/* ****************************************************************************
 *
 * Project:  GDAL Utilities
 * Purpose:  Dump overviews to external files.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 * ****************************************************************************
 * Copyright (c) 2005, Frank Warmerdam
 * Copyright (c) 2009-2010, Even Rouault <even dot rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "cpl_conv.h"
#include "cpl_string.h"
#include "gdal_priv.h"
#include "ogr_spatialref.h"

static bool DumpBand(GDALDatasetH hBaseDS, GDALRasterBandH hBand,
                     const char *pszName);

/************************************************************************/
/*                               Usage()                                */
/************************************************************************/
static void Usage()

{
    printf("Usage: dumpoverviews [-masks] <filename> [<overview>]...\n");
    exit(1);
}

/************************************************************************/
/*                                main()                                */
/************************************************************************/

int main(int argc, char **argv)

{
    GDALAllRegister();

    argc = GDALGeneralCmdLineProcessor(argc, &argv, 0);
    if (argc < 1)
        exit(-argc);

    /* -------------------------------------------------------------------- */
    /*      Process arguments.                                              */
    /* -------------------------------------------------------------------- */
    const char *pszSrcFilename = nullptr;
    int anReqOverviews[1000] = {};
    int nReqOverviewCount = 0;
    bool bMasks = false;

    for (int iArg = 1; iArg < argc; iArg++)
    {
        if (EQUAL(argv[iArg], "-masks"))
        {
            bMasks = true;
        }
        else if (pszSrcFilename == nullptr)
        {
            pszSrcFilename = argv[iArg];
        }
        else if (atoi(argv[iArg]) > 0 || EQUAL(argv[iArg], "0"))
        {
            anReqOverviews[nReqOverviewCount++] = atoi(argv[iArg]);
        }
        else
        {
            Usage();
        }
    }

    if (pszSrcFilename == nullptr)
        Usage();

    /* -------------------------------------------------------------------- */
    /*      Open the input file.                                            */
    /* -------------------------------------------------------------------- */
    GDALDatasetH hSrcDS = GDALOpen(pszSrcFilename, GA_ReadOnly);

    if (hSrcDS == nullptr)
        exit(1);

    /* ==================================================================== */
    /*      Process all bands.                                              */
    /* ==================================================================== */
    const int nBandCount = GDALGetRasterCount(hSrcDS);

    bool bRet = true;
    for (int iBand = 0; iBand < nBandCount; iBand++)
    {
        GDALRasterBandH hBaseBand = GDALGetRasterBand(hSrcDS, iBand + 1);

        /* --------------------------------------------------------------------
         */
        /*      Process all overviews. */
        /* --------------------------------------------------------------------
         */
        const int nOverviewCount = GDALGetOverviewCount(hBaseBand);

        for (int iOverview = 0; iOverview < nOverviewCount; iOverview++)
        {
            GDALRasterBandH hSrcOver = GDALGetOverview(hBaseBand, iOverview);

            if (hSrcOver == nullptr)
            {
                fprintf(stderr, "skipping overview %d as being null\n",
                        iOverview);
                continue;
            }

            /* --------------------------------------------------------------------
             */
            /*      Is this a requested overview? */
            /* --------------------------------------------------------------------
             */
            if (nReqOverviewCount > 0)
            {
                int i = 0;  // Used after for.

                for (; i < nReqOverviewCount; i++)
                {
                    if (anReqOverviews[i] == iOverview)
                        break;
                }

                if (i == nReqOverviewCount)
                    continue;
            }

            /* --------------------------------------------------------------------
             */
            /*      Create matching output file. */
            /* --------------------------------------------------------------------
             */
            CPLString osFilename;
            osFilename.Printf("%s_%d_%d.tif",
                              CPLGetBasenameSafe(pszSrcFilename).c_str(),
                              iBand + 1, iOverview);
            if (!DumpBand(hSrcDS, hSrcOver, osFilename))
                bRet = false;

            if (bMasks)
            {
                CPLString osMaskFilename;
                osMaskFilename.Printf(
                    "%s_%d_%d_mask.tif",
                    CPLGetBasenameSafe(pszSrcFilename).c_str(), iBand + 1,
                    iOverview);
                if (!DumpBand(hSrcDS, GDALGetMaskBand(hSrcOver),
                              osMaskFilename))
                    bRet = false;
            }
        }

        /* --------------------------------------------------------------------
         */
        /*      Do we dump the mask? */
        /* --------------------------------------------------------------------
         */
        if (bMasks)
        {
            CPLString osFilename;
            osFilename.Printf("%s_%d_mask.tif",
                              CPLGetBasenameSafe(pszSrcFilename).c_str(),
                              iBand + 1);
            if (!DumpBand(hSrcDS, GDALGetMaskBand(hBaseBand), osFilename))
                bRet = false;
        }
    }

    GDALClose(hSrcDS);

    CSLDestroy(argv);
    GDALDestroyDriverManager();

    return bRet ? 0 : 1;
}

/************************************************************************/
/*                              DumpBand()                              */
/************************************************************************/

static bool DumpBand(GDALDatasetH hBaseDS, GDALRasterBandH hSrcOver,
                     const char *pszName)

{
    /* -------------------------------------------------------------------- */
    /*      Get base ds info.                                               */
    /* -------------------------------------------------------------------- */
    double adfGeoTransform[6] = {0.0, 0.0, 0.0, 0.0, 0.0, 0.0};
    bool bHaveGT = GDALGetGeoTransform(hBaseDS, adfGeoTransform) == CE_None;

    const int nOrigXSize = GDALGetRasterXSize(hBaseDS);
    const int nOrigYSize = GDALGetRasterYSize(hBaseDS);

    /* -------------------------------------------------------------------- */
    /*      Create matching output file.                                    */
    /* -------------------------------------------------------------------- */
    const int nXSize = GDALGetRasterBandXSize(hSrcOver);
    const int nYSize = GDALGetRasterBandYSize(hSrcOver);
    const GDALDataType eDT = GDALGetRasterDataType(hSrcOver);
    GDALDriverH hDriver = GDALGetDriverByName("GTiff");

    GDALDatasetH hDstDS =
        GDALCreate(hDriver, pszName, nXSize, nYSize, 1, eDT, nullptr);

    if (hDstDS == nullptr)
        exit(1);

    /* -------------------------------------------------------------------- */
    /*      Apply corresponding georeferencing, scaled to size.             */
    /* -------------------------------------------------------------------- */
    if (bHaveGT)
    {
        double adfOvGeoTransform[6] = {0.0, 0.0, 0.0, 0.0, 0.0, 0.0};

        memcpy(adfOvGeoTransform, adfGeoTransform, sizeof(double) * 6);

        adfOvGeoTransform[1] *= nOrigXSize / static_cast<double>(nXSize);
        adfOvGeoTransform[2] *= nOrigXSize / static_cast<double>(nXSize);
        adfOvGeoTransform[4] *= nOrigYSize / static_cast<double>(nYSize);
        adfOvGeoTransform[5] *= nOrigYSize / static_cast<double>(nYSize);

        GDALSetGeoTransform(hDstDS, adfOvGeoTransform);

        GDALSetProjection(hDstDS, GDALGetProjectionRef(hBaseDS));
    }

    /* -------------------------------------------------------------------- */
    /*      Copy over all the image data.                                   */
    /* -------------------------------------------------------------------- */
    void *pData = CPLMalloc(64 * nXSize);

    bool bRet = true;
    for (int iLine = 0; iLine < nYSize; iLine++)
    {
        {
            const CPLErr err = GDALRasterIO(hSrcOver, GF_Read, 0, iLine, nXSize,
                                            1, pData, nXSize, 1, eDT, 0, 0);
            if (err != CE_None)
            {
                bRet = false;
                CPLError(CE_Failure, CPLE_FileIO,
                         "GDALRasterIO read failed at %d.", iLine);
            }
        }

        const CPLErr err =
            GDALRasterIO(GDALGetRasterBand(hDstDS, 1), GF_Write, 0, iLine,
                         nXSize, 1, pData, nXSize, 1, eDT, 0, 0);
        if (err != CE_None)
        {
            bRet = false;
            CPLError(CE_Failure, CPLE_FileIO,
                     "GDALRasterIO write failed at %d.", iLine);
        }
    }
    CPLFree(pData);

    if (GDALClose(hDstDS) != CE_None)
        bRet = false;
    return bRet;
}