/******************************************************************************
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  OGRSpatialReference translation to/from "Panorama" GIS
 *           georeferencing information (also know as GIS "Integration").
 * Author:   Andrey Kiselev, dron@ak4719.spb.edu
 *
 ******************************************************************************
 * Copyright (c) 2005, Andrey Kiselev <dron@ak4719.spb.edu>
 * Copyright (c) 2008-2012, Even Rouault <even dot rouault at spatialys.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/

#include "ogr_spatialref.h"
#include "cpl_conv.h"
#include "cpl_csv.h"
#include "ogr_p.h"

#include <cmath>

constexpr double TO_DEGREES = 57.2957795130823208766;
constexpr double TO_RADIANS = 0.017453292519943295769;

// XXX: this macro computes zone number from the central meridian parameter.
// Note, that "Panorama" parameters are set in radians.
// In degrees it means formula:
//
//              zone = (central_meridian + 3) / 6
//
static int TO_ZONE(double x)
{
    return static_cast<int>((x + 0.05235987755982989) / 0.1047197551196597 +
                            0.5);
}

/************************************************************************/
/*  "Panorama" projection codes.                                        */
/************************************************************************/

constexpr long PAN_PROJ_NONE = -1L;
constexpr long PAN_PROJ_TM = 1L;       // Gauss-Kruger (Transverse Mercator)
constexpr long PAN_PROJ_LCC = 2L;      // Lambert Conformal Conic 2SP
constexpr long PAN_PROJ_STEREO = 5L;   // Stereographic
constexpr long PAN_PROJ_AE = 6L;       // Azimuthal Equidistant (Postel)
constexpr long PAN_PROJ_MERCAT = 8L;   // Mercator
constexpr long PAN_PROJ_POLYC = 10L;   // Polyconic
constexpr long PAN_PROJ_PS = 13L;      // Polar Stereographic
constexpr long PAN_PROJ_GNOMON = 15L;  // Gnomonic
constexpr long PAN_PROJ_UTM = 17L;     // Universal Transverse Mercator (UTM)
constexpr long PAN_PROJ_WAG1 = 18L;    // Wagner I (Kavraisky VI)
constexpr long PAN_PROJ_MOLL = 19L;    // Mollweide
constexpr long PAN_PROJ_EC = 20L;      // Equidistant Conic
constexpr long PAN_PROJ_LAEA = 24L;    // Lambert Azimuthal Equal Area
constexpr long PAN_PROJ_EQC = 27L;     // Equirectangular
constexpr long PAN_PROJ_CEA = 28L;     // Cylindrical Equal Area (Lambert)
constexpr long PAN_PROJ_IMWP = 29L;  // International Map of the World Polyconic
constexpr long PAN_PROJ_MILLER = 34L;  // Miller
/************************************************************************/
/*  "Panorama" datum codes.                                             */
/************************************************************************/

constexpr long PAN_DATUM_NONE = -1L;
constexpr long PAN_DATUM_PULKOVO42 = 1L;  // Pulkovo 1942
constexpr long PAN_DATUM_WGS84 = 2L;      // WGS84

/************************************************************************/
/*  "Panorama" ellipsoid codes.                                         */
/************************************************************************/

constexpr long PAN_ELLIPSOID_NONE = -1L;
constexpr long PAN_ELLIPSOID_KRASSOVSKY = 1L;  // Krassovsky, 1940
// constexpr long PAN_ELLIPSOID_WGS72       = 2L;  // WGS, 1972
// constexpr long PAN_ELLIPSOID_INT1924     = 3L;  // International, 1924
// (Hayford, 1909) constexpr long PAN_ELLIPSOID_CLARCKE1880 = 4L;  // Clarke,
// 1880 constexpr long PAN_ELLIPSOID_CLARCKE1866 = 5L;  // Clarke, 1866
// (NAD1927) constexpr long PAN_ELLIPSOID_EVEREST1830 = 6L;  // Everest, 1830
// constexpr long PAN_ELLIPSOID_BESSEL1841  = 7L;  // Bessel, 1841
// constexpr long PAN_ELLIPSOID_AIRY1830    = 8L;  // Airy, 1830
constexpr long PAN_ELLIPSOID_WGS84 = 9L;     // WGS, 1984 (GPS)
constexpr long PAN_ELLIPSOID_GSK2011 = 46L;  // GSK-2011
constexpr long PAN_ELLIPSOID_PZ90 = 47L;     // PZ90

/************************************************************************/
/*  Correspondence between "Panorama" and EPSG datum codes.             */
/************************************************************************/

constexpr int aoDatums[] = {
    0,
    4284,  // Pulkovo, 1942
    4326,  // WGS, 1984,
    4277,  // OSGB 1936 (British National Grid)
    0,    0, 0, 0, 0,
    4200  // Pulkovo, 1995
};

#define NUMBER_OF_DATUMS static_cast<long>(CPL_ARRAYSIZE(aoDatums))

/************************************************************************/
/*  Correspondence between "Panorama" and EPSG ellipsoid codes.         */
/************************************************************************/

constexpr int aoEllips[] = {
    0,
    7024,  // Krassovsky, 1940
    7043,  // WGS, 1972
    7022,  // International, 1924 (Hayford, 1909)
    7034,  // Clarke, 1880
    7008,  // Clarke, 1866 (NAD1927)
    7015,  // Everest, 1830
    7004,  // Bessel, 1841
    7001,  // Airy, 1830
    7030,  // WGS, 1984 (GPS)
    0,     // FIXME: PZ90.02
    7019,  // GRS, 1980 (NAD1983)
    7022,  // International, 1924 (Hayford, 1909) XXX?
    7036,  // South American, 1969
    7021,  // Indonesian, 1974
    7020,  // Helmert 1906
    0,     // FIXME: Fisher 1960
    0,     // FIXME: Fisher 1968
    0,     // FIXME: Haff 1960
    7042,  // Everest, 1830
    7003   // Australian National, 1965
};

constexpr int NUMBER_OF_ELLIPSOIDS = static_cast<int>(CPL_ARRAYSIZE(aoEllips));

/************************************************************************/
/*  Correspondence between "Panorama" and EPSG vertical CS.             */
/************************************************************************/

constexpr int aoVCS[] = {
    0,
    8357,  // 1
    5711,  // 2
    0,     // 3
    5710,  // 4
    5710,  // 5
    0,     // 6
    0,     // 7
    0,     // 8
    0,     // 9
    5716,  // 10
    5733,  // 11
    0,     // 12
    0,     // 13
    0,     // 14
    0,     // 15
    5709,  // 16
    5776,  // 17
    0,     // 18
    0,     // 19
    5717,  // 20
    5613,  // 21
    0,     // 22
    5775,  // 23
    5702,  // 24
    5705,  // 25
    0,     // 26
    5714   // 27
};

constexpr int NUMBER_OF_VERTICALCS = (sizeof(aoVCS) / sizeof(aoVCS[0]));

/************************************************************************/
/*                        OSRImportFromPanorama()                       */
/************************************************************************/

/** Import coordinate system from "Panorama" GIS projection definition.
 *
 * See OGRSpatialReference::importFromPanorama()
 */

OGRErr OSRImportFromPanorama(OGRSpatialReferenceH hSRS, long iProjSys,
                             long iDatum, long iEllips, double *padfPrjParams)

{
    VALIDATE_POINTER1(hSRS, "OSRImportFromPanorama", OGRERR_FAILURE);

    return reinterpret_cast<OGRSpatialReference *>(hSRS)->importFromPanorama(
        iProjSys, iDatum, iEllips, padfPrjParams);
}

/************************************************************************/
/*                          importFromPanorama()                        */
/************************************************************************/

/**
 * Import coordinate system from "Panorama" GIS projection definition.
 *
 * This method will import projection definition in style, used by
 * "Panorama" GIS.
 *
 * This function is the equivalent of the C function OSRImportFromPanorama().
 *
 * @param iProjSys Input projection system code, used in GIS "Panorama".
 *
 * Supported Projections are:
 * <ul>
 * <li>1:  Gauss-Kruger (Transverse Mercator)</li>
 * <li>2:  Lambert Conformal Conic 2SP</li>
 * <li>5:  Stereographic</li>
 * <li>6:  Azimuthal Equidistant (Postel)</li>
 * <li>8:  Mercator</li>
 * <li>10: Polyconic</li>
 * <li>13: Polar Stereographic</li>
 * <li>15: Gnomonic</li>
 * <li>17: Universal Transverse Mercator (UTM)</li>
 * <li>18: Wagner I (Kavraisky VI)</li>
 * <li>19: Mollweide</li>
 * <li>20: Equidistant Conic</li>
 * <li>24: Lambert Azimuthal Equal Area</li>
 * <li>27: Equirectangular</li>
 * <li>28: Cylindrical Equal Area (Lambert)</li>
 * <li>29: International Map of the World Polyconic</li>
 * </ul>
 *
 * @param iDatum Input coordinate system.
 *
 * Supported Datums are:
 * <ul>
 * <li>1: Pulkovo, 1942</li>
 * <li>2: WGS, 1984</li>
 * <li>3: OSGB 1936 (British National Grid)</li>
 * <li>9: Pulkovo, 1995</li>
 * </ul>
 *
 * @param iEllips Input spheroid.
 *
 * Supported Spheroids are:
 * <ul>
 * <li>1: Krassovsky, 1940</li>
 * <li>2: WGS, 1972</li>
 * <li>3: International, 1924 (Hayford, 1909)</li>
 * <li>4: Clarke, 1880</li>
 * <li>5: Clarke, 1866 (NAD1927)</li>
 * <li>6: Everest, 1830</li>
 * <li>7: Bessel, 1841</li>
 * <li>8: Airy, 1830</li>
 * <li>9: WGS, 1984 (GPS)</li>
 * </ul>
 *
 * @param padfPrjParams Array of 8 coordinate system parameters:
 *
 * <ul>
 * <li>[0]  Latitude of the first standard parallel (radians)</li>
 * <li>[1]  Latitude of the second standard parallel (radians)</li>
 * <li>[2]  Latitude of center of projection (radians)</li>
 * <li>[3]  Longitude of center of projection (radians)</li>
 * <li>[4]  Scaling factor</li>
 * <li>[5]  False Easting</li>
 * <li>[6]  False Northing</li>
 * <li>[7]  Zone number</li>
 * </ul>
 *
 * Particular projection uses different parameters, unused ones may be set to
 * zero. If NULL supplied instead of array pointer default values will be used
 * (i.e., zeroes).
 *
 * @return OGRERR_NONE on success or an error code in case of failure.
 */

OGRErr OGRSpatialReference::importFromPanorama(long iProjSys, long iDatum,
                                               long iEllips,
                                               double *padfPrjParams)

{
    Clear();

    /* -------------------------------------------------------------------- */
    /*      Use safe defaults if projection parameters are not supplied.    */
    /* -------------------------------------------------------------------- */
    bool bProjAllocated = false;

    if (padfPrjParams == nullptr)
    {
        padfPrjParams = static_cast<double *>(CPLMalloc(8 * sizeof(double)));
        if (!padfPrjParams)
            return OGRERR_NOT_ENOUGH_MEMORY;
        for (int i = 0; i < 7; i++)
            padfPrjParams[i] = 0.0;
        bProjAllocated = true;
    }

    /* -------------------------------------------------------------------- */
    /*      Operate on the basis of the projection code.                    */
    /* -------------------------------------------------------------------- */
    switch (iProjSys)
    {
        case PAN_PROJ_NONE:
            break;

        case PAN_PROJ_UTM:
        {
            const int nZone = padfPrjParams[7] == 0.0
                                  ? TO_ZONE(padfPrjParams[3])
                                  : static_cast<int>(padfPrjParams[7]);

            // XXX: no way to determine south hemisphere. Always assume
            // northern hemisphere.
            SetUTM(nZone, TRUE);
        }
        break;

        case PAN_PROJ_WAG1:
            SetWagner(1, 0.0, padfPrjParams[5], padfPrjParams[6]);
            break;

        case PAN_PROJ_MERCAT:
            SetMercator(TO_DEGREES * padfPrjParams[0],
                        TO_DEGREES * padfPrjParams[3], padfPrjParams[4],
                        padfPrjParams[5], padfPrjParams[6]);
            break;

        case PAN_PROJ_PS:
            SetPS(TO_DEGREES * padfPrjParams[2], TO_DEGREES * padfPrjParams[3],
                  padfPrjParams[4], padfPrjParams[5], padfPrjParams[6]);
            break;

        case PAN_PROJ_POLYC:
            SetPolyconic(TO_DEGREES * padfPrjParams[2],
                         TO_DEGREES * padfPrjParams[3], padfPrjParams[5],
                         padfPrjParams[6]);
            break;

        case PAN_PROJ_EC:
            SetEC(TO_DEGREES * padfPrjParams[0], TO_DEGREES * padfPrjParams[1],
                  TO_DEGREES * padfPrjParams[2], TO_DEGREES * padfPrjParams[3],
                  padfPrjParams[5], padfPrjParams[6]);
            break;

        case PAN_PROJ_LCC:
            SetLCC(TO_DEGREES * padfPrjParams[0], TO_DEGREES * padfPrjParams[1],
                   TO_DEGREES * padfPrjParams[2], TO_DEGREES * padfPrjParams[3],
                   padfPrjParams[5], padfPrjParams[6]);
            break;

        case PAN_PROJ_TM:
        {
            // XXX: we need zone number to compute false easting
            // parameter, because usually it is not contained in the
            // "Panorama" projection definition.
            // FIXME: what to do with negative values?
            int nZone = 0;
            double dfCenterLong = 0.0;

            if (padfPrjParams[7] == 0.0)
            {
                nZone = TO_ZONE(padfPrjParams[3]);
                dfCenterLong = TO_DEGREES * padfPrjParams[3];
            }
            else
            {
                nZone = static_cast<int>(padfPrjParams[7]);
                dfCenterLong = 6.0 * nZone - 3.0;
            }

            padfPrjParams[5] = nZone * 1000000.0 + 500000.0;
            padfPrjParams[4] = 1.0;
            SetTM(TO_DEGREES * padfPrjParams[2], dfCenterLong, padfPrjParams[4],
                  padfPrjParams[5], padfPrjParams[6]);
        }
        break;

        case PAN_PROJ_STEREO:
            SetStereographic(TO_DEGREES * padfPrjParams[2],
                             TO_DEGREES * padfPrjParams[3], padfPrjParams[4],
                             padfPrjParams[5], padfPrjParams[6]);
            break;

        case PAN_PROJ_AE:
            SetAE(TO_DEGREES * padfPrjParams[0], TO_DEGREES * padfPrjParams[3],
                  padfPrjParams[5], padfPrjParams[6]);
            break;

        case PAN_PROJ_GNOMON:
            SetGnomonic(TO_DEGREES * padfPrjParams[2],
                        TO_DEGREES * padfPrjParams[3], padfPrjParams[5],
                        padfPrjParams[6]);
            break;

        case PAN_PROJ_MOLL:
            SetMollweide(TO_DEGREES * padfPrjParams[3], padfPrjParams[5],
                         padfPrjParams[6]);
            break;

        case PAN_PROJ_LAEA:
            SetLAEA(TO_DEGREES * padfPrjParams[0],
                    TO_DEGREES * padfPrjParams[3], padfPrjParams[5],
                    padfPrjParams[6]);
            break;

        case PAN_PROJ_EQC:
            SetEquirectangular(TO_DEGREES * padfPrjParams[0],
                               TO_DEGREES * padfPrjParams[3], padfPrjParams[5],
                               padfPrjParams[6]);
            break;

        case PAN_PROJ_CEA:
            SetCEA(TO_DEGREES * padfPrjParams[0], TO_DEGREES * padfPrjParams[3],
                   padfPrjParams[5], padfPrjParams[6]);
            break;

        case PAN_PROJ_IMWP:
            SetIWMPolyconic(TO_DEGREES * padfPrjParams[0],
                            TO_DEGREES * padfPrjParams[1],
                            TO_DEGREES * padfPrjParams[3], padfPrjParams[5],
                            padfPrjParams[6]);
            break;

        case PAN_PROJ_MILLER:
            SetMC(TO_DEGREES * padfPrjParams[5], TO_DEGREES * padfPrjParams[4],
                  padfPrjParams[6], padfPrjParams[7]);
            break;

        default:
            CPLDebug("OSR_Panorama", "Unsupported projection: %ld", iProjSys);
            SetLocalCS(CPLString().Printf("\"Panorama\" projection number %ld",
                                          iProjSys));
            break;
    }

    /* -------------------------------------------------------------------- */
    /*      Try to translate the datum/spheroid.                            */
    /* -------------------------------------------------------------------- */

    if (!IsLocal())
    {
        if (iDatum > 0 && iDatum < NUMBER_OF_DATUMS && aoDatums[iDatum])
        {
            OGRSpatialReference oGCS;
            oGCS.importFromEPSG(aoDatums[iDatum]);
            CopyGeogCSFrom(&oGCS);
        }
        else if (iEllips == PAN_ELLIPSOID_GSK2011)
        {
            OGRSpatialReference oGCS;
            oGCS.importFromEPSG(7683);
            CopyGeogCSFrom(&oGCS);
        }
        else if (iEllips == PAN_ELLIPSOID_PZ90)
        {
            SetGeogCS("PZ-90.11", "Parametry_Zemli_1990_11", "PZ-90", 6378136,
                      298.257839303);
            SetAuthority("SPHEROID", "EPSG", 7054);
        }
        else if (iEllips > 0 && iEllips < NUMBER_OF_ELLIPSOIDS &&
                 aoEllips[iEllips])
        {
            char *pszName = nullptr;
            double dfSemiMajor = 0.0;
            double dfInvFlattening = 0.0;

            if (OSRGetEllipsoidInfo(aoEllips[iEllips], &pszName, &dfSemiMajor,
                                    &dfInvFlattening) == OGRERR_NONE)
            {
                SetGeogCS(
                    CPLString().Printf(
                        "Unknown datum based upon the %s ellipsoid", pszName),
                    CPLString().Printf("Not specified (based on %s spheroid)",
                                       pszName),
                    pszName, dfSemiMajor, dfInvFlattening, nullptr, 0.0,
                    nullptr, 0.0);
                SetAuthority("SPHEROID", "EPSG", aoEllips[iEllips]);
            }
            else
            {
                CPLError(CE_Warning, CPLE_AppDefined,
                         "Failed to lookup ellipsoid code %ld. "
                         "Falling back to use Pulkovo 42.",
                         iEllips);
                SetWellKnownGeogCS("EPSG:4284");
            }

            CPLFree(pszName);
        }
        else
        {
            CPLError(CE_Warning, CPLE_AppDefined,
                     "Wrong datum code %ld. Supported datums are 1--%ld "
                     "only.  Falling back to use Pulkovo 42.",
                     iDatum, NUMBER_OF_DATUMS - 1);
            SetWellKnownGeogCS("EPSG:4284");
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Grid units translation                                          */
    /* -------------------------------------------------------------------- */
    if (IsLocal() || IsProjected())
        SetLinearUnits(SRS_UL_METER, 1.0);

    if (bProjAllocated && padfPrjParams)
        CPLFree(padfPrjParams);

    return OGRERR_NONE;
}

/**
 * Import vertical coordinate system from "Panorama" GIS projection definition.
 *
 * @param iVCS Input vertical coordinate system ID.
 *
 * Supported VCS are:
 * <ul>
 * <li>1: Baltic 1977 height (EPSG:5705)</li>
 * <li>2: AHD height (EPSG:5711)</li>
 * <li>4: Ostend height (EPSG:5710)</li>
 * <li>5: Ostend height (EPSG:5710)</li>
 * <li>10: Piraeus height (EPSG:5716)</li>
 * <li>11: DNN height (EPSG:5733)</li>
 * <li>16: NAP height (EPSG:5709)</li>
 * <li>17: NN54 height (EPSG:5776)</li>
 * <li>20: N60 height (EPSG:5717)</li>
 * <li>21: RH2000 height (EPSG:5613)</li>
 * <li>23: Antalya height (EPSG:5775)</li>
 * <li>24: NGVD29 height (ftUS) (EPSG:5702)</li>
 * <li>25: Baltic 1977 height (EPSG:5705)</li>
 * <li>27: MSL height (EPSG:5714)</li>
 * </ul>
 */
OGRErr OGRSpatialReference::importVertCSFromPanorama(int iVCS)
{
    if (iVCS < 0 || iVCS >= NUMBER_OF_VERTICALCS)
    {
        return OGRERR_CORRUPT_DATA;
    }

    const int nEPSG = aoVCS[iVCS];

    if (nEPSG == 0)
    {
        CPLError(CE_Warning, CPLE_NotSupported,
                 "Vertical coordinate system (Panorama index %d) not supported",
                 iVCS);
        return OGRERR_UNSUPPORTED_SRS;
    }

    OGRSpatialReference sr;
    sr.SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER);
    OGRErr eImportFromEPSGErr = sr.importFromEPSG(nEPSG);
    if (eImportFromEPSGErr != OGRERR_NONE)
    {
        CPLError(CE_Warning, CPLE_None,
                 "Vertical coordinate system (Panorama index %d, EPSG %d) "
                 "import from EPSG error",
                 iVCS, nEPSG);
        return OGRERR_UNSUPPORTED_SRS;
    }

    if (sr.IsVertical() != 1)
    {
        CPLError(CE_Warning, CPLE_None,
                 "Coordinate system (Panorama index %d, EPSG %d) "
                 "is not Vertical",
                 iVCS, nEPSG);
        return OGRERR_UNSUPPORTED_SRS;
    }

    OGRErr eSetVertCSErr =
        SetVertCS(sr.GetAttrValue("VERT_CS"), sr.GetAttrValue("VERT_DATUM"));
    if (eSetVertCSErr != OGRERR_NONE)
    {
        CPLError(CE_Warning, CPLE_None,
                 "Vertical coordinate system (Panorama index %d, EPSG %d) "
                 "set error",
                 iVCS, nEPSG);
        return eSetVertCSErr;
    }
    return OGRERR_NONE;
}

/************************************************************************/
/*                      OSRExportToPanorama()                           */
/************************************************************************/

/** Export coordinate system in "Panorama" GIS projection definition.
 *
 * See OGRSpatialReference::exportToPanorama()
 */

OGRErr OSRExportToPanorama(OGRSpatialReferenceH hSRS, long *piProjSys,
                           long *piDatum, long *piEllips, long *piZone,
                           double *padfPrjParams)

{
    VALIDATE_POINTER1(hSRS, "OSRExportToPanorama", OGRERR_FAILURE);
    VALIDATE_POINTER1(piProjSys, "OSRExportToPanorama", OGRERR_FAILURE);
    VALIDATE_POINTER1(piDatum, "OSRExportToPanorama", OGRERR_FAILURE);
    VALIDATE_POINTER1(piEllips, "OSRExportToPanorama", OGRERR_FAILURE);
    VALIDATE_POINTER1(padfPrjParams, "OSRExportToPanorama", OGRERR_FAILURE);

    return reinterpret_cast<OGRSpatialReference *>(hSRS)->exportToPanorama(
        piProjSys, piDatum, piEllips, piZone, padfPrjParams);
}

/************************************************************************/
/*                           exportToPanorama()                         */
/************************************************************************/

/**
 * Export coordinate system in "Panorama" GIS projection definition.
 *
 * This method is the equivalent of the C function OSRExportToPanorama().
 *
 * @param piProjSys Pointer to variable, where the projection system code will
 * be returned.
 *
 * @param piDatum Pointer to variable, where the coordinate system code will
 * be returned.
 *
 * @param piEllips Pointer to variable, where the spheroid code will be
 * returned.
 *
 * @param piZone Pointer to variable, where the zone for UTM projection
 * system will be returned.
 *
 * @param padfPrjParams an existing 7 double buffer into which the
 * projection parameters will be placed. See importFromPanorama()
 * for the list of parameters.
 *
 * @return OGRERR_NONE on success or an error code on failure.
 */

OGRErr OGRSpatialReference::exportToPanorama(long *piProjSys, long *piDatum,
                                             long *piEllips, long *piZone,
                                             double *padfPrjParams) const

{
    CPLAssert(padfPrjParams);

    const char *pszProjection = GetAttrValue("PROJECTION");

    /* -------------------------------------------------------------------- */
    /*      Fill all projection parameters with zero.                       */
    /* -------------------------------------------------------------------- */
    *piDatum = 0L;
    *piEllips = 0L;
    *piZone = 0L;
    for (int i = 0; i < 7; i++)
        padfPrjParams[i] = 0.0;

    /* ==================================================================== */
    /*      Handle the projection definition.                               */
    /* ==================================================================== */
    if (IsLocal())
    {
        *piProjSys = PAN_PROJ_NONE;
    }
    else if (pszProjection == nullptr)
    {
#ifdef DEBUG
        CPLDebug("OSR_Panorama",
                 "Empty projection definition, considered as Geographic");
#endif
        *piProjSys = PAN_PROJ_NONE;
    }
    else if (EQUAL(pszProjection, SRS_PT_MERCATOR_1SP))
    {
        *piProjSys = PAN_PROJ_MERCAT;
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[0] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_ORIGIN, 0.0);
        padfPrjParams[4] = GetNormProjParm(SRS_PP_SCALE_FACTOR, 1.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_POLAR_STEREOGRAPHIC))
    {
        *piProjSys = PAN_PROJ_PS;
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[2] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_ORIGIN, 0.0);
        padfPrjParams[4] = GetNormProjParm(SRS_PP_SCALE_FACTOR, 1.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_POLYCONIC))
    {
        *piProjSys = PAN_PROJ_POLYC;
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[2] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_ORIGIN, 0.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_EQUIDISTANT_CONIC))
    {
        *piProjSys = PAN_PROJ_EC;
        padfPrjParams[0] =
            TO_RADIANS * GetNormProjParm(SRS_PP_STANDARD_PARALLEL_1, 0.0);
        padfPrjParams[1] =
            TO_RADIANS * GetNormProjParm(SRS_PP_STANDARD_PARALLEL_2, 0.0);
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[2] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_ORIGIN, 0.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_LAMBERT_CONFORMAL_CONIC_2SP))
    {
        *piProjSys = PAN_PROJ_LCC;
        padfPrjParams[0] =
            TO_RADIANS * GetNormProjParm(SRS_PP_STANDARD_PARALLEL_1, 0.0);
        padfPrjParams[1] =
            TO_RADIANS * GetNormProjParm(SRS_PP_STANDARD_PARALLEL_2, 0.0);
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[2] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_ORIGIN, 0.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_TRANSVERSE_MERCATOR))
    {
        int bNorth = FALSE;

        *piZone = GetUTMZone(&bNorth);

        if (*piZone != 0)
        {
            *piProjSys = PAN_PROJ_UTM;
            if (!bNorth)
                *piZone = -*piZone;
        }
        else
        {
            *piProjSys = PAN_PROJ_TM;
            padfPrjParams[3] =
                TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
            padfPrjParams[2] =
                TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_ORIGIN, 0.0);
            padfPrjParams[4] = GetNormProjParm(SRS_PP_SCALE_FACTOR, 1.0);
            padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
            padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
        }
    }
    else if (EQUAL(pszProjection, SRS_PT_WAGNER_I))
    {
        *piProjSys = PAN_PROJ_WAG1;
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_STEREOGRAPHIC))
    {
        *piProjSys = PAN_PROJ_STEREO;
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[2] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_ORIGIN, 0.0);
        padfPrjParams[4] = GetNormProjParm(SRS_PP_SCALE_FACTOR, 1.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_AZIMUTHAL_EQUIDISTANT))
    {
        *piProjSys = PAN_PROJ_AE;
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LONGITUDE_OF_CENTER, 0.0);
        padfPrjParams[0] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_CENTER, 0.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_GNOMONIC))
    {
        *piProjSys = PAN_PROJ_GNOMON;
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[2] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_ORIGIN, 0.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_MOLLWEIDE))
    {
        *piProjSys = PAN_PROJ_MOLL;
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_LAMBERT_AZIMUTHAL_EQUAL_AREA))
    {
        *piProjSys = PAN_PROJ_LAEA;
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[0] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_ORIGIN, 0.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_EQUIRECTANGULAR))
    {
        *piProjSys = PAN_PROJ_EQC;
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[0] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_ORIGIN, 0.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_CYLINDRICAL_EQUAL_AREA))
    {
        *piProjSys = PAN_PROJ_CEA;
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[2] =
            TO_RADIANS * GetNormProjParm(SRS_PP_STANDARD_PARALLEL_1, 0.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    else if (EQUAL(pszProjection, SRS_PT_IMW_POLYCONIC))
    {
        *piProjSys = PAN_PROJ_IMWP;
        padfPrjParams[3] =
            TO_RADIANS * GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN, 0.0);
        padfPrjParams[0] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_1ST_POINT, 0.0);
        padfPrjParams[1] =
            TO_RADIANS * GetNormProjParm(SRS_PP_LATITUDE_OF_2ND_POINT, 0.0);
        padfPrjParams[5] = GetNormProjParm(SRS_PP_FALSE_EASTING, 0.0);
        padfPrjParams[6] = GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0);
    }
    // Projection unsupported by "Panorama" GIS
    else
    {
        CPLDebug("OSR_Panorama",
                 "Projection \"%s\" unsupported by \"Panorama\" GIS. "
                 "Geographic system will be used.",
                 pszProjection);
        *piProjSys = PAN_PROJ_NONE;
    }

    /* -------------------------------------------------------------------- */
    /*      Translate the datum.                                            */
    /* -------------------------------------------------------------------- */
    const char *pszDatum = GetAttrValue("DATUM");

    if (pszDatum == nullptr)
    {
        *piDatum = PAN_DATUM_NONE;
        *piEllips = PAN_ELLIPSOID_NONE;
    }
    else if (EQUAL(pszDatum, "Pulkovo_1942"))
    {
        *piDatum = PAN_DATUM_PULKOVO42;
        *piEllips = PAN_ELLIPSOID_KRASSOVSKY;
    }
    else if (EQUAL(pszDatum, SRS_DN_WGS84))
    {
        *piDatum = PAN_DATUM_WGS84;
        *piEllips = PAN_ELLIPSOID_WGS84;
    }

    // If not found well known datum, translate ellipsoid.
    else
    {
        const double dfSemiMajor = GetSemiMajor();
        const double dfInvFlattening = GetInvFlattening();

#ifdef DEBUG
        CPLDebug("OSR_Panorama",
                 "Datum \"%s\" unsupported by \"Panorama\" GIS. "
                 "Trying to translate an ellipsoid definition.",
                 pszDatum);
#endif

        int i = 0;  // Used after for.
        for (; i < NUMBER_OF_ELLIPSOIDS; i++)
        {
            if (aoEllips[i])
            {
                double dfSM = 0.0;
                double dfIF = 1.0;

                if (OSRGetEllipsoidInfo(aoEllips[i], nullptr, &dfSM, &dfIF) ==
                        OGRERR_NONE &&
                    std::abs(dfSemiMajor - dfSM) < 1e-10 * dfSemiMajor &&
                    std::abs(dfInvFlattening - dfIF) < 1e-10 * dfInvFlattening)
                {
                    *piEllips = i;
                    break;
                }
            }
        }

        if (i == NUMBER_OF_ELLIPSOIDS)  // Didn't found matches.
        {
#ifdef DEBUG
            CPLDebug("OSR_Panorama",
                     R"(Ellipsoid "%s" unsupported by "Panorama" GIS.)",
                     pszDatum);
#endif
            *piDatum = PAN_DATUM_NONE;
            *piEllips = PAN_ELLIPSOID_NONE;
        }
    }

    return OGRERR_NONE;
}