/******************************************************************************
 * $Id: aaigriddataset.cpp,v 1.18 2002/11/23 18:54:17 warmerda Exp $
 *
 * Project:  GDAL
 * Purpose:  Implements Arc/Info ASCII Grid Format.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 2001, 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: aaigriddataset.cpp,v $
 * Revision 1.18  2002/11/23 18:54:17  warmerda
 * added CREATIONDATATYPES metadata for drivers
 *
 * Revision 1.17  2002/10/02 13:10:16  warmerda
 * Fixed bug in setting of Y offset derived from yllcenter,  was off 1 pixel.
 * As per GRASS RT bug https://intevation.de/rt/webrt?serial_num=1332.
 *
 * Revision 1.16  2002/09/04 06:50:36  warmerda
 * avoid static driver pointers
 *
 * Revision 1.15  2002/07/09 21:06:54  warmerda
 * fixed free of SrcDS pszProjection in CreateCopy
 *
 * Revision 1.14  2002/06/15 00:07:23  aubin
 * mods to enable 64bit file i/o
 *
 * Revision 1.13  2002/06/14 12:28:41  dron
 * No data handling at writing.
 *
 * Revision 1.12  2002/06/13 13:48:28  dron
 * Added writing of .prj files for Arc/Info 8
 *
 * Revision 1.11  2002/06/12 21:12:24  warmerda
 * update to metadata based driver info
 *
 * Revision 1.10  2002/06/11 13:13:02  dron
 * Write support implemented with CreateCopy() function
 *
 * Revision 1.9  2002/06/04 17:37:23  dron
 * Header records may follow in any order now.
 *
 * Revision 1.8  2001/11/20 14:52:26  warmerda
 * Fix from Markus for center of pixel positioning.
 *
 * Revision 1.7  2001/11/11 23:50:59  warmerda
 * added required class keyword to friend declarations
 *
 * Revision 1.6  2001/11/06 14:34:22  warmerda
 * Fixed bug in YLLCENTER handling.  Added case for alternate line ordering.
 *
 * Revision 1.5  2001/07/18 04:51:56  warmerda
 * added CPL_CVSID
 *
 * Revision 1.4  2001/03/24 20:58:30  warmerda
 * Fixed typo.
 *
 * Revision 1.3  2001/03/13 19:39:03  warmerda
 * Added help link
 *
 * Revision 1.2  2001/03/12 15:35:05  warmerda
 * Fixed prj file naming.
 *
 * Revision 1.1  2001/03/12 15:15:30  warmerda
 * New
 *
 */

#include "gdal_priv.h"
#include <ctype.h>
#include "cpl_string.h"
#include "ogr_spatialref.h"

CPL_CVSID("$Id: aaigriddataset.cpp,v 1.18 2002/11/23 18:54:17 warmerda Exp $");

CPL_C_START
void    GDALRegister_AAIGrid(void);
CPL_C_END

/************************************************************************/
/* ==================================================================== */
/*                              AAIGDataset                             */
/* ==================================================================== */
/************************************************************************/

class AAIGRasterBand;

class CPL_DLL AAIGDataset : public GDALDataset
{
    friend class AAIGRasterBand;
    
    FILE        *fp;

    double      adfGeoTransform[6];
    char        **papszPrj;
    char        *pszProjection;

    int         bNoDataSet;
    double      dfNoDataValue;

  public:
                AAIGDataset();
                ~AAIGDataset();

    static GDALDataset *Open( GDALOpenInfo * );

    virtual CPLErr GetGeoTransform( double * );
    virtual const char *GetProjectionRef(void);
};

/************************************************************************/
/* ==================================================================== */
/*                            AAIGRasterBand                             */
/* ==================================================================== */
/************************************************************************/

class AAIGRasterBand : public GDALRasterBand
{
    friend class AAIGDataset;

    int         *panLineOffset;

  public:

                   AAIGRasterBand( AAIGDataset *, int, GDALDataType );
    virtual       ~AAIGRasterBand();

    virtual double GetNoDataValue( int * );
    virtual CPLErr SetNoDataValue( double );
    virtual CPLErr IReadBlock( int, int, void * );
};

/************************************************************************/
/*                           AAIGRasterBand()                            */
/************************************************************************/

AAIGRasterBand::AAIGRasterBand( AAIGDataset *poDS, int nDataStart, 
                                GDALDataType eTypeIn )

{
    this->poDS = poDS;

    nBand = 1;
    eDataType = eTypeIn;

    nBlockXSize = poDS->nRasterXSize;
    nBlockYSize = 1;

    panLineOffset = (int *) CPLCalloc(poDS->nRasterYSize,sizeof(int));
    panLineOffset[0] = nDataStart;
}

/************************************************************************/
/*                          ~AAIGRasterBand()                           */
/************************************************************************/

AAIGRasterBand::~AAIGRasterBand()

{
    CPLFree( panLineOffset );
}

/************************************************************************/
/*                             IReadBlock()                             */
/************************************************************************/

CPLErr AAIGRasterBand::IReadBlock( int nBlockXOff, int nBlockYOff,
                                  void * pImage )

{
    AAIGDataset *poODS = (AAIGDataset *) poDS;
    const char  *pszLine;
    char        **papszTokens;
    int         i;

    if( nBlockYOff < 0 || nBlockYOff > poODS->nRasterYSize - 1 
        || nBlockXOff != 0 )
        return CE_Failure;

    if( panLineOffset[nBlockYOff] == 0 )
        IReadBlock( nBlockXOff, nBlockYOff-1, NULL );

    if( panLineOffset[nBlockYOff] == 0 )
        return CE_Failure;

    if( VSIFSeek( poODS->fp, panLineOffset[nBlockYOff], SEEK_SET ) != 0 )
        return CE_Failure;

    pszLine = CPLReadLine( poODS->fp );
    if( pszLine == NULL )
        return CE_Failure;

    if( nBlockYOff < poODS->nRasterYSize - 1 )
        panLineOffset[nBlockYOff+1] = VSIFTell( poODS->fp );

    if( pImage == NULL )
        return CE_None;

    papszTokens = CSLTokenizeString( pszLine );
    if( papszTokens == NULL )
        return CE_Failure;

    for( i = 0; i < poODS->nRasterXSize && papszTokens[i] != NULL; i++ )
    {
        if( eDataType == GDT_Float32 )
            ((float *) pImage)[i] = atof(papszTokens[i]);
        else
            ((GInt16 *) pImage)[i] = atoi(papszTokens[i]);
    }

    CSLDestroy( papszTokens );
    
    return CE_None;
}

/************************************************************************/
/*                           GetNoDataValue()                           */
/************************************************************************/

double AAIGRasterBand::GetNoDataValue( int * pbSuccess )

{
    AAIGDataset *poODS = (AAIGDataset *) poDS;

    if( pbSuccess )
        *pbSuccess = poODS->bNoDataSet;

    return poODS->dfNoDataValue;
}

/************************************************************************/
/*                           SetNoDataValue()                           */
/************************************************************************/

CPLErr AAIGRasterBand::SetNoDataValue( double dfNoData )

{
    AAIGDataset *poODS = (AAIGDataset *) poDS;

    poODS->bNoDataSet = TRUE;
    poODS->dfNoDataValue = dfNoData;

    return CE_None;
}

/************************************************************************/
/* ==================================================================== */
/*                            AAIGDataset                               */
/* ==================================================================== */
/************************************************************************/


/************************************************************************/
/*                            AAIGDataset()                            */
/************************************************************************/

AAIGDataset::AAIGDataset()

{
    papszPrj = NULL;
    pszProjection = CPLStrdup("");
    fp = NULL;
    bNoDataSet = FALSE;
    dfNoDataValue = -9999.0;

    adfGeoTransform[0] = 0.0;
    adfGeoTransform[1] = 1.0;
    adfGeoTransform[2] = 0.0;
    adfGeoTransform[3] = 0.0;
    adfGeoTransform[4] = 0.0;
    adfGeoTransform[5] = 1.0;
}

/************************************************************************/
/*                           ~AAIGDataset()                            */
/************************************************************************/

AAIGDataset::~AAIGDataset()

{
    if( fp != NULL )
        VSIFClose( fp );

    CPLFree( pszProjection );
    CSLDestroy( papszPrj );
}

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

GDALDataset *AAIGDataset::Open( GDALOpenInfo * poOpenInfo )

{
    int         i, j;
    GDALDataType eDataType;
    char        **papszTokens;

/* -------------------------------------------------------------------- */
/*      Does this look like an AI grid file?                            */
/* -------------------------------------------------------------------- */
    if( poOpenInfo->nHeaderBytes < 100
        || poOpenInfo->fp == NULL
        || !( EQUALN((const char *) poOpenInfo->pabyHeader,"ncols",5) ||
              EQUALN((const char *) poOpenInfo->pabyHeader,"nrows",5) ||
              EQUALN((const char *) poOpenInfo->pabyHeader,"xllcorner",9)||
              EQUALN((const char *) poOpenInfo->pabyHeader,"yllcorner",9)||
              EQUALN((const char *) poOpenInfo->pabyHeader,"xllcenter",9)||
              EQUALN((const char *) poOpenInfo->pabyHeader,"yllcenter",9)||
              EQUALN((const char *) poOpenInfo->pabyHeader,"cellsize",8)) )
        return NULL;

    papszTokens =  
        CSLTokenizeString2( (const char *) poOpenInfo->pabyHeader,
                                  " \n\r", 0 );

/* -------------------------------------------------------------------- */
/*      Create a corresponding GDALDataset.                             */
/* -------------------------------------------------------------------- */
    AAIGDataset         *poDS;

    poDS = new AAIGDataset();

    poDS->fp = poOpenInfo->fp;
    poOpenInfo->fp = NULL;
    
/* -------------------------------------------------------------------- */
/*      Parse the header.                                               */
/* -------------------------------------------------------------------- */
    double dfCellSize;

    if ( (i = CSLFindString( papszTokens, "ncols" )) < 0 )
    {
        CSLDestroy( papszTokens );
        return NULL;
    }
    poDS->nRasterXSize = atoi(papszTokens[i + 1]);
    if ( (i = CSLFindString( papszTokens, "nrows" )) < 0 )
    {
        CSLDestroy( papszTokens );
        return NULL;
    }
    poDS->nRasterYSize = atoi(papszTokens[i + 1]);
    if ( (i = CSLFindString( papszTokens, "cellsize" )) < 0 )
    {
        CSLDestroy( papszTokens );
        return NULL;
    }    
    dfCellSize = atof( papszTokens[i + 1] );
    if ((i = CSLFindString( papszTokens, "xllcorner" )) >= 0 &&
        (j = CSLFindString( papszTokens, "yllcorner" )) >= 0 )
    {
        poDS->adfGeoTransform[0] = atof( papszTokens[i + 1] );
        poDS->adfGeoTransform[1] = dfCellSize;
        poDS->adfGeoTransform[2] = 0.0;
        poDS->adfGeoTransform[3] = atof( papszTokens[j + 1] )
            + poDS->nRasterYSize * dfCellSize;
        poDS->adfGeoTransform[4] = 0.0;
        poDS->adfGeoTransform[5] = - dfCellSize;
    }
    else if ((i = CSLFindString( papszTokens, "xllcenter" )) >= 0 &&
             (j = CSLFindString( papszTokens, "yllcenter" )) >= 0 )
    {
        poDS->adfGeoTransform[0] = atof(papszTokens[i + 1]) - 0.5 * dfCellSize;
        poDS->adfGeoTransform[1] = dfCellSize;
        poDS->adfGeoTransform[2] = 0.0;
        poDS->adfGeoTransform[3] = atof( papszTokens[j + 1] )
            - 0.5 * dfCellSize
            + poDS->nRasterYSize * dfCellSize ;
        poDS->adfGeoTransform[4] = 0.0;
        poDS->adfGeoTransform[5] = - dfCellSize;
    }
    else
    {
        CSLDestroy( papszTokens );
        return NULL;
    }
    if( (i = CSLFindString( papszTokens, "NODATA_value" )) >= 0 )
    {
        poDS->bNoDataSet = TRUE;
        poDS->dfNoDataValue = atof(papszTokens[i + 1]);
    }
    
    CSLDestroy( papszTokens );

/* -------------------------------------------------------------------- */
/*      Find the start of real data.                                    */
/* -------------------------------------------------------------------- */
    int         nStartOfData;

    for( i = 2; TRUE ; i++ )
    {
        if( poOpenInfo->pabyHeader[i] == '\0' )
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "Couldn't find data values in ASCII Grid file.\n" );
            return NULL;                        
        }

        if( poOpenInfo->pabyHeader[i-1] == '\n' 
            || poOpenInfo->pabyHeader[i-2] == '\n' )
        {
            if( !isalpha(poOpenInfo->pabyHeader[i]) )
            {
                nStartOfData = i;
                if( strstr((const char *)poOpenInfo->pabyHeader+i,".") != NULL)
                    eDataType = GDT_Float32;
                else
                    eDataType = GDT_Int16;

                break;
            }
        }
    }

/* -------------------------------------------------------------------- */
/*      Create band information objects.                                */
/* -------------------------------------------------------------------- */
    poDS->SetBand( 1, new AAIGRasterBand( poDS, nStartOfData, eDataType ) );

/* -------------------------------------------------------------------- */
/*      Try to read projection file.                                    */
/* -------------------------------------------------------------------- */
    char        *pszDirname, *pszBasename;
    const char  *pszPrjFilename;
    VSIStatBuf   sStatBuf;

    pszDirname = CPLStrdup(CPLGetPath(poOpenInfo->pszFilename));
    pszBasename = CPLStrdup(CPLGetBasename(poOpenInfo->pszFilename));

    pszPrjFilename = CPLFormFilename( pszDirname, pszBasename, "prj" );
    if( VSIStat( pszPrjFilename, &sStatBuf ) == 0 )
    {
        OGRSpatialReference     oSRS;

        poDS->papszPrj = CSLLoad( pszPrjFilename );

        if( oSRS.importFromESRI( poDS->papszPrj ) == OGRERR_NONE )
        {
            CPLFree( poDS->pszProjection );
            oSRS.exportToWkt( &(poDS->pszProjection) );
        }
    }

    CPLFree( pszDirname );
    CPLFree( pszBasename );

    return( poDS );
}

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

CPLErr AAIGDataset::GetGeoTransform( double * padfTransform )

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

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

const char *AAIGDataset::GetProjectionRef()

{
    return pszProjection;
}

/************************************************************************/
/*                        AAIGCreateCopy()                              */
/************************************************************************/

static GDALDataset *
AAIGCreateCopy( const char * pszFilename, GDALDataset *poSrcDS, 
                int bStrict, char ** papszOptions, 
                GDALProgressFunc pfnProgress, void * pProgressData )

{
    int  nBands = poSrcDS->GetRasterCount();
    int  nXSize = poSrcDS->GetRasterXSize();
    int  nYSize = poSrcDS->GetRasterYSize();

/* -------------------------------------------------------------------- */
/*      Some rudimentary checks                                         */
/* -------------------------------------------------------------------- */
    if( nBands != 1 )
    {
        CPLError( CE_Failure, CPLE_NotSupported, 
                  "AAIG driver doesn't support %d bands.  Must be 1 band.\n",
                  nBands );

        return NULL;
    }

    if( !pfnProgress( 0.0, NULL, pProgressData ) )
        return NULL;

/* -------------------------------------------------------------------- */
/*      Create the dataset.                                             */
/* -------------------------------------------------------------------- */
    FILE        *fpImage;

    fpImage = VSIFOpen( pszFilename, "wt" );
    if( fpImage == NULL )
    {
        CPLError( CE_Failure, CPLE_OpenFailed, 
                  "Unable to create file %s.\n", 
                  pszFilename );
        return NULL;
    }

/* -------------------------------------------------------------------- */
/*      Write ASCII Grid file header                                    */
/* -------------------------------------------------------------------- */
    double      adfGeoTransform[6];

    poSrcDS->GetGeoTransform( adfGeoTransform );
    VSIFPrintf( fpImage, "ncols        %d\n", nXSize );
    VSIFPrintf( fpImage, "nrows        %d\n", nYSize );
    VSIFPrintf( fpImage, "xllcorner    %.12f\n", adfGeoTransform[0] );
    VSIFPrintf( fpImage, "yllcorner    %.12f\n", 
        adfGeoTransform[3]- nYSize * adfGeoTransform[1] );
    VSIFPrintf( fpImage, "cellsize     %.12f\n", adfGeoTransform[1] );

/* -------------------------------------------------------------------- */
/*      Loop over image, copying image data.                            */
/* -------------------------------------------------------------------- */
    double      *padfScanline, dfNoData;
    int         iLine, iPixel, bSuccess;
    CPLErr      eErr = CE_None;
    
    GDALRasterBand * poBand = poSrcDS->GetRasterBand( 1 );

    // Write `nodata' value to header if it is exists in source dataset
    dfNoData = poBand->GetNoDataValue( &bSuccess );
    if ( bSuccess )
        VSIFPrintf( fpImage, "NODATA_value %6.20g\n", dfNoData );
    
    // Write scanlines to output file
    padfScanline = (double *) CPLMalloc( nXSize *
                                GDALGetDataTypeSize(GDT_CFloat64) / 8 );
    for( iLine = 0; eErr == CE_None && iLine < nYSize; iLine++ )
    {
        eErr = poBand->RasterIO( GF_Read, 0, iLine, nXSize, 1, 
                              padfScanline, nXSize, 1, GDT_CFloat64,
                              sizeof(double), sizeof(double) * nXSize );
        for ( iPixel = 0; iPixel < nXSize; iPixel++ )
           VSIFPrintf( fpImage, " %6.20g", padfScanline[iPixel] );
        VSIFPrintf( fpImage, "\n" );
        if( eErr == CE_None &&
            !pfnProgress((iLine + 1) / ((double) nYSize), NULL, pProgressData) )
        {
            eErr = CE_Failure;
            CPLError( CE_Failure, CPLE_UserInterrupt, 
                      "User terminated CreateCopy()" );
        }
    }

    CPLFree( padfScanline );
    VSIFClose( fpImage );

/* -------------------------------------------------------------------- */
/*      Try to write projection file.                                   */
/* -------------------------------------------------------------------- */
    const char  *pszOriginalProjection;

    pszOriginalProjection = (char *)poSrcDS->GetProjectionRef();
    if( !EQUAL( pszOriginalProjection, "" ) )
    {
        char                    *pszDirname, *pszBasename;
        const char              *pszPrjFilename;
        char                    *pszESRIProjection = NULL;
        FILE                    *fp;
        OGRSpatialReference     oSRS;

        pszDirname = CPLStrdup( CPLGetPath(pszFilename) );
        pszBasename = CPLStrdup( CPLGetBasename(pszFilename) );

        pszPrjFilename = CPLFormFilename( pszDirname, pszBasename, "prj" );
        fp = VSIFOpen( pszPrjFilename, "wt" );
        
        oSRS.importFromWkt( (char **) &pszOriginalProjection );
        oSRS.morphToESRI();
        oSRS.exportToWkt( &pszESRIProjection );
        VSIFPuts( pszESRIProjection, fp );

        VSIFClose( fp );
        CPLFree( pszDirname );
        CPLFree( pszBasename );
        CPLFree( pszESRIProjection );
    }
    
    return (GDALDataset *) GDALOpen( pszFilename, GA_Update );
}

/************************************************************************/
/*                        GDALRegister_AAIGrid()                        */
/************************************************************************/

void GDALRegister_AAIGrid()

{
    GDALDriver  *poDriver;

    if( GDALGetDriverByName( "AAIGrid" ) == NULL )
    {
        poDriver = new GDALDriver();
        
        poDriver->SetDescription( "AAIGrid" );
        poDriver->SetMetadataItem( GDAL_DMD_LONGNAME, 
                                   "Arc/Info ASCII Grid" );
        poDriver->SetMetadataItem( GDAL_DMD_HELPTOPIC, 
                                   "frmt_various.html#AAIGrid" );
        poDriver->SetMetadataItem( GDAL_DMD_EXTENSION, "asc" );
        poDriver->SetMetadataItem( GDAL_DMD_CREATIONDATATYPES, 
                                   "Byte UInt16 Int16 Float32" );

        poDriver->pfnOpen = AAIGDataset::Open;
        poDriver->pfnCreateCopy = AAIGCreateCopy;
        
        GetGDALDriverManager()->RegisterDriver( poDriver );
    }
}

