/******************************************************************************
 * $Id: pdsdataset.cpp,v 1.3 2006/11/13 21:35:34 fwarmerdam Exp $
 *
 * Project:  PDS Driver; Planetary Data System Format
 * Purpose:  Implementation of PDSDataset
 * Author:   Trent Hare (thare@usgs.gov),
 *           Robert Soricone (rsoricone@usgs.gov)
 *
 * NOTE: Original code authored by Trent and Robert and placed in the public 
 * domain as per US government policy.  I have (within my rights) appropriated 
 * it and placed it under the following license.  This is not intended to 
 * diminish Trent and Roberts contribution. 
 ******************************************************************************
 * Copyright (c) 2006, Frank Warmerdam <warmerdam@pobox.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.
 ******************************************************************************
 * $Log: pdsdataset.cpp,v $
 * Revision 1.3  2006/11/13 21:35:34  fwarmerdam
 * Fixed up handling of quoted strings, particularly for projections.
 *
 * Revision 1.2  2006/11/13 19:51:47  fwarmerdam
 * Added preliminary support for external image data files.
 *
 * Revision 1.1  2006/11/13 17:52:03  fwarmerdam
 * New
 *
 */

// Set up PDS NULL values
#define NULL1 0
#define NULL2 -32768
//#define NULL3 -0.3402822655089E+39
#define NULL3 0xFF7FFFFB //in hex

#include "rawdataset.h"
#include "ogr_spatialref.h"
#include "cpl_string.h" 
#include "nasakeywordhandler.h"

CPL_CVSID("$Id: pdsdataset.cpp,v 1.3 2006/11/13 21:35:34 fwarmerdam Exp $");

CPL_C_START
void	GDALRegister_PDS(void);
CPL_C_END

/************************************************************************/
/* ==================================================================== */
/*			       PDSDataset	                        */
/* ==================================================================== */
/************************************************************************/

class PDSDataset : public RawDataset
{
    FILE	*fpImage;	// image data file.

    NASAKeywordHandler  oKeywords;
  
    int         bGotTransform;
    double      adfGeoTransform[6];
  
    CPLString   osProjection;

    //functions replaced by "NASAKeywordHandler" - ReadWord, ReadPair, ReadGroup
    //int parse_label(const char *file, char *keyword, char *value);
    //int strstrip(char instr[], char outstr[], int position);

    CPLString   osTempResult;

    void        CleanString( CPLString &osInput );

    const char *GetKeyword( const char *pszPath, 
                            const char *pszDefault = "");
    const char *GetKeywordSub( const char *pszPath, 
                               int iSubscript, 
                               const char *pszDefault = "");
    
public:
    PDSDataset();
    ~PDSDataset();
  
    virtual CPLErr GetGeoTransform( double * padfTransform );
    virtual const char *GetProjectionRef(void);
  
    static GDALDataset *Open( GDALOpenInfo * );
    static GDALDataset *Create( const char * pszFilename,
                                int nXSize, int nYSize, int nBands,
                                GDALDataType eType, char ** papszParmList );
};

/************************************************************************/
/*                            PDSDataset()                            */
/************************************************************************/

PDSDataset::PDSDataset()
{
    fpImage = NULL;
    bGotTransform = FALSE;
    adfGeoTransform[0] = 0.0;
    adfGeoTransform[1] = 1.0;
    adfGeoTransform[2] = 0.0;
    adfGeoTransform[3] = 0.0;
    adfGeoTransform[4] = 0.0;
    adfGeoTransform[5] = 1.0;
}

/************************************************************************/
/*                            ~PDSDataset()                            */
/************************************************************************/

PDSDataset::~PDSDataset()

{
    FlushCache();
    if( fpImage != NULL )
        VSIFCloseL( fpImage );
}

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

const char *PDSDataset::GetProjectionRef()

{
    if( strlen(osProjection) > 0 )
        return osProjection;
    else
        return GDALPamDataset::GetProjectionRef();
}

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

CPLErr PDSDataset::GetGeoTransform( double * padfTransform )

{
    if( bGotTransform )
    {
        memcpy( padfTransform, adfGeoTransform, sizeof(double) * 6 );
        return CE_None;
    }
    else
    {
        return GDALPamDataset::GetGeoTransform( padfTransform );
    }
}

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

GDALDataset *PDSDataset::Open( GDALOpenInfo * poOpenInfo )
{
/* -------------------------------------------------------------------- */
/*      Does this look like a PDS Img dataset?                          */
/* -------------------------------------------------------------------- */
    if( poOpenInfo->pabyHeader == NULL
        || (strstr((const char *)poOpenInfo->pabyHeader,"PDS_VERSION_ID") == NULL ))
    
        return NULL;

/* -------------------------------------------------------------------- */
/*      Open the file using the large file API.                         */
/* -------------------------------------------------------------------- */
    FILE *fpQube = VSIFOpenL( poOpenInfo->pszFilename, "rb" );

    if( fpQube == NULL )
        return NULL;

    PDSDataset 	*poDS;

    poDS = new PDSDataset();

    if( ! poDS->oKeywords.Ingest( fpQube, 0 ) )
    {
        delete poDS;
        return NULL;
    }
    VSIFCloseL( fpQube );

/* -------------------------------------------------------------------- */
/*	We assume the user is pointing to the label (ie. .lbl) file.  	*/
/* -------------------------------------------------------------------- */
    // IMAGE can be inline or detached and point to an image name
    // ^IMAGE = 3
    // ^IMAGE                         = "GLOBAL_ALBEDO_8PPD.IMG"
    // ^IMAGE                         = "MEGT90N000CB.IMG"
    // ^SPECTRAL_QUBE = 5  for multi-band images

    const char *pszQube = poDS->GetKeyword( "^IMAGE", "" );
    CPLString osTargetFile = poOpenInfo->pszFilename;

    if (EQUAL(pszQube,"")) {
        pszQube = poDS->GetKeyword( "^SPECTRAL_QUBE" );
    }
    int nQube = atoi(pszQube);

    if( pszQube[0] == '"' )
    {
        CPLString osTPath = CPLGetPath(poOpenInfo->pszFilename);
        CPLString osFilename = pszQube;
        poDS->CleanString( osFilename );
        osTargetFile = CPLFormCIFilename( osTPath, osFilename, NULL );
    }
    else if( pszQube[0] == '(' )
    {
        CPLAssert( FALSE ); // TODO
    }
/* -------------------------------------------------------------------- */
/*      Check if file an PDS header file?  Read a few lines of text   */
/*      searching for something starting with nrows or ncols.           */
/* -------------------------------------------------------------------- */
    GDALDataType eDataType = GDT_Byte;
    OGRSpatialReference oSRS;

    int	nRows = -1;
    int nCols = -1;
    int nBands = 1;
    int nSkipBytes = 0;
    int itype;
    int record_bytes;
    double dfULXMap=0.5;
    double dfULYMap = 0.5;
    double dfXDim = 1.0;
    double dfYDim = 1.0;
    double dfNoData = 0.0;
    int	bNoDataSet = FALSE;
    char chByteOrder = 'M';  //default to MSB
    char szLayout[10] = "BSQ"; //default to band seq.
    const char *target_name; //planet name
    const char *value;
    //projection parameters
    float xulcenter = 0.0;
    float yulcenter = 0.0;
    CPLString map_proj_name;
    int	bProjectionSet = TRUE;
    char proj_target_name[200]; 
    char datum_name[60];  
    char sphere_name[60];
    char bIsGeographic = TRUE;
    double semi_major = 0.0;
    double semi_minor = 0.0;
    double iflattening = 0.0;
    float center_lat = 0.0;
    float center_lon = 0.0;
    float first_std_parallel = 0.0;
    float second_std_parallel = 0.0;
    FILE	*fp;

    /* -------------------------------------------------------------------- */
    /*      Checks to see if this is raw PDS image not compressed image     */
    /*      so ENCODING_TYPE either does not exist or it equals "N/A".      */
    /*      Compressed types will not be supported in this routine          */
    /* -------------------------------------------------------------------- */
    value = poDS->GetKeyword( "IMAGE.ENCODING_TYPE", "N/A" );
    if ( !(EQUAL(value,"N/A") ) )
    {
        CPLError( CE_Failure, CPLE_OpenFailed, 
                  "*** PDS image file has an invalid ENCODING_TYPE parameter:\n"
                  "*** gdal pds driver does not support compressed image types\n"
                  "found: (%s)\n\n", value );
        delete poDS;
        return NULL;
    } 
    /**************** end ENCODING_TYPE check ***********************/
    
    
    /***********   Grab layout type (BSQ, BIP, BIL) ************/
    //  AXIS_NAME = (SAMPLE,LINE,BAND)
    /***********   Grab samples lines band        **************/
    /** if AXIS_NAME = "" then Bands=1 and Sample and Lines   **/
    /** are there own keywords  "LINES" and "LINE_SAMPLES"    **/
    /** if not NULL then CORE_ITEMS keyword i.e. (234,322,2)  **/
    /***********************************************************/
    value = poDS->GetKeyword( "IMAGE.AXIS_NAME", "" );
    if (EQUAL(value,"(SAMPLE,LINE,BAND)") ) {
        strcpy(szLayout,"BSQ");
        nCols = atoi(poDS->GetKeywordSub("IMAGE.CORE_ITEMS",1));
        nRows = atoi(poDS->GetKeywordSub("IMAGE.CORE_ITEMS",2));
        nBands = atoi(poDS->GetKeywordSub("IMAGE.CORE_ITEMS",3));
    }
    else if (EQUAL(value,"(BAND,LINE,SAMPLE)") ) {
        strcpy(szLayout,"BIP");
        nBands = atoi(poDS->GetKeywordSub("IMAGE.CORE_ITEMS",1));
        nRows = atoi(poDS->GetKeywordSub("IMAGE.CORE_ITEMS",2));
        nCols = atoi(poDS->GetKeywordSub("IMAGE.CORE_ITEMS",3));
    }
    else if (EQUAL(value,"(SAMPLE,BAND,LINE)") ) {
        strcpy(szLayout,"BIL");
        nCols = atoi(poDS->GetKeywordSub("IMAGE.CORE_ITEMS",1));
        nBands = atoi(poDS->GetKeywordSub("IMAGE.CORE_ITEMS",2));
        nRows = atoi(poDS->GetKeywordSub("IMAGE.CORE_ITEMS",3));
    }
    else if ( EQUAL(value,"") ) {
        strcpy(szLayout,"BSQ");
        nCols = atoi(poDS->GetKeyword("IMAGE.LINE_SAMPLES",""));
        nRows = atoi(poDS->GetKeyword("IMAGE.LINES",""));
        nBands = atoi(poDS->GetKeyword("IMAGE.BANDS","1"));        
    }
    else {
        CPLError( CE_Failure, CPLE_OpenFailed, 
                  "%s layout not supported. Abort\n\n", value);
        delete poDS;
        return NULL;
    }
    
    /***********   Grab Qube record bytes  **********/
    record_bytes = atoi(poDS->GetKeyword("IMAGE.RECORD_BYTES"));

    if (nQube > 0)
        nSkipBytes = (nQube - 1) * record_bytes;     
    else
        nSkipBytes = 0;     
     
    /**** Grab format type - pds supports 1,2,4,8,16,32,64 (in theory) **/
    /**** I have only seen 8, 16, 32 in released datasets              **/
    itype = atoi(poDS->GetKeyword("IMAGE.SAMPLE_BITS",""));
    switch(itype) {
      case 8 :
        eDataType = GDT_Byte;
        dfNoData = NULL1;
        bNoDataSet = TRUE;
        break;
      case 16 :
        eDataType = GDT_Int16;
        dfNoData = NULL2;
        bNoDataSet = TRUE;
        break;
      case 32 :
        eDataType = GDT_Float32;
        dfNoData = NULL3;
        bNoDataSet = TRUE;
        break;
      case 64 :
        eDataType = GDT_Float64;
        dfNoData = NULL3;
        bNoDataSet = TRUE;
        break;
      default :
        CPLError( CE_Failure, CPLE_AppDefined,
                  "Sample_bits of %d is not supported in this gdal PDS reader.",
                  itype); 
        delete poDS;
        return NULL;
    }

    /***********   Grab SAMPLE_TYPE *****************/
    /** if keyword not found leave and "M" or MSB **/
    value = poDS->GetKeyword( "IMAGE.SAMPLE_TYPE" );
    if( (EQUAL(value,"LSB_INTEGER")) || 
        (EQUAL(value,"LSB_UNSIGNED_INTEGER")) || 
        (EQUAL(value,"UNSIGNED_INTEGER")) || 
        (EQUAL(value,"VAX_REAL")) || 
        (EQUAL(value,"PC_REAL")) ) {
        chByteOrder = 'I';
    }
    
    /***********   Grab Cellsize ************/
    value = poDS->GetKeyword("IMAGE_MAP_PROJECTION.MAP_SCALE");
    if (strlen(value) > 0 ) {
        dfXDim = (float) atof(value) * 1000.0; /* convert from km to m */
        dfYDim = (float) atof(value) * 1000.0 * -1;
    }
    
    //  Calculate upper left center of pixel in meters **/
    // This should be correct for what is documented in the PDS manual **/
    // It doesn't mean it will work for ever PDS image, as they are released all different ways. **/
    // For some reason PDS is negated where ISIS is not??

    /***********   Grab LINE_PROJECTION_OFFSET ************/
    value = poDS->GetKeyword("IMAGE_MAP_PROJECTION.LINE_PROJECTION_OFFSET");
    if (strlen(value) > 0) {
        yulcenter = (float) atof(value);
        yulcenter = ((yulcenter) * dfYDim);
        dfULYMap = (yulcenter - (dfYDim/2)) * -1;
    }
     
    /***********   Grab SAMPLE_PROJECTION_OFFSET ************/
    value = poDS->GetKeyword("IMAGE_MAP_PROJECTION.SAMPLE_PROJECTION_OFFSET");
    if( strlen(value) > 0 ) {
        xulcenter = (float) atof(value);
        xulcenter = ((xulcenter) * dfXDim);
        dfULXMap = (xulcenter - (dfXDim/2)) * -1;
    }
     
    /***********  Grab TARGET_NAME  ************/
    /**** This is the planets name i.e. MARS ***/
    target_name = poDS->GetKeyword("TARGET_NAME");
     
    /***********   Grab MAP_PROJECTION_TYPE ************/
    map_proj_name = 
        poDS->GetKeyword( "IMAGE_MAP_PROJECTION.MAP_PROJECTION_TYPE");
    poDS->CleanString( map_proj_name );
     
    /***********   Grab SEMI-MAJOR ************/
    semi_major = 
        atof(poDS->GetKeyword( "IMAGE_MAP_PROJECTION.A_AXIS_RADIUS"));

    /***********   Grab semi-minor ************/
    semi_minor = 
        atof(poDS->GetKeyword( "IMAGE_MAP_PROJECTION.C_AXIS_RADIUS"));

    /***********   Grab CENTER_LAT ************/
    center_lat = 
        atof(poDS->GetKeyword( "IMAGE_MAP_PROJECTION.CENTER_LATITUDE"));

    /***********   Grab CENTER_LON ************/
    center_lon = 
        atof(poDS->GetKeyword( "IMAGE_MAP_PROJECTION.CENTER_LONGITUDE"));

    /***********   Grab 1st std parallel ************/
    first_std_parallel = 
        atof(poDS->GetKeyword( "IMAGE_MAP_PROJECTION.FIRST_STANDARD_PARALLEL"));

    /***********   Grab 2nd std parallel ************/
    second_std_parallel = 
        atof(poDS->GetKeyword( "IMAGE_MAP_PROJECTION.SECOND_STANDARD_PARALLEL"));
     
    /*** grab  PROJECTION_LATITUDE_TYPE = "PLANETOCENTRIC" ****/
    // Need to further study how ocentric/ographic will effect the gdal library.
    // So far we will use this fact to define a sphere or ellipse for some projections
    // Frank - may need to talk this over
    value = poDS->GetKeyword("IMAGE_MAP_PROJECTION.COORDINATE_SYSTEM_NAME");
    
    if (EQUAL( value, "\"PLANETOCENTRIC\"" )
        || EQUAL( value, "PLANETOCENTRIC") )
        bIsGeographic = FALSE; 

    //Set oSRS projection and parameters --- all PDS supported types added if apparently supported in oSRS
/**  "AITOFF",  ** Not supported in GDAL??
     "ALBERS", 
     "BONNE",
     "BRIESEMEISTER",   ** Not supported in GDAL??
     "CYLINDRICAL EQUAL AREA",
     "EQUIDISTANT",
     "EQUIRECTANGULAR",
     "GNOMONIC",
     "HAMMER",    ** Not supported in GDAL??
     "HENDU",     ** Not supported in GDAL??
     "LAMBERT AZIMUTHAL EQUAL AREA",
     "LAMBERT CONFORMAL",
     "MERCATOR",
     "MOLLWEIDE",
     "OBLIQUE CYLINDRICAL",
     "ORTHOGRAPHIC",
     "SIMPLE CYLINDRICAL",
     "SINUSOIDAL",
     "STEREOGRAPHIC",
     "TRANSVERSE MERCATOR",
     "VAN DER GRINTEN",     ** Not supported in GDAL??
     "WERNER"     ** Not supported in GDAL?? 
**/ 
    if ((EQUAL( map_proj_name, "EQUIRECTANGULAR" )) ||
        (EQUAL( map_proj_name, "SIMPLE_CYLINDRICAL" )) ||
        (EQUAL( map_proj_name, "EQUIDISTANT" )) )  {
        oSRS.SetEquirectangular ( center_lat, center_lon, 0, 0 );

    } else if (EQUAL( map_proj_name, "ORTHOGRAPHIC" )) {
        oSRS.SetOrthographic ( center_lat, center_lon, 0, 0 );

    } else if (EQUAL( map_proj_name, "SINUSOIDAL" )) {
        oSRS.SetSinusoidal ( center_lon, 0, 0 );

    } else if (EQUAL( map_proj_name, "MERCATOR" )) {
        oSRS.SetMercator ( center_lat, center_lon, 1, 0, 0 );

    } else if (EQUAL( map_proj_name, "STEREOGRAPHIC" )) {
        oSRS.SetPS ( center_lat, center_lon, 1, 0, 0 );

    } else if (EQUAL( map_proj_name, "TRANSVERSE_MERCATOR" )) {
        oSRS.SetTM ( center_lat, center_lon, 1, 0, 0 );

    } else if (EQUAL( map_proj_name, "LAMBERT_CONFORMAL_CONIC" )) {
        oSRS.SetLCC ( first_std_parallel, second_std_parallel, 
                      center_lat, center_lon, 0, 0 );
    } else if (EQUAL( map_proj_name, "LAMBERT_AZIMUTHAL_EQUAL_AREA" )) {
        oSRS.SetLAEA( center_lat, center_lon, 0, 0 );

    } else if (EQUAL( map_proj_name, "CYLINDRICAL_EQUAL_AREA" )) {
        oSRS.SetCEA  ( first_std_parallel, center_lon, 0, 0 );

    } else if (EQUAL( map_proj_name, "MOLLWEIDE" )) {
        oSRS.SetMollweide ( center_lon, 0, 0 );

    } else if (EQUAL( map_proj_name, "ALBERS" )) {
        oSRS.SetACEA ( first_std_parallel, second_std_parallel, 
                       center_lat, center_lon, 0, 0 );

    } else if (EQUAL( map_proj_name, "BONNE" )) {
        oSRS.SetBonne ( first_std_parallel, center_lon, 0, 0 );
    } else if (EQUAL( map_proj_name, "GNOMONIC" )) {
        oSRS.SetGnomonic ( center_lat, center_lon, 0, 0 );
    } else if (EQUAL( map_proj_name, "OBLIQUE_CYLINDRICAL" )) { 
        /* hope Swiss Oblique Cylindrical is the same */
        oSRS.SetSOC ( center_lat, center_lon, 0, 0 );

    } else {
        CPLError( CE_Warning, CPLE_AppDefined,
                  "No projection define or supported! Are you sure this is a map projected image?" );
        bProjectionSet = FALSE;
    }

    if (bProjectionSet) {
        //Create projection name, i.e. MARS_MERCATOR
        strcpy(proj_target_name, map_proj_name);
        strcat(proj_target_name, " ");
        strcat(proj_target_name, target_name);
     
        //The datum name will be the same basic name aas the planet
        strcpy(datum_name, "D_");
        strcat(datum_name, target_name);
     
        strcpy(sphere_name, target_name);
        //strcat(sphere_name, "_IAU_IAG");  //Might not be IAU defined so don't add
          
        //calculate inverse flattening from major and minor axis: 1/f = a/(a-b)
        iflattening = semi_major / (semi_major - semi_minor);
     
        //The use of a Sphere, polar radius or ellipse here is based on how PDS 2 does it internally
        //Notice that most PDS 2 projections are spherical 
        if ( (EQUAL( map_proj_name, "EQUIRECTANGULAR" )) ||
	     (EQUAL( map_proj_name, "SIMPLE CYLINDRICAL" )) || 
	     (EQUAL( map_proj_name, "EQUIDISTANT" )) || 
	     (EQUAL( map_proj_name, "ORTHOGRAPHIC" )) || 
	     (EQUAL( map_proj_name, "SINUSOIDAL" )) ) { //flattening = 1.0 for sphere
            oSRS.SetGeogCS( proj_target_name, datum_name, sphere_name,
                            semi_major*1000, 0.0, 
                            "Reference_Meridian", 0.0 );
            //Here isis2 uses the polar radius to define m/p, so we should use the polar radius for body
        } else if  (EQUAL( map_proj_name, "STEREOGRAPHIC" )  && fabs(center_lat) > 70) { 
            oSRS.SetGeogCS( proj_target_name, datum_name, sphere_name,
                            semi_minor*1000.0, 1.0, 
                            "Reference_Meridian", 0.0 );
        } else { //ellipse => Mercator, Transverse Mercator, Lambert Conformal
            if (bIsGeographic) {
                oSRS.SetGeogCS( proj_target_name, datum_name, sphere_name,
                                semi_major*1000, iflattening, 
                                "Reference_Meridian", 0.0 );
            } else { //we have Ocentric so use a sphere! I hope... 
                oSRS.SetGeogCS( proj_target_name, datum_name, sphere_name,
                                semi_major*1000, 0.0, 
                                "Reference_Meridian", 0.0 );
            }
        }

        // translate back into a projection string.
        char *pszResult = NULL;
        oSRS.exportToWkt( &pszResult );
        poDS->osProjection = pszResult;
        CPLFree( pszResult );
    }

/* END PDS Label Read */
/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
    
/* -------------------------------------------------------------------- */
/*     Is the Image detached - if so, reset name to binary file?        */
/* -------------------------------------------------------------------- */
#ifdef notdef
    // Frank - is this correct? --To Do
    //The extension already added on so don't add another. But is this needed?
    char *pszPath = CPLStrdup( CPLGetPath( poOpenInfo->pszFilename ) );
    char *pszName = CPLStrdup( CPLGetBasename( poOpenInfo->pszFilename ) );
    if (bIsDetached)
        pszFilename = CPLFormCIFilename( pszPath, detachedCub, "" );
#endif

/* -------------------------------------------------------------------- */
/*      Did we get the required keywords?  If not we return with        */
/*      this never having been considered to be a match. This isn't     */
/*      an error!                                                       */
/* -------------------------------------------------------------------- */
    if( nRows < 1 || nCols < 1 || nBands < 1 )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "File %s appears to be a PDS file, but failed to find some required keywords.", 
                  poOpenInfo->pszFilename );
        delete poDS;
        return NULL;
    }

/* -------------------------------------------------------------------- */
/*      Capture some information from the file that is of interest.     */
/* -------------------------------------------------------------------- */
    poDS->nRasterXSize = nCols;
    poDS->nRasterYSize = nRows;

/* -------------------------------------------------------------------- */
/*      Open target binary file.                                        */
/* -------------------------------------------------------------------- */
    
    if( poOpenInfo->eAccess == GA_ReadOnly )
        poDS->fpImage = VSIFOpenL( osTargetFile, "rb" );
    else
        poDS->fpImage = VSIFOpenL( osTargetFile, "r+b" );

    if( poDS->fpImage == NULL )
    {
        CPLError( CE_Failure, CPLE_OpenFailed, 
                  "Failed to open %s with write permission.\n%s", 
                  osTargetFile.c_str(),
                  VSIStrerror( errno ) );
        delete poDS;
        return NULL;
    }

    poDS->eAccess = poOpenInfo->eAccess;

/* -------------------------------------------------------------------- */
/*      Compute the line offset.                                        */
/* -------------------------------------------------------------------- */
    int     nItemSize = GDALGetDataTypeSize(eDataType)/8;
    int		nLineOffset, nPixelOffset, nBandOffset;
    
    if( EQUAL(szLayout,"BIP") )
    {
        nPixelOffset = nItemSize * nBands;
        nLineOffset = nPixelOffset * nCols;
        nBandOffset = nItemSize;
    }
    else if( EQUAL(szLayout,"BSQ") )
    {
        nPixelOffset = nItemSize;
        nLineOffset = nPixelOffset * nCols;
        nBandOffset = nLineOffset * nRows;
    }
    else /* assume BIL */
    {
        nPixelOffset = nItemSize;
        nLineOffset = nItemSize * nBands * nCols;
        nBandOffset = nItemSize * nCols;
    }
    
/* -------------------------------------------------------------------- */
/*      Create band information objects.                                */
/* -------------------------------------------------------------------- */
    int i;

    poDS->nBands = nBands;;
    for( i = 0; i < poDS->nBands; i++ )
    {
        RawRasterBand	*poBand;

        poBand = 
            new RawRasterBand( poDS, i+1, poDS->fpImage,
                               nSkipBytes + nBandOffset * i, 
                               nPixelOffset, nLineOffset, eDataType,
#ifdef CPL_LSB                               
                               chByteOrder == 'I' || chByteOrder == 'L',
#else
                               chByteOrder == 'M',
#endif        
                               TRUE );

        if( bNoDataSet )
            poBand->StoreNoDataValue( dfNoData );

        poDS->SetBand( i+1, poBand );
    }

/* -------------------------------------------------------------------- */
/*      Check for a .prj file. For pds I would like to keep this in   */
/* -------------------------------------------------------------------- */
    {
        CPLString osPath, osName;

        osPath = CPLGetPath( poOpenInfo->pszFilename );
        osName = CPLGetBasename(poOpenInfo->pszFilename);
        const char  *pszPrjFile = CPLFormCIFilename( osPath, osName, "prj" );

        fp = VSIFOpen( pszPrjFile, "r" );
        if( fp != NULL )
        {
            char	**papszLines;
            OGRSpatialReference oSRS;

            VSIFClose( fp );
        
            papszLines = CSLLoad( pszPrjFile );

            if( oSRS.importFromESRI( papszLines ) == OGRERR_NONE )
            {
                char *pszResult = NULL;
                oSRS.exportToWkt( &pszResult );
                poDS->osProjection = pszResult;
                CPLFree( pszResult );
            }

            CSLDestroy( papszLines );
        }
    }
    
    if( dfULYMap != 0.5 || dfULYMap != 0.5 || dfXDim != 1.0 || dfYDim != 1.0 )
    {
        poDS->bGotTransform = TRUE;
        poDS->adfGeoTransform[0] = dfULXMap;
        poDS->adfGeoTransform[1] = dfXDim;
        poDS->adfGeoTransform[2] = 0.0;
        poDS->adfGeoTransform[3] = dfULYMap;
        poDS->adfGeoTransform[4] = 0.0;
        poDS->adfGeoTransform[5] = dfYDim;
    }
    
    if( !poDS->bGotTransform )
        poDS->bGotTransform = 
            GDALReadWorldFile( poOpenInfo->pszFilename, "cbw", 
                               poDS->adfGeoTransform );

    if( !poDS->bGotTransform )
        poDS->bGotTransform = 
            GDALReadWorldFile( poOpenInfo->pszFilename, "wld", 
                               poDS->adfGeoTransform );

/* -------------------------------------------------------------------- */
/*      Check for overviews.                                            */
/* -------------------------------------------------------------------- */
    poDS->oOvManager.Initialize( poDS, poOpenInfo->pszFilename );

    return( poDS );
}

/************************************************************************/
/*                             GetKeyword()                             */
/************************************************************************/

const char *PDSDataset::GetKeyword( const char *pszPath, 
                                      const char *pszDefault )

{
    return oKeywords.GetKeyword( pszPath, pszDefault );
}

/************************************************************************/
/*                            GetKeywordSub()                           */
/************************************************************************/

const char *PDSDataset::GetKeywordSub( const char *pszPath, 
                                         int iSubscript,
                                         const char *pszDefault )

{
    const char *pszResult = oKeywords.GetKeyword( pszPath, NULL );
    
    if( pszResult == NULL )
        return pszDefault;

    if( pszResult[0] != '(' )
        return pszDefault;

    char **papszTokens = CSLTokenizeString2( pszResult, "(,)", 
                                             CSLT_HONOURSTRINGS );

    if( iSubscript <= CSLCount(papszTokens) )
    {
        osTempResult = papszTokens[iSubscript-1];
        CSLDestroy( papszTokens );
        return osTempResult.c_str();
    }
    else
    {
        CSLDestroy( papszTokens );
        return pszDefault;
    }
}

/************************************************************************/
/*                            CleanString()                             */
/*                                                                      */
/*      Removes double quotes, and converts spaces to underscores.      */
/*      The change is made in-place to CPLString.                       */
/************************************************************************/

void PDSDataset::CleanString( CPLString &osInput )

{
    if( osInput.size() < 2 || osInput.at(0) != '"' 
        || osInput.at(osInput.size()-1) != '"' )
        return;

    char *pszWrk = CPLStrdup(osInput.c_str() + 1);
    int i;

    pszWrk[strlen(pszWrk)-1] = '\0';
    
    for( i = 0; pszWrk[i] != '\0'; i++ )
    {
        if( pszWrk[i] == ' ' )
            pszWrk[i] = '_';
    }

    osInput = pszWrk;
    CPLFree( pszWrk );
}

/************************************************************************/
/* ==================================================================== */
/*                          NASAKeywordHandler                          */
/* ==================================================================== */
/************************************************************************/

/************************************************************************/
/*                         NASAKeywordHandler()                         */
/************************************************************************/

NASAKeywordHandler::NASAKeywordHandler()

{
    papszKeywordList = NULL;
}

/************************************************************************/
/*                        ~NASAKeywordHandler()                         */
/************************************************************************/

NASAKeywordHandler::~NASAKeywordHandler()

{
    CSLDestroy( papszKeywordList );
    papszKeywordList = NULL;
}

/************************************************************************/
/*                               Ingest()                               */
/************************************************************************/

int NASAKeywordHandler::Ingest( FILE *fp, int nOffset )

{
/* -------------------------------------------------------------------- */
/*      Read in buffer till we find END all on it's own line.           */
/* -------------------------------------------------------------------- */
    if( VSIFSeekL( fp, nOffset, SEEK_SET ) != 0 )
        return FALSE;

    for( ; TRUE; ) 
    {
        const char *pszCheck;
        char szChunk[513];

        int nBytesRead = VSIFReadL( szChunk, 1, 512, fp );

        szChunk[nBytesRead] = '\0';
        osHeaderText += szChunk;

        if( nBytesRead < 512 )
            break;

        if( osHeaderText.size() > 520 )
            pszCheck = osHeaderText.c_str() + (osHeaderText.size() - 520);
        else
            pszCheck = szChunk;

        if( strstr(pszCheck,"\r\nEND\r\n") != NULL 
            || strstr(pszCheck,"\nEND\n") != NULL )
            break;
    }

    pszHeaderNext = osHeaderText.c_str();

/* -------------------------------------------------------------------- */
/*      Process name/value pairs, keeping track of a "path stack".      */
/* -------------------------------------------------------------------- */
    return ReadGroup( "" );
}

/************************************************************************/
/*                             ReadGroup()                              */
/************************************************************************/

int NASAKeywordHandler::ReadGroup( const char *pszPathPrefix )

{
    CPLString osName, osValue;

    for( ; TRUE; )
    {
        if( !ReadPair( osName, osValue ) )
            return FALSE;

        if( osName == "OBJECT" || osName == "GROUP" )
        {
            if( !ReadGroup( (CPLString(pszPathPrefix) + osValue + ".").c_str() ) )
                return FALSE;
        }
        else if( EQUALN(osName.c_str(),"END",3) )
        {
            return TRUE;
        }
        else
        {
            osName = pszPathPrefix + osName;
            papszKeywordList = CSLSetNameValue( papszKeywordList, 
                                                osName, osValue );
        }
    }
}

/************************************************************************/
/*                              ReadPair()                              */
/*                                                                      */
/*      Read a name/value pair from the input stream.  Strip off        */
/*      white space, ignore comments, split on '='.                     */
/************************************************************************/

int NASAKeywordHandler::ReadPair( CPLString &osName, CPLString &osValue )

{
    osName = "";
    osValue = "";

    if( !ReadWord( osName ) )
        return FALSE;

    SkipWhite();

    if( EQUAL(osName,"END") )
        return TRUE;

    if( *pszHeaderNext != '=' )
        return FALSE;
    
    pszHeaderNext++;
    
    SkipWhite();
    
    osValue = "";

    if( *pszHeaderNext == '(' )
    {
        CPLString osWord;

        while( ReadWord( osWord ) )
        {
            SkipWhite();

            osValue += osWord;
            if( osWord[strlen(osWord)-1] == ')' )
                break;
        }

        return TRUE;
    }
    else
    {
        if( !ReadWord( osValue ) )
            return FALSE;

        SkipWhite();
        
        // No units keyword?   
        if( *pszHeaderNext != '<' )
            return TRUE;

        // Append units keyword.  For lines that like like this:
        //  MAP_RESOLUTION               = 4.0 <PIXEL/DEGREE>

        CPLString osWord;
        
        osValue += " ";
        
        while( ReadWord( osWord ) )
        {
            SkipWhite();
            
            osValue += osWord;
            if( osWord[strlen(osWord)-1] == '>' )
                break;
        }

        return TRUE;
    }
}

/************************************************************************/
/*                              ReadWord()                              */
/************************************************************************/

int NASAKeywordHandler::ReadWord( CPLString &osWord )

{
    osWord = "";

    SkipWhite();

    if( pszHeaderNext == '\0' )
        return FALSE;

    while( *pszHeaderNext != '\0' 
           && !isspace(*pszHeaderNext) )
    {
        if( *pszHeaderNext == '"' )
        {
            osWord += *(pszHeaderNext++);
            while( *pszHeaderNext != '"' )
            {
                if( *pszHeaderNext == '\0' )
                    return FALSE;

                osWord += *(pszHeaderNext++);
            }
            osWord += *(pszHeaderNext++);
        }
        else
        {
            osWord += *pszHeaderNext;
            pszHeaderNext++;
        }
    }
    
    return TRUE;
}

/************************************************************************/
/*                             SkipWhite()                              */
/************************************************************************/

void NASAKeywordHandler::SkipWhite()

{
    for( ; TRUE; )
    {
        // Skip white space (newline, space, tab, etc )
        if( isspace( *pszHeaderNext ) )
        {
            pszHeaderNext++; 
            continue;
        }
        
        // Skip C style comments 
        if( *pszHeaderNext == '/' && pszHeaderNext[1] == '*' )
        {
            pszHeaderNext += 2;
            
            while( *pszHeaderNext != '\0' 
                   && (*pszHeaderNext != '*' 
                       || pszHeaderNext[1] != '/' ) )
            {
                pszHeaderNext++;
            }

            pszHeaderNext += 2;
            continue;
        }

        // not white space, return. 
        return;
    }
}

/************************************************************************/
/*                             GetKeyword()                             */
/************************************************************************/

const char *NASAKeywordHandler::GetKeyword( const char *pszPath,
                                            const char *pszDefault )

{
    const char *pszResult;

    pszResult = CSLFetchNameValue( papszKeywordList, pszPath );
    if( pszResult == NULL )
        return pszDefault;
    else
        return pszResult;
}

/************************************************************************/
/*                         GDALRegister_PDS()                         */
/************************************************************************/

void GDALRegister_PDS()

{
    GDALDriver	*poDriver;

    if( GDALGetDriverByName( "PDS" ) == NULL )
    {
        poDriver = new GDALDriver();
        
        poDriver->SetDescription( "PDS" );
        poDriver->SetMetadataItem( GDAL_DMD_LONGNAME, 
                                   "NASA Planetary Data System" );
        poDriver->SetMetadataItem( GDAL_DMD_HELPTOPIC, 
                                   "frmt_various.html#PDS" );

        poDriver->pfnOpen = PDSDataset::Open;

        GetGDALDriverManager()->RegisterDriver( poDriver );
    }
}

