = QUrl(tr(m_uRL_OSMB_JSON).arg(QString::number(tile.ZoomLevel),QString::number(tile.TileX),QString::number(tile.TileY)) );
    QNetworkReply * reply = m_networkAccessManager.get( QNetworkRequest(url));
    connect( reply, &QNetworkReply::finished, this, [this, reply, tile, url](){
        reply->deleteLater();
        if ( reply->error() == QNetworkReply::NoError ) {
            QByteArray data = reply->readAll();
            emit buildingsDataReady( importGeoJson(QJsonDocument::fromJson( data )), tile.TileX, tile.TileY, tile.ZoomLevel );
        }else {
            qWarning() << "OSMRequest::getBuildingsData" << reply->error() << url;
        }
        --m_buildingsNumberOfRequestsInFlight;
    } );
}



void OSMRequest::getMapsData(const QQueue<OSMTileData> &mapsQueue) {

    if ( mapsQueue.isEmpty() )
        return;
    m_mapsQueue = mapsQueue;
    if ( !m_queuesTimer.isActive() )
        m_queuesTimer.start();
}

void OSMRequest::getMapsDataRequest(const OSMTileData &tile)
{
    QString fileName = "data/" + QString::number(tile.ZoomLevel) + "," + QString::number(tile.TileX)
                       + "," + QString::number(tile.TileY) + ".png";
    QFileInfo file(fileName);
    if ( file.size() )
    {
        QFile file(fileName);
        if (file.open(QFile::ReadOnly)){
            QByteArray data = file.readAll();
            file.close();
            emit mapsDataReady(  data, tile.TileX, tile.TileY, tile.ZoomLevel );
            --m_mapsNumberOfRequestsInFlight;
            return;
        }
    }

    QUrl url = QUrl(tr(m_uRL_OSMB_MAP).arg(QString::number(tile.ZoomLevel),QString::number(tile.TileX),QString::number(tile.TileY)) );
    QNetworkReply * reply = m_networkAccessManager.get( QNetworkRequest(url));
    connect( reply, &QNetworkReply::finished, this, [this, reply, tile, url](){
        reply->deleteLater();
        if ( reply->error() == QNetworkReply::NoError ) {
            QByteArray data = reply->readAll();
            emit mapsDataReady( data, tile.TileX, tile.TileY, tile.ZoomLevel );
        }else {
            qWarning() << "OSMRequest::getMapsDataRequest" << reply->error() << url;
        }
        --m_mapsNumberOfRequestsInFlight;
    } );
}