/******************************************************************************
 *
 * Project:  RPF A.TOC read Library
 * Purpose:  Module responsible for opening a RPF TOC file, populating RPFToc
 *           structure
 * Author:   Even Rouault, even.rouault at spatialys.com
 *
 **********************************************************************
 * Copyright (c) 2007-2010, Even Rouault <even dot rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

/* Portions of code are placed under the following copyright : */
/*
 ******************************************************************************
 * Copyright (C) 1995 Logiciels et Applications Scientifiques (L.A.S.) Inc
 * Permission to use, copy, modify and distribute this software and
 * its documentation for any purpose and without fee is hereby granted,
 * provided that the above copyright notice appear in all copies, that
 * both the copyright notice and this permission notice appear in
 * supporting documentation, and that the name of L.A.S. Inc not be used
 * in advertising or publicity pertaining to distribution of the software
 * without specific, written prior permission. L.A.S. Inc. makes no
 * representations about the suitability of this software for any purpose.
 * It is provided "as is" without express or implied warranty.
 ******************************************************************************
 */

#include "cpl_port.h"
#include "rpftoclib.h"

#include <climits>
#include <cmath>
#include <cstring>
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif

#include "cpl_conv.h"
#include "cpl_error.h"
#include "cpl_string.h"
#include "cpl_vsi.h"
#include "nitflib.h"

/************************************************************************/
/*                        RPFTOCTrim()                                    */
/************************************************************************/

static void RPFTOCTrim(char *str)
{
    char *c = str;
    if (str == nullptr || *str == 0)
        return;

    while (*c == ' ')
    {
        c++;
    }
    if (c != str)
    {
        memmove(str, c, strlen(c) + 1);
    }

    int i = static_cast<int>(strlen(str)) - 1;
    while (i >= 0 && str[i] == ' ')
    {
        str[i] = 0;
        i--;
    }
}

/************************************************************************/
/*                        RPFTOCRead()                                 */
/************************************************************************/

RPFToc *RPFTOCRead(const char *pszFilename, NITFFile *psFile)
{
    int nTRESize;
    const char *pachTRE =
        NITFFindTRE(psFile->pachTRE, psFile->nTREBytes, "RPFHDR", &nTRESize);
    if (pachTRE == nullptr)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Invalid TOC file. Can't find RPFHDR.");
        return nullptr;
    }

    if (nTRESize != 48)
    {
        CPLError(CE_Failure, CPLE_NotSupported, "RPFHDR TRE wrong size.");
        return nullptr;
    }

    return RPFTOCReadFromBuffer(pszFilename, psFile->fp, pachTRE);
}

/* This function is directly inspired by function parse_toc coming from
 * ogdi/driver/rpf/utils.c */

RPFToc *RPFTOCReadFromBuffer(const char *pszFilename, VSILFILE *fp,
                             const char *tocHeader)
{
    tocHeader += 1;  /* skip endian */
    tocHeader += 2;  /* skip header length */
    tocHeader += 12; /* skip file name : this should be A.TOC (padded) */
    tocHeader += 1;  /* skip new  */
    tocHeader += 15; /* skip standard_num  */
    tocHeader += 8;  /* skip standard_date  */
    tocHeader += 1;  /* skip classification  */
    tocHeader += 2;  /* skip country  */
    tocHeader += 2;  /* skip release  */

    unsigned int locationSectionPhysicalLocation;
    memcpy(&locationSectionPhysicalLocation, tocHeader, sizeof(unsigned int));
    CPL_MSBPTR32(&locationSectionPhysicalLocation);

    if (VSIFSeekL(fp, locationSectionPhysicalLocation, SEEK_SET) != 0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Invalid TOC file. Unable to seek to "
                 "locationSectionPhysicalLocation at offset %d.",
                 locationSectionPhysicalLocation);
        return nullptr;
    }

    int nSections;
    NITFLocation *pasLocations = NITFReadRPFLocationTable(fp, &nSections);

    unsigned int boundaryRectangleSectionSubHeaderPhysIndex = 0;
    unsigned int boundaryRectangleTablePhysIndex = 0;
    unsigned int frameFileIndexSectionSubHeaderPhysIndex = 0;
    unsigned int frameFileIndexSubsectionPhysIndex = 0;

    for (int i = 0; i < nSections; i++)
    {
        if (pasLocations[i].nLocId == LID_BoundaryRectangleSectionSubheader)
        {
            boundaryRectangleSectionSubHeaderPhysIndex =
                pasLocations[i].nLocOffset;
        }
        else if (pasLocations[i].nLocId == LID_BoundaryRectangleTable)
        {
            boundaryRectangleTablePhysIndex = pasLocations[i].nLocOffset;
        }
        else if (pasLocations[i].nLocId == LID_FrameFileIndexSectionSubHeader)
        {
            frameFileIndexSectionSubHeaderPhysIndex =
                pasLocations[i].nLocOffset;
        }
        else if (pasLocations[i].nLocId == LID_FrameFileIndexSubsection)
        {
            frameFileIndexSubsectionPhysIndex = pasLocations[i].nLocOffset;
        }
    }

    CPLFree(pasLocations);

    if (boundaryRectangleSectionSubHeaderPhysIndex == 0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Invalid TOC file. Can't find "
                 "LID_BoundaryRectangleSectionSubheader.");
        return nullptr;
    }
    if (boundaryRectangleTablePhysIndex == 0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Invalid TOC file. Can't find LID_BoundaryRectangleTable.");
        return nullptr;
    }
    if (frameFileIndexSectionSubHeaderPhysIndex == 0)
    {
        CPLError(
            CE_Failure, CPLE_NotSupported,
            "Invalid TOC file. Can't find LID_FrameFileIndexSectionSubHeader.");
        return nullptr;
    }
    if (frameFileIndexSubsectionPhysIndex == 0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Invalid TOC file. Can't find LID_FrameFileIndexSubsection.");
        return nullptr;
    }

    if (VSIFSeekL(fp, boundaryRectangleSectionSubHeaderPhysIndex, SEEK_SET) !=
        0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Invalid TOC file. Unable to seek to "
                 "boundaryRectangleSectionSubHeaderPhysIndex at offset %d.",
                 boundaryRectangleSectionSubHeaderPhysIndex);
        return nullptr;
    }

    unsigned int boundaryRectangleTableOffset;
    bool bOK = VSIFReadL(&boundaryRectangleTableOffset,
                         sizeof(boundaryRectangleTableOffset), 1, fp) == 1;
    CPL_MSBPTR32(&boundaryRectangleTableOffset);

    unsigned short boundaryRectangleCount;
    bOK &= VSIFReadL(&boundaryRectangleCount, sizeof(boundaryRectangleCount), 1,
                     fp) == 1;
    CPL_MSBPTR16(&boundaryRectangleCount);

    if (!bOK || VSIFSeekL(fp, boundaryRectangleTablePhysIndex, SEEK_SET) != 0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Invalid TOC file. Unable to seek to "
                 "boundaryRectangleTablePhysIndex at offset %d.",
                 boundaryRectangleTablePhysIndex);
        return nullptr;
    }

    RPFToc *toc = reinterpret_cast<RPFToc *>(CPLMalloc(sizeof(RPFToc)));
    toc->nEntries = boundaryRectangleCount;
    toc->entries = reinterpret_cast<RPFTocEntry *>(
        CPLMalloc(boundaryRectangleCount * sizeof(RPFTocEntry)));
    memset(toc->entries, 0, boundaryRectangleCount * sizeof(RPFTocEntry));

    for (int i = 0; i < toc->nEntries; i++)
    {
        toc->entries[i].isOverviewOrLegend = 0;

        bOK &= VSIFReadL(toc->entries[i].type, 1, 5, fp) == 5;
        toc->entries[i].type[5] = 0;
        RPFTOCTrim(toc->entries[i].type);

        bOK &= VSIFReadL(toc->entries[i].compression, 1, 5, fp) == 5;
        toc->entries[i].compression[5] = 0;
        RPFTOCTrim(toc->entries[i].compression);

        bOK &= VSIFReadL(toc->entries[i].scale, 1, 12, fp) == 12;
        toc->entries[i].scale[12] = 0;
        RPFTOCTrim(toc->entries[i].scale);
        if (toc->entries[i].scale[0] == '1' && toc->entries[i].scale[1] == ':')
        {
            memmove(toc->entries[i].scale, toc->entries[i].scale + 2,
                    strlen(toc->entries[i].scale + 2) + 1);
        }

        bOK &= VSIFReadL(toc->entries[i].zone, 1, 1, fp) == 1;
        toc->entries[i].zone[1] = 0;
        RPFTOCTrim(toc->entries[i].zone);

        bOK &= VSIFReadL(toc->entries[i].producer, 1, 5, fp) == 5;
        toc->entries[i].producer[5] = 0;
        RPFTOCTrim(toc->entries[i].producer);

        bOK &= VSIFReadL(&toc->entries[i].nwLat, sizeof(double), 1, fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].nwLat);

        bOK &= VSIFReadL(&toc->entries[i].nwLong, sizeof(double), 1, fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].nwLong);

        bOK &= VSIFReadL(&toc->entries[i].swLat, sizeof(double), 1, fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].swLat);

        bOK &= VSIFReadL(&toc->entries[i].swLong, sizeof(double), 1, fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].swLong);

        bOK &= VSIFReadL(&toc->entries[i].neLat, sizeof(double), 1, fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].neLat);

        bOK &= VSIFReadL(&toc->entries[i].neLong, sizeof(double), 1, fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].neLong);

        bOK &= VSIFReadL(&toc->entries[i].seLat, sizeof(double), 1, fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].seLat);

        bOK &= VSIFReadL(&toc->entries[i].seLong, sizeof(double), 1, fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].seLong);

        bOK &= VSIFReadL(&toc->entries[i].vertResolution, sizeof(double), 1,
                         fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].vertResolution);

        bOK &= VSIFReadL(&toc->entries[i].horizResolution, sizeof(double), 1,
                         fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].horizResolution);

        bOK &= VSIFReadL(&toc->entries[i].vertInterval, sizeof(double), 1,
                         fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].vertInterval);

        bOK &= VSIFReadL(&toc->entries[i].horizInterval, sizeof(double), 1,
                         fp) == 1;
        CPL_MSBPTR64(&toc->entries[i].horizInterval);

        bOK &= VSIFReadL(&toc->entries[i].nVertFrames, sizeof(int), 1, fp) == 1;
        CPL_MSBPTR32(&toc->entries[i].nVertFrames);

        bOK &=
            VSIFReadL(&toc->entries[i].nHorizFrames, sizeof(int), 1, fp) == 1;
        CPL_MSBPTR32(&toc->entries[i].nHorizFrames);

        if (!bOK)
        {
            CPLError(CE_Failure, CPLE_FileIO, "I/O error");
            toc->entries[i].nVertFrames = 0;
            toc->entries[i].nHorizFrames = 0;
            RPFTOCFree(toc);
            return nullptr;
        }

        // do some basic plausibility checks for all entries
        if (toc->entries[i].vertInterval <= 1e-10 ||
            !std::isfinite(toc->entries[i].vertInterval) ||
            toc->entries[i].horizInterval <= 1e-10 ||
            !std::isfinite(toc->entries[i].horizInterval) ||
            toc->entries[i].nHorizFrames == 0 ||
            toc->entries[i].nVertFrames == 0 ||
            toc->entries[i].nHorizFrames >
                INT_MAX / toc->entries[i].nVertFrames)
        {
            CPLError(CE_Failure, CPLE_FileIO, "Invalid TOC entry");
            toc->entries[i].nVertFrames = 0;
            toc->entries[i].nHorizFrames = 0;
            RPFTOCFree(toc);
            return nullptr;
        }

        // Overview has ZONE 'R' and Legend ZONE 'D' but because the Zone 'D' is
        // also a valid Zone we need an additional check. -> In all cases of
        // Overview/Legend the values of the BoundingBox are equal so we simply
        // check here that NW == SE is.
        toc->entries[i].isOverviewOrLegend =
            (toc->entries[i].zone[0] == 'R' ||   // Overview
             (toc->entries[i].zone[0] == 'D' &&  // Legend
              memcmp(&(toc->entries[i].seLong), &(toc->entries[i].nwLong),
                     sizeof(toc->entries[i].nwLong)) == 0 &&
              memcmp(&(toc->entries[i].seLat), &(toc->entries[i].nwLat),
                     sizeof(toc->entries[i].nwLat)) == 0));

        bool isPolarZone = (toc->entries[i].zone[0] == '9') ||
                           (toc->entries[i].zone[0] == 'J');

        // make additional checks of the bounding for charts (without Legends
        // and Overviews)
        if (!toc->entries[i].isOverviewOrLegend)
        {
            if (!(fabs(toc->entries[i].seLong) <= 360.0) ||
                !(fabs(toc->entries[i].nwLong) <= 360.0) ||
                !(fabs(toc->entries[i].nwLat) <= 90.0) ||
                !(fabs(toc->entries[i].seLat) <= 90.0) ||
                // check only for non-polar zones, because the values are not
                // always correct here
                (!isPolarZone &&
                 (toc->entries[i].seLong < toc->entries[i].nwLong ||
                  toc->entries[i].nwLat < toc->entries[i].seLat)))
            {
                CPLError(CE_Failure, CPLE_FileIO, "Invalid TOC entry");
                toc->entries[i].nVertFrames = 0;
                toc->entries[i].nHorizFrames = 0;
                RPFTOCFree(toc);
                return nullptr;
            }
        }

        // TODO: We could probably use another data structure, like a list,
        // instead of an array referenced by the frame coordinate...
        if (static_cast<int>(toc->entries[i].nHorizFrames *
                             toc->entries[i].nVertFrames) >
            atoi(CPLGetConfigOption("RPFTOC_MAX_FRAME_COUNT", "1000000")))
        {
            CPLError(
                CE_Failure, CPLE_AppDefined,
                "nHorizFrames=%d x nVertFrames=%d > %d. Please raise "
                "the value of the RPFTOC_MAX_FRAME_COUNT configuration "
                "option to more than %d if this dataset is legitimate.",
                toc->entries[i].nHorizFrames, toc->entries[i].nVertFrames,
                atoi(CPLGetConfigOption("RPFTOC_MAX_FRAME_COUNT", "1000000")),
                toc->entries[i].nHorizFrames * toc->entries[i].nVertFrames);
            toc->entries[i].frameEntries = nullptr;
        }
        else
        {
            toc->entries[i].frameEntries =
                reinterpret_cast<RPFTocFrameEntry *>(VSI_CALLOC_VERBOSE(
                    static_cast<size_t>(toc->entries[i].nVertFrames) *
                        toc->entries[i].nHorizFrames,
                    sizeof(RPFTocFrameEntry)));
        }
        if (toc->entries[i].frameEntries == nullptr)
        {
            toc->entries[i].nVertFrames = 0;
            toc->entries[i].nHorizFrames = 0;
            RPFTOCFree(toc);
            return nullptr;
        }

        CPLDebug("RPFTOC",
                 "[%d] type=%s, compression=%s, scale=%s, zone=%s, "
                 "producer=%s, nVertFrames=%d, nHorizFrames=%d",
                 i, toc->entries[i].type, toc->entries[i].compression,
                 toc->entries[i].scale, toc->entries[i].zone,
                 toc->entries[i].producer, toc->entries[i].nVertFrames,
                 toc->entries[i].nHorizFrames);
    }

    if (VSIFSeekL(fp, frameFileIndexSectionSubHeaderPhysIndex, SEEK_SET) != 0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Invalid TOC file. Unable to seek to "
                 "frameFileIndexSectionSubHeaderPhysIndex at offset %d.",
                 frameFileIndexSectionSubHeaderPhysIndex);
        RPFTOCFree(toc);
        return nullptr;
    }

    /* Skip 1 byte security classification */
    bOK &= VSIFSeekL(fp, 1, SEEK_CUR) == 0;

    unsigned int frameIndexTableOffset;
    bOK &= VSIFReadL(&frameIndexTableOffset, sizeof(frameIndexTableOffset), 1,
                     fp) == 1;
    CPL_MSBPTR32(&frameIndexTableOffset);

    unsigned int nFrameFileIndexRecords;
    bOK &= VSIFReadL(&nFrameFileIndexRecords, sizeof(nFrameFileIndexRecords), 1,
                     fp) == 1;
    CPL_MSBPTR32(&nFrameFileIndexRecords);

    unsigned short nFrameFilePathnameRecords;
    bOK &= VSIFReadL(&nFrameFilePathnameRecords,
                     sizeof(nFrameFilePathnameRecords), 1, fp) == 1;
    CPL_MSBPTR16(&nFrameFilePathnameRecords);

    unsigned short frameFileIndexRecordLength;
    bOK &= VSIFReadL(&frameFileIndexRecordLength,
                     sizeof(frameFileIndexRecordLength), 1, fp) == 1;
    CPL_MSBPTR16(&frameFileIndexRecordLength);
    if (frameFileIndexRecordLength < 3 * sizeof(short))
    {
        CPLError(CE_Failure, CPLE_FileIO, "Invalid file");
        RPFTOCFree(toc);
        return nullptr;
    }

    if (!bOK)
    {
        CPLError(CE_Failure, CPLE_FileIO, "I/O error");
        RPFTOCFree(toc);
        return nullptr;
    }

    int newBoundaryId = 0;

    for (int i = 0; i < static_cast<int>(nFrameFileIndexRecords); i++)
    {
        vsi_l_offset nFrameOffset =
            static_cast<vsi_l_offset>(frameFileIndexSubsectionPhysIndex) +
            static_cast<vsi_l_offset>(frameFileIndexRecordLength) * i;
        if (VSIFSeekL(fp, nFrameOffset, SEEK_SET) != 0)
        {
            CPLError(
                CE_Failure, CPLE_NotSupported,
                "Invalid TOC file. Unable to seek to "
                "frameFileIndexSubsectionPhysIndex(%d) at offset " CPL_FRMT_GUIB
                ".",
                i, static_cast<GUIntBig>(nFrameOffset));
            RPFTOCFree(toc);
            return nullptr;
        }

        unsigned short boundaryId;
        if (VSIFReadL(&boundaryId, sizeof(boundaryId), 1, fp) != 1)
        {
            CPLError(CE_Failure, CPLE_FileIO, "I/O error");
            RPFTOCFree(toc);
            return nullptr;
        }
        CPL_MSBPTR16(&boundaryId);

        if (i == 0 && boundaryId == 0)
            newBoundaryId = 1;
        if (newBoundaryId == 0)
            boundaryId--;

        if (boundaryId >= toc->nEntries)
        {
            CPLError(CE_Failure, CPLE_NotSupported,
                     "Invalid TOC file. Bad boundary id (%d) for frame file "
                     "index %d.",
                     boundaryId, i);
            RPFTOCFree(toc);
            return nullptr;
        }

        RPFTocEntry *entry = &toc->entries[boundaryId];
        entry->boundaryId = boundaryId;

        unsigned short frameRow;
        bOK &= VSIFReadL(&frameRow, sizeof(frameRow), 1, fp) == 1;
        CPL_MSBPTR16(&frameRow);

        unsigned short frameCol;
        bOK &= VSIFReadL(&frameCol, sizeof(frameCol), 1, fp) == 1;
        CPL_MSBPTR16(&frameCol);
        if (!bOK)
        {
            CPLError(CE_Failure, CPLE_FileIO, "I/O error");
            RPFTOCFree(toc);
            return nullptr;
        }

        if (newBoundaryId == 0)
        {
            frameRow--;
            frameCol--;
        }
        else
        {
            /* Trick so that frames are numbered north to south */
            if (entry->nVertFrames - 1 < frameRow)
            {
                CPLError(CE_Failure, CPLE_FileIO,
                         "Invalid nVertFrames vs frameRow");
                RPFTOCFree(toc);
                return nullptr;
            }
            frameRow = (unsigned short)((entry->nVertFrames - 1) - frameRow);
        }

        if (frameRow >= entry->nVertFrames)
        {
            CPLError(
                CE_Failure, CPLE_NotSupported,
                "Invalid TOC file. Bad row num (%d) for frame file index %d.",
                frameRow, i);
            RPFTOCFree(toc);
            return nullptr;
        }

        if (frameCol >= entry->nHorizFrames)
        {
            CPLError(
                CE_Failure, CPLE_NotSupported,
                "Invalid TOC file. Bad col num (%d) for frame file index %d.",
                frameCol, i);
            RPFTOCFree(toc);
            return nullptr;
        }

        RPFTocFrameEntry *frameEntry =
            &entry->frameEntries[frameRow * entry->nHorizFrames + frameCol];
        frameEntry->frameRow = frameRow;
        frameEntry->frameCol = frameCol;

        if (frameEntry->exists)
        {
            CPLError(
                CE_Warning, CPLE_AppDefined,
                "Frame entry(%d,%d) for frame file index %d was already found.",
                frameRow, frameCol, i);
            CPLFree(frameEntry->directory);
            frameEntry->directory = nullptr;
            CPLFree(frameEntry->fullFilePath);
            frameEntry->fullFilePath = nullptr;
            frameEntry->exists = 0;
        }

        unsigned int offsetFrameFilePathName;
        bOK &= VSIFReadL(&offsetFrameFilePathName,
                         sizeof(offsetFrameFilePathName), 1, fp) == 1;
        CPL_MSBPTR32(&offsetFrameFilePathName);

        bOK &= VSIFReadL(frameEntry->filename, 1, 12, fp) == 12;
        if (!bOK)
        {
            CPLError(CE_Failure, CPLE_FileIO, "I/O error");
            RPFTOCFree(toc);
            return nullptr;
        }
        frameEntry->filename[12] = '\0';
        bOK &= strlen(frameEntry->filename) > 0;

        // Check (case insensitive) if the filename is an overview or legend
        // some CADRG maps have legend name smaller than 8.3 then the extension
        // has blanks (0x20) at the end -> check only the first 3 letters of the
        // extension.
        const std::string fileExt = CPLGetExtensionSafe(frameEntry->filename);
        if (EQUALN(fileExt.c_str(), "ovr", 3) ||
            EQUALN(fileExt.c_str(), "lgd", 3))
        {
            entry->isOverviewOrLegend = TRUE;
        }

        /* Extract series code */
        if (entry->seriesAbbreviation == nullptr)
        {
            const NITFSeries *series = NITFGetSeriesInfo(frameEntry->filename);
            if (series)
            {
                entry->seriesAbbreviation = series->abbreviation;
                entry->seriesName = series->name;
            }
        }

        /* Get file geo reference */
        bOK &= VSIFReadL(frameEntry->georef, 1, 6, fp) == 6;
        frameEntry->georef[6] = '\0';

        /* Go to start of pathname record */
        /* New path_off offset from start of frame file index section of TOC??
         */
        /* Add pathoffset wrt frame file index table subsection (loc[3]) */
        if (!bOK || VSIFSeekL(fp,
                              static_cast<vsi_l_offset>(
                                  frameFileIndexSubsectionPhysIndex) +
                                  offsetFrameFilePathName,
                              SEEK_SET) != 0)
        {
            CPLError(CE_Failure, CPLE_NotSupported,
                     "Invalid TOC file. Unable to seek to "
                     "frameFileIndexSubsectionPhysIndex + "
                     "offsetFrameFilePathName(%d) at offset " CPL_FRMT_GUIB ".",
                     i,
                     static_cast<GUIntBig>(frameFileIndexSubsectionPhysIndex) +
                         offsetFrameFilePathName);
            RPFTOCFree(toc);
            return nullptr;
        }

        unsigned short pathLength;
        bOK &= VSIFReadL(&pathLength, sizeof(pathLength), 1, fp) == 1;
        CPL_MSBPTR16(&pathLength);

        /* if nFrameFileIndexRecords == 65535 and pathLength == 65535 for each
           record, this leads to 4 GB allocation... Protect against this case */
        if (!bOK || pathLength == 0 || pathLength > 256)
        {
            CPLError(
                CE_Failure, CPLE_NotSupported,
                "Path length is invalid : %d. Probably corrupted TOC file.",
                static_cast<int>(pathLength));
            RPFTOCFree(toc);
            return nullptr;
        }

        frameEntry->directory =
            reinterpret_cast<char *>(CPLMalloc(pathLength + 1));
        bOK &=
            VSIFReadL(frameEntry->directory, 1, pathLength, fp) == pathLength;
        if (!bOK)
        {
            CPLError(CE_Failure, CPLE_FileIO, "I/O error");
            RPFTOCFree(toc);
            return nullptr;
        }
        frameEntry->directory[pathLength] = 0;
        if (frameEntry->directory[pathLength - 1] == '/')
            frameEntry->directory[pathLength - 1] = 0;

        if (frameEntry->directory[0] == '.' && frameEntry->directory[1] == '/')
        {
            memmove(frameEntry->directory, frameEntry->directory + 2,
                    strlen(frameEntry->directory + 2) + 1);

            // Some A.TOC have subdirectory names like ".//X/" ... (#5979)
            // Check if it was not intended to be "./X/" instead.
            VSIStatBufL sStatBuf;
            if (frameEntry->directory[0] == '/' &&
                VSIStatL(
                    CPLFormFilenameSafe(CPLGetDirnameSafe(pszFilename).c_str(),
                                        frameEntry->directory + 1, nullptr)
                        .c_str(),
                    &sStatBuf) == 0 &&
                VSI_ISDIR(sStatBuf.st_mode))
            {
                memmove(frameEntry->directory, frameEntry->directory + 1,
                        strlen(frameEntry->directory + 1) + 1);
            }
        }

        {
            char *baseDir = CPLStrdup(CPLGetDirnameSafe(pszFilename).c_str());
            VSIStatBufL sStatBuf;
            char *subdir = nullptr;
            if (CPLIsFilenameRelative(frameEntry->directory) == FALSE)
                subdir = CPLStrdup(frameEntry->directory);
            else if (frameEntry->directory[0] == '.' &&
                     frameEntry->directory[1] == 0)
                subdir = CPLStrdup(baseDir);
            else
                subdir = CPLStrdup(
                    CPLFormFilenameSafe(baseDir, frameEntry->directory, nullptr)
                        .c_str());
#if !defined(_WIN32) && !defined(_WIN32_CE)
            if (VSIStatL(subdir, &sStatBuf) != 0 &&
                strlen(subdir) > strlen(baseDir))
            {
                char *c = subdir + strlen(baseDir) + 1;
                while (*c)
                {
                    if (*c >= 'A' && *c <= 'Z')
                        *c += 'a' - 'A';
                    c++;
                }
            }
#endif
            frameEntry->fullFilePath = CPLStrdup(
                CPLFormFilenameSafe(subdir, frameEntry->filename, nullptr)
                    .c_str());
            if (VSIStatL(frameEntry->fullFilePath, &sStatBuf) != 0)
            {
#if !defined(_WIN32) && !defined(_WIN32_CE)
                if (strlen(frameEntry->fullFilePath) > strlen(subdir))
                {
                    char *c = frameEntry->fullFilePath + strlen(subdir) + 1;
                    while (*c)
                    {
                        if (*c >= 'A' && *c <= 'Z')
                            *c += 'a' - 'A';
                        c++;
                    }
                }
                if (VSIStatL(frameEntry->fullFilePath, &sStatBuf) != 0)
#endif
                {
                    frameEntry->fileExists = 0;
                    CPLError(CE_Warning, CPLE_AppDefined,
                             "File %s does not exist.",
                             frameEntry->fullFilePath);
                }
#if !defined(_WIN32) && !defined(_WIN32_CE)
                else
                {
                    frameEntry->fileExists = 1;
                }
#endif
            }
            else
            {
                frameEntry->fileExists = 1;
            }
            CPLFree(subdir);
            CPLFree(baseDir);
        }

        CPLDebug("RPFTOC", "Entry %d : %s,%s (%d, %d)", boundaryId,
                 frameEntry->directory, frameEntry->filename, frameRow,
                 frameCol);

        frameEntry->exists = 1;
    }

    return toc;
}

/************************************************************************/
/*                        RPFTOCFree()                                 */
/************************************************************************/

void RPFTOCFree(RPFToc *toc)
{
    if (!toc)
        return;

    for (int i = 0; i < toc->nEntries; i++)
    {
        for (int j = 0; j < static_cast<int>(toc->entries[i].nVertFrames *
                                             toc->entries[i].nHorizFrames);
             j++)
        {
            CPLFree(toc->entries[i].frameEntries[j].fullFilePath);
            CPLFree(toc->entries[i].frameEntries[j].directory);
        }
        CPLFree(toc->entries[i].frameEntries);
    }

    CPLFree(toc->entries);
    CPLFree(toc);
}
