/* ============================================================
 *
 * This file is a part of digiKam project
 * https://www.digikam.org
 *
 * Date        : 2023-05-15
 * Description : geolocation engine based on Marble.
 *               (c) 2007-2022 Marble Team
 *               https://invent.kde.org/education/marble/-/raw/master/data/credits_authors.html
 *
 * SPDX-FileCopyrightText: 2023-2026 by Gilles Caulier <caulier dot gilles at gmail dot com>
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 *
 * ============================================================ */

#include "ViewportParams.h"

// Qt includes

#include <QRect>
#include <QPainterPath>
#include <QRegion>

// Local includes

#include "GeoDataLatLonAltBox.h"
#include "SphericalProjection.h"
#include "EquirectProjection.h"
#include "MercatorProjection.h"
#include "GnomonicProjection.h"
#include "LambertAzimuthalProjection.h"
#include "AzimuthalEquidistantProjection.h"
#include "StereographicProjection.h"
#include "VerticalPerspectiveProjection.h"
#include "digikam_debug.h"

namespace Marble
{

class Q_DECL_HIDDEN ViewportParamsPrivate
{
public:

    ViewportParamsPrivate(Projection projection,
                          qreal centerLongitude, qreal centerLatitude,
                          int radius,
                          const QSize& size);

    static const AbstractProjection* abstractProjection(Projection projection);

    // These two go together.  m_currentProjection points to one of
    // the static Projection classes at the bottom.
    Projection           m_projection;
    const AbstractProjection* m_currentProjection;

    // Parameters that determine the painting
    qreal                m_centerLongitude;
    qreal                m_centerLatitude;
    qreal                m_heading;
    Quaternion           m_planetAxis;   // Position, coded in a quaternion
    matrix               m_planetAxisMatrix;
    int                  m_radius;       // Zoom level (pixels / globe radius)
    qreal                m_angularResolution;

    QSize                m_size;         // width, height


    bool                 m_dirtyBox;
    GeoDataLatLonAltBox  m_viewLatLonAltBox;

    static const SphericalProjection  s_sphericalProjection;
    static const EquirectProjection   s_equirectProjection;
    static const MercatorProjection   s_mercatorProjection;
    static const GnomonicProjection   s_gnomonicProjection;
    static const StereographicProjection   s_stereographicProjection;
    static const LambertAzimuthalProjection   s_lambertAzimuthalProjection;
    static const AzimuthalEquidistantProjection   s_azimuthalEquidistantProjection;
    static const VerticalPerspectiveProjection   s_verticalPerspectiveProjection;

    GeoDataCoordinates   m_focusPoint;
};

const SphericalProjection  ViewportParamsPrivate::s_sphericalProjection;
const EquirectProjection   ViewportParamsPrivate::s_equirectProjection;
const MercatorProjection   ViewportParamsPrivate::s_mercatorProjection;
const GnomonicProjection   ViewportParamsPrivate::s_gnomonicProjection;
const StereographicProjection   ViewportParamsPrivate::s_stereographicProjection;
const LambertAzimuthalProjection   ViewportParamsPrivate::s_lambertAzimuthalProjection;
const AzimuthalEquidistantProjection   ViewportParamsPrivate::s_azimuthalEquidistantProjection;
const VerticalPerspectiveProjection   ViewportParamsPrivate::s_verticalPerspectiveProjection;

ViewportParamsPrivate::ViewportParamsPrivate(Projection projection,
                                             qreal centerLongitude, qreal centerLatitude,
                                             int radius,
                                             const QSize& size)
    : m_projection(projection),
      m_currentProjection(abstractProjection(projection)),
      m_centerLongitude(centerLongitude),
      m_centerLatitude(centerLatitude),
      m_heading(0),
      m_planetAxis(),
      m_planetAxisMatrix(),
      m_radius(radius),
      m_angularResolution(4.0 / abs(m_radius)),
      m_size(size),
      m_dirtyBox(true),
      m_viewLatLonAltBox()
{
}

const AbstractProjection* ViewportParamsPrivate::abstractProjection(Projection projection)
{
    switch (projection)
    {
        case Spherical:
            return &s_sphericalProjection;

        case Equirectangular:
            return &s_equirectProjection;

        case Mercator:
            return &s_mercatorProjection;

        case Gnomonic:
            return &s_gnomonicProjection;

        case Stereographic:
            return &s_stereographicProjection;

        case LambertAzimuthal:
            return &s_lambertAzimuthalProjection;

        case AzimuthalEquidistant:
            return &s_azimuthalEquidistantProjection;

        case VerticalPerspective:
            return &s_verticalPerspectiveProjection;
    }

    return nullptr;
}


ViewportParams::ViewportParams()
    : d(new ViewportParamsPrivate(Spherical, 0, 0, 2000, QSize(100, 100)))
{
    centerOn(d->m_centerLongitude, d->m_centerLatitude);
}

ViewportParams::ViewportParams(Projection projection,
                               qreal centerLongitude, qreal centerLatitude,
                               int radius,
                               const QSize& size)
    : d(new ViewportParamsPrivate(projection, centerLongitude, centerLatitude, radius, size))
{
    centerOn(d->m_centerLongitude, d->m_centerLatitude);
}

ViewportParams::~ViewportParams()
{
    delete d;
}


// ================================================================
//                    Getters and setters


Projection ViewportParams::projection() const
{
    return d->m_projection;
}

const AbstractProjection* ViewportParams::currentProjection() const
{
    return d->m_currentProjection;
}

void ViewportParams::setProjection(Projection newProjection)
{
    d->m_projection = newProjection;
    d->m_currentProjection = ViewportParamsPrivate::abstractProjection(newProjection);

    // We now need to reset the planetAxis to make sure
    // that it's a valid axis orientation!
    // So this line is important (although it might look odd) ! :
    centerOn(d->m_centerLongitude, d->m_centerLatitude);
}

int ViewportParams::polarity() const
{
    // For mercator this just gives the extreme latitudes
    // instead of the actual poles but it works fine as well:
    GeoDataCoordinates northPole(0.0, +currentProjection()->maxLat());
    GeoDataCoordinates southPole(0.0, -currentProjection()->maxLat());

    bool globeHidesN, globeHidesS;
    qreal x;
    qreal yN, yS;

    currentProjection()->screenCoordinates(northPole, this,
                                           x, yN, globeHidesN);
    currentProjection()->screenCoordinates(southPole, this,
                                           x, yS, globeHidesS);

    int polarity = 0;

    // case of the flat map:
    if (!globeHidesN && !globeHidesS)
    {
        if (yN < yS)
        {
            polarity = +1;
        }

        if (yS < yN)
        {
            polarity = -1;
        }
    }

    else
    {
        if (!globeHidesN && yN < height() / 2)
        {
            polarity = +1;
        }

        if (!globeHidesN && yN > height() / 2)
        {
            polarity = -1;
        }

        if (!globeHidesS && yS > height() / 2)
        {
            polarity = +1;
        }

        if (!globeHidesS && yS < height() / 2)
        {
            polarity = -1;
        }
    }

    return polarity;
}

int ViewportParams::radius() const
{
    return d->m_radius;
}

void ViewportParams::setRadius(int newRadius)
{
    if (newRadius > 0)
    {
        d->m_dirtyBox = true;

        d->m_radius = newRadius;
        d->m_angularResolution = 4.0 / d->m_radius;
    }
}

void ViewportParams::centerOn(qreal lon, qreal lat)
{
    if (!d->m_currentProjection->traversablePoles())
    {
        if (lat > d->m_currentProjection->maxLat())
        {
            lat = d->m_currentProjection->maxLat();
        }

        if (lat < d->m_currentProjection->minLat())
        {
            lat = d->m_currentProjection->minLat();
        }
    }

    else
    {
        while (lat > M_PI)
        {
            lat -= 2 * M_PI;
        }

        while (lat < -M_PI)
        {
            lat += 2 * M_PI;
        }
    }

    while (lon > M_PI)
    {
        lon -= 2 * M_PI;
    }

    while (lon < -M_PI)
    {
        lon += 2 * M_PI;
    }

    d->m_centerLongitude = lon;
    d->m_centerLatitude = lat;

    const Quaternion roll = Quaternion::fromEuler(0, 0, d->m_heading);
    const Quaternion quat = Quaternion::fromEuler(-lat, lon, 0.0);

    d->m_planetAxis = quat * roll;
    d->m_planetAxis.normalize();

    d->m_dirtyBox = true;
    d->m_planetAxis.inverse().toMatrix(d->m_planetAxisMatrix);
    d->m_planetAxis.normalize();
}

void ViewportParams::setHeading(qreal heading)
{
    d->m_heading = heading;

    const Quaternion roll = Quaternion::fromEuler(0, 0, heading);

    const qreal centerLat = centerLatitude();
    const qreal centerLon = centerLongitude();

    const Quaternion quat = Quaternion::fromEuler(-centerLat, centerLon, 0);

    d->m_planetAxis = quat * roll;
    d->m_planetAxis.normalize();

    d->m_dirtyBox = true;
    d->m_planetAxis.inverse().toMatrix(d->m_planetAxisMatrix);
    d->m_planetAxis.normalize();
}

qreal ViewportParams::heading() const
{
    return d->m_heading;
}

Quaternion ViewportParams::planetAxis() const
{
    return d->m_planetAxis;
}

const matrix& ViewportParams::planetAxisMatrix() const
{
    return d->m_planetAxisMatrix;
}

int ViewportParams::width()  const
{
    return d->m_size.width();
}

int ViewportParams::height() const
{
    return d->m_size.height();
}

QSize ViewportParams::size() const
{
    return d->m_size;
}


void ViewportParams::setWidth(int newWidth)
{
    setSize(QSize(newWidth, height()));
}

void ViewportParams::setHeight(int newHeight)
{
    setSize(QSize(width(), newHeight));
}

void ViewportParams::setSize(const QSize& newSize)
{
    if (newSize == d->m_size)
    {
        return;
    }

    d->m_dirtyBox = true;

    d->m_size = newSize;
}

// ================================================================
//                        Other functions

qreal ViewportParams::centerLongitude() const
{
    return d->m_centerLongitude;
}

qreal ViewportParams::centerLatitude() const
{
    return d->m_centerLatitude;
}

const GeoDataLatLonAltBox& ViewportParams::viewLatLonAltBox() const
{
    if (d->m_dirtyBox)
    {
        d->m_viewLatLonAltBox = d->m_currentProjection->latLonAltBox(QRect(QPoint(0, 0),
                                                                           d->m_size),
                                                                     this);
        d->m_dirtyBox = false;
    }

    return d->m_viewLatLonAltBox;
}

GeoDataLatLonAltBox ViewportParams::latLonAltBox(const QRect& screenRect) const
{
    return d->m_currentProjection->latLonAltBox(screenRect, this);
}

qreal ViewportParams::angularResolution() const
{
    // We essentially divide the diameter by 180 deg and
    // take half of the result as a guess for the angle per pixel resolution.
    // d->m_angularResolution = 0.25 * M_PI / fabs( (qreal)(d->m_radius);
    return d->m_angularResolution;
}

bool ViewportParams::resolves(const GeoDataLatLonBox& latLonBox, qreal pixel) const
{
    return latLonBox.width() + latLonBox.height() > pixel * d->m_angularResolution;
}


bool ViewportParams::resolves(const GeoDataLatLonAltBox& latLonAltBox, qreal pixel, qreal altitude) const
{
    return    latLonAltBox.width() + latLonAltBox.height() > pixel * d->m_angularResolution
              || latLonAltBox.maxAltitude() - latLonAltBox.minAltitude() > altitude;
}

bool ViewportParams::resolves(const GeoDataCoordinates& coord1,
                              const GeoDataCoordinates& coord2) const
{
    qreal lon1, lat1;
    coord1.geoCoordinates(lon1, lat1);

    qreal lon2, lat2;
    coord2.geoCoordinates(lon2, lat2);

    // We take the manhattan length as an approximation for the distance
    return (fabs(lon2 - lon1) + fabs(lat2 - lat1) > d->m_angularResolution);
}


bool ViewportParams::screenCoordinates(const qreal lon, const qreal lat,
                                       qreal& x, qreal& y) const
{
    return d->m_currentProjection->screenCoordinates(lon, lat, this, x, y);
}

bool ViewportParams::screenCoordinates(const GeoDataCoordinates& geopoint,
                                       qreal& x, qreal& y,
                                       bool& globeHidesPoint) const
{
    return d->m_currentProjection->screenCoordinates(geopoint, this, x, y, globeHidesPoint);
}

bool ViewportParams::screenCoordinates(const GeoDataCoordinates& geopoint,
                                       qreal& x, qreal& y) const
{
    return d->m_currentProjection->screenCoordinates(geopoint, this, x, y);
}

bool ViewportParams::screenCoordinates(const GeoDataCoordinates& coordinates,
                                       qreal* x, qreal& y, int& pointRepeatNum,
                                       const QSizeF& size,
                                       bool& globeHidesPoint) const
{
    return d->m_currentProjection->screenCoordinates(coordinates, this, x, y, pointRepeatNum, size, globeHidesPoint);
}


bool ViewportParams::screenCoordinates(const GeoDataLineString& lineString,
                                       QVector<QPolygonF*>& polygons) const
{
    return d->m_currentProjection->screenCoordinates(lineString, this, polygons);
}

bool ViewportParams::geoCoordinates(const int x, const int y,
                                    qreal& lon, qreal& lat,
                                    GeoDataCoordinates::Unit unit) const
{
    return d->m_currentProjection->geoCoordinates(x, y, this, lon, lat, unit);
}

bool  ViewportParams::mapCoversViewport() const
{
    return d->m_currentProjection->mapCoversViewport(this);
}

QPainterPath ViewportParams::mapShape() const
{
    return d->m_currentProjection->mapShape(this);
}

QRegion ViewportParams::mapRegion() const
{
    return d->m_currentProjection->mapRegion(this);
}

GeoDataCoordinates ViewportParams::focusPoint() const
{
    if (d->m_focusPoint.isValid())
    {
        return d->m_focusPoint;
    }

    else
    {
        const qreal lon = d->m_centerLongitude;
        const qreal lat = d->m_centerLatitude;

        return GeoDataCoordinates(lon, lat, 0.0, GeoDataCoordinates::Radian);
    }

}

void ViewportParams::setFocusPoint(const GeoDataCoordinates& focusPoint)
{
    d->m_focusPoint = focusPoint;
}

void ViewportParams::resetFocusPoint()
{
    d->m_focusPoint = GeoDataCoordinates();
}

} // namespace Marble
