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

 *

 * Project:  GDAL Core

 * Purpose:  Common code shared between the GTiff and libertiff drivers

 * Author:   Even Rouault <even dot rouault at spatialys.com>

 *

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

 * Copyright (c) 2024, Even Rouault <even dot rouault at spatialys.com>

 *

 * SPDX-License-Identifier: MIT

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

#include "tiff_common.h"

#include <algorithm>

#include "gdal_mdreader.h"

namespace gdal

{

namespace tiff_common

{

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

/*                       PrepareTIFFErrorFormat()                       */

/*                                                                      */

/*      sometimes the "module" has stuff in it that has special         */

/*      meaning in a printf() style format, so we try to escape it.     */

/*      For now we hope the only thing we have to escape is %'s.        */

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

char *PrepareTIFFErrorFormat(const char *module, const char *fmt)

{

    const size_t nModuleSize = strlen(module);

    const size_t nModFmtSize = nModuleSize * 2 + strlen(fmt) + 2;

    char *pszModFmt = static_cast<char *>(CPLMalloc(nModFmtSize));

    size_t iOut = 0;  // Used after for.

    for (size_t iIn = 0; iIn < nModuleSize; ++iIn)

    {

        if (module[iIn] == '%')

        {

            CPLAssert(iOut < nModFmtSize - 2);

            pszModFmt[iOut++] = '%';

            pszModFmt[iOut++] = '%';

        }

        else

        {

            CPLAssert(iOut < nModFmtSize - 1);

            pszModFmt[iOut++] = module[iIn];

        }

    }

    CPLAssert(iOut < nModFmtSize);

    pszModFmt[iOut] = '\0';

    strcat(pszModFmt, ":");

    strcat(pszModFmt, fmt);

    return pszModFmt;

}

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

/*                     TIFFColorMapTagToColorTable()                    */

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

std::unique_ptr<GDALColorTable> TIFFColorMapTagToColorTable(

    const unsigned short *panRed, const unsigned short *panGreen,

    const unsigned short *panBlue, int nColorCount, int &nColorTableMultiplier,

    int nDefaultColorTableMultiplier, bool bNoDataSet, double dfNoDataValue)

{

    auto poColorTable = std::make_unique<GDALColorTable>();

    if (nColorTableMultiplier == 0)

    {

        // TIFF color maps are in the [0, 65535] range, so some remapping must

        // be done to get values in the [0, 255] range, but it is not clear

        // how to do that exactly. Since GDAL 2.3.0 we have standardized on

        // using a 257 multiplication factor (https://github.com/OSGeo/gdal/commit/eeec5b62e385d53e7f2edaba7b73c7c74bc2af39)

        // but other software uses 256 (cf https://github.com/OSGeo/gdal/issues/10310)

        // Do a first pass to check if all values are multiples of 256 or 257.

        bool bFoundNonZeroEntry = false;

        bool bAllValuesMultipleOf256 = true;

        bool bAllValuesMultipleOf257 = true;

        unsigned short nMaxColor = 0;

        for (int iColor = 0; iColor < nColorCount; ++iColor)

        {

            if (panRed[iColor] > 0 || panGreen[iColor] > 0 ||

                panBlue[iColor] > 0)

            {

                bFoundNonZeroEntry = true;

            }

            if ((panRed[iColor] % 256) != 0 || (panGreen[iColor] % 256) != 0 ||

                (panBlue[iColor] % 256) != 0)

            {

                bAllValuesMultipleOf256 = false;

            }

            if ((panRed[iColor] % 257) != 0 || (panGreen[iColor] % 257) != 0 ||

                (panBlue[iColor] % 257) != 0)

            {

                bAllValuesMultipleOf257 = false;

            }

            nMaxColor = std::max(nMaxColor, panRed[iColor]);

            nMaxColor = std::max(nMaxColor, panGreen[iColor]);

            nMaxColor = std::max(nMaxColor, panBlue[iColor]);

        }

        if (nMaxColor > 0 && nMaxColor < 256)

        {

            // Bug 1384 - Some TIFF files are generated with color map entry

            // values in range 0-255 instead of 0-65535 - try to handle these

            // gracefully.

            nColorTableMultiplier = 1;

            CPLDebug("GTiff",

                     "TIFF ColorTable seems to be improperly scaled with "

                     "values all in [0,255] range, fixing up.");

        }

        else

        {

            if (!bAllValuesMultipleOf256 && !bAllValuesMultipleOf257)

            {

                CPLDebug("GTiff",

                         "The color map contains entries which are not "

                         "multiple of 256 or 257, so we don't know for "

                         "sure how to remap them to [0, 255]. Default to "

                         "using a 257 multiplication factor");

            }

            nColorTableMultiplier =

                (bFoundNonZeroEntry && bAllValuesMultipleOf256)

                    ? 256

                    : nDefaultColorTableMultiplier;

        }

    }

    CPLAssert(nColorTableMultiplier > 0);

    CPLAssert(nColorTableMultiplier <= 257);

    for (int iColor = nColorCount - 1; iColor >= 0; iColor--)

    {

        const GDALColorEntry oEntry = {

            static_cast<short>(panRed[iColor] / nColorTableMultiplier),

            static_cast<short>(panGreen[iColor] / nColorTableMultiplier),

            static_cast<short>(panBlue[iColor] / nColorTableMultiplier),

            static_cast<short>(

                bNoDataSet && static_cast<int>(dfNoDataValue) == iColor ? 0

                                                                        : 255)};

        poColorTable->SetColorEntry(iColor, &oEntry);

    }

    return poColorTable;

}

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

/*                      TIFFRPCTagToRPCMetadata()                       */

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

CPLStringList TIFFRPCTagToRPCMetadata(const double adfRPC[92])

{

    CPLStringList asMD;

    asMD.SetNameValue(RPC_ERR_BIAS, CPLOPrintf("%.15g", adfRPC[0]));

    asMD.SetNameValue(RPC_ERR_RAND, CPLOPrintf("%.15g", adfRPC[1]));

    asMD.SetNameValue(RPC_LINE_OFF, CPLOPrintf("%.15g", adfRPC[2]));

    asMD.SetNameValue(RPC_SAMP_OFF, CPLOPrintf("%.15g", adfRPC[3]));

    asMD.SetNameValue(RPC_LAT_OFF, CPLOPrintf("%.15g", adfRPC[4]));

    asMD.SetNameValue(RPC_LONG_OFF, CPLOPrintf("%.15g", adfRPC[5]));

    asMD.SetNameValue(RPC_HEIGHT_OFF, CPLOPrintf("%.15g", adfRPC[6]));

    asMD.SetNameValue(RPC_LINE_SCALE, CPLOPrintf("%.15g", adfRPC[7]));

    asMD.SetNameValue(RPC_SAMP_SCALE, CPLOPrintf("%.15g", adfRPC[8]));

    asMD.SetNameValue(RPC_LAT_SCALE, CPLOPrintf("%.15g", adfRPC[9]));

    asMD.SetNameValue(RPC_LONG_SCALE, CPLOPrintf("%.15g", adfRPC[10]));

    asMD.SetNameValue(RPC_HEIGHT_SCALE, CPLOPrintf("%.15g", adfRPC[11]));

    CPLString osField;

    CPLString osMultiField;

    for (int i = 0; i < 20; ++i)

    {

        osField.Printf("%.15g", adfRPC[12 + i]);

        if (i > 0)

            osMultiField += " ";

        else

            osMultiField = "";

        osMultiField += osField;

    }

    asMD.SetNameValue(RPC_LINE_NUM_COEFF, osMultiField);

    for (int i = 0; i < 20; ++i)

    {

        osField.Printf("%.15g", adfRPC[32 + i]);

        if (i > 0)

            osMultiField += " ";

        else

            osMultiField = "";

        osMultiField += osField;

    }

    asMD.SetNameValue(RPC_LINE_DEN_COEFF, osMultiField);

    for (int i = 0; i < 20; ++i)

    {

        osField.Printf("%.15g", adfRPC[52 + i]);

        if (i > 0)

            osMultiField += " ";

        else

            osMultiField = "";

        osMultiField += osField;

    }

    asMD.SetNameValue(RPC_SAMP_NUM_COEFF, osMultiField);

    for (int i = 0; i < 20; ++i)

    {

        osField.Printf("%.15g", adfRPC[72 + i]);

        if (i > 0)

            osMultiField += " ";

        else

            osMultiField = "";

        osMultiField += osField;

    }

    asMD.SetNameValue(RPC_SAMP_DEN_COEFF, osMultiField);

    return asMD;

}

}  // namespace tiff_common

}  // namespace gdal