/******************************************************************************
 *
 * Project:  EOSAT FAST Format reader
 * Purpose:  Reads Landsat FAST-L7A, IRS 1C/1D
 * Author:   Andrey Kiselev, dron@ak4719.spb.edu
 *
 ******************************************************************************
 * Copyright (c) 2002, Andrey Kiselev <dron@ak4719.spb.edu>
 * Copyright (c) 2007-2011, 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 "cpl_conv.h"
#include "cpl_string.h"
#include "gdal_frmts.h"
#include "ogr_spatialref.h"
#include "rawdataset.h"

CPL_CVSID("$Id: fastdataset.cpp 4b46f534fed80d31c3e15c1517169f40694a4a3e 2021-10-14 19:17:37 +0200 Even Rouault $")

// constexpr int ADM_STD_HEADER_SIZE = 4608;  // Format specification says it
constexpr int ADM_HEADER_SIZE = 5000;  // Should be 4608, but some vendors
                                          // ship broken large datasets.
constexpr size_t ADM_MIN_HEADER_SIZE = 1536;  // And sometimes it can be
                                                 // even 1/3 of standard size.

static const char ACQUISITION_DATE[] = "ACQUISITION DATE";
constexpr int ACQUISITION_DATE_SIZE = 8;

static const char SATELLITE_NAME[] = "SATELLITE";
constexpr int SATELLITE_NAME_SIZE = 10;

static const char SENSOR_NAME[] = "SENSOR";
constexpr int SENSOR_NAME_SIZE = 10;

static const char BANDS_PRESENT[] = "BANDS PRESENT";
constexpr int BANDS_PRESENT_SIZE = 32;

static const char FILENAME[] = "FILENAME";
constexpr int FILENAME_SIZE = 29;

static const char PIXELS[] = "PIXELS PER LINE";
constexpr int PIXELS_SIZE = 5;

static const char LINES1[] = "LINES PER BAND";
static const char LINES2[] = "LINES PER IMAGE";
constexpr int LINES_SIZE = 5;

static const char BITS_PER_PIXEL[] = "OUTPUT BITS PER PIXEL";
constexpr int BITS_PER_PIXEL_SIZE = 2;

static const char PROJECTION_NAME[] = "MAP PROJECTION";
constexpr int PROJECTION_NAME_SIZE = 4;

static const char ELLIPSOID_NAME[] = "ELLIPSOID";
constexpr int ELLIPSOID_NAME_SIZE = 18;

static const char DATUM_NAME[] = "DATUM";
constexpr int DATUM_NAME_SIZE = 6;

static const char ZONE_NUMBER[] = "USGS MAP ZONE";
constexpr int ZONE_NUMBER_SIZE = 6;

static const char USGS_PARAMETERS[] = "USGS PROJECTION PARAMETERS";

static const char CORNER_UPPER_LEFT[] = "UL ";
static const char CORNER_UPPER_RIGHT[] = "UR ";
static const char CORNER_LOWER_LEFT[] = "LL ";
static const char CORNER_LOWER_RIGHT[] = "LR ";
constexpr int CORNER_VALUE_SIZE = 13;

constexpr int VALUE_SIZE = 24;

enum FASTSatellite  // Satellites:
{
    LANDSAT,        // Landsat 7
    IRS,            // IRS 1C/1D
    FAST_UNKNOWN
};

/************************************************************************/
/* ==================================================================== */
/*                              FASTDataset                             */
/* ==================================================================== */
/************************************************************************/

class FASTDataset final: public GDALPamDataset
{
    friend class FASTRasterBand;

    double       adfGeoTransform[6];
    char        *pszProjection;

    VSILFILE    *fpHeader;
    CPLString    apoChannelFilenames[7];
    VSILFILE    *fpChannels[7];
    const char  *pszFilename;
    char        *pszDirname;
    GDALDataType eDataType;
    FASTSatellite iSatellite;

    int         OpenChannel( const char *pszFilename, int iBand );

    CPL_DISALLOW_COPY_ASSIGN(FASTDataset)

  public:
    FASTDataset();
    ~FASTDataset() override;

    static GDALDataset *Open( GDALOpenInfo * );

    CPLErr      GetGeoTransform( double * ) override;
    const char  *_GetProjectionRef() override;
    const OGRSpatialReference* GetSpatialRef() const override {
        return GetSpatialRefFromOldGetProjectionRef();
    }
    VSILFILE    *FOpenChannel( const char *, int iBand, int iFASTBand );
    void        TryEuromap_IRS_1C_1D_ChannelNameConvention();

    char** GetFileList() override;
};

/************************************************************************/
/* ==================================================================== */
/*                            FASTRasterBand                            */
/* ==================================================================== */
/************************************************************************/

class FASTRasterBand final: public RawRasterBand
{
    friend class FASTDataset;

    CPL_DISALLOW_COPY_ASSIGN(FASTRasterBand)

  public:
                FASTRasterBand( FASTDataset *, int, VSILFILE *, vsi_l_offset,
                                int, int, GDALDataType, int );
};

/************************************************************************/
/*                           FASTRasterBand()                           */
/************************************************************************/

FASTRasterBand::FASTRasterBand( FASTDataset *poDSIn, int nBandIn, VSILFILE * fpRawIn,
                                vsi_l_offset nImgOffsetIn, int nPixelOffsetIn,
                                int nLineOffsetIn,
                                GDALDataType eDataTypeIn, int bNativeOrderIn ) :
    RawRasterBand( poDSIn, nBandIn, fpRawIn, nImgOffsetIn, nPixelOffsetIn,
                   nLineOffsetIn, eDataTypeIn, bNativeOrderIn,
                   RawRasterBand::OwnFP::NO )
{}

/************************************************************************/
/* ==================================================================== */
/*                              FASTDataset                             */
/* ==================================================================== */
/************************************************************************/

/************************************************************************/
/*                           FASTDataset()                              */
/************************************************************************/

FASTDataset::FASTDataset() :
    pszProjection(CPLStrdup("")),
    fpHeader(nullptr),
    pszFilename(nullptr),
    pszDirname(nullptr),
    eDataType(GDT_Unknown),
    iSatellite(FAST_UNKNOWN)
{
    adfGeoTransform[0] = 0.0;
    adfGeoTransform[1] = 1.0;
    adfGeoTransform[2] = 0.0;
    adfGeoTransform[3] = 0.0;
    adfGeoTransform[4] = 0.0;
    adfGeoTransform[5] = 1.0;
    // TODO: Why does this not work?
    //   fill( fpChannels, fpChannels + CPL_ARRAYSIZE(fpChannels), NULL );
    for (int i=0; i < 7; ++i)
        fpChannels[i] = nullptr;
    nBands = 0;
}

/************************************************************************/
/*                            ~FASTDataset()                            */
/************************************************************************/

FASTDataset::~FASTDataset()

{
    FlushCache(true);

    CPLFree( pszDirname );
    CPLFree( pszProjection );
    for ( int i = 0; i < nBands; i++ )
        if ( fpChannels[i] )
            CPL_IGNORE_RET_VAL(VSIFCloseL( fpChannels[i] ));
    if( fpHeader != nullptr )
        CPL_IGNORE_RET_VAL(VSIFCloseL( fpHeader ));
}

/************************************************************************/
/*                          GetGeoTransform()                           */
/************************************************************************/

CPLErr FASTDataset::GetGeoTransform( double * padfTransform )

{
    memcpy( padfTransform, adfGeoTransform, sizeof(double) * 6 );
    return CE_None;
}

/************************************************************************/
/*                          GetProjectionRef()                          */
/************************************************************************/

const char *FASTDataset::_GetProjectionRef()

{
    if( pszProjection )
        return pszProjection;

    return "";
}

/************************************************************************/
/*                             GetFileList()                            */
/************************************************************************/

char** FASTDataset::GetFileList()
{
    char** papszFileList = GDALPamDataset::GetFileList();

    for( int i = 0; i < 6; i++ )
    {
        if (!apoChannelFilenames[i].empty())
            papszFileList =
                CSLAddString(papszFileList, apoChannelFilenames[i].c_str());
    }

    return papszFileList;
}

/************************************************************************/
/*                             OpenChannel()                            */
/************************************************************************/

int FASTDataset::OpenChannel( const char *pszFilenameIn, int iBand )
{
    fpChannels[iBand] = VSIFOpenL( pszFilenameIn, "rb" );
    if (fpChannels[iBand])
        apoChannelFilenames[iBand] = pszFilenameIn;
    return fpChannels[iBand] != nullptr;
}

/************************************************************************/
/*                             FOpenChannel()                           */
/************************************************************************/

VSILFILE *FASTDataset::FOpenChannel( const char *pszBandname,
                                     int iBand, int iFASTBand )
{
    const char  *pszChannelFilename = nullptr;
    char *pszPrefix = CPLStrdup( CPLGetBasename( pszFilename ) );
    char *pszSuffix = CPLStrdup( CPLGetExtension( pszFilename ) );

    fpChannels[iBand] = nullptr;

    switch ( iSatellite )
    {
        case LANDSAT:
            if ( pszBandname && !EQUAL( pszBandname, "" ) )
            {
                pszChannelFilename =
                    CPLFormCIFilename( pszDirname, pszBandname, nullptr );
                if ( OpenChannel( pszChannelFilename, iBand ) )
                    break;
                pszChannelFilename =
                    CPLFormFilename( pszDirname,
                            CPLSPrintf( "%s.b%02d", pszPrefix, iFASTBand ),
                            nullptr );
                CPL_IGNORE_RET_VAL(OpenChannel( pszChannelFilename, iBand ));
            }
            break;
        case IRS:
        default:
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "%s.%d", pszPrefix, iFASTBand ), pszSuffix );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "IMAGERY%d", iFASTBand ), pszSuffix );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "imagery%d", iFASTBand ), pszSuffix );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "IMAGERY%d.DAT", iFASTBand ), nullptr );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "imagery%d.dat", iFASTBand ), nullptr );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "IMAGERY%d.dat", iFASTBand ), nullptr );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "imagery%d.DAT", iFASTBand ), nullptr );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "BAND%d", iFASTBand ), pszSuffix );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "band%d", iFASTBand ), pszSuffix );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "BAND%d.DAT", iFASTBand ), nullptr );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "band%d.dat", iFASTBand ), nullptr );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "BAND%d.dat", iFASTBand ), nullptr );
            if ( OpenChannel( pszChannelFilename, iBand ) )
                break;
            pszChannelFilename = CPLFormFilename( pszDirname,
                CPLSPrintf( "band%d.DAT", iFASTBand ), nullptr );
            CPL_IGNORE_RET_VAL(OpenChannel( pszChannelFilename, iBand ));
            break;
    }

    CPLDebug( "FAST", "Band %d filename=%s",
              iBand + 1, pszChannelFilename ? pszChannelFilename : "(null)" );

    CPLFree( pszPrefix );
    CPLFree( pszSuffix );
    return fpChannels[iBand];
}

/************************************************************************/
/*                TryEuromap_IRS_1C_1D_ChannelNameConvention()          */
/************************************************************************/

void FASTDataset::TryEuromap_IRS_1C_1D_ChannelNameConvention()
{
    // Filename convention explained in:
    // http://www.euromap.de/download/em_names.pdf

    char chLastLetterHeader = pszFilename[strlen(pszFilename)-1];
    if( EQUAL(GetMetadataItem("SENSOR"), "PAN") )
    {
        /* Converting upper-case to lower case */
        if( chLastLetterHeader >= 'A' && chLastLetterHeader <= 'M' )
            chLastLetterHeader += 'a' - 'A';

        if( chLastLetterHeader >= 'a' && chLastLetterHeader <= 'j' )
        {
            const char chLastLetterData = chLastLetterHeader - 'a' + '0';
            char* pszChannelFilename = CPLStrdup(pszFilename);
            pszChannelFilename[strlen(pszChannelFilename)-1] = chLastLetterData;
            if( OpenChannel( pszChannelFilename, 0 ) )
                nBands++;
            else
                CPLDebug("FAST", "Could not find %s", pszChannelFilename);
            CPLFree(pszChannelFilename);
        }
        else if( chLastLetterHeader >= 'k' && chLastLetterHeader <= 'm' )
        {
            const char chLastLetterData = chLastLetterHeader - 'k' + 'n';
            char* pszChannelFilename = CPLStrdup(pszFilename);
            pszChannelFilename[strlen(pszChannelFilename)-1] = chLastLetterData;
            if( OpenChannel( pszChannelFilename, 0 ) )
            {
                nBands++;
            }
            else
            {
                /* Trying upper-case */
                pszChannelFilename[strlen(pszChannelFilename)-1] =
                    chLastLetterData - 'a' + 'A';
                if( OpenChannel( pszChannelFilename, 0 ) )
                    nBands++;
                else
                    CPLDebug("FAST", "Could not find %s", pszChannelFilename);
            }
            CPLFree(pszChannelFilename);
        }
        else
        {
            CPLDebug(
                "FAST",
                "Unknown last letter (%c) for a IRS PAN Euromap FAST dataset",
                chLastLetterHeader );
        }
    }
    else if( EQUAL(GetMetadataItem("SENSOR"), "LISS3") )
    {
        const char apchLISSFilenames[7][5] = {
            { '0', '2', '3', '4', '5' },
            { '6', '7', '8', '9', 'a' },
            { 'b', 'c', 'd', 'e', 'f' },
            { 'g', 'h', 'i', 'j', 'k' },
            { 'l', 'm', 'n', 'o', 'p' },
            { 'q', 'r', 's', 't', 'u' },
            { 'v', 'w', 'x', 'y', 'z' } };

        int i = 0;
        for ( ; i < 7 ; i++ )
        {
            if( chLastLetterHeader == apchLISSFilenames[i][0] ||
                (apchLISSFilenames[i][0] >= 'a' &&
                 apchLISSFilenames[i][0] <= 'z' &&
                    (apchLISSFilenames[i][0] - chLastLetterHeader == 0 ||
                    apchLISSFilenames[i][0] - chLastLetterHeader == 32)) )
            {
                for ( int j = 0; j < 4; j ++ )
                {
                    char* pszChannelFilename = CPLStrdup(pszFilename);
                    pszChannelFilename[strlen(pszChannelFilename)-1] =
                        apchLISSFilenames[i][j+1];
                    if( OpenChannel( pszChannelFilename, nBands ) )
                        nBands++;
                    else if( apchLISSFilenames[i][j+1] >= 'a' &&
                             apchLISSFilenames[i][j+1] <= 'z' )
                    {
                        /* Trying upper-case */
                        pszChannelFilename[strlen(pszChannelFilename)-1] =
                            apchLISSFilenames[i][j+1] - 'a' + 'A';
                        if( OpenChannel( pszChannelFilename, nBands ) )
                        {
                            nBands++;
                        }
                        else
                        {
                            CPLDebug(
                                "FAST", "Could not find %s",
                                pszChannelFilename );
                        }
                    }
                    else
                    {
                        CPLDebug(
                            "FAST", "Could not find %s", pszChannelFilename );
                    }
                    CPLFree(pszChannelFilename);
                }
                break;
            }
        }
        if( i == 7 )
        {
            CPLDebug(
                "FAST",
                "Unknown last letter (%c) for a IRS LISS3 Euromap FAST dataset",
                chLastLetterHeader );
        }
    }
    else if( EQUAL(GetMetadataItem("SENSOR"), "WIFS") )
    {
        if( chLastLetterHeader == '0' )
        {
            for( int j = 0; j < 2; j++ )
            {
                char* pszChannelFilename = CPLStrdup(pszFilename);
                pszChannelFilename[strlen(pszChannelFilename)-1]
                    = static_cast<char>( '1' + j );
                if (OpenChannel( pszChannelFilename, nBands ))
                {
                    nBands++;
                }
                else
                {
                    CPLDebug( "FAST", "Could not find %s", pszChannelFilename );
                }
                CPLFree(pszChannelFilename);
            }
        }
        else
        {
            CPLDebug(
                "FAST",
                "Unknown last letter (%c) for a IRS WIFS Euromap FAST dataset",
                chLastLetterHeader );
        }
    }
    else
    {
        CPLAssert(false);
    }
}

/************************************************************************/
/*                          GetValue()                                  */
/************************************************************************/

static char *GetValue( const char *pszString, const char *pszName,
                       int iValueSize, int bNormalize )
{
    char *pszTemp = strstr( const_cast<char *>( pszString ), pszName );
    if( pszTemp )
    {
        // Skip the parameter name
        pszTemp += strlen( pszName );
        // Skip whitespaces and equal signs
        while ( *pszTemp == ' ' )
            pszTemp++;
        while ( *pszTemp == '=' )
            pszTemp++;

        pszTemp = CPLScanString( pszTemp, iValueSize, TRUE, bNormalize );
    }

    return pszTemp;
}

/************************************************************************/
/*                        USGSMnemonicToCode()                          */
/************************************************************************/

static long USGSMnemonicToCode( const char* pszMnemonic )
{
    if ( EQUAL(pszMnemonic, "UTM") )
        return 1L;
    else if ( EQUAL(pszMnemonic, "LCC") )
        return 4L;
    else if ( EQUAL(pszMnemonic, "PS") )
        return 6L;
    else if ( EQUAL(pszMnemonic, "PC") )
        return 7L;
    else if ( EQUAL(pszMnemonic, "TM") )
        return 9L;
    else if ( EQUAL(pszMnemonic, "OM") )
        return 20L;
    else if ( EQUAL(pszMnemonic, "SOM") )
        return 22L;
    else
        return 1L;  // UTM by default
}

/************************************************************************/
/*                        USGSEllipsoidToCode()                         */
/************************************************************************/

static long USGSEllipsoidToCode( const char* pszMnemonic )
{
    if ( EQUAL(pszMnemonic, "CLARKE_1866") )
        return 0L;
    else if ( EQUAL(pszMnemonic, "CLARKE_1880") )
        return 1L;
    else if ( EQUAL(pszMnemonic, "BESSEL") )
        return 2L;
    else if ( EQUAL(pszMnemonic, "INTERNATL_1967") )
        return 3L;
    else if ( EQUAL(pszMnemonic, "INTERNATL_1909") )
        return 4L;
    else if ( EQUAL(pszMnemonic, "WGS72") || EQUAL(pszMnemonic, "WGS_72") )
        return 5L;
    else if ( EQUAL(pszMnemonic, "EVEREST") )
        return 6L;
    else if ( EQUAL(pszMnemonic, "WGS66") || EQUAL(pszMnemonic, "WGS_66") )
        return 7L;
    else if ( EQUAL(pszMnemonic, "GRS_80") )
        return 8L;
    else if ( EQUAL(pszMnemonic, "AIRY") )
        return 9L;
    else if ( EQUAL(pszMnemonic, "MODIFIED_EVEREST") )
        return 10L;
    else if ( EQUAL(pszMnemonic, "MODIFIED_AIRY") )
        return 11L;
    else if ( EQUAL(pszMnemonic, "WGS84") || EQUAL(pszMnemonic, "WGS_84") )
        return 12L;
    else if ( EQUAL(pszMnemonic, "SOUTHEAST_ASIA") )
        return 13L;
    else if ( EQUAL(pszMnemonic, "AUSTRALIAN_NATL") )
        return 14L;
    else if ( EQUAL(pszMnemonic, "KRASSOVSKY") )
        return 15L;
    else if ( EQUAL(pszMnemonic, "HOUGH") )
        return 16L;
    else if ( EQUAL(pszMnemonic, "MERCURY_1960") )
        return 17L;
    else if ( EQUAL(pszMnemonic, "MOD_MERC_1968") )
        return 18L;
    else if ( EQUAL(pszMnemonic, "6370997_M_SPHERE") )
        return 19L;
    else
        return 0L;
}

/************************************************************************/
/*                                Open()                                */
/************************************************************************/

GDALDataset *FASTDataset::Open( GDALOpenInfo * poOpenInfo )

{
    if( poOpenInfo->nHeaderBytes < 1024 || poOpenInfo->fpL == nullptr )
        return nullptr;

    if( !EQUALN((const char *) poOpenInfo->pabyHeader + 52,
                "ACQUISITION DATE =", 18)
        && !EQUALN((const char *) poOpenInfo->pabyHeader + 36,
                "ACQUISITION DATE =", 18) )
        return nullptr;

/* -------------------------------------------------------------------- */
/*  Create a corresponding GDALDataset.                                 */
/* -------------------------------------------------------------------- */
    FASTDataset *poDS = new FASTDataset();

    poDS->fpHeader = poOpenInfo->fpL;
    poOpenInfo->fpL = nullptr;

    poDS->pszFilename = poOpenInfo->pszFilename;
    poDS->pszDirname = CPLStrdup( CPLGetDirname( poOpenInfo->pszFilename ) );

/* -------------------------------------------------------------------- */
/*  Read the administrative record.                                     */
/* -------------------------------------------------------------------- */
    char *pszHeader =
        static_cast<char *>( CPLMalloc( ADM_HEADER_SIZE + 1 ) );

    size_t nBytesRead = 0;
    if( VSIFSeekL( poDS->fpHeader, 0, SEEK_SET ) >= 0 )
        nBytesRead = VSIFReadL( pszHeader, 1, ADM_HEADER_SIZE, poDS->fpHeader );
    if ( nBytesRead < ADM_MIN_HEADER_SIZE )
    {
        CPLDebug( "FAST", "Header file too short. Reading failed" );
        CPLFree(pszHeader);
        delete poDS;
        return nullptr;
    }
    pszHeader[nBytesRead] = '\0';

    // Read acquisition date
    char *pszTemp = GetValue( pszHeader, ACQUISITION_DATE,
                              ACQUISITION_DATE_SIZE, TRUE );
    if (pszTemp == nullptr)
    {
        CPLDebug( "FAST", "Cannot get ACQUISITION_DATE, using empty value." );
        pszTemp = CPLStrdup("");
    }
    poDS->SetMetadataItem( "ACQUISITION_DATE", pszTemp );
    CPLFree( pszTemp );

    // Read satellite name (will read the first one only)
    pszTemp = GetValue( pszHeader, SATELLITE_NAME, SATELLITE_NAME_SIZE, TRUE );
    if (pszTemp == nullptr)
    {
        CPLDebug( "FAST", "Cannot get SATELLITE_NAME, using empty value." );
        pszTemp = CPLStrdup( "" );
    }
    poDS->SetMetadataItem( "SATELLITE", pszTemp );
    if ( STARTS_WITH_CI(pszTemp, "LANDSAT") )
        poDS->iSatellite = LANDSAT;
    // TODO(schwehr): Was this a bug that both are IRS?
    // else if ( STARTS_WITH_CI(pszTemp, "IRS") )
    //    poDS->iSatellite = IRS;
    else
      poDS->iSatellite = IRS;  // TODO(schwehr): Should this be FAST_UNKNOWN?
    CPLFree( pszTemp );

    // Read sensor name (will read the first one only)
    pszTemp = GetValue( pszHeader, SENSOR_NAME, SENSOR_NAME_SIZE, TRUE );
    if (pszTemp == nullptr)
    {
        CPLDebug( "FAST", "Cannot get SENSOR_NAME, using empty value." );
        pszTemp = CPLStrdup("");
    }
    poDS->SetMetadataItem( "SENSOR", pszTemp );
    CPLFree( pszTemp );

    // Read filenames
    poDS->nBands = 0;

    if (strstr( pszHeader, FILENAME ) == nullptr)
    {
        if (strstr(pszHeader, "GENERATING AGENCY =EUROMAP"))
        {
            // If we don't find the FILENAME field, let's try with the Euromap
            // PAN / LISS3 / WIFS IRS filename convention.
            if ((EQUAL(poDS->GetMetadataItem("SATELLITE"), "IRS 1C") ||
                 EQUAL(poDS->GetMetadataItem("SATELLITE"), "IRS 1D")) &&
                (EQUAL(poDS->GetMetadataItem("SENSOR"), "PAN") ||
                 EQUAL(poDS->GetMetadataItem("SENSOR"), "LISS3") ||
                 EQUAL(poDS->GetMetadataItem("SENSOR"), "WIFS")))
            {
                poDS->TryEuromap_IRS_1C_1D_ChannelNameConvention();
            }
            else if (EQUAL(poDS->GetMetadataItem("SATELLITE"), "CARTOSAT-1") &&
                     (EQUAL(poDS->GetMetadataItem("SENSOR"), "FORE") ||
                      EQUAL(poDS->GetMetadataItem("SENSOR"), "AFT")))
            {
                // See appendix F in
                // http://www.euromap.de/download/p5fast_20050301.pdf
                const CPLString osSuffix = CPLGetExtension( poDS->pszFilename );
                const char *papszBasenames[] =
                    { "BANDF", "bandf", "BANDA", "banda" };
                for ( int i = 0; i < 4; i++ )
                {
                    const CPLString osChannelFilename =
                        CPLFormFilename( poDS->pszDirname, papszBasenames[i],
                                         osSuffix );
                    if( poDS->OpenChannel( osChannelFilename, 0 ) )
                    {
                        poDS->nBands = 1;
                        break;
                    }
                }
            }
            else if( EQUAL(poDS->GetMetadataItem("SATELLITE"), "IRS P6") )
            {
                // If BANDS_PRESENT="2345", the file bands are "BAND2.DAT",
                // "BAND3.DAT", etc.
                pszTemp =
                    GetValue( pszHeader, BANDS_PRESENT, BANDS_PRESENT_SIZE,
                              TRUE );
                if (pszTemp)
                {
                    for( int i=0; pszTemp[i] != '\0'; i++ )
                    {
                        if( pszTemp[i] >= '2' && pszTemp[i] <= '5' )
                        {
                            if( poDS->FOpenChannel(
                                   poDS->pszFilename,
                                   poDS->nBands, pszTemp[i] - '0'))
                                poDS->nBands++;
                        }
                    }
                    CPLFree( pszTemp );
                }
            }
        }
    }

    // If the previous lookup for band files didn't success, fallback to the
    // standard way of finding them, either by the FILENAME field, either with
    // the usual patterns like bandX.dat, etc.
    if( !poDS->nBands )
    {
        pszTemp = pszHeader;
        for ( int i = 0; i < 7; i++ )
        {
            char *pszFilename = nullptr ;
            if ( pszTemp )
                pszTemp = strstr( pszTemp, FILENAME );
            if ( pszTemp )
            {
                // Skip the parameter name
                pszTemp += strlen(FILENAME);
                // Skip whitespaces and equal signs
                while ( *pszTemp == ' ' )
                    pszTemp++;
                while ( *pszTemp == '=' )
                    pszTemp++;
                pszFilename =
                    CPLScanString( pszTemp, FILENAME_SIZE, TRUE, FALSE );
            }
            else
                pszTemp = nullptr;
            if ( poDS->FOpenChannel( pszFilename, poDS->nBands,
                                     poDS->nBands + 1 ) )
                poDS->nBands++;
            if ( pszFilename )
                CPLFree( pszFilename );
        }
    }

    if ( !poDS->nBands )
    {
        CPLError( CE_Failure, CPLE_NotSupported,
                  "Failed to find and open band data files." );
        CPLFree(pszHeader);
        delete poDS;
        return nullptr;
    }

    // Read number of pixels/lines and bit depth
    pszTemp = GetValue( pszHeader, PIXELS, PIXELS_SIZE, FALSE );
    if ( pszTemp )
    {
        poDS->nRasterXSize = atoi( pszTemp );
        CPLFree( pszTemp );
    }
    else
    {
        CPLDebug( "FAST", "Failed to find number of pixels in line." );
        CPLFree(pszHeader);
        delete poDS;
        return nullptr;
    }

    pszTemp = GetValue( pszHeader, LINES1, LINES_SIZE, FALSE );
    if ( !pszTemp )
        pszTemp = GetValue( pszHeader, LINES2, LINES_SIZE, FALSE );
    if ( pszTemp )
    {
        poDS->nRasterYSize = atoi( pszTemp );
        CPLFree( pszTemp );
    }
    else
    {
        CPLDebug( "FAST", "Failed to find number of lines in raster." );
        CPLFree(pszHeader);
        delete poDS;
        return nullptr;
    }

    if (!GDALCheckDatasetDimensions(poDS->nRasterXSize, poDS->nRasterYSize))
    {
        CPLFree(pszHeader);
        delete poDS;
        return nullptr;
    }

    pszTemp = GetValue( pszHeader, BITS_PER_PIXEL, BITS_PER_PIXEL_SIZE, FALSE );
    if ( pszTemp )
    {
        switch( atoi(pszTemp) )
        {
            case 8:
            default:
                poDS->eDataType = GDT_Byte;
                break;
            // For a strange reason, some Euromap products declare 10 bits
            // output, but are 16 bits.
            case 10:
            case 16:
                poDS->eDataType = GDT_UInt16;
                break;
        }
        CPLFree( pszTemp );
    }
    else
    {
        poDS->eDataType = GDT_Byte;
    }

/* -------------------------------------------------------------------- */
/*  Read radiometric record.                                            */
/* -------------------------------------------------------------------- */
    const char *pszFirst = nullptr;
    const char *pszSecond = nullptr;

    // Read gains and biases. This is a trick!
    pszTemp = strstr( pszHeader, "BIASES" );// It may be "BIASES AND GAINS"
                                            // or "GAINS AND BIASES"
    const char* pszGains = strstr( pszHeader, "GAINS" );
    if( pszTemp == nullptr || pszGains == nullptr )
    {
        CPLDebug( "FAST", "No BIASES and/or GAINS" );
        CPLFree( pszHeader );
        delete poDS;
        return nullptr;
    }
    if ( pszTemp > pszGains )
    {
        pszFirst = "GAIN%d";
        pszSecond = "BIAS%d";
    }
    else
    {
        pszFirst = "BIAS%d";
        pszSecond = "GAIN%d";
    }

    // Now search for the first number occurrence after that string.
    for ( int i = 1; i <= poDS->nBands; i++ )
    {
        char *pszValue = nullptr;
        size_t nValueLen = VALUE_SIZE;

        pszTemp = strpbrk( pszTemp, "-.0123456789" );
        if ( pszTemp )
        {
            nValueLen = strspn( pszTemp, "+-.0123456789" );
            pszValue =
                CPLScanString( pszTemp, static_cast<int>(nValueLen),
                               TRUE, TRUE );
            poDS->SetMetadataItem( CPLSPrintf(pszFirst, i ), pszValue );
            CPLFree( pszValue );
        }
        else
        {
            CPLFree(pszHeader);
            delete poDS;
            return nullptr;
        }
        pszTemp += nValueLen;
        pszTemp = strpbrk( pszTemp, "-.0123456789" );
        if ( pszTemp )
        {
            nValueLen = strspn( pszTemp, "+-.0123456789" );
            pszValue =
                CPLScanString( pszTemp, static_cast<int>(nValueLen),
                               TRUE, TRUE );
            poDS->SetMetadataItem( CPLSPrintf(pszSecond, i ), pszValue );
            CPLFree( pszValue );
        }
        else
        {
            CPLFree(pszHeader);
            delete poDS;
            return nullptr;
        }
        pszTemp += nValueLen;
    }

/* -------------------------------------------------------------------- */
/*  Read geometric record.                                              */
/* -------------------------------------------------------------------- */
   // Coordinates of pixel's centers
    double dfULX = 0.0;
    double dfULY = 0.0;
    double dfURX = 0.0;
    double dfURY = 0.0;
    double dfLLX = 0.0;
    double dfLLY = 0.0;
    double dfLRX = 0.0;
    double dfLRY = 0.0;

    // Read projection name
    pszTemp = GetValue( pszHeader, PROJECTION_NAME,
                        PROJECTION_NAME_SIZE, FALSE );
    long iProjSys = 0;
    if ( pszTemp && !EQUAL( pszTemp, "" ) )
        iProjSys = USGSMnemonicToCode( pszTemp );
    else
        iProjSys = 1L;  // UTM by default
    CPLFree( pszTemp );

    // Read ellipsoid name
    pszTemp = GetValue( pszHeader, ELLIPSOID_NAME, ELLIPSOID_NAME_SIZE, FALSE );
    long iDatum = 0;   // Clarke, 1866 (NAD1927) by default.
    if ( pszTemp && !EQUAL( pszTemp, "" ) )
        iDatum = USGSEllipsoidToCode( pszTemp );
    CPLFree( pszTemp );

    // Read zone number.
    pszTemp = GetValue( pszHeader, ZONE_NUMBER, ZONE_NUMBER_SIZE, FALSE );
    long iZone = 0;
    if ( pszTemp && !EQUAL( pszTemp, "" ) )
        iZone = atoi( pszTemp );
    CPLFree( pszTemp );

    // Read 15 USGS projection parameters
    double adfProjParams[15] = { 0.0 };
    pszTemp = strstr( pszHeader, USGS_PARAMETERS );
    if ( pszTemp && !EQUAL( pszTemp, "" ) )
    {
        pszTemp += strlen( USGS_PARAMETERS );
        for ( int i = 0; i < 15; i++ )
        {
            pszTemp = strpbrk( pszTemp, "-.0123456789" );
            if ( pszTemp )
            {
                adfProjParams[i] = CPLScanDouble( pszTemp, VALUE_SIZE );
                pszTemp = strpbrk( pszTemp, " \t" );
            }
            if (pszTemp == nullptr )
            {
                CPLFree(pszHeader);
                delete poDS;
                return nullptr;
            }
        }
    }

    // Coordinates should follow the word "PROJECTION", otherwise we can
    // be confused by other occurrences of the corner keywords.
    char *pszGeomRecord = strstr( pszHeader, "PROJECTION" );
    if( pszGeomRecord )
    {
        // Read corner coordinates
        pszTemp = strstr( pszGeomRecord, CORNER_UPPER_LEFT );
        if ( pszTemp && !EQUAL( pszTemp, "" ) &&
             strlen(pszTemp) >= strlen( CORNER_UPPER_LEFT ) +
                                28 + CORNER_VALUE_SIZE + 1 )
        {
            pszTemp += strlen( CORNER_UPPER_LEFT ) + 28;
            dfULX = CPLScanDouble( pszTemp, CORNER_VALUE_SIZE );
            pszTemp += CORNER_VALUE_SIZE + 1;
            dfULY = CPLScanDouble( pszTemp, CORNER_VALUE_SIZE );
        }

        pszTemp = strstr( pszGeomRecord, CORNER_UPPER_RIGHT );
        if ( pszTemp && !EQUAL( pszTemp, "" ) &&
             strlen(pszTemp) >= strlen( CORNER_UPPER_RIGHT ) +
                                28 + CORNER_VALUE_SIZE + 1 )
        {
            pszTemp += strlen( CORNER_UPPER_RIGHT ) + 28;
            dfURX = CPLScanDouble( pszTemp, CORNER_VALUE_SIZE );
            pszTemp += CORNER_VALUE_SIZE + 1;
            dfURY = CPLScanDouble( pszTemp, CORNER_VALUE_SIZE );
        }

        pszTemp = strstr( pszGeomRecord, CORNER_LOWER_LEFT );
        if ( pszTemp && !EQUAL( pszTemp, "" ) &&
             strlen(pszTemp) >= strlen( CORNER_LOWER_LEFT ) +
                                28 + CORNER_VALUE_SIZE + 1 )
        {
            pszTemp += strlen( CORNER_LOWER_LEFT ) + 28;
            dfLLX = CPLScanDouble( pszTemp, CORNER_VALUE_SIZE );
            pszTemp += CORNER_VALUE_SIZE + 1;
            dfLLY = CPLScanDouble( pszTemp, CORNER_VALUE_SIZE );
        }

        pszTemp = strstr( pszGeomRecord, CORNER_LOWER_RIGHT );
        if ( pszTemp && !EQUAL( pszTemp, "" ) &&
             strlen(pszTemp) >= strlen( CORNER_LOWER_RIGHT ) +
                                28 + CORNER_VALUE_SIZE + 1 )
        {
            pszTemp += strlen( CORNER_LOWER_RIGHT ) + 28;
            dfLRX = CPLScanDouble( pszTemp, CORNER_VALUE_SIZE );
            pszTemp += CORNER_VALUE_SIZE + 1;
            dfLRY = CPLScanDouble( pszTemp, CORNER_VALUE_SIZE );
        }
    }

    if ( dfULX != 0.0 && dfULY != 0.0
         && dfURX != 0.0 && dfURY != 0.0
         && dfLLX != 0.0 && dfLLY != 0.0
         && dfLRX != 0.0 && dfLRY != 0.0 )
    {
        // Strip out zone number from the easting values, if either
        if ( dfULX >= 1000000.0 )
            dfULX -= static_cast<double>( iZone ) * 1000000.0;
        if ( dfURX >= 1000000.0 )
            dfURX -= static_cast<double>( iZone ) * 1000000.0;
        if ( dfLLX >= 1000000.0 )
            dfLLX -= static_cast<double>( iZone ) * 1000000.0;
        if ( dfLRX >= 1000000.0 )
            dfLRX -= static_cast<double>( iZone ) * 1000000.0;

        // In EOSAT FAST Rev C, the angles are in decimal degrees
        // otherwise they are in packed DMS format.
        const int bAnglesInPackedDMSFormat =
            strstr( pszHeader, "REV            C" ) == nullptr;

        // Create projection definition
        OGRSpatialReference oSRS;
        OGRErr eErr =
            oSRS.importFromUSGS( iProjSys, iZone, adfProjParams, iDatum, bAnglesInPackedDMSFormat );
        if ( eErr != OGRERR_NONE )
            CPLDebug( "FAST", "Import projection from USGS failed: %d", eErr );
        oSRS.SetLinearUnits( SRS_UL_METER, 1.0 );

        // Read datum name
        pszTemp = GetValue( pszHeader, DATUM_NAME, DATUM_NAME_SIZE, FALSE );
        if ( pszTemp )
        {
            if ( EQUAL( pszTemp, "WGS84" ) )
                oSRS.SetWellKnownGeogCS( "WGS84" );
            else if ( EQUAL( pszTemp, "NAD27" ) )
                oSRS.SetWellKnownGeogCS( "NAD27" );
            else if ( EQUAL( pszTemp, "NAD83" ) )
                oSRS.SetWellKnownGeogCS( "NAD83" );
            CPLFree( pszTemp );
        }
        else
        {
            // Reasonable fallback
            oSRS.SetWellKnownGeogCS( "WGS84" );
        }

        if ( poDS->pszProjection )
            CPLFree( poDS->pszProjection );
        eErr = oSRS.exportToWkt( &poDS->pszProjection );
        if ( eErr != OGRERR_NONE )
            CPLDebug("FAST", "Export projection to WKT USGS failed: %d", eErr);

        // Generate GCPs
        GDAL_GCP *pasGCPList
            = static_cast<GDAL_GCP *>( CPLCalloc( sizeof( GDAL_GCP ), 4 ) );
        GDALInitGCPs( 4, pasGCPList );
        CPLFree(pasGCPList[0].pszId);
        CPLFree(pasGCPList[1].pszId);
        CPLFree(pasGCPList[2].pszId);
        CPLFree(pasGCPList[3].pszId);

        /* Let's order the GCP in TL, TR, BR, BL order to benefit from the */
        /* GDALGCPsToGeoTransform optimization */
        pasGCPList[0].pszId = CPLStrdup("UPPER_LEFT");
        pasGCPList[0].dfGCPX = dfULX;
        pasGCPList[0].dfGCPY = dfULY;
        pasGCPList[0].dfGCPZ = 0.0;
        pasGCPList[0].dfGCPPixel = 0.5;
        pasGCPList[0].dfGCPLine = 0.5;
        pasGCPList[1].pszId = CPLStrdup("UPPER_RIGHT");
        pasGCPList[1].dfGCPX = dfURX;
        pasGCPList[1].dfGCPY = dfURY;
        pasGCPList[1].dfGCPZ = 0.0;
        pasGCPList[1].dfGCPPixel = poDS->nRasterXSize-0.5;
        pasGCPList[1].dfGCPLine = 0.5;
        pasGCPList[2].pszId = CPLStrdup("LOWER_RIGHT");
        pasGCPList[2].dfGCPX = dfLRX;
        pasGCPList[2].dfGCPY = dfLRY;
        pasGCPList[2].dfGCPZ = 0.0;
        pasGCPList[2].dfGCPPixel = poDS->nRasterXSize-0.5;
        pasGCPList[2].dfGCPLine = poDS->nRasterYSize-0.5;
        pasGCPList[3].pszId = CPLStrdup("LOWER_LEFT");
        pasGCPList[3].dfGCPX = dfLLX;
        pasGCPList[3].dfGCPY = dfLLY;
        pasGCPList[3].dfGCPZ = 0.0;
        pasGCPList[3].dfGCPPixel = 0.5;
        pasGCPList[3].dfGCPLine = poDS->nRasterYSize-0.5;

        // Calculate transformation matrix, if accurate
        const bool transform_ok
            = CPL_TO_BOOL(
                GDALGCPsToGeoTransform( 4, pasGCPList,
                                        poDS->adfGeoTransform, 0 ) );
        if( !transform_ok )
        {
            poDS->adfGeoTransform[0] = 0.0;
            poDS->adfGeoTransform[1] = 1.0;
            poDS->adfGeoTransform[2] = 0.0;
            poDS->adfGeoTransform[3] = 0.0;
            poDS->adfGeoTransform[4] = 0.0;
            poDS->adfGeoTransform[5] = 1.0;
            if ( poDS->pszProjection )
                CPLFree( poDS->pszProjection );
            poDS->pszProjection = CPLStrdup("");
        }

        GDALDeinitGCPs(4, pasGCPList);
        CPLFree(pasGCPList);
    }

/* -------------------------------------------------------------------- */
/*      Create band information objects.                                */
/* -------------------------------------------------------------------- */
    const int nPixelOffset = GDALGetDataTypeSize(poDS->eDataType) / 8;
    const int nLineOffset = poDS->nRasterXSize * nPixelOffset;

    for( int i = 1; i <= poDS->nBands; i++ )
    {
        poDS->SetBand( i, new FASTRasterBand( poDS, i, poDS->fpChannels[i - 1],
            0, nPixelOffset, nLineOffset, poDS->eDataType, TRUE));
    }

    CPLFree( pszHeader );

/* -------------------------------------------------------------------- */
/*      Initialize any PAM information.                                 */
/* -------------------------------------------------------------------- */
    poDS->SetDescription( poOpenInfo->pszFilename );
    poDS->TryLoadXML();

    // opens overviews.
    poDS->oOvManager.Initialize(poDS, poDS->pszFilename);

/* -------------------------------------------------------------------- */
/*      Confirm the requested access is supported.                      */
/* -------------------------------------------------------------------- */
    if( poOpenInfo->eAccess == GA_Update )
    {
        delete poDS;
        CPLError( CE_Failure, CPLE_NotSupported,
                  "The FAST driver does not support update access to existing"
                  " datasets." );
        return nullptr;
    }

    return poDS;
}

/************************************************************************/
/*                        GDALRegister_FAST()                           */
/************************************************************************/

void GDALRegister_FAST()

{
    if( GDALGetDriverByName( "FAST" ) != nullptr )
        return;

    GDALDriver *poDriver = new GDALDriver();

    poDriver->SetDescription( "FAST" );
    poDriver->SetMetadataItem( GDAL_DCAP_RASTER, "YES" );
    poDriver->SetMetadataItem( GDAL_DMD_LONGNAME,
                               "EOSAT FAST Format" );
    poDriver->SetMetadataItem( GDAL_DMD_HELPTOPIC,
                               "drivers/raster/fast.html" );
    poDriver->SetMetadataItem( GDAL_DCAP_VIRTUALIO, "YES" );

    poDriver->pfnOpen = FASTDataset::Open;

    GetGDALDriverManager()->RegisterDriver( poDriver );
}
