/******************************************************************************
 *
 * Project:  Raster Matrix Format
 * Purpose:  Implementation of the JPEG decompression algorithm as used in
 *           GIS "Panorama" raster files.
 * Author:   Andrew Sudorgin (drons [a] list dot ru)
 *
 ******************************************************************************
 * Copyright (c) 2018, Andrew Sudorgin
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#ifdef HAVE_LIBJPEG

#include <algorithm>
#include "cpl_conv.h"
#include "cpl_vsi.h"
#include "rmfdataset.h"
#include "memdataset.h"

/************************************************************************/
/*                          JPEGDecompress()                            */
/************************************************************************/

size_t RMFDataset::JPEGDecompress(const GByte *pabyIn, GUInt32 nSizeIn,
                                  GByte *pabyOut, GUInt32 nSizeOut,
                                  GUInt32 nRawXSize, GUInt32 nRawYSize)
{
    if (pabyIn == nullptr || pabyOut == nullptr || nSizeOut < nSizeIn ||
        nSizeIn < 2)
        return 0;

    const CPLString osTmpFilename(VSIMemGenerateHiddenFilename("rmfjpeg.jpg"));

    VSILFILE *fp = VSIFileFromMemBuffer(
        osTmpFilename, const_cast<GByte *>(pabyIn), nSizeIn, FALSE);

    if (fp == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "RMF JPEG: Can't create %s file",
                 osTmpFilename.c_str());
        return 0;
    }

    const char *apszAllowedDrivers[] = {"JPEG", nullptr};
    GDALDatasetH hTile;

    CPLConfigOptionSetter oNoReadDir("GDAL_DISABLE_READDIR_ON_OPEN",
                                     "EMPTY_DIR", false);

    hTile = GDALOpenEx(osTmpFilename, GDAL_OF_RASTER | GDAL_OF_INTERNAL,
                       apszAllowedDrivers, nullptr, nullptr);

    if (hTile == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "RMF JPEG: Can't open %s file",
                 osTmpFilename.c_str());
        VSIFCloseL(fp);
        VSIUnlink(osTmpFilename);
        return 0;
    }

    if (GDALGetRasterCount(hTile) != RMF_JPEG_BAND_COUNT)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "RMF JPEG: Invalid band count %d in tile, must be %d",
                 GDALGetRasterCount(hTile), RMF_JPEG_BAND_COUNT);
        GDALClose(hTile);
        VSIFCloseL(fp);
        VSIUnlink(osTmpFilename);
        return 0;
    }

    int nBandCount = GDALGetRasterCount(hTile);

    int nImageWidth =
        std::min(GDALGetRasterXSize(hTile), static_cast<int>(nRawXSize));
    int nImageHeight =
        std::min(GDALGetRasterYSize(hTile), static_cast<int>(nRawYSize));

    if (nRawXSize * nBandCount * nImageHeight > nSizeOut)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "RMF JPEG: Too small output buffer");
        GDALClose(hTile);
        VSIFCloseL(fp);
        VSIUnlink(osTmpFilename);
        return 0;
    }

    CPLErr eErr;
    size_t nRet;
    int aBandMap[RMF_JPEG_BAND_COUNT] = {3, 2, 1};
    eErr = GDALDatasetRasterIO(hTile, GF_Read, 0, 0, nImageWidth, nImageHeight,
                               pabyOut, nImageWidth, nImageHeight, GDT_Byte,
                               nBandCount, aBandMap, nBandCount,
                               nRawXSize * nBandCount, 1);
    if (CE_None != eErr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "RMF JPEG: Error decompress JPEG tile");
        nRet = 0;
    }
    else
    {
        nRet = static_cast<size_t>(nRawXSize * nBandCount * nImageHeight);
    }

    GDALClose(hTile);
    VSIFCloseL(fp);
    VSIUnlink(osTmpFilename);

    return nRet;
}

/************************************************************************/
/*                            JPEGCompress()                            */
/************************************************************************/

size_t RMFDataset::JPEGCompress(const GByte *pabyIn, GUInt32 nSizeIn,
                                GByte *pabyOut, GUInt32 nSizeOut,
                                GUInt32 nRawXSize, GUInt32 nRawYSize,
                                const RMFDataset *poDS)
{
    if (pabyIn == nullptr || pabyOut == nullptr || nSizeIn < 2)
        return 0;

    GDALDriverH hJpegDriver = GDALGetDriverByName("JPEG");

    if (hJpegDriver == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "RMF: JPEG driver not found");
        return 0;
    }

    const GDALDataType eType = GDT_Byte;
    auto poMemDS = std::unique_ptr<MEMDataset>(
        MEMDataset::Create("", nRawXSize, nRawYSize, 0, eType, nullptr));

    for (int iBand = 0; iBand < RMF_JPEG_BAND_COUNT; ++iBand)
    {
        const GByte *pabyBand = pabyIn + (RMF_JPEG_BAND_COUNT - iBand - 1);
        auto hBand = MEMCreateRasterBandEx(
            poMemDS.get(), iBand + 1, const_cast<GByte *>(pabyBand), eType, 3,
            nRawXSize * RMF_JPEG_BAND_COUNT, false);
        poMemDS->AddMEMBand(hBand);
    }

    const CPLString osTmpFilename(VSIMemGenerateHiddenFilename("rmfjpeg.jpg"));

    char szQuality[32] = {};
    if (poDS != nullptr && poDS->sHeader.iJpegQuality > 0)
    {
        snprintf(szQuality, sizeof(szQuality), "QUALITY=%d",
                 poDS->sHeader.iJpegQuality);
    }
    else
    {
        snprintf(szQuality, sizeof(szQuality), "QUALITY=75");
    }

    char *apszJpegOptions[2] = {szQuality, nullptr};

    GDALDatasetH hJpeg =
        GDALCreateCopy(hJpegDriver, osTmpFilename, poMemDS.get(), 0,
                       apszJpegOptions, nullptr, nullptr);
    poMemDS.reset();

    if (hJpeg == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "RMF JPEG: Error compress JPEG tile");
        VSIUnlink(osTmpFilename);
        return 0;
    }

    GDALClose(hJpeg);

    vsi_l_offset nDataLength = 0;
    GByte *pabyBuffer = VSIGetMemFileBuffer(osTmpFilename, &nDataLength, TRUE);

    if (nDataLength < nSizeOut)
    {
        memcpy(pabyOut, pabyBuffer, static_cast<size_t>(nDataLength));
        CPLFree(pabyBuffer);
        return static_cast<size_t>(nDataLength);
    }

    CPLFree(pabyBuffer);
    return 0;
}
#endif  // HAVE_LIBJPEG