/******************************************************************************

 *

 * Project:  GXF Reader

 * Purpose:  GDAL binding for GXF reader.

 * Author:   Frank Warmerdam, warmerdam@pobox.com

 *

 ******************************************************************************

 * Copyright (c) 1998, Frank Warmerdam

 * Copyright (c) 2008-2012, Even Rouault <even dot rouault at spatialys.com>

 *

 * SPDX-License-Identifier: MIT

 ****************************************************************************/

#include "gdal_frmts.h"

#include "gdal_pam.h"

#include "gdal_driver.h"

#include "gdal_drivermanager.h"

#include "gdal_openinfo.h"

#include "gdal_cpp_functions.h"

#include "gxfopen.h"

/************************************************************************/

/* ==================================================================== */

/*                              GXFDataset                              */

/* ==================================================================== */

/************************************************************************/

class GXFRasterBand;

class GXFDataset final : public GDALPamDataset

{

    friend class GXFRasterBand;

    GXFHandle hGXF;

    OGRSpatialReference m_oSRS{};

    double dfNoDataValue;

    GDALDataType eDataType;

  public:

    GXFDataset();

    ~GXFDataset() override;

    static GDALDataset *Open(GDALOpenInfo *);

    CPLErr GetGeoTransform(GDALGeoTransform &gt) const override;

    const OGRSpatialReference *GetSpatialRef() const override;

};

/************************************************************************/

/* ==================================================================== */

/*                            GXFRasterBand                             */

/* ==================================================================== */

/************************************************************************/

class GXFRasterBand final : public GDALPamRasterBand

{

    friend class GXFDataset;

  public:

    GXFRasterBand(GXFDataset *, int);

    double GetNoDataValue(int *bGotNoDataValue) override;

    CPLErr IReadBlock(int, int, void *) override;

};

/************************************************************************/

/*                           GXFRasterBand()                            */

/************************************************************************/

GXFRasterBand::GXFRasterBand(GXFDataset *poDSIn, int nBandIn)

{

    poDS = poDSIn;

    nBand = nBandIn;

    eDataType = poDSIn->eDataType;

    nBlockXSize = poDS->GetRasterXSize();

    nBlockYSize = 1;

}

/************************************************************************/

/*                          GetNoDataValue()                          */

/************************************************************************/

double GXFRasterBand::GetNoDataValue(int *bGotNoDataValue)

{

    GXFDataset *poGXF_DS = cpl::down_cast<GXFDataset *>(poDS);

    if (bGotNoDataValue)

        *bGotNoDataValue = (fabs(poGXF_DS->dfNoDataValue - -1e12) > .1);

    if (eDataType == GDT_Float32)

        return (double)(float)poGXF_DS->dfNoDataValue;

    return poGXF_DS->dfNoDataValue;

}

/************************************************************************/

/*                             IReadBlock()                             */

/************************************************************************/

CPLErr GXFRasterBand::IReadBlock(CPL_UNUSED int nBlockXOff, int nBlockYOff,

                                 void *pImage)

{

    GXFDataset *const poGXF_DS = cpl::down_cast<GXFDataset *>(poDS);

    if (eDataType == GDT_Float32)

    {

        double *padfBuffer = (double *)VSIMalloc2(sizeof(double), nBlockXSize);

        if (padfBuffer == nullptr)

            return CE_Failure;

        const CPLErr eErr =

            GXFGetScanline(poGXF_DS->hGXF, nBlockYOff, padfBuffer);

        float *pafBuffer = (float *)pImage;

        for (int i = 0; i < nBlockXSize; i++)

            pafBuffer[i] = (float)padfBuffer[i];

        CPLFree(padfBuffer);

        return eErr;

    }

    const CPLErr eErr =

        eDataType == GDT_Float64

            ? GXFGetScanline(poGXF_DS->hGXF, nBlockYOff, (double *)pImage)

            : CE_Failure;

    return eErr;

}

/************************************************************************/

/* ==================================================================== */

/*                              GXFDataset                              */

/* ==================================================================== */

/************************************************************************/

/************************************************************************/

/*                             GXFDataset()                             */

/************************************************************************/

GXFDataset::GXFDataset()

    : hGXF(nullptr), dfNoDataValue(0), eDataType(GDT_Float32)

{

    m_oSRS.SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER);

}

/************************************************************************/

/*                            ~GXFDataset()                             */

/************************************************************************/

GXFDataset::~GXFDataset()

{

    FlushCache(true);

    if (hGXF != nullptr)

        GXFClose(hGXF);

}

/************************************************************************/

/*                          GetGeoTransform()                           */

/************************************************************************/

CPLErr GXFDataset::GetGeoTransform(GDALGeoTransform &gt) const

{

    double dfXOrigin = 0.0;

    double dfYOrigin = 0.0;

    double dfXSize = 0.0;

    double dfYSize = 0.0;

    double dfRotation = 0.0;

    const CPLErr eErr = GXFGetPosition(hGXF, &dfXOrigin, &dfYOrigin, &dfXSize,

                                       &dfYSize, &dfRotation);

    if (eErr != CE_None)

        return eErr;

    // Transform to radians.

    dfRotation = (dfRotation / 360.0) * 2.0 * M_PI;

    gt[1] = dfXSize * cos(dfRotation);

    gt[2] = dfYSize * sin(dfRotation);

    gt[4] = dfXSize * sin(dfRotation);

    gt[5] = -1 * dfYSize * cos(dfRotation);

    // take into account that GXF is point or center of pixel oriented.

    gt[0] = dfXOrigin - 0.5 * gt[1] - 0.5 * gt[2];

    gt[3] = dfYOrigin - 0.5 * gt[4] - 0.5 * gt[5];

    return CE_None;

}

/************************************************************************/

/*                         GetSpatialRef()                              */

/************************************************************************/

const OGRSpatialReference *GXFDataset::GetSpatialRef() const

{

    return m_oSRS.IsEmpty() ? nullptr : &m_oSRS;

}

/************************************************************************/

/*                                Open()                                */

/************************************************************************/

GDALDataset *GXFDataset::Open(GDALOpenInfo *poOpenInfo)

{

    /* -------------------------------------------------------------------- */

    /*      Before trying GXFOpen() we first verify that there is at        */

    /*      least one "\n#keyword" type signature in the first chunk of     */

    /*      the file.                                                       */

    /* -------------------------------------------------------------------- */

    if (poOpenInfo->nHeaderBytes < 50 || poOpenInfo->fpL == nullptr)

        return nullptr;

    bool bFoundKeyword = false;

    bool bFoundIllegal = false;

    for (int i = 0; i < poOpenInfo->nHeaderBytes - 1; i++)

    {

        if ((poOpenInfo->pabyHeader[i] == 10 ||

             poOpenInfo->pabyHeader[i] == 13) &&

            poOpenInfo->pabyHeader[i + 1] == '#')

        {

            if (STARTS_WITH((const char *)poOpenInfo->pabyHeader + i + 2,

                            "include"))

                return nullptr;

            if (STARTS_WITH((const char *)poOpenInfo->pabyHeader + i + 2,

                            "define"))

                return nullptr;

            if (STARTS_WITH((const char *)poOpenInfo->pabyHeader + i + 2,

                            "ifdef"))

                return nullptr;

            bFoundKeyword = true;

        }

        if (poOpenInfo->pabyHeader[i] == 0)

        {

            bFoundIllegal = true;

            break;

        }

    }

    if (!bFoundKeyword || bFoundIllegal)

        return nullptr;

    /* -------------------------------------------------------------------- */

    /*      At this point it is plausible that this is a GXF file, but      */

    /*      we also now verify that there is a #GRID keyword before         */

    /*      passing it off to GXFOpen().  We check in the first 50K.        */

    /* -------------------------------------------------------------------- */

    CPL_IGNORE_RET_VAL(poOpenInfo->TryToIngest(50000));

    bool bGotGrid = false;

    const char *pszBigBuf = (const char *)poOpenInfo->pabyHeader;

    for (int i = 0; i < poOpenInfo->nHeaderBytes - 5 && !bGotGrid; i++)

    {

        if (pszBigBuf[i] == '#' && STARTS_WITH_CI(pszBigBuf + i + 1, "GRID"))

            bGotGrid = true;

    }

    if (!bGotGrid)

        return nullptr;

    VSIFCloseL(poOpenInfo->fpL);

    poOpenInfo->fpL = nullptr;

    /* -------------------------------------------------------------------- */

    /*      Try opening the dataset.                                        */

    /* -------------------------------------------------------------------- */

    GXFHandle l_hGXF = GXFOpen(poOpenInfo->pszFilename);

    if (l_hGXF == nullptr)

        return nullptr;

    /* -------------------------------------------------------------------- */

    /*      Confirm the requested access is supported.                      */

    /* -------------------------------------------------------------------- */

    if (poOpenInfo->eAccess == GA_Update)

    {

        GXFClose(l_hGXF);

        ReportUpdateNotSupportedByDriver("GXF");

        return nullptr;

    }

    /* -------------------------------------------------------------------- */

    /*      Create a corresponding GDALDataset.                             */

    /* -------------------------------------------------------------------- */

    GXFDataset *poDS = new GXFDataset();

    const char *pszGXFDataType = CPLGetConfigOption("GXF_DATATYPE", "Float32");

    GDALDataType eDT = GDALGetDataTypeByName(pszGXFDataType);

    if (!(eDT == GDT_Float32 || eDT == GDT_Float64))

    {

        CPLError(CE_Warning, CPLE_NotSupported,

                 "Unsupported value for GXF_DATATYPE : %s", pszGXFDataType);

        eDT = GDT_Float32;

    }

    poDS->hGXF = l_hGXF;

    poDS->eDataType = eDT;

    /* -------------------------------------------------------------------- */

    /*      Establish the projection.                                       */

    /* -------------------------------------------------------------------- */

    char *pszProjection = GXFGetMapProjectionAsOGCWKT(l_hGXF);

    if (pszProjection && pszProjection[0] != '\0')

        poDS->m_oSRS.importFromWkt(pszProjection);

    CPLFree(pszProjection);

    /* -------------------------------------------------------------------- */

    /*      Capture some information from the file that is of interest.     */

    /* -------------------------------------------------------------------- */

    GXFGetRawInfo(l_hGXF, &(poDS->nRasterXSize), &(poDS->nRasterYSize), nullptr,

                  nullptr, nullptr, &(poDS->dfNoDataValue));

    if (poDS->nRasterXSize <= 0 || poDS->nRasterYSize <= 0)

    {

        CPLError(CE_Failure, CPLE_AppDefined, "Invalid dimensions : %d x %d",

                 poDS->nRasterXSize, poDS->nRasterYSize);

        delete poDS;

        return nullptr;

    }

    /* -------------------------------------------------------------------- */

    /*      Create band information objects.                                */

    /* -------------------------------------------------------------------- */

    poDS->nBands = 1;

    poDS->SetBand(1, new GXFRasterBand(poDS, 1));

    /* -------------------------------------------------------------------- */

    /*      Initialize any PAM information.                                 */

    /* -------------------------------------------------------------------- */

    poDS->SetDescription(poOpenInfo->pszFilename);

    poDS->TryLoadXML();

    /* -------------------------------------------------------------------- */

    /*      Check for external overviews.                                   */

    /* -------------------------------------------------------------------- */

    poDS->oOvManager.Initialize(poDS, poOpenInfo->pszFilename,

                                poOpenInfo->GetSiblingFiles());

    return poDS;

}

/************************************************************************/

/*                          GDALRegister_GXF()                          */

/************************************************************************/

void GDALRegister_GXF()

{

    if (GDALGetDriverByName("GXF") != nullptr)

        return;

    GDALDriver *poDriver = new GDALDriver();

    poDriver->SetDescription("GXF");

    poDriver->SetMetadataItem(GDAL_DCAP_RASTER, "YES");

    poDriver->SetMetadataItem(GDAL_DMD_LONGNAME,

                              "GeoSoft Grid Exchange Format");

    poDriver->SetMetadataItem(GDAL_DMD_HELPTOPIC, "drivers/raster/gxf.html");

    poDriver->SetMetadataItem(GDAL_DMD_EXTENSION, "gxf");

    poDriver->SetMetadataItem(GDAL_DCAP_VIRTUALIO, "YES");

    poDriver->pfnOpen = GXFDataset::Open;

    GetGDALDriverManager()->RegisterDriver(poDriver);

}