/******************************************************************************
 *
 * Project:  ACE2 Driver
 * Purpose:  Implementation of ACE2 elevation format read support.
 *           http://tethys.eaprs.cse.dmu.ac.uk/ACE2/shared/documentation
 * Author:   Even Rouault, <even dot rouault at spatialys.com>
 *
 ******************************************************************************
 * Copyright (c) 2011-2012, Even Rouault <even dot rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "gdal_frmts.h"
#include "gdal_priv.h"
#include "gdal_pam.h"
#include "ogr_spatialref.h"
#include "rawdataset.h"

static const char *const apszCategorySource[] = {
    "Pure SRTM (above 60deg N pure GLOBE data, below 60S pure ACE [original] "
    "data)",
    "SRTM voids filled by interpolation and/or altimeter data",
    "SRTM data warped using the ERS-1 Geodetic Mission",
    "SRTM data warped using EnviSat & ERS-2 data",
    "Mean lake level data derived from Altimetry",
    "GLOBE/ACE data warped using combined altimetry (only above 60deg N)",
    "Pure altimetry data (derived from ERS-1 Geodetic Mission, ERS-2 and "
    "EnviSat data using Delaunay Triangulation",
    nullptr};

static const char *const apszCategoryQuality[] = {
    "Generic - use base datasets",
    "Accuracy of greater than +/- 16m",
    "Accuracy between +/- 16m - +/- 10m",
    "Accuracy between +/-10m - +/-5m",
    "Accuracy between +/-5m - +/-1m",
    "Accuracy between +/-1m",
    nullptr};

static const char *const apszCategoryConfidence[] = {
    "No confidence could be derived due to lack of data",
    "Heights generated by interpolation",
    "Low confidence",
    "Low confidence",
    "Low confidence",
    "Medium confidence",
    "Medium confidence",
    "Medium confidence",
    "Medium confidence",
    "Medium confidence",
    "Medium confidence",
    "Medium confidence",
    "Medium confidence",
    "High confidence",
    "High confidence",
    "High confidence",
    "High confidence",
    "Inland water confidence",
    "Inland water confidence",
    "Inland water confidence",
    "Inland water confidence",
    "Inland water confidence",
    nullptr};

/************************************************************************/
/* ==================================================================== */
/*                             ACE2Dataset                              */
/* ==================================================================== */
/************************************************************************/

class ACE2Dataset final : public GDALPamDataset
{
    friend class ACE2RasterBand;

    OGRSpatialReference m_oSRS{};
    GDALGeoTransform m_gt{};

  public:
    ACE2Dataset();

    const OGRSpatialReference *GetSpatialRef() const override
    {
        return &m_oSRS;
    }

    CPLErr GetGeoTransform(GDALGeoTransform &gt) const override;

    static GDALDataset *Open(GDALOpenInfo *);
    static int Identify(GDALOpenInfo *);
};

/************************************************************************/
/* ==================================================================== */
/*                            ACE2RasterBand                            */
/* ==================================================================== */
/************************************************************************/

class ACE2RasterBand final : public RawRasterBand
{
  public:
    ACE2RasterBand(VSILFILE *fpRaw, GDALDataType eDataType, int nXSize,
                   int nYSize);

    const char *GetUnitType() override;
    char **GetCategoryNames() override;
};

/************************************************************************/
/* ==================================================================== */
/*                             ACE2Dataset                              */
/* ==================================================================== */
/************************************************************************/

/************************************************************************/
/*                            ACE2Dataset()                             */
/************************************************************************/

ACE2Dataset::ACE2Dataset()
{
    m_oSRS.SetFromUserInput(SRS_WKT_WGS84_LAT_LONG);
    m_oSRS.SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER);
}

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

CPLErr ACE2Dataset::GetGeoTransform(GDALGeoTransform &gt) const

{
    gt = m_gt;
    return CE_None;
}

/************************************************************************/
/*                          ACE2RasterBand()                            */
/************************************************************************/

ACE2RasterBand::ACE2RasterBand(VSILFILE *fpRawIn, GDALDataType eDataTypeIn,
                               int nXSize, int nYSize)
    : RawRasterBand(fpRawIn, 0, GDALGetDataTypeSizeBytes(eDataTypeIn),
                    nXSize * GDALGetDataTypeSizeBytes(eDataTypeIn), eDataTypeIn,
                    CPL_IS_LSB, nXSize, nYSize, RawRasterBand::OwnFP::YES)
{
}

/************************************************************************/
/*                             GetUnitType()                            */
/************************************************************************/

const char *ACE2RasterBand::GetUnitType()
{
    if (eDataType == GDT_Float32)
        return "m";

    return "";
}

/************************************************************************/
/*                         GetCategoryNames()                           */
/************************************************************************/

char **ACE2RasterBand::GetCategoryNames()
{
    if (eDataType != GDT_Int16)
        return nullptr;

    const char *pszName = poDS->GetDescription();

    if (strstr(pszName, "_SOURCE_"))
        return const_cast<char **>(apszCategorySource);
    if (strstr(pszName, "_QUALITY_"))
        return const_cast<char **>(apszCategoryQuality);
    if (strstr(pszName, "_CONF_"))
        return const_cast<char **>(apszCategoryConfidence);

    return nullptr;
}

/************************************************************************/
/*                             Identify()                               */
/************************************************************************/

int ACE2Dataset::Identify(GDALOpenInfo *poOpenInfo)

{
    if (!(poOpenInfo->IsExtensionEqualToCI("ACE2") ||
          strstr(poOpenInfo->pszFilename, ".ACE2.gz") ||
          strstr(poOpenInfo->pszFilename, ".ace2.gz")))
        return FALSE;

    return TRUE;
}

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

GDALDataset *ACE2Dataset::Open(GDALOpenInfo *poOpenInfo)

{
    if (!Identify(poOpenInfo))
        return nullptr;

    const std::string osBasename = CPLGetBasenameSafe(poOpenInfo->pszFilename);
    const char *pszBasename = osBasename.c_str();

    if (strlen(pszBasename) < 7)
        return nullptr;

    /* Determine southwest coordinates from filename */

    /* e.g. 30S120W_5M.ACE2 */
    char pszLatLonValueString[4] = {'\0'};
    memset(pszLatLonValueString, 0, 4);
    // cppcheck-suppress redundantCopy
    strncpy(pszLatLonValueString, &pszBasename[0], 2);
    int southWestLat = atoi(pszLatLonValueString);
    memset(pszLatLonValueString, 0, 4);
    // cppcheck-suppress redundantCopy
    strncpy(pszLatLonValueString, &pszBasename[3], 3);
    int southWestLon = atoi(pszLatLonValueString);

    if (pszBasename[2] == 'N' || pszBasename[2] == 'n')
        /*southWestLat = southWestLat*/;
    else if (pszBasename[2] == 'S' || pszBasename[2] == 's')
        southWestLat = southWestLat * -1;
    else
        return nullptr;

    if (pszBasename[6] == 'E' || pszBasename[6] == 'e')
        /*southWestLon = southWestLon*/;
    else if (pszBasename[6] == 'W' || pszBasename[6] == 'w')
        southWestLon = southWestLon * -1;
    else
        return nullptr;

    GDALDataType eDT = GDT_Unknown;
    if (strstr(pszBasename, "_CONF_") || strstr(pszBasename, "_QUALITY_") ||
        strstr(pszBasename, "_SOURCE_"))
        eDT = GDT_Int16;
    else
        eDT = GDT_Float32;
    const int nWordSize = GDALGetDataTypeSizeBytes(eDT);

    VSIStatBufL sStat;
    if (strstr(pszBasename, "_5M"))
        sStat.st_size = 180 * 180 * nWordSize;
    else if (strstr(pszBasename, "_30S"))
        sStat.st_size = 1800 * 1800 * nWordSize;
    else if (strstr(pszBasename, "_9S"))
        sStat.st_size = 6000 * 6000 * nWordSize;
    else if (strstr(pszBasename, "_3S"))
        sStat.st_size = 18000 * 18000 * nWordSize;
    /* Check file size otherwise */
    else if (VSIStatL(poOpenInfo->pszFilename, &sStat) != 0)
    {
        return nullptr;
    }

    int nXSize = 0;
    int nYSize = 0;

    double dfPixelSize = 0;
    if (sStat.st_size == 180 * 180 * nWordSize)
    {
        /* 5 minute */
        nXSize = 180;
        nYSize = 180;
        dfPixelSize = 5.0 / 60;
    }
    else if (sStat.st_size == 1800 * 1800 * nWordSize)
    {
        /* 30 s */
        nXSize = 1800;
        nYSize = 1800;
        dfPixelSize = 30.0 / 3600;
    }
    else if (sStat.st_size == 6000 * 6000 * nWordSize)
    {
        /* 9 s */
        nXSize = 6000;
        nYSize = 6000;
        dfPixelSize = 9.0 / 3600;
    }
    else if (sStat.st_size == 18000 * 18000 * nWordSize)
    {
        /* 3 s */
        nXSize = 18000;
        nYSize = 18000;
        dfPixelSize = 3.0 / 3600;
    }
    else
        return nullptr;

    /* -------------------------------------------------------------------- */
    /*      Open file.                                                      */
    /* -------------------------------------------------------------------- */

    CPLString osFilename = poOpenInfo->pszFilename;
    if ((strstr(poOpenInfo->pszFilename, ".ACE2.gz") ||
         strstr(poOpenInfo->pszFilename, ".ace2.gz")) &&
        !STARTS_WITH(poOpenInfo->pszFilename, "/vsigzip/"))
        osFilename = "/vsigzip/" + osFilename;

    VSILFILE *fpImage = VSIFOpenL(osFilename, "rb+");
    if (fpImage == nullptr)
        return nullptr;

    /* -------------------------------------------------------------------- */
    /*      Create the dataset.                                             */
    /* -------------------------------------------------------------------- */
    auto poDS = std::make_unique<ACE2Dataset>();

    poDS->nRasterXSize = nXSize;
    poDS->nRasterYSize = nYSize;

    poDS->m_gt[0] = southWestLon;
    poDS->m_gt[1] = dfPixelSize;
    poDS->m_gt[2] = 0.0;
    poDS->m_gt[3] = southWestLat + nYSize * dfPixelSize;
    poDS->m_gt[4] = 0.0;
    poDS->m_gt[5] = -dfPixelSize;

    /* -------------------------------------------------------------------- */
    /*      Create band information objects                                 */
    /* -------------------------------------------------------------------- */
    auto poBand =
        std::make_unique<ACE2RasterBand>(fpImage, eDT, nXSize, nYSize);
    if (!poBand->IsValid())
        return nullptr;
    poDS->SetBand(1, std::move(poBand));

    /* -------------------------------------------------------------------- */
    /*      Initialize any PAM information.                                 */
    /* -------------------------------------------------------------------- */
    poDS->SetDescription(poOpenInfo->pszFilename);
    poDS->TryLoadXML();

    /* -------------------------------------------------------------------- */
    /*      Check for overviews.                                            */
    /* -------------------------------------------------------------------- */
    poDS->oOvManager.Initialize(poDS.get(), poOpenInfo->pszFilename);

    return poDS.release();
}

/************************************************************************/
/*                          GDALRegister_ACE2()                         */
/************************************************************************/

void GDALRegister_ACE2()

{
    if (GDALGetDriverByName("ACE2") != nullptr)
        return;

    GDALDriver *poDriver = new GDALDriver();

    poDriver->SetDescription("ACE2");
    poDriver->SetMetadataItem(GDAL_DCAP_RASTER, "YES");
    poDriver->SetMetadataItem(GDAL_DMD_LONGNAME, "ACE2");
    poDriver->SetMetadataItem(GDAL_DMD_HELPTOPIC, "drivers/raster/ace2.html");
    poDriver->SetMetadataItem(GDAL_DMD_EXTENSION, "ACE2");
    poDriver->SetMetadataItem(GDAL_DCAP_VIRTUALIO, "YES");

    poDriver->pfnOpen = ACE2Dataset::Open;
    poDriver->pfnIdentify = ACE2Dataset::Identify;

    GetGDALDriverManager()->RegisterDriver(poDriver);
}