/******************************************************************************
 *
 * Project:  GDAL
 * Purpose:  Sentinel2 products
 * Author:   Even Rouault, <even.rouault at spatialys.com>
 * Funded by: Centre National d'Etudes Spatiales (CNES)
 *
 ******************************************************************************
 * Copyright (c) 2015, Even Rouault, <even.rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "cpl_minixml.h"
#include "cpl_string.h"
#include "gdal_pam.h"
#include "ogr_spatialref.h"
#include "ogr_geometry.h"
#include "gdaljp2metadata.h"
#include "../vrt/vrtdataset.h"

#include <algorithm>
#include <map>
#include <set>
#include <vector>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifndef STARTS_WITH_CI
#define STARTS_WITH_CI(a, b) EQUALN(a, b, strlen(b))
#endif

#define DIGIT_ZERO '0'

CPL_C_START
// TODO: Leave this declaration while Sentinel2 folks use this as a
// plugin with GDAL 1.x.
void GDALRegister_SENTINEL2();
CPL_C_END

typedef enum
{
    SENTINEL2_L1B,
    SENTINEL2_L1C,
    SENTINEL2_L2A
} SENTINEL2Level;

typedef enum
{
    MSI2Ap,
    MSI2A
} SENTINEL2ProductType;

typedef struct
{
    const char *pszBandName;
    int nResolution; /* meters */
    int nWaveLength; /* nanometers */
    int nBandWidth;  /* nanometers */
    GDALColorInterp eColorInterp;
} SENTINEL2BandDescription;

/* clang-format off */
static const SENTINEL2BandDescription asBandDesc[] = {
    {"B1", 60, 443, 20, GCI_CoastalBand},
    {"B2", 10, 490, 65, GCI_BlueBand},
    {"B3", 10, 560, 35, GCI_GreenBand},
    {"B4", 10, 665, 30, GCI_RedBand},
    {"B5", 20, 705, 15, GCI_RedEdgeBand},   // rededge071
    {"B6", 20, 740, 15, GCI_RedEdgeBand},   // rededge075
    {"B7", 20, 783, 20, GCI_RedEdgeBand},   // rededge078
    {"B8", 10, 842, 115, GCI_NIRBand},      // nir
    {"B8A", 20, 865, 20, GCI_NIRBand},      // nir08
    {"B9", 60, 945, 20, GCI_NIRBand},       // nir09
    {"B10", 60, 1375, 30, GCI_OtherIRBand}, // cirrus
    {"B11", 20, 1610, 90, GCI_SWIRBand},    // swir16
    {"B12", 20, 2190, 180, GCI_SWIRBand},   // swir11
};
/* clang-format on */

#define NB_BANDS (sizeof(asBandDesc) / sizeof(asBandDesc[0]))

typedef enum
{
    TL_IMG_DATA,      /* Tile is located in IMG_DATA/ */
    TL_IMG_DATA_Rxxm, /* Tile is located in IMG_DATA/Rxxm/ */
    TL_QI_DATA        /* Tile is located in QI_DATA/ */
} SENTINEL2_L2A_Tilelocation;

typedef struct
{
    const char *pszBandName;
    const char *pszBandDescription;
    int nResolution; /* meters */
    SENTINEL2_L2A_Tilelocation eLocation;
} SENTINEL2_L2A_BandDescription;

class L1CSafeCompatGranuleDescription
{
  public:
    CPLString
        osMTDTLPath;  // GRANULE/L1C_T30TXT_A007999_20170102T111441/MTD_TL.xml
    CPLString
        osBandPrefixPath;  // GRANULE/L1C_T30TXT_A007999_20170102T111441/IMG_DATA/T30TXT_20170102T111442_
};

static const char *L2A_BandDescription_AOT =
    "Aerosol Optical Thickness map (at 550nm)";
static const char *L2A_BandDescription_WVP = "Scene-average Water Vapour map";
static const char *L2A_BandDescription_SCL = "Scene Classification";
static const char *L2A_BandDescription_CLD =
    "Raster mask values range from 0 for high confidence clear sky to 100 for "
    "high confidence cloudy";
static const char *L2A_BandDescription_SNW =
    "Raster mask values range from 0 for high confidence NO snow/ice to 100 "
    "for high confidence snow/ice";

static const SENTINEL2_L2A_BandDescription asL2ABandDesc[] = {
    {"AOT", L2A_BandDescription_AOT, 10, TL_IMG_DATA_Rxxm},
    {"AOT", L2A_BandDescription_AOT, 20, TL_IMG_DATA_Rxxm},
    {"AOT", L2A_BandDescription_AOT, 60, TL_IMG_DATA_Rxxm},
    {"WVP", L2A_BandDescription_WVP, 10, TL_IMG_DATA_Rxxm},
    {"WVP", L2A_BandDescription_WVP, 20, TL_IMG_DATA_Rxxm},
    {"WVP", L2A_BandDescription_WVP, 60, TL_IMG_DATA_Rxxm},
    {"SCL", L2A_BandDescription_SCL, 20, TL_IMG_DATA_Rxxm},
    {"SCL", L2A_BandDescription_SCL, 60, TL_IMG_DATA_Rxxm},
    {"CLD", L2A_BandDescription_CLD, 20, TL_QI_DATA},
    {"CLD", L2A_BandDescription_CLD, 60, TL_QI_DATA},
    {"SNW", L2A_BandDescription_SNW, 20, TL_QI_DATA},
    {"SNW", L2A_BandDescription_SNW, 60, TL_QI_DATA},
};

#define NB_L2A_BANDS (sizeof(asL2ABandDesc) / sizeof(asL2ABandDesc[0]))

static bool SENTINEL2isZipped(const char *pszHeader, int nHeaderBytes);
static const char *SENTINEL2GetOption(GDALOpenInfo *poOpenInfo,
                                      const char *pszName,
                                      const char *pszDefaultVal = nullptr);
static bool SENTINEL2GetTileInfo(const char *pszFilename, int *pnWidth,
                                 int *pnHeight, int *pnBits);

/************************************************************************/
/*                           SENTINEL2GranuleInfo                       */
/************************************************************************/

class SENTINEL2GranuleInfo
{
  public:
    CPLString osPath;
    CPLString osBandPrefixPath;  // for Sentinel 2C SafeCompact
    double dfMinX, dfMinY, dfMaxX, dfMaxY;
    int nWidth, nHeight;
};

/************************************************************************/
/* ==================================================================== */
/*                         SENTINEL2Dataset                             */
/* ==================================================================== */
/************************************************************************/

class SENTINEL2DatasetContainer final : public GDALPamDataset
{
  public:
    SENTINEL2DatasetContainer()
    {
    }
};

class SENTINEL2Dataset final : public VRTDataset
{
    std::vector<CPLString> aosNonJP2Files;

    void AddL1CL2ABandMetadata(SENTINEL2Level eLevel, CPLXMLNode *psRoot,
                               const std::vector<CPLString> &aosBands);

    static SENTINEL2Dataset *CreateL1CL2ADataset(
        SENTINEL2Level eLevel, SENTINEL2ProductType pType, bool bIsSafeCompact,
        const std::vector<CPLString> &aosGranuleList,
        const std::vector<L1CSafeCompatGranuleDescription>
            &aoL1CSafeCompactGranuleList,
        std::vector<CPLString> &aosNonJP2Files, int nSubDSPrecision,
        bool bIsPreview, bool bIsTCI, int nSubDSEPSGCode, bool bAlpha,
        const std::vector<CPLString> &aosBands, int nSaturatedVal,
        int nNodataVal, const CPLString &osProductURI);

  public:
    SENTINEL2Dataset(int nXSize, int nYSize);
    virtual ~SENTINEL2Dataset();

    virtual char **GetFileList() override;

    static GDALDataset *Open(GDALOpenInfo *);
    static GDALDataset *OpenL1BUserProduct(GDALOpenInfo *);
    static GDALDataset *
    OpenL1BGranule(const char *pszFilename, CPLXMLNode **ppsRoot = nullptr,
                   int nResolutionOfInterest = 0,
                   std::set<CPLString> *poBandSet = nullptr);
    static GDALDataset *OpenL1BSubdataset(GDALOpenInfo *);
    static GDALDataset *OpenL1C_L2A(const char *pszFilename,
                                    SENTINEL2Level eLevel);
    static GDALDataset *OpenL1CTile(const char *pszFilename,
                                    CPLXMLNode **ppsRootMainMTD = nullptr,
                                    int nResolutionOfInterest = 0,
                                    std::set<CPLString> *poBandSet = nullptr);
    static GDALDataset *OpenL1CTileSubdataset(GDALOpenInfo *);
    static GDALDataset *OpenL1C_L2ASubdataset(GDALOpenInfo *,
                                              SENTINEL2Level eLevel);

    static int Identify(GDALOpenInfo *);
};

/************************************************************************/
/* ==================================================================== */
/*                         SENTINEL2AlphaBand                           */
/* ==================================================================== */
/************************************************************************/

class SENTINEL2AlphaBand final : public VRTSourcedRasterBand
{
    int m_nSaturatedVal;
    int m_nNodataVal;

  public:
    SENTINEL2AlphaBand(GDALDataset *poDS, int nBand, GDALDataType eType,
                       int nXSize, int nYSize, int nSaturatedVal,
                       int nNodataVal);

    virtual CPLErr IRasterIO(GDALRWFlag, int, int, int, int, void *, int, int,
                             GDALDataType,
#ifdef GDAL_DCAP_RASTER
                             GSpacing nPixelSpace, GSpacing nLineSpace,
                             GDALRasterIOExtraArg *psExtraArg
#else
                             int nPixelSpace, int nLineSpace
#endif
                             ) override;
};

/************************************************************************/
/*                         SENTINEL2AlphaBand()                         */
/************************************************************************/

SENTINEL2AlphaBand::SENTINEL2AlphaBand(GDALDataset *poDSIn, int nBandIn,
                                       GDALDataType eType, int nXSize,
                                       int nYSize, int nSaturatedVal,
                                       int nNodataVal)
    : VRTSourcedRasterBand(poDSIn, nBandIn, eType, nXSize, nYSize),
      m_nSaturatedVal(nSaturatedVal), m_nNodataVal(nNodataVal)
{
}

/************************************************************************/
/*                             IRasterIO()                              */
/************************************************************************/

CPLErr SENTINEL2AlphaBand::IRasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff,
                                     int nXSize, int nYSize, void *pData,
                                     int nBufXSize, int nBufYSize,
                                     GDALDataType eBufType,
#ifdef GDAL_DCAP_RASTER
                                     GSpacing nPixelSpace, GSpacing nLineSpace,
                                     GDALRasterIOExtraArg *psExtraArg
#else
                                     int nPixelSpace, int nLineSpace
#endif
)
{
    // Query the first band. Quite arbitrary, but hopefully all bands have
    // the same nodata/saturated pixels.
    CPLErr eErr = poDS->GetRasterBand(1)->RasterIO(
        eRWFlag, nXOff, nYOff, nXSize, nYSize, pData, nBufXSize, nBufYSize,
        eBufType, nPixelSpace, nLineSpace
#ifdef GDAL_DCAP_RASTER
        ,
        psExtraArg
#endif
    );
    if (eErr == CE_None)
    {
        const char *pszNBITS = GetMetadataItem("NBITS", "IMAGE_STRUCTURE");
        const int nBits = (pszNBITS) ? atoi(pszNBITS) : 16;
        const GUInt16 nMaxVal = (GUInt16)((1 << nBits) - 1);

        // Replace pixels matching m_nSaturatedVal and m_nNodataVal by 0
        // and others by the maxVal.
        for (int iY = 0; iY < nBufYSize; iY++)
        {
            for (int iX = 0; iX < nBufXSize; iX++)
            {
                // Optimized path for likely most common case
                if (eBufType == GDT_UInt16)
                {
                    GUInt16 *panPtr =
                        (GUInt16 *)((GByte *)pData + iY * nLineSpace +
                                    iX * nPixelSpace);
                    if (*panPtr == 0 || *panPtr == m_nSaturatedVal ||
                        *panPtr == m_nNodataVal)
                    {
                        *panPtr = 0;
                    }
                    else
                        *panPtr = nMaxVal;
                }
                // Generic path for other datatypes
                else
                {
                    double dfVal;
                    GDALCopyWords((GByte *)pData + iY * nLineSpace +
                                      iX * nPixelSpace,
                                  eBufType, 0, &dfVal, GDT_Float64, 0, 1);
                    if (dfVal == 0.0 || dfVal == m_nSaturatedVal ||
                        dfVal == m_nNodataVal)
                    {
                        dfVal = 0;
                    }
                    else
                        dfVal = nMaxVal;
                    GDALCopyWords(&dfVal, GDT_Float64, 0,
                                  (GByte *)pData + iY * nLineSpace +
                                      iX * nPixelSpace,
                                  eBufType, 0, 1);
                }
            }
        }
    }

    return eErr;
}

/************************************************************************/
/*                          SENTINEL2Dataset()                          */
/************************************************************************/

SENTINEL2Dataset::SENTINEL2Dataset(int nXSize, int nYSize)
    : VRTDataset(nXSize, nYSize)
{
    poDriver = nullptr;
    SetWritable(FALSE);
}

/************************************************************************/
/*                         ~SENTINEL2Dataset()                          */
/************************************************************************/

SENTINEL2Dataset::~SENTINEL2Dataset()
{
}

/************************************************************************/
/*                            GetFileList()                             */
/************************************************************************/

char **SENTINEL2Dataset::GetFileList()
{
    CPLStringList aosList;
    for (size_t i = 0; i < aosNonJP2Files.size(); i++)
        aosList.AddString(aosNonJP2Files[i]);
    char **papszFileList = VRTDataset::GetFileList();
    for (char **papszIter = papszFileList; papszIter && *papszIter; ++papszIter)
        aosList.AddString(*papszIter);
    CSLDestroy(papszFileList);
    return aosList.StealList();
}

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

int SENTINEL2Dataset::Identify(GDALOpenInfo *poOpenInfo)
{
    if (STARTS_WITH_CI(poOpenInfo->pszFilename, "SENTINEL2_L1B:"))
        return TRUE;
    if (STARTS_WITH_CI(poOpenInfo->pszFilename, "SENTINEL2_L1C:"))
        return TRUE;
    if (STARTS_WITH_CI(poOpenInfo->pszFilename, "SENTINEL2_L1C_TILE:"))
        return TRUE;
    if (STARTS_WITH_CI(poOpenInfo->pszFilename, "SENTINEL2_L2A:"))
        return TRUE;

    const char *pszJustFilename = CPLGetFilename(poOpenInfo->pszFilename);

    // We don't handle direct tile access for L1C SafeCompact products
    // We could, but this isn't just done yet.
    if (EQUAL(pszJustFilename, "MTD_TL.xml"))
        return FALSE;

    /* Accept directly .zip as provided by https://scihub.esa.int/
     * First we check just by file name as it is faster than looking
     * inside to detect content. */
    if ((STARTS_WITH_CI(pszJustFilename, "S2A_MSIL1C_") ||
         STARTS_WITH_CI(pszJustFilename, "S2B_MSIL1C_") ||
         STARTS_WITH_CI(pszJustFilename, "S2A_MSIL2A_") ||
         STARTS_WITH_CI(pszJustFilename, "S2B_MSIL2A_") ||
         STARTS_WITH_CI(pszJustFilename, "S2A_OPER_PRD_MSI") ||
         STARTS_WITH_CI(pszJustFilename, "S2B_OPER_PRD_MSI") ||
         STARTS_WITH_CI(pszJustFilename, "S2A_USER_PRD_MSI") ||
         STARTS_WITH_CI(pszJustFilename, "S2B_USER_PRD_MSI")) &&
        EQUAL(CPLGetExtension(pszJustFilename), "zip"))
    {
        return TRUE;
    }

    if (poOpenInfo->nHeaderBytes < 100)
        return FALSE;

    const char *pszHeader =
        reinterpret_cast<const char *>(poOpenInfo->pabyHeader);

    if (strstr(pszHeader, "<n1:Level-1B_User_Product") != nullptr &&
        strstr(pszHeader, "User_Product_Level-1B.xsd") != nullptr)
        return TRUE;

    if (strstr(pszHeader, "<n1:Level-1B_Granule_ID") != nullptr &&
        strstr(pszHeader, "S2_PDI_Level-1B_Granule_Metadata.xsd") != nullptr)
        return TRUE;

    if (strstr(pszHeader, "<n1:Level-1C_User_Product") != nullptr &&
        strstr(pszHeader, "User_Product_Level-1C.xsd") != nullptr)
        return TRUE;

    if (strstr(pszHeader, "<n1:Level-1C_Tile_ID") != nullptr &&
        strstr(pszHeader, "S2_PDI_Level-1C_Tile_Metadata.xsd") != nullptr)
        return TRUE;

    if (strstr(pszHeader, "<n1:Level-2A_User_Product") != nullptr &&
        strstr(pszHeader, "User_Product_Level-2A") != nullptr)
        return TRUE;

    if (SENTINEL2isZipped(pszHeader, poOpenInfo->nHeaderBytes))
        return TRUE;

    return FALSE;
}

/************************************************************************/
/*                         SENTINEL2_CPLXMLNodeHolder                   */
/************************************************************************/

class SENTINEL2_CPLXMLNodeHolder
{
    CPLXMLNode *m_psNode;

  public:
    explicit SENTINEL2_CPLXMLNodeHolder(CPLXMLNode *psNode) : m_psNode(psNode)
    {
    }

    ~SENTINEL2_CPLXMLNodeHolder()
    {
        if (m_psNode)
            CPLDestroyXMLNode(m_psNode);
    }

    CPLXMLNode *Release()
    {
        CPLXMLNode *psRet = m_psNode;
        m_psNode = nullptr;
        return psRet;
    }
};

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

GDALDataset *SENTINEL2Dataset::Open(GDALOpenInfo *poOpenInfo)
{
    if (!Identify(poOpenInfo))
    {
        return nullptr;
    }

    if (STARTS_WITH_CI(poOpenInfo->pszFilename, "SENTINEL2_L1B:"))
    {
        CPLDebug("SENTINEL2", "Trying OpenL1BSubdataset");
        return OpenL1BSubdataset(poOpenInfo);
    }

    if (STARTS_WITH_CI(poOpenInfo->pszFilename, "SENTINEL2_L1C:"))
    {
        CPLDebug("SENTINEL2", "Trying OpenL1C_L2ASubdataset");
        return OpenL1C_L2ASubdataset(poOpenInfo, SENTINEL2_L1C);
    }

    if (STARTS_WITH_CI(poOpenInfo->pszFilename, "SENTINEL2_L1C_TILE:"))
    {
        CPLDebug("SENTINEL2", "Trying OpenL1CTileSubdataset");
        return OpenL1CTileSubdataset(poOpenInfo);
    }

    if (STARTS_WITH_CI(poOpenInfo->pszFilename, "SENTINEL2_L2A:"))
    {
        CPLDebug("SENTINEL2", "Trying OpenL1C_L2ASubdataset");
        return OpenL1C_L2ASubdataset(poOpenInfo, SENTINEL2_L2A);
    }

    const char *pszJustFilename = CPLGetFilename(poOpenInfo->pszFilename);
    if ((STARTS_WITH_CI(pszJustFilename, "S2A_OPER_PRD_MSI") ||
         STARTS_WITH_CI(pszJustFilename, "S2B_OPER_PRD_MSI") ||
         STARTS_WITH_CI(pszJustFilename, "S2A_USER_PRD_MSI") ||
         STARTS_WITH_CI(pszJustFilename, "S2B_USER_PRD_MSI")) &&
        EQUAL(CPLGetExtension(pszJustFilename), "zip"))
    {
        const CPLString osBasename(CPLGetBasename(pszJustFilename));
        CPLString osFilename(poOpenInfo->pszFilename);
        CPLString osMTD(osBasename);
        // Normally given above constraints, osMTD.size() should be >= 16
        // but if pszJustFilename is too long, CPLGetBasename() will return
        // an empty string.
        if (osMTD.size() < 16)
            return nullptr;
        osMTD[9] = 'M';
        osMTD[10] = 'T';
        osMTD[11] = 'D';
        osMTD[13] = 'S';
        osMTD[14] = 'A';
        osMTD[15] = 'F';
        CPLString osSAFE(CPLString(osBasename) + ".SAFE");
        osFilename = osFilename + "/" + osSAFE + "/" + osMTD + ".xml";
        if (strncmp(osFilename, "/vsizip/", strlen("/vsizip/")) != 0)
            osFilename = "/vsizip/" + osFilename;
        CPLDebug("SENTINEL2", "Trying %s", osFilename.c_str());
        GDALOpenInfo oOpenInfo(osFilename, GA_ReadOnly);
        return Open(&oOpenInfo);
    }
    else if ((STARTS_WITH_CI(pszJustFilename, "S2A_MSIL1C_") ||
              STARTS_WITH_CI(pszJustFilename, "S2B_MSIL1C_")) &&
             EQUAL(CPLGetExtension(pszJustFilename), "zip"))
    {
        const CPLString osBasename(CPLGetBasename(pszJustFilename));
        CPLString osFilename(poOpenInfo->pszFilename);
        CPLString osSAFE(osBasename);
        // S2B_MSIL1C_20171004T233419_N0206_R001_T54DWM_20171005T001811.SAFE.zip
        // has .SAFE.zip extension, but other products have just a .zip
        // extension. So for the subdir in the zip only add .SAFE when needed
        if (!EQUAL(CPLGetExtension(osSAFE), "SAFE"))
            osSAFE += ".SAFE";
        osFilename = osFilename + "/" + osSAFE + "/MTD_MSIL1C.xml";
        if (strncmp(osFilename, "/vsizip/", strlen("/vsizip/")) != 0)
            osFilename = "/vsizip/" + osFilename;
        CPLDebug("SENTINEL2", "Trying %s", osFilename.c_str());
        GDALOpenInfo oOpenInfo(osFilename, GA_ReadOnly);
        return Open(&oOpenInfo);
    }
    else if ((STARTS_WITH_CI(pszJustFilename, "S2A_MSIL2A_") ||
              STARTS_WITH_CI(pszJustFilename, "S2B_MSIL2A_")) &&
             EQUAL(CPLGetExtension(pszJustFilename), "zip"))
    {
        const CPLString osBasename(CPLGetBasename(pszJustFilename));
        CPLString osFilename(poOpenInfo->pszFilename);
        CPLString osSAFE(osBasename);
        // S2B_MSIL1C_20171004T233419_N0206_R001_T54DWM_20171005T001811.SAFE.zip
        // has .SAFE.zip extension, but other products have just a .zip
        // extension. So for the subdir in the zip only add .SAFE when needed
        if (!EQUAL(CPLGetExtension(osSAFE), "SAFE"))
            osSAFE += ".SAFE";
        osFilename = osFilename + "/" + osSAFE + "/MTD_MSIL2A.xml";
        if (strncmp(osFilename, "/vsizip/", strlen("/vsizip/")) != 0)
            osFilename = "/vsizip/" + osFilename;
        CPLDebug("SENTINEL2", "Trying %s", osFilename.c_str());
        GDALOpenInfo oOpenInfo(osFilename, GA_ReadOnly);
        return Open(&oOpenInfo);
    }

    const char *pszHeader =
        reinterpret_cast<const char *>(poOpenInfo->pabyHeader);

    if (strstr(pszHeader, "<n1:Level-1B_User_Product") != nullptr &&
        strstr(pszHeader, "User_Product_Level-1B.xsd") != nullptr)
    {
        CPLDebug("SENTINEL2", "Trying OpenL1BUserProduct");
        return OpenL1BUserProduct(poOpenInfo);
    }

    if (strstr(pszHeader, "<n1:Level-1B_Granule_ID") != nullptr &&
        strstr(pszHeader, "S2_PDI_Level-1B_Granule_Metadata.xsd") != nullptr)
    {
        CPLDebug("SENTINEL2", "Trying OpenL1BGranule");
        return OpenL1BGranule(poOpenInfo->pszFilename);
    }

    if (strstr(pszHeader, "<n1:Level-1C_User_Product") != nullptr &&
        strstr(pszHeader, "User_Product_Level-1C.xsd") != nullptr)
    {
        CPLDebug("SENTINEL2", "Trying OpenL1C_L2A");
        return OpenL1C_L2A(poOpenInfo->pszFilename, SENTINEL2_L1C);
    }

    if (strstr(pszHeader, "<n1:Level-1C_Tile_ID") != nullptr &&
        strstr(pszHeader, "S2_PDI_Level-1C_Tile_Metadata.xsd") != nullptr)
    {
        CPLDebug("SENTINEL2", "Trying OpenL1CTile");
        return OpenL1CTile(poOpenInfo->pszFilename);
    }

    if (strstr(pszHeader, "<n1:Level-2A_User_Product") != nullptr &&
        strstr(pszHeader, "User_Product_Level-2A") != nullptr)
    {
        CPLDebug("SENTINEL2", "Trying OpenL1C_L2A");
        return OpenL1C_L2A(poOpenInfo->pszFilename, SENTINEL2_L2A);
    }

    if (SENTINEL2isZipped(pszHeader, poOpenInfo->nHeaderBytes))
    {
        CPLString osFilename(poOpenInfo->pszFilename);
        if (strncmp(osFilename, "/vsizip/", strlen("/vsizip/")) != 0)
            osFilename = "/vsizip/" + osFilename;

        auto psDir = VSIOpenDir(osFilename.c_str(), 1, nullptr);
        if (psDir == nullptr)
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "SENTINEL2: Cannot open ZIP file %s", osFilename.c_str());
            return nullptr;
        }
        while (const VSIDIREntry *psEntry = VSIGetNextDirEntry(psDir))
        {
            const char *pszInsideFilename = CPLGetFilename(psEntry->pszName);
            if (VSI_ISREG(psEntry->nMode) &&
                (STARTS_WITH_CI(pszInsideFilename, "MTD_MSIL2A") ||
                 STARTS_WITH_CI(pszInsideFilename, "MTD_MSIL1C") ||
                 STARTS_WITH_CI(pszInsideFilename, "S2A_OPER_MTD_SAFL1B") ||
                 STARTS_WITH_CI(pszInsideFilename, "S2B_OPER_MTD_SAFL1B") ||
                 STARTS_WITH_CI(pszInsideFilename, "S2A_OPER_MTD_SAFL1C") ||
                 STARTS_WITH_CI(pszInsideFilename, "S2B_OPER_MTD_SAFL1C") ||
                 STARTS_WITH_CI(pszInsideFilename, "S2A_USER_MTD_SAFL2A") ||
                 STARTS_WITH_CI(pszInsideFilename, "S2B_USER_MTD_SAFL2A")))
            {
                osFilename = osFilename + "/" + psEntry->pszName;
                CPLDebug("SENTINEL2", "Trying %s", osFilename.c_str());
                GDALOpenInfo oOpenInfo(osFilename, GA_ReadOnly);
                VSICloseDir(psDir);
                return Open(&oOpenInfo);
            }
        }
        VSICloseDir(psDir);
    }

    return nullptr;
}

/************************************************************************/
/*                        SENTINEL2isZipped()                           */
/************************************************************************/

static bool SENTINEL2isZipped(const char *pszHeader, int nHeaderBytes)
{
    if (nHeaderBytes < 50)
        return FALSE;

    /* According to Sentinel-2 Products Specification Document,
     * all files are located inside a folder with a specific name pattern
     * Ref: S2-PDGS-TAS-DI-PSD Issue: 14.6.
     */
    return (
        // inside a ZIP file
        memcmp(pszHeader, "\x50\x4b", 2) == 0 &&
        (
            // a "4.2.1 Compact Naming Convention" confirming file
            (memcmp(pszHeader + 34, "MSIL2A", 6) == 0 ||
             memcmp(pszHeader + 34, "MSIL1C", 6) == 0) ||
            // a "4.2 S2 User Product Naming Convention" confirming file
            (memcmp(pszHeader + 34, "OPER_PRD_MSIL2A", 15) == 0 ||
             memcmp(pszHeader + 34, "OPER_PRD_MSIL1B", 15) == 0 ||
             memcmp(pszHeader + 34, "OPER_PRD_MSIL1C", 15) == 0) ||
            // some old / validation naming convention
            (memcmp(pszHeader + 34, "USER_PRD_MSIL2A", 15) == 0 ||
             memcmp(pszHeader + 34, "USER_PRD_MSIL1B", 15) == 0 ||
             memcmp(pszHeader + 34, "USER_PRD_MSIL1C", 15) == 0)));
}

/************************************************************************/
/*                        SENTINEL2GetBandDesc()                        */
/************************************************************************/

static const SENTINEL2BandDescription *
SENTINEL2GetBandDesc(const char *pszBandName)
{
    for (size_t i = 0; i < NB_BANDS; i++)
    {
        if (EQUAL(asBandDesc[i].pszBandName, pszBandName))
            return &(asBandDesc[i]);
    }
    return nullptr;
}

/************************************************************************/
/*                       SENTINEL2GetL2ABandDesc()                      */
/************************************************************************/

static const SENTINEL2_L2A_BandDescription *
SENTINEL2GetL2ABandDesc(const char *pszBandName)
{
    for (size_t i = 0; i < NB_L2A_BANDS; i++)
    {
        if (EQUAL(asL2ABandDesc[i].pszBandName, pszBandName))
            return &(asL2ABandDesc[i]);
    }
    return nullptr;
}

/************************************************************************/
/*                        SENTINEL2GetGranuleInfo()                     */
/************************************************************************/

static bool SENTINEL2GetGranuleInfo(
    SENTINEL2Level eLevel, const CPLString &osGranuleMTDPath,
    int nDesiredResolution, int *pnEPSGCode = nullptr, double *pdfULX = nullptr,
    double *pdfULY = nullptr, int *pnResolution = nullptr,
    int *pnWidth = nullptr, int *pnHeight = nullptr)
{
    static bool bTryOptimization = true;
    CPLXMLNode *psRoot = nullptr;

    if (bTryOptimization)
    {
        /* Small optimization: in practice the interesting info are in the */
        /* first bytes of the Granule MTD, which can be very long sometimes */
        /* so only read them, and hack the buffer a bit to form a valid XML */
        char szBuffer[3072];
        VSILFILE *fp = VSIFOpenL(osGranuleMTDPath, "rb");
        size_t nRead = 0;
        if (fp == nullptr ||
            (nRead = VSIFReadL(szBuffer, 1, sizeof(szBuffer) - 1, fp)) == 0)
        {
            if (fp)
                VSIFCloseL(fp);
            CPLError(CE_Failure, CPLE_AppDefined,
                     "SENTINEL2GetGranuleInfo: Cannot read %s",
                     osGranuleMTDPath.c_str());
            return false;
        }
        szBuffer[nRead] = 0;
        VSIFCloseL(fp);
        char *pszTileGeocoding = strstr(szBuffer, "</Tile_Geocoding>");
        if (eLevel == SENTINEL2_L1C && pszTileGeocoding != nullptr &&
            strstr(szBuffer, "<n1:Level-1C_Tile_ID") != nullptr &&
            strstr(szBuffer, "<n1:Geometric_Info") != nullptr &&
            static_cast<size_t>(pszTileGeocoding - szBuffer) <
                sizeof(szBuffer) -
                    strlen("</Tile_Geocoding></n1:Geometric_Info></"
                           "n1:Level-1C_Tile_ID>") -
                    1)
        {
            strcpy(
                pszTileGeocoding,
                "</Tile_Geocoding></n1:Geometric_Info></n1:Level-1C_Tile_ID>");
            psRoot = CPLParseXMLString(szBuffer);
        }
        else if (eLevel == SENTINEL2_L2A && pszTileGeocoding != nullptr &&
                 strstr(szBuffer, "<n1:Level-2A_Tile_ID") != nullptr &&
                 strstr(szBuffer, "<n1:Geometric_Info") != nullptr &&
                 static_cast<size_t>(pszTileGeocoding - szBuffer) <
                     sizeof(szBuffer) -
                         strlen("</Tile_Geocoding></n1:Geometric_Info></"
                                "n1:Level-2A_Tile_ID>") -
                         1)
        {
            strcpy(
                pszTileGeocoding,
                "</Tile_Geocoding></n1:Geometric_Info></n1:Level-2A_Tile_ID>");
            psRoot = CPLParseXMLString(szBuffer);
        }
        else
            bTryOptimization = false;
    }

    // If the above doesn't work, then read the whole file...
    if (psRoot == nullptr)
        psRoot = CPLParseXMLFile(osGranuleMTDPath);
    if (psRoot == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot XML parse %s",
                 osGranuleMTDPath.c_str());
        return false;
    }
    SENTINEL2_CPLXMLNodeHolder oXMLHolder(psRoot);
    CPLStripXMLNamespace(psRoot, nullptr, TRUE);

    const char *pszNodePath =
        (eLevel == SENTINEL2_L1C)
            ? "=Level-1C_Tile_ID.Geometric_Info.Tile_Geocoding"
            : "=Level-2A_Tile_ID.Geometric_Info.Tile_Geocoding";
    CPLXMLNode *psTileGeocoding = CPLGetXMLNode(psRoot, pszNodePath);
    if (psTileGeocoding == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s in %s",
                 pszNodePath, osGranuleMTDPath.c_str());
        return false;
    }

    const char *pszCSCode =
        CPLGetXMLValue(psTileGeocoding, "HORIZONTAL_CS_CODE", nullptr);
    if (pszCSCode == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s in %s",
                 "HORIZONTAL_CS_CODE", osGranuleMTDPath.c_str());
        return false;
    }
    if (!STARTS_WITH_CI(pszCSCode, "EPSG:"))
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Invalid CS code (%s) for %s",
                 pszCSCode, osGranuleMTDPath.c_str());
        return false;
    }
    int nEPSGCode = atoi(pszCSCode + strlen("EPSG:"));
    if (pnEPSGCode != nullptr)
        *pnEPSGCode = nEPSGCode;

    for (CPLXMLNode *psIter = psTileGeocoding->psChild; psIter != nullptr;
         psIter = psIter->psNext)
    {
        if (psIter->eType != CXT_Element)
            continue;
        if (EQUAL(psIter->pszValue, "Size") &&
            (nDesiredResolution == 0 ||
             atoi(CPLGetXMLValue(psIter, "resolution", "")) ==
                 nDesiredResolution))
        {
            nDesiredResolution = atoi(CPLGetXMLValue(psIter, "resolution", ""));
            const char *pszRows = CPLGetXMLValue(psIter, "NROWS", nullptr);
            if (pszRows == nullptr)
            {
                CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s in %s",
                         "NROWS", osGranuleMTDPath.c_str());
                return false;
            }
            const char *pszCols = CPLGetXMLValue(psIter, "NCOLS", nullptr);
            if (pszCols == nullptr)
            {
                CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s in %s",
                         "NCOLS", osGranuleMTDPath.c_str());
                return false;
            }
            if (pnResolution)
                *pnResolution = nDesiredResolution;
            if (pnWidth)
                *pnWidth = atoi(pszCols);
            if (pnHeight)
                *pnHeight = atoi(pszRows);
        }
        else if (EQUAL(psIter->pszValue, "Geoposition") &&
                 (nDesiredResolution == 0 ||
                  atoi(CPLGetXMLValue(psIter, "resolution", "")) ==
                      nDesiredResolution))
        {
            nDesiredResolution = atoi(CPLGetXMLValue(psIter, "resolution", ""));
            const char *pszULX = CPLGetXMLValue(psIter, "ULX", nullptr);
            if (pszULX == nullptr)
            {
                CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s in %s",
                         "ULX", osGranuleMTDPath.c_str());
                return false;
            }
            const char *pszULY = CPLGetXMLValue(psIter, "ULY", nullptr);
            if (pszULY == nullptr)
            {
                CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s in %s",
                         "ULY", osGranuleMTDPath.c_str());
                return false;
            }
            if (pnResolution)
                *pnResolution = nDesiredResolution;
            if (pdfULX)
                *pdfULX = CPLAtof(pszULX);
            if (pdfULY)
                *pdfULY = CPLAtof(pszULY);
        }
    }

    return true;
}

/************************************************************************/
/*                      SENTINEL2GetPathSeparator()                     */
/************************************************************************/

// For the sake of simplifying our unit tests, we limit the use of \\ to when
// it is strictly necessary. Otherwise we could use CPLFormFilename()...
static char SENTINEL2GetPathSeparator(const char *pszBasename)
{
    if (STARTS_WITH_CI(pszBasename, "\\\\?\\"))
        return '\\';
    else
        return '/';
}

/************************************************************************/
/*                      SENTINEL2GetGranuleList()                       */
/************************************************************************/

static bool SENTINEL2GetGranuleList(
    CPLXMLNode *psMainMTD, SENTINEL2Level eLevel, const char *pszFilename,
    std::vector<CPLString> &osList, std::set<int> *poSetResolutions = nullptr,
    std::map<int, std::set<CPLString>> *poMapResolutionsToBands = nullptr)
{
    const char *pszNodePath =
        (eLevel == SENTINEL2_L1B)   ? "Level-1B_User_Product"
        : (eLevel == SENTINEL2_L1C) ? "Level-1C_User_Product"
                                    : "Level-2A_User_Product";

    CPLXMLNode *psRoot =
        CPLGetXMLNode(psMainMTD, CPLSPrintf("=%s", pszNodePath));
    if (psRoot == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find =%s", pszNodePath);
        return false;
    }
    pszNodePath = "General_Info.Product_Info";
    CPLXMLNode *psProductInfo = CPLGetXMLNode(psRoot, pszNodePath);
    if (psProductInfo == nullptr && eLevel == SENTINEL2_L2A)
    {
        pszNodePath = "General_Info.L2A_Product_Info";
        psProductInfo = CPLGetXMLNode(psRoot, pszNodePath);
    }
    if (psProductInfo == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s", pszNodePath);
        return false;
    }

    pszNodePath = "Product_Organisation";
    CPLXMLNode *psProductOrganisation =
        CPLGetXMLNode(psProductInfo, pszNodePath);
    if (psProductOrganisation == nullptr && eLevel == SENTINEL2_L2A)
    {
        pszNodePath = "L2A_Product_Organisation";
        psProductOrganisation = CPLGetXMLNode(psProductInfo, pszNodePath);
    }
    if (psProductOrganisation == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s", pszNodePath);
        return false;
    }

    CPLString osDirname(CPLGetDirname(pszFilename));
#ifdef HAVE_READLINK
    char szPointerFilename[2048];
    int nBytes = static_cast<int>(
        readlink(pszFilename, szPointerFilename, sizeof(szPointerFilename)));
    if (nBytes != -1)
    {
        const int nOffset =
            std::min(nBytes, static_cast<int>(sizeof(szPointerFilename) - 1));
        szPointerFilename[nOffset] = '\0';
        osDirname = CPLGetDirname(szPointerFilename);
    }
#endif

    const bool bIsMSI2Ap =
        EQUAL(CPLGetXMLValue(psProductInfo, "PRODUCT_TYPE", ""), "S2MSI2Ap");
    const bool bIsCompact = EQUAL(
        CPLGetXMLValue(psProductInfo, "PRODUCT_FORMAT", ""), "SAFE_COMPACT");
    CPLString oGranuleId("L2A_");
    std::set<CPLString> aoSetGranuleId;
    for (CPLXMLNode *psIter = psProductOrganisation->psChild; psIter != nullptr;
         psIter = psIter->psNext)
    {
        if (psIter->eType != CXT_Element ||
            !EQUAL(psIter->pszValue, "Granule_List"))
        {
            continue;
        }
        for (CPLXMLNode *psIter2 = psIter->psChild; psIter2 != nullptr;
             psIter2 = psIter2->psNext)
        {
            if (psIter2->eType != CXT_Element ||
                (!EQUAL(psIter2->pszValue, "Granule") &&
                 !EQUAL(psIter2->pszValue, "Granules")))
            {
                continue;
            }
            const char *pszGranuleId =
                CPLGetXMLValue(psIter2, "granuleIdentifier", nullptr);
            if (pszGranuleId == nullptr)
            {
                CPLDebug("SENTINEL2", "Missing granuleIdentifier attribute");
                continue;
            }

            if (eLevel == SENTINEL2_L2A)
            {
                for (CPLXMLNode *psIter3 = psIter2->psChild; psIter3 != nullptr;
                     psIter3 = psIter3->psNext)
                {
                    if (psIter3->eType != CXT_Element ||
                        (!EQUAL(psIter3->pszValue, "IMAGE_ID_2A") &&
                         !EQUAL(psIter3->pszValue, "IMAGE_FILE") &&
                         !EQUAL(psIter3->pszValue, "IMAGE_FILE_2A")))
                    {
                        continue;
                    }
                    const char *pszTileName =
                        CPLGetXMLValue(psIter3, nullptr, "");
                    size_t nLen = strlen(pszTileName);
                    // If granule name ends with resolution: _60m
                    if (nLen > 4 && pszTileName[nLen - 4] == '_' &&
                        pszTileName[nLen - 1] == 'm')
                    {
                        int nResolution = atoi(pszTileName + nLen - 3);
                        if (poSetResolutions != nullptr)
                            (*poSetResolutions).insert(nResolution);
                        if (poMapResolutionsToBands != nullptr)
                        {
                            nLen -= 4;
                            if (nLen > 4 && pszTileName[nLen - 4] == '_' &&
                                pszTileName[nLen - 3] == 'B')
                            {
                                (*poMapResolutionsToBands)[nResolution].insert(
                                    CPLString(pszTileName).substr(nLen - 2, 2));
                            }
                            else if (nLen > strlen("S2A_USER_MSI_") &&
                                     pszTileName[8] == '_' &&
                                     pszTileName[12] == '_' &&
                                     !EQUALN(pszTileName + 9, "MSI", 3))
                            {
                                (*poMapResolutionsToBands)[nResolution].insert(
                                    CPLString(pszTileName).substr(9, 3));
                            }
                        }
                    }
                }
            }

            // For L2A we can have several time the same granuleIdentifier
            // for the different resolutions
            if (aoSetGranuleId.find(pszGranuleId) != aoSetGranuleId.end())
                continue;
            aoSetGranuleId.insert(pszGranuleId);

            /* S2A_OPER_MSI_L1C_TL_SGS__20151024T023555_A001758_T53JLJ_N01.04
             * --> */
            /* S2A_OPER_MTD_L1C_TL_SGS__20151024T023555_A001758_T53JLJ */
            // S2B_OPER_MSI_L2A_TL_MPS__20180823T122014_A007641_T34VFJ_N02.08
            CPLString osGranuleMTD = pszGranuleId;
            if (bIsCompact == 0 &&
                osGranuleMTD.size() > strlen("S2A_OPER_MSI_") &&
                osGranuleMTD[8] == '_' && osGranuleMTD[12] == '_' &&
                osGranuleMTD[osGranuleMTD.size() - 7] == '_' &&
                osGranuleMTD[osGranuleMTD.size() - 6] == 'N' &&
                osGranuleMTD[7] == 'R')
            {
                osGranuleMTD[9] = 'M';
                osGranuleMTD[10] = 'T';
                osGranuleMTD[11] = 'D';
                osGranuleMTD.resize(osGranuleMTD.size() - 7);
            }
            else if (bIsMSI2Ap)
            {
                osGranuleMTD = "MTD_TL";
                oGranuleId = "L2A_";
                // S2A_MSIL2A_20170823T094031_N0205_R036_T34VFJ_20170823T094252.SAFE
                // S2A_USER_MSI_L2A_TL_SGS__20170823T133142_A011330_T34VFJ_N02.05
                // --> L2A_T34VFJ_A011330_20170823T094252
                const char *pszProductURI =
                    CPLGetXMLValue(psProductInfo, "PRODUCT_URI_2A", nullptr);
                if (pszProductURI != nullptr)
                {
                    CPLString psProductURI(pszProductURI);
                    if (psProductURI.size() < 60)
                    {
                        CPLDebug("SENTINEL2", "Invalid PRODUCT_URI_2A");
                        continue;
                    }
                    oGranuleId += psProductURI.substr(38, 7);
                    oGranuleId += CPLString(pszGranuleId).substr(41, 8).c_str();
                    oGranuleId += psProductURI.substr(45, 15);
                    pszGranuleId = oGranuleId.c_str();
                }
            }
            else
            {
                CPLDebug("SENTINEL2", "Invalid granule ID: %s", pszGranuleId);
                continue;
            }
            osGranuleMTD += ".xml";

            const char chSeparator = SENTINEL2GetPathSeparator(osDirname);
            CPLString osGranuleMTDPath = osDirname;
            osGranuleMTDPath += chSeparator;
            osGranuleMTDPath += "GRANULE";
            osGranuleMTDPath += chSeparator;
            osGranuleMTDPath += pszGranuleId;
            osGranuleMTDPath += chSeparator;
            osGranuleMTDPath += osGranuleMTD;
            osList.push_back(osGranuleMTDPath);
        }
    }

    return true;
}

/************************************************************************/
/*                     SENTINEL2GetUserProductMetadata()                */
/************************************************************************/

static char **SENTINEL2GetUserProductMetadata(CPLXMLNode *psMainMTD,
                                              const char *pszRootNode)
{
    CPLStringList aosList;

    CPLXMLNode *psRoot =
        CPLGetXMLNode(psMainMTD, CPLSPrintf("=%s", pszRootNode));
    if (psRoot == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find =%s", pszRootNode);
        return nullptr;
    }
    const char *psPIPath = "General_Info.Product_Info";
    CPLXMLNode *psProductInfo = CPLGetXMLNode(psRoot, psPIPath);
    if (psProductInfo == nullptr && EQUAL(pszRootNode, "Level-2A_User_Product"))
    {
        psPIPath = "General_Info.L2A_Product_Info";
        psProductInfo = CPLGetXMLNode(psRoot, psPIPath);
    }
    if (psProductInfo == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find =%s", psPIPath);
        return nullptr;
    }
    int nDataTakeCounter = 1;
    for (CPLXMLNode *psIter = psProductInfo->psChild; psIter != nullptr;
         psIter = psIter->psNext)
    {
        if (psIter->eType != CXT_Element)
            continue;
        if (psIter->psChild != nullptr && psIter->psChild->eType == CXT_Text)
        {
            aosList.AddNameValue(psIter->pszValue, psIter->psChild->pszValue);
        }
        else if (EQUAL(psIter->pszValue, "Datatake"))
        {
            CPLString osPrefix(CPLSPrintf("DATATAKE_%d_", nDataTakeCounter));
            nDataTakeCounter++;
            const char *pszId =
                CPLGetXMLValue(psIter, "datatakeIdentifier", nullptr);
            if (pszId)
                aosList.AddNameValue((osPrefix + "ID").c_str(), pszId);
            for (CPLXMLNode *psIter2 = psIter->psChild; psIter2 != nullptr;
                 psIter2 = psIter2->psNext)
            {
                if (psIter2->eType != CXT_Element)
                    continue;
                if (psIter2->psChild != nullptr &&
                    psIter2->psChild->eType == CXT_Text)
                {
                    aosList.AddNameValue((osPrefix + psIter2->pszValue).c_str(),
                                         psIter2->psChild->pszValue);
                }
            }
        }
    }

    const char *psICPath = "General_Info.Product_Image_Characteristics";
    CPLXMLNode *psIC = CPLGetXMLNode(psRoot, psICPath);
    if (psIC == nullptr)
    {
        psICPath = "General_Info.L2A_Product_Image_Characteristics";
        psIC = CPLGetXMLNode(psRoot, psICPath);
    }
    if (psIC != nullptr)
    {
        for (CPLXMLNode *psIter = psIC->psChild; psIter != nullptr;
             psIter = psIter->psNext)
        {
            if (psIter->eType != CXT_Element ||
                !EQUAL(psIter->pszValue, "Special_Values"))
            {
                continue;
            }
            const char *pszText =
                CPLGetXMLValue(psIter, "SPECIAL_VALUE_TEXT", nullptr);
            const char *pszIndex =
                CPLGetXMLValue(psIter, "SPECIAL_VALUE_INDEX", nullptr);
            if (pszText && pszIndex)
            {
                aosList.AddNameValue(
                    (CPLString("SPECIAL_VALUE_") + pszText).c_str(), pszIndex);
            }
        }

        const char *pszQuantValue =
            CPLGetXMLValue(psIC, "QUANTIFICATION_VALUE", nullptr);
        if (pszQuantValue != nullptr)
            aosList.AddNameValue("QUANTIFICATION_VALUE", pszQuantValue);

        const char *pszRCU =
            CPLGetXMLValue(psIC, "Reflectance_Conversion.U", nullptr);
        if (pszRCU != nullptr)
            aosList.AddNameValue("REFLECTANCE_CONVERSION_U", pszRCU);

        // L2A specific
        CPLXMLNode *psQVL =
            CPLGetXMLNode(psIC, "L1C_L2A_Quantification_Values_List");
        if (psQVL == nullptr)
        {
            psQVL = CPLGetXMLNode(psIC, "Quantification_Values_List");
        }
        for (CPLXMLNode *psIter = psQVL ? psQVL->psChild : nullptr;
             psIter != nullptr; psIter = psIter->psNext)
        {
            if (psIter->eType != CXT_Element)
            {
                continue;
            }
            aosList.AddNameValue(psIter->pszValue,
                                 CPLGetXMLValue(psIter, nullptr, nullptr));
            const char *pszUnit = CPLGetXMLValue(psIter, "unit", nullptr);
            if (pszUnit)
                aosList.AddNameValue(CPLSPrintf("%s_UNIT", psIter->pszValue),
                                     pszUnit);
        }

        const char *pszRefBand =
            CPLGetXMLValue(psIC, "REFERENCE_BAND", nullptr);
        if (pszRefBand != nullptr)
        {
            int nIdx = atoi(pszRefBand);
            if (nIdx >= 0 && nIdx < (int)NB_BANDS)
                aosList.AddNameValue("REFERENCE_BAND",
                                     asBandDesc[nIdx].pszBandName);
        }
    }

    CPLXMLNode *psQII = CPLGetXMLNode(psRoot, "Quality_Indicators_Info");
    if (psQII != nullptr)
    {
        const char *pszCC =
            CPLGetXMLValue(psQII, "Cloud_Coverage_Assessment", nullptr);
        if (pszCC)
            aosList.AddNameValue("CLOUD_COVERAGE_ASSESSMENT", pszCC);

        const char *pszDegradedAnc = CPLGetXMLValue(
            psQII, "Technical_Quality_Assessment.DEGRADED_ANC_DATA_PERCENTAGE",
            nullptr);
        if (pszDegradedAnc)
            aosList.AddNameValue("DEGRADED_ANC_DATA_PERCENTAGE",
                                 pszDegradedAnc);

        const char *pszDegradedMSI = CPLGetXMLValue(
            psQII, "Technical_Quality_Assessment.DEGRADED_MSI_DATA_PERCENTAGE",
            nullptr);
        if (pszDegradedMSI)
            aosList.AddNameValue("DEGRADED_MSI_DATA_PERCENTAGE",
                                 pszDegradedMSI);

        CPLXMLNode *psQualInspect =
            CPLGetXMLNode(psQII, "Quality_Control_Checks.Quality_Inspections");
        for (CPLXMLNode *psIter =
                 (psQualInspect ? psQualInspect->psChild : nullptr);
             psIter != nullptr; psIter = psIter->psNext)
        {
            // MSIL2A approach
            if (psIter->psChild != nullptr &&
                psIter->psChild->psChild != nullptr &&
                psIter->psChild->psNext != nullptr &&
                psIter->psChild->psChild->eType == CXT_Text &&
                psIter->psChild->psNext->eType == CXT_Text)
            {
                aosList.AddNameValue(psIter->psChild->psChild->pszValue,
                                     psIter->psChild->psNext->pszValue);
                continue;
            }

            if (psIter->eType != CXT_Element)
                continue;
            if (psIter->psChild != nullptr &&
                psIter->psChild->eType == CXT_Text)
            {
                aosList.AddNameValue(psIter->pszValue,
                                     psIter->psChild->pszValue);
            }
        }

        CPLXMLNode *psICCQI = CPLGetXMLNode(psQII, "Image_Content_QI");
        if (psICCQI == nullptr)
        {
            CPLXMLNode *psL2A_QII =
                CPLGetXMLNode(psRoot, "L2A_Quality_Indicators_Info");
            if (psL2A_QII != nullptr)
            {
                psICCQI = CPLGetXMLNode(psL2A_QII, "Image_Content_QI");
            }
        }
        if (psICCQI != nullptr)
        {
            for (CPLXMLNode *psIter = psICCQI->psChild; psIter != nullptr;
                 psIter = psIter->psNext)
            {
                if (psIter->eType != CXT_Element)
                    continue;
                if (psIter->psChild != nullptr &&
                    psIter->psChild->eType == CXT_Text)
                {
                    aosList.AddNameValue(psIter->pszValue,
                                         psIter->psChild->pszValue);
                }
            }
        }
    }

    return aosList.StealList();
}

/************************************************************************/
/*                        SENTINEL2GetResolutionSet()                   */
/************************************************************************/

static bool SENTINEL2GetResolutionSet(
    CPLXMLNode *psProductInfo, std::set<int> &oSetResolutions,
    std::map<int, std::set<CPLString>> &oMapResolutionsToBands)
{

    CPLXMLNode *psBandList =
        CPLGetXMLNode(psProductInfo, "Query_Options.Band_List");
    if (psBandList == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s",
                 "Query_Options.Band_List");
        return false;
    }

    for (CPLXMLNode *psIter = psBandList->psChild; psIter != nullptr;
         psIter = psIter->psNext)
    {
        if (psIter->eType != CXT_Element ||
            !EQUAL(psIter->pszValue, "BAND_NAME"))
        {
            continue;
        }
        const char *pszBandName = CPLGetXMLValue(psIter, nullptr, "");
        const SENTINEL2BandDescription *psBandDesc =
            SENTINEL2GetBandDesc(pszBandName);
        if (psBandDesc == nullptr)
        {
            CPLDebug("SENTINEL2", "Unknown band name %s", pszBandName);
            continue;
        }
        oSetResolutions.insert(psBandDesc->nResolution);
        CPLString osName = psBandDesc->pszBandName + 1; /* skip B character */
        if (atoi(osName) < 10)
            osName = "0" + osName;
        oMapResolutionsToBands[psBandDesc->nResolution].insert(osName);
    }
    if (oSetResolutions.empty())
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find any band");
        return false;
    }
    return true;
}

/************************************************************************/
/*                  SENTINEL2GetPolygonWKTFromPosList()                 */
/************************************************************************/

static CPLString SENTINEL2GetPolygonWKTFromPosList(const char *pszPosList)
{
    CPLString osPolygon;
    char **papszTokens = CSLTokenizeString(pszPosList);
    int nTokens = CSLCount(papszTokens);
    int nDim = 2;
    if ((nTokens % 3) == 0 && nTokens >= 3 * 4 &&
        EQUAL(papszTokens[0], papszTokens[nTokens - 3]) &&
        EQUAL(papszTokens[1], papszTokens[nTokens - 2]) &&
        EQUAL(papszTokens[2], papszTokens[nTokens - 1]))
    {
        nDim = 3;
    }
    if ((nTokens % nDim) == 0)
    {
        osPolygon = "POLYGON((";
        for (char **papszIter = papszTokens; *papszIter; papszIter += nDim)
        {
            if (papszIter != papszTokens)
                osPolygon += ", ";
            osPolygon += papszIter[1];
            osPolygon += " ";
            osPolygon += papszIter[0];
            if (nDim == 3)
            {
                osPolygon += " ";
                osPolygon += papszIter[2];
            }
        }
        osPolygon += "))";
    }
    CSLDestroy(papszTokens);
    return osPolygon;
}

/************************************************************************/
/*                    SENTINEL2GetBandListForResolution()               */
/************************************************************************/

static CPLString
SENTINEL2GetBandListForResolution(const std::set<CPLString> &oBandnames)
{
    CPLString osBandNames;
    for (std::set<CPLString>::const_iterator oIterBandnames =
             oBandnames.begin();
         oIterBandnames != oBandnames.end(); ++oIterBandnames)
    {
        if (!osBandNames.empty())
            osBandNames += ", ";
        const char *pszName = *oIterBandnames;
        if (*pszName == DIGIT_ZERO)
            pszName++;
        if (atoi(pszName) > 0)
            osBandNames += "B" + CPLString(pszName);
        else
            osBandNames += pszName;
    }
    return osBandNames;
}

/************************************************************************/
/*                         OpenL1BUserProduct()                         */
/************************************************************************/

GDALDataset *SENTINEL2Dataset::OpenL1BUserProduct(GDALOpenInfo *poOpenInfo)
{
    CPLXMLNode *psRoot = CPLParseXMLFile(poOpenInfo->pszFilename);
    if (psRoot == nullptr)
    {
        CPLDebug("SENTINEL2", "Cannot XML parse %s", poOpenInfo->pszFilename);
        return nullptr;
    }

    char *pszOriginalXML = CPLSerializeXMLTree(psRoot);
    CPLString osOriginalXML;
    if (pszOriginalXML)
        osOriginalXML = pszOriginalXML;
    CPLFree(pszOriginalXML);

    SENTINEL2_CPLXMLNodeHolder oXMLHolder(psRoot);
    CPLStripXMLNamespace(psRoot, nullptr, TRUE);

    CPLXMLNode *psProductInfo = CPLGetXMLNode(
        psRoot, "=Level-1B_User_Product.General_Info.Product_Info");
    if (psProductInfo == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s",
                 "=Level-1B_User_Product.General_Info.Product_Info");
        return nullptr;
    }

    std::set<int> oSetResolutions;
    std::map<int, std::set<CPLString>> oMapResolutionsToBands;
    if (!SENTINEL2GetResolutionSet(psProductInfo, oSetResolutions,
                                   oMapResolutionsToBands))
    {
        CPLDebug("SENTINEL2", "Failed to get resolution set");
        return nullptr;
    }

    std::vector<CPLString> aosGranuleList;
    if (!SENTINEL2GetGranuleList(psRoot, SENTINEL2_L1B, poOpenInfo->pszFilename,
                                 aosGranuleList))
    {
        CPLDebug("SENTINEL2", "Failed to get granule list");
        return nullptr;
    }

    SENTINEL2DatasetContainer *poDS = new SENTINEL2DatasetContainer();
    char **papszMD =
        SENTINEL2GetUserProductMetadata(psRoot, "Level-1B_User_Product");
    poDS->GDALDataset::SetMetadata(papszMD);
    CSLDestroy(papszMD);

    if (!osOriginalXML.empty())
    {
        char *apszXMLMD[2] = {nullptr};
        apszXMLMD[0] = const_cast<char *>(osOriginalXML.c_str());
        apszXMLMD[1] = nullptr;
        poDS->GDALDataset::SetMetadata(apszXMLMD, "xml:SENTINEL2");
    }

    /* Create subdatsets per granules and resolution (10, 20, 60m) */
    int iSubDSNum = 1;
    for (size_t i = 0; i < aosGranuleList.size(); i++)
    {
        for (std::set<int>::const_iterator oIterRes = oSetResolutions.begin();
             oIterRes != oSetResolutions.end(); ++oIterRes)
        {
            const int nResolution = *oIterRes;

            poDS->GDALDataset::SetMetadataItem(
                CPLSPrintf("SUBDATASET_%d_NAME", iSubDSNum),
                CPLSPrintf("SENTINEL2_L1B:%s:%dm", aosGranuleList[i].c_str(),
                           nResolution),
                "SUBDATASETS");

            CPLString osBandNames = SENTINEL2GetBandListForResolution(
                oMapResolutionsToBands[nResolution]);

            CPLString osDesc(
                CPLSPrintf("Bands %s of granule %s with %dm resolution",
                           osBandNames.c_str(),
                           CPLGetFilename(aosGranuleList[i]), nResolution));
            poDS->GDALDataset::SetMetadataItem(
                CPLSPrintf("SUBDATASET_%d_DESC", iSubDSNum), osDesc.c_str(),
                "SUBDATASETS");

            iSubDSNum++;
        }
    }

    const char *pszPosList = CPLGetXMLValue(
        psRoot,
        "=Level-1B_User_Product.Geometric_Info.Product_Footprint."
        "Product_Footprint.Global_Footprint.EXT_POS_LIST",
        nullptr);
    if (pszPosList != nullptr)
    {
        CPLString osPolygon = SENTINEL2GetPolygonWKTFromPosList(pszPosList);
        if (!osPolygon.empty())
            poDS->GDALDataset::SetMetadataItem("FOOTPRINT", osPolygon.c_str());
    }

    return poDS;
}

/************************************************************************/
/*                    SENTINEL2GetL1BGranuleMetadata()                  */
/************************************************************************/

static char **SENTINEL2GetL1BGranuleMetadata(CPLXMLNode *psMainMTD)
{
    CPLStringList aosList;

    CPLXMLNode *psRoot = CPLGetXMLNode(psMainMTD, "=Level-1B_Granule_ID");
    if (psRoot == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Cannot find =Level-1B_Granule_ID");
        return nullptr;
    }
    CPLXMLNode *psGeneralInfo = CPLGetXMLNode(psRoot, "General_Info");
    for (CPLXMLNode *psIter =
             (psGeneralInfo ? psGeneralInfo->psChild : nullptr);
         psIter != nullptr; psIter = psIter->psNext)
    {
        if (psIter->eType != CXT_Element)
            continue;
        const char *pszValue = CPLGetXMLValue(psIter, nullptr, nullptr);
        if (pszValue != nullptr)
        {
            aosList.AddNameValue(psIter->pszValue, pszValue);
        }
    }

    CPLXMLNode *psGeometryHeader = CPLGetXMLNode(
        psRoot, "Geometric_Info.Granule_Position.Geometric_Header");
    if (psGeometryHeader != nullptr)
    {
        const char *pszVal = CPLGetXMLValue(
            psGeometryHeader, "Incidence_Angles.ZENITH_ANGLE", nullptr);
        if (pszVal)
            aosList.AddNameValue("INCIDENCE_ZENITH_ANGLE", pszVal);

        pszVal = CPLGetXMLValue(psGeometryHeader,
                                "Incidence_Angles.AZIMUTH_ANGLE", nullptr);
        if (pszVal)
            aosList.AddNameValue("INCIDENCE_AZIMUTH_ANGLE", pszVal);

        pszVal = CPLGetXMLValue(psGeometryHeader, "Solar_Angles.ZENITH_ANGLE",
                                nullptr);
        if (pszVal)
            aosList.AddNameValue("SOLAR_ZENITH_ANGLE", pszVal);

        pszVal = CPLGetXMLValue(psGeometryHeader, "Solar_Angles.AZIMUTH_ANGLE",
                                nullptr);
        if (pszVal)
            aosList.AddNameValue("SOLAR_AZIMUTH_ANGLE", pszVal);
    }

    CPLXMLNode *psQII = CPLGetXMLNode(psRoot, "Quality_Indicators_Info");
    if (psQII != nullptr)
    {
        CPLXMLNode *psICCQI = CPLGetXMLNode(psQII, "Image_Content_QI");
        for (CPLXMLNode *psIter = (psICCQI ? psICCQI->psChild : nullptr);
             psIter != nullptr; psIter = psIter->psNext)
        {
            if (psIter->eType != CXT_Element)
                continue;
            if (psIter->psChild != nullptr &&
                psIter->psChild->eType == CXT_Text)
            {
                aosList.AddNameValue(psIter->pszValue,
                                     psIter->psChild->pszValue);
            }
        }
    }

    return aosList.StealList();
}

/************************************************************************/
/*                        SENTINEL2GetTilename()                        */
/************************************************************************/

static CPLString SENTINEL2GetTilename(
    const CPLString &osGranulePath, const CPLString &osGranuleName,
    const CPLString &osBandName, const CPLString &osProductURI = CPLString(),
    bool bIsPreview = false, int nPrecisionL2A = 0)
{
    bool granuleNameMatchTilename = true;
    CPLString osJPEG2000Name(osGranuleName);
    if (osJPEG2000Name.size() > 7 &&
        osJPEG2000Name[osJPEG2000Name.size() - 7] == '_' &&
        osJPEG2000Name[osJPEG2000Name.size() - 6] == 'N')
    {
        osJPEG2000Name.resize(osJPEG2000Name.size() - 7);
    }

    const SENTINEL2_L2A_BandDescription *psL2ABandDesc =
        (nPrecisionL2A) ? SENTINEL2GetL2ABandDesc(osBandName) : nullptr;

    CPLString osTile(osGranulePath);
    const char chSeparator = SENTINEL2GetPathSeparator(osTile);
    if (!osTile.empty())
        osTile += chSeparator;
    bool procBaseLineIs1 = false;
    if (osJPEG2000Name.size() > 12 && osJPEG2000Name[8] == '_' &&
        osJPEG2000Name[12] == '_')
        procBaseLineIs1 = true;
    if (bIsPreview ||
        (psL2ABandDesc != nullptr && (psL2ABandDesc->eLocation == TL_QI_DATA)))
    {
        osTile += "QI_DATA";
        osTile += chSeparator;
        if (procBaseLineIs1)
        {
            if (atoi(osBandName) > 0)
            {
                osJPEG2000Name[9] = 'P';
                osJPEG2000Name[10] = 'V';
                osJPEG2000Name[11] = 'I';
            }
            else if (nPrecisionL2A && osBandName.size() == 3)
            {
                osJPEG2000Name[9] = osBandName[0];
                osJPEG2000Name[10] = osBandName[1];
                osJPEG2000Name[11] = osBandName[2];
            }
            osTile += osJPEG2000Name;
        }
        else
        {
            osTile += "MSK_";
            osTile += osBandName;
            osTile += "PRB";
        }
        if (nPrecisionL2A && !bIsPreview)
            osTile += CPLSPrintf("_%02dm", nPrecisionL2A);
    }
    else
    {
        osTile += "IMG_DATA";
        osTile += chSeparator;
        if (((psL2ABandDesc != nullptr &&
              psL2ABandDesc->eLocation == TL_IMG_DATA_Rxxm) ||
             (psL2ABandDesc == nullptr && nPrecisionL2A != 0)) &&
            (!procBaseLineIs1 || osBandName != "SCL"))
        {
            osTile += CPLSPrintf("R%02dm", nPrecisionL2A);
            osTile += chSeparator;
        }
        if (procBaseLineIs1)
        {
            if (atoi(osBandName) > 0)
            {
                osJPEG2000Name[9] = 'M';
                osJPEG2000Name[10] = 'S';
                osJPEG2000Name[11] = 'I';
            }
            else if (nPrecisionL2A && osBandName.size() == 3)
            {
                osJPEG2000Name[9] = osBandName[0];
                osJPEG2000Name[10] = osBandName[1];
                osJPEG2000Name[11] = osBandName[2];
            }
        }
        else if (osProductURI.size() > 44 &&
                 osProductURI.substr(3, 8) == "_MSIL2A_")
        {
            osTile += osProductURI.substr(38, 6);
            osTile += osProductURI.substr(10, 16);
            granuleNameMatchTilename = false;
        }
        else
        {
            CPLDebug("SENTINEL2", "Invalid granule path: %s",
                     osGranulePath.c_str());
        }
        if (granuleNameMatchTilename)
            osTile += osJPEG2000Name;
        if (atoi(osBandName) > 0)
        {
            osTile += "_B";
            if (osBandName.size() == 3 && osBandName[0] == '0')
                osTile += osBandName.substr(1);
            else
                osTile += osBandName;
        }
        else if (!procBaseLineIs1)
        {
            osTile += "_";
            osTile += osBandName;
        }
        if (nPrecisionL2A)
            osTile += CPLSPrintf("_%02dm", nPrecisionL2A);
    }
    osTile += ".jp2";
    return osTile;
}

/************************************************************************/
/*                 SENTINEL2GetMainMTDFilenameFromGranuleMTD()          */
/************************************************************************/

static CPLString
SENTINEL2GetMainMTDFilenameFromGranuleMTD(const char *pszFilename)
{
    // Look for product MTD file
    CPLString osTopDir(CPLFormFilename(
        CPLFormFilename(CPLGetDirname(pszFilename), "..", nullptr), "..",
        nullptr));

    // Workaround to avoid long filenames on Windows
    if (CPLIsFilenameRelative(pszFilename))
    {
        // GRANULE/bla/bla.xml
        const char *pszPath = CPLGetPath(pszFilename);
        if (strchr(pszPath, '/') || strchr(pszPath, '\\'))
        {
            osTopDir = CPLGetPath(CPLGetPath(pszPath));
            if (osTopDir == "")
                osTopDir = ".";
        }
    }

    char **papszContents = VSIReadDir(osTopDir);
    CPLString osMainMTD;
    for (char **papszIter = papszContents; papszIter && *papszIter; ++papszIter)
    {
        if (strlen(*papszIter) >= strlen("S2A_XXXX_MTD") &&
            (STARTS_WITH_CI(*papszIter, "S2A_") ||
             STARTS_WITH_CI(*papszIter, "S2B_")) &&
            EQUALN(*papszIter + strlen("S2A_XXXX"), "_MTD", 4))
        {
            osMainMTD = CPLFormFilename(osTopDir, *papszIter, nullptr);
            break;
        }
    }
    CSLDestroy(papszContents);
    return osMainMTD;
}

/************************************************************************/
/*            SENTINEL2GetResolutionSetAndMainMDFromGranule()           */
/************************************************************************/

static void SENTINEL2GetResolutionSetAndMainMDFromGranule(
    const char *pszFilename, const char *pszRootPathWithoutEqual,
    int nResolutionOfInterest, std::set<int> &oSetResolutions,
    std::map<int, std::set<CPLString>> &oMapResolutionsToBands, char **&papszMD,
    CPLXMLNode **ppsRootMainMTD)
{
    CPLString osMainMTD(SENTINEL2GetMainMTDFilenameFromGranuleMTD(pszFilename));

    // Parse product MTD if available
    papszMD = nullptr;
    if (!osMainMTD.empty() &&
        /* env var for debug only */
        CPLTestBool(CPLGetConfigOption("SENTINEL2_USE_MAIN_MTD", "YES")))
    {
        CPLXMLNode *psRootMainMTD = CPLParseXMLFile(osMainMTD);
        if (psRootMainMTD != nullptr)
        {
            CPLStripXMLNamespace(psRootMainMTD, nullptr, TRUE);

            CPLXMLNode *psProductInfo = CPLGetXMLNode(
                psRootMainMTD, CPLSPrintf("=%s.General_Info.Product_Info",
                                          pszRootPathWithoutEqual));
            if (psProductInfo != nullptr)
            {
                SENTINEL2GetResolutionSet(psProductInfo, oSetResolutions,
                                          oMapResolutionsToBands);
            }

            papszMD = SENTINEL2GetUserProductMetadata(psRootMainMTD,
                                                      pszRootPathWithoutEqual);
            if (ppsRootMainMTD != nullptr)
                *ppsRootMainMTD = psRootMainMTD;
            else
                CPLDestroyXMLNode(psRootMainMTD);
        }
    }
    else
    {
        // If no main MTD file found, then probe all bands for resolution (of
        // interest if there's one, or all resolutions otherwise)
        for (size_t i = 0; i < NB_BANDS; i++)
        {
            if (nResolutionOfInterest != 0 &&
                asBandDesc[i].nResolution != nResolutionOfInterest)
            {
                continue;
            }
            CPLString osBandName =
                asBandDesc[i].pszBandName + 1; /* skip B character */
            if (atoi(osBandName) < 10)
                osBandName = "0" + osBandName;

            CPLString osTile(SENTINEL2GetTilename(CPLGetPath(pszFilename),
                                                  CPLGetBasename(pszFilename),
                                                  osBandName));
            VSIStatBufL sStat;
            if (VSIStatExL(osTile, &sStat, VSI_STAT_EXISTS_FLAG) == 0)
            {
                oMapResolutionsToBands[asBandDesc[i].nResolution].insert(
                    osBandName);
                oSetResolutions.insert(asBandDesc[i].nResolution);
            }
        }
    }
}

/************************************************************************/
/*                           OpenL1BGranule()                           */
/************************************************************************/

GDALDataset *SENTINEL2Dataset::OpenL1BGranule(const char *pszFilename,
                                              CPLXMLNode **ppsRoot,
                                              int nResolutionOfInterest,
                                              std::set<CPLString> *poBandSet)
{
    CPLXMLNode *psRoot = CPLParseXMLFile(pszFilename);
    if (psRoot == nullptr)
    {
        CPLDebug("SENTINEL2", "Cannot XML parse %s", pszFilename);
        return nullptr;
    }

    char *pszOriginalXML = CPLSerializeXMLTree(psRoot);
    CPLString osOriginalXML;
    if (pszOriginalXML)
        osOriginalXML = pszOriginalXML;
    CPLFree(pszOriginalXML);

    SENTINEL2_CPLXMLNodeHolder oXMLHolder(psRoot);
    CPLStripXMLNamespace(psRoot, nullptr, TRUE);

    SENTINEL2DatasetContainer *poDS = new SENTINEL2DatasetContainer();

    if (!osOriginalXML.empty())
    {
        char *apszXMLMD[2];
        apszXMLMD[0] = const_cast<char *>(osOriginalXML.c_str());
        apszXMLMD[1] = nullptr;
        poDS->GDALDataset::SetMetadata(apszXMLMD, "xml:SENTINEL2");
    }

    std::set<int> oSetResolutions;
    std::map<int, std::set<CPLString>> oMapResolutionsToBands;
    char **papszMD = nullptr;
    SENTINEL2GetResolutionSetAndMainMDFromGranule(
        pszFilename, "Level-1B_User_Product", nResolutionOfInterest,
        oSetResolutions, oMapResolutionsToBands, papszMD, nullptr);
    if (poBandSet != nullptr)
        *poBandSet = oMapResolutionsToBands[nResolutionOfInterest];

    char **papszGranuleMD = SENTINEL2GetL1BGranuleMetadata(psRoot);
    papszMD = CSLMerge(papszMD, papszGranuleMD);
    CSLDestroy(papszGranuleMD);

    // Remove CLOUD_COVERAGE_ASSESSMENT that comes from main metadata, if
    // granule CLOUDY_PIXEL_PERCENTAGE is present.
    if (CSLFetchNameValue(papszMD, "CLOUDY_PIXEL_PERCENTAGE") != nullptr &&
        CSLFetchNameValue(papszMD, "CLOUD_COVERAGE_ASSESSMENT") != nullptr)
    {
        papszMD =
            CSLSetNameValue(papszMD, "CLOUD_COVERAGE_ASSESSMENT", nullptr);
    }

    poDS->GDALDataset::SetMetadata(papszMD);
    CSLDestroy(papszMD);

    // Get the footprint
    const char *pszPosList =
        CPLGetXMLValue(psRoot,
                       "=Level-1B_Granule_ID.Geometric_Info.Granule_Footprint."
                       "Granule_Footprint.Footprint.EXT_POS_LIST",
                       nullptr);
    if (pszPosList != nullptr)
    {
        CPLString osPolygon = SENTINEL2GetPolygonWKTFromPosList(pszPosList);
        if (!osPolygon.empty())
            poDS->GDALDataset::SetMetadataItem("FOOTPRINT", osPolygon.c_str());
    }

    /* Create subdatsets per resolution (10, 20, 60m) */
    int iSubDSNum = 1;
    for (std::set<int>::const_iterator oIterRes = oSetResolutions.begin();
         oIterRes != oSetResolutions.end(); ++oIterRes)
    {
        const int nResolution = *oIterRes;

        poDS->GDALDataset::SetMetadataItem(
            CPLSPrintf("SUBDATASET_%d_NAME", iSubDSNum),
            CPLSPrintf("SENTINEL2_L1B:%s:%dm", pszFilename, nResolution),
            "SUBDATASETS");

        CPLString osBandNames = SENTINEL2GetBandListForResolution(
            oMapResolutionsToBands[nResolution]);

        CPLString osDesc(CPLSPrintf("Bands %s with %dm resolution",
                                    osBandNames.c_str(), nResolution));
        poDS->GDALDataset::SetMetadataItem(
            CPLSPrintf("SUBDATASET_%d_DESC", iSubDSNum), osDesc.c_str(),
            "SUBDATASETS");

        iSubDSNum++;
    }

    if (ppsRoot != nullptr)
    {
        *ppsRoot = oXMLHolder.Release();
    }

    return poDS;
}

/************************************************************************/
/*                     SENTINEL2SetBandMetadata()                       */
/************************************************************************/

static void SENTINEL2SetBandMetadata(GDALRasterBand *poBand,
                                     const CPLString &osBandName)
{
    CPLString osLookupBandName(osBandName);
    if (osLookupBandName[0] == '0')
        osLookupBandName = osLookupBandName.substr(1);
    if (atoi(osLookupBandName) > 0)
        osLookupBandName = "B" + osLookupBandName;

    CPLString osBandDesc(osLookupBandName);
    const SENTINEL2BandDescription *psBandDesc =
        SENTINEL2GetBandDesc(osLookupBandName);
    if (psBandDesc != nullptr)
    {
        osBandDesc +=
            CPLSPrintf(", central wavelength %d nm", psBandDesc->nWaveLength);
        poBand->SetColorInterpretation(psBandDesc->eColorInterp);
        poBand->SetMetadataItem("BANDNAME", psBandDesc->pszBandName);
        poBand->SetMetadataItem("BANDWIDTH",
                                CPLSPrintf("%d", psBandDesc->nBandWidth));
        poBand->SetMetadataItem("BANDWIDTH_UNIT", "nm");
        poBand->SetMetadataItem("WAVELENGTH",
                                CPLSPrintf("%d", psBandDesc->nWaveLength));
        poBand->SetMetadataItem("WAVELENGTH_UNIT", "nm");

        poBand->SetMetadataItem(
            "CENTRAL_WAVELENGTH_UM",
            CPLSPrintf("%.3f", double(psBandDesc->nWaveLength) / 1000),
            "IMAGERY");
        poBand->SetMetadataItem(
            "FWHM_UM",
            CPLSPrintf("%.3f", double(psBandDesc->nBandWidth) / 1000),
            "IMAGERY");
    }
    else
    {
        const SENTINEL2_L2A_BandDescription *psL2ABandDesc =
            SENTINEL2GetL2ABandDesc(osBandName);
        if (psL2ABandDesc != nullptr)
        {
            osBandDesc += ", ";
            osBandDesc += psL2ABandDesc->pszBandDescription;
        }

        poBand->SetMetadataItem("BANDNAME", osBandName);
    }
    poBand->SetDescription(osBandDesc);
}

/************************************************************************/
/*                         OpenL1BSubdataset()                          */
/************************************************************************/

GDALDataset *SENTINEL2Dataset::OpenL1BSubdataset(GDALOpenInfo *poOpenInfo)
{
    CPLString osFilename;
    CPLAssert(STARTS_WITH_CI(poOpenInfo->pszFilename, "SENTINEL2_L1B:"));
    osFilename = poOpenInfo->pszFilename + strlen("SENTINEL2_L1B:");
    const char *pszPrecision = strrchr(osFilename.c_str(), ':');
    if (pszPrecision == nullptr || pszPrecision == osFilename.c_str())
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Invalid syntax for SENTINEL2_L1B:");
        return nullptr;
    }
    const int nSubDSPrecision = atoi(pszPrecision + 1);
    if (nSubDSPrecision != 10 && nSubDSPrecision != 20 && nSubDSPrecision != 60)
    {
        CPLError(CE_Failure, CPLE_NotSupported, "Unsupported precision: %d",
                 nSubDSPrecision);
        return nullptr;
    }
    osFilename.resize(pszPrecision - osFilename.c_str());

    CPLXMLNode *psRoot = nullptr;
    std::set<CPLString> oSetBands;
    GDALDataset *poTmpDS =
        OpenL1BGranule(osFilename, &psRoot, nSubDSPrecision, &oSetBands);
    if (poTmpDS == nullptr)
    {
        CPLDebug("SENTINEL2", "Failed to open L1B granule %s",
                 osFilename.c_str());
        return nullptr;
    }

    SENTINEL2_CPLXMLNodeHolder oXMLHolder(psRoot);

    std::vector<CPLString> aosBands;
    for (std::set<CPLString>::const_iterator oIterBandnames = oSetBands.begin();
         oIterBandnames != oSetBands.end(); ++oIterBandnames)
    {
        aosBands.push_back(*oIterBandnames);
    }
    /* Put 2=Blue, 3=Green, 4=Band bands in RGB order for conveniency */
    if (aosBands.size() >= 3 && aosBands[0] == "02" && aosBands[1] == "03" &&
        aosBands[2] == "04")
    {
        aosBands[0] = "04";
        aosBands[2] = "02";
    }

    int nBits = 0;   /* 0 = unknown yet*/
    int nValMax = 0; /* 0 = unknown yet*/
    int nRows = 0;
    int nCols = 0;
    CPLXMLNode *psGranuleDimensions = CPLGetXMLNode(
        psRoot, "=Level-1B_Granule_ID.Geometric_Info.Granule_Dimensions");
    if (psGranuleDimensions == nullptr)
    {
        for (size_t i = 0; i < aosBands.size(); i++)
        {
            CPLString osTile(SENTINEL2GetTilename(CPLGetPath(osFilename),
                                                  CPLGetBasename(osFilename),
                                                  aosBands[i]));
            if (SENTINEL2GetTileInfo(osTile, &nCols, &nRows, &nBits))
            {
                if (nBits <= 16)
                    nValMax = (1 << nBits) - 1;
                else
                {
                    CPLDebug("SENTINEL2", "Unexpected bit depth %d", nBits);
                    nValMax = 65535;
                }
                break;
            }
        }
    }
    else
    {
        for (CPLXMLNode *psIter = psGranuleDimensions->psChild;
             psIter != nullptr; psIter = psIter->psNext)
        {
            if (psIter->eType != CXT_Element)
                continue;
            if (EQUAL(psIter->pszValue, "Size") &&
                atoi(CPLGetXMLValue(psIter, "resolution", "")) ==
                    nSubDSPrecision)
            {
                const char *pszRows = CPLGetXMLValue(psIter, "NROWS", nullptr);
                if (pszRows == nullptr)
                {
                    CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s",
                             "NROWS");
                    delete poTmpDS;
                    return nullptr;
                }
                const char *pszCols = CPLGetXMLValue(psIter, "NCOLS", nullptr);
                if (pszCols == nullptr)
                {
                    CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s",
                             "NCOLS");
                    delete poTmpDS;
                    return nullptr;
                }
                nRows = atoi(pszRows);
                nCols = atoi(pszCols);
                break;
            }
        }
    }
    if (nRows <= 0 || nCols <= 0)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find granule dimension");
        delete poTmpDS;
        return nullptr;
    }

    SENTINEL2Dataset *poDS = new SENTINEL2Dataset(nCols, nRows);
    poDS->aosNonJP2Files.push_back(osFilename);

    // Transfer metadata
    poDS->GDALDataset::SetMetadata(poTmpDS->GetMetadata());
    poDS->GDALDataset::SetMetadata(poTmpDS->GetMetadata("xml:SENTINEL2"),
                                   "xml:SENTINEL2");

    delete poTmpDS;

    /* -------------------------------------------------------------------- */
    /*      Initialize bands.                                               */
    /* -------------------------------------------------------------------- */

    int nSaturatedVal = atoi(CSLFetchNameValueDef(
        poDS->GetMetadata(), "SPECIAL_VALUE_SATURATED", "-1"));
    int nNodataVal = atoi(CSLFetchNameValueDef(poDS->GetMetadata(),
                                               "SPECIAL_VALUE_NODATA", "-1"));

    const bool bAlpha =
        CPLTestBool(SENTINEL2GetOption(poOpenInfo, "ALPHA", "FALSE"));
    const int nBands = ((bAlpha) ? 1 : 0) + static_cast<int>(aosBands.size());
    const int nAlphaBand = (!bAlpha) ? 0 : nBands;
    const GDALDataType eDT = GDT_UInt16;

    for (int nBand = 1; nBand <= nBands; nBand++)
    {
        VRTSourcedRasterBand *poBand = nullptr;

        if (nBand != nAlphaBand)
        {
            poBand = new VRTSourcedRasterBand(
                poDS, nBand, eDT, poDS->nRasterXSize, poDS->nRasterYSize);
        }
        else
        {
            poBand = new SENTINEL2AlphaBand(
                poDS, nBand, eDT, poDS->nRasterXSize, poDS->nRasterYSize,
                nSaturatedVal, nNodataVal);
        }

        poDS->SetBand(nBand, poBand);
        if (nBand == nAlphaBand)
            poBand->SetColorInterpretation(GCI_AlphaBand);

        CPLString osBandName;
        if (nBand != nAlphaBand)
        {
            osBandName = aosBands[nBand - 1];
            SENTINEL2SetBandMetadata(poBand, osBandName);
        }
        else
            osBandName = aosBands[0];

        CPLString osTile(SENTINEL2GetTilename(
            CPLGetPath(osFilename), CPLGetBasename(osFilename), osBandName));

        bool bTileFound = false;
        if (nValMax == 0)
        {
            /* It is supposed to be 12 bits, but some products have 15 bits */
            if (SENTINEL2GetTileInfo(osTile, nullptr, nullptr, &nBits))
            {
                bTileFound = true;
                if (nBits <= 16)
                    nValMax = (1 << nBits) - 1;
                else
                {
                    CPLDebug("SENTINEL2", "Unexpected bit depth %d", nBits);
                    nValMax = 65535;
                }
            }
        }
        else
        {
            VSIStatBufL sStat;
            if (VSIStatExL(osTile, &sStat, VSI_STAT_EXISTS_FLAG) == 0)
                bTileFound = true;
        }
        if (!bTileFound)
        {
            CPLError(CE_Warning, CPLE_AppDefined,
                     "Tile %s not found on filesystem. Skipping it",
                     osTile.c_str());
            continue;
        }

        if (nBand != nAlphaBand)
        {
            poBand->AddSimpleSource(osTile, 1, 0, 0, poDS->nRasterXSize,
                                    poDS->nRasterYSize, 0, 0,
                                    poDS->nRasterXSize, poDS->nRasterYSize);
        }
        else
        {
            poBand->AddComplexSource(osTile, 1, 0, 0, poDS->nRasterXSize,
                                     poDS->nRasterYSize, 0, 0,
                                     poDS->nRasterXSize, poDS->nRasterYSize,
                                     nValMax /* offset */, 0 /* scale */);
        }

        if ((nBits % 8) != 0)
        {
            poBand->SetMetadataItem("NBITS", CPLSPrintf("%d", nBits),
                                    "IMAGE_STRUCTURE");
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Add georeferencing.                                             */
    /* -------------------------------------------------------------------- */
    // const char* pszDirection =
    // poDS->GetMetadataItem("DATATAKE_1_SENSING_ORBIT_DIRECTION");
    const char *pszFootprint = poDS->GetMetadataItem("FOOTPRINT");
    if (pszFootprint != nullptr)
    {
        // For descending orbits, we have observed that the order of points in
        // the polygon is UL, LL, LR, UR. That might not be true for ascending
        // orbits but let's assume it...
        OGRGeometry *poGeom = nullptr;
        if (OGRGeometryFactory::createFromWkt(pszFootprint, nullptr, &poGeom) ==
                OGRERR_NONE &&
            poGeom != nullptr &&
            wkbFlatten(poGeom->getGeometryType()) == wkbPolygon)
        {
            OGRLinearRing *poRing =
                reinterpret_cast<OGRPolygon *>(poGeom)->getExteriorRing();
            if (poRing != nullptr && poRing->getNumPoints() == 5)
            {
                GDAL_GCP asGCPList[5];
                memset(asGCPList, 0, sizeof(asGCPList));
                for (int i = 0; i < 4; i++)
                {
                    asGCPList[i].dfGCPX = poRing->getX(i);
                    asGCPList[i].dfGCPY = poRing->getY(i);
                    asGCPList[i].dfGCPZ = poRing->getZ(i);
                }
                asGCPList[0].dfGCPPixel = 0;
                asGCPList[0].dfGCPLine = 0;
                asGCPList[1].dfGCPPixel = 0;
                asGCPList[1].dfGCPLine = poDS->nRasterYSize;
                asGCPList[2].dfGCPPixel = poDS->nRasterXSize;
                asGCPList[2].dfGCPLine = poDS->nRasterYSize;
                asGCPList[3].dfGCPPixel = poDS->nRasterXSize;
                asGCPList[3].dfGCPLine = 0;

                int nGCPCount = 4;
                CPLXMLNode *psGeometryHeader =
                    CPLGetXMLNode(psRoot, "=Level-1B_Granule_ID.Geometric_Info."
                                          "Granule_Position.Geometric_Header");
                if (psGeometryHeader != nullptr)
                {
                    const char *pszGC = CPLGetXMLValue(
                        psGeometryHeader, "GROUND_CENTER", nullptr);
                    const char *pszQLCenter =
                        CPLGetXMLValue(psGeometryHeader, "QL_CENTER", nullptr);
                    if (pszGC != nullptr && pszQLCenter != nullptr &&
                        EQUAL(pszQLCenter, "0 0"))
                    {
                        char **papszTokens = CSLTokenizeString(pszGC);
                        if (CSLCount(papszTokens) >= 2)
                        {
                            nGCPCount = 5;
                            asGCPList[4].dfGCPX = CPLAtof(papszTokens[1]);
                            asGCPList[4].dfGCPY = CPLAtof(papszTokens[0]);
                            if (CSLCount(papszTokens) >= 3)
                                asGCPList[4].dfGCPZ = CPLAtof(papszTokens[2]);
                            asGCPList[4].dfGCPLine = poDS->nRasterYSize / 2.0;
                            asGCPList[4].dfGCPPixel = poDS->nRasterXSize / 2.0;
                        }
                        CSLDestroy(papszTokens);
                    }
                }

                poDS->SetGCPs(nGCPCount, asGCPList, SRS_WKT_WGS84_LAT_LONG);
                GDALDeinitGCPs(nGCPCount, asGCPList);
            }
        }
        delete poGeom;
    }

    /* -------------------------------------------------------------------- */
    /*      Initialize overview information.                                */
    /* -------------------------------------------------------------------- */
    poDS->SetDescription(poOpenInfo->pszFilename);
    CPLString osOverviewFile;
    osOverviewFile =
        CPLSPrintf("%s_%dm.tif.ovr", osFilename.c_str(), nSubDSPrecision);
    poDS->SetMetadataItem("OVERVIEW_FILE", osOverviewFile, "OVERVIEWS");
    poDS->oOvManager.Initialize(poDS, ":::VIRTUAL:::");

    return poDS;
}

/************************************************************************/
/*                 SENTINEL2GetGranuleList_L1CSafeCompact()             */
/************************************************************************/

static bool SENTINEL2GetGranuleList_L1CSafeCompact(
    CPLXMLNode *psMainMTD, const char *pszFilename,
    std::vector<L1CSafeCompatGranuleDescription> &osList)
{
    CPLXMLNode *psProductInfo = CPLGetXMLNode(
        psMainMTD, "=Level-1C_User_Product.General_Info.Product_Info");
    if (psProductInfo == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s",
                 "=Level-1C_User_Product.General_Info.Product_Info");
        return false;
    }

    CPLXMLNode *psProductOrganisation =
        CPLGetXMLNode(psProductInfo, "Product_Organisation");
    if (psProductOrganisation == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s",
                 "Product_Organisation");
        return false;
    }

    CPLString osDirname(CPLGetDirname(pszFilename));
#ifdef HAVE_READLINK
    char szPointerFilename[2048];
    int nBytes = static_cast<int>(
        readlink(pszFilename, szPointerFilename, sizeof(szPointerFilename)));
    if (nBytes != -1)
    {
        const int nOffset =
            std::min(nBytes, static_cast<int>(sizeof(szPointerFilename) - 1));
        szPointerFilename[nOffset] = '\0';
        osDirname = CPLGetDirname(szPointerFilename);
    }
#endif

    const char chSeparator = SENTINEL2GetPathSeparator(osDirname);
    for (CPLXMLNode *psIter = psProductOrganisation->psChild; psIter != nullptr;
         psIter = psIter->psNext)
    {
        if (psIter->eType != CXT_Element ||
            !EQUAL(psIter->pszValue, "Granule_List"))
        {
            continue;
        }
        for (CPLXMLNode *psIter2 = psIter->psChild; psIter2 != nullptr;
             psIter2 = psIter2->psNext)
        {
            if (psIter2->eType != CXT_Element ||
                !EQUAL(psIter2->pszValue, "Granule"))
            {
                continue;
            }

            const char *pszImageFile =
                CPLGetXMLValue(psIter2, "IMAGE_FILE", nullptr);
            if (pszImageFile == nullptr || strlen(pszImageFile) < 3)
            {
                CPLDebug("SENTINEL2", "Missing IMAGE_FILE element");
                continue;
            }
            L1CSafeCompatGranuleDescription oDesc;
            oDesc.osBandPrefixPath = osDirname + chSeparator + pszImageFile;
            oDesc.osBandPrefixPath.resize(oDesc.osBandPrefixPath.size() -
                                          3);  // strip B12
            // GRANULE/L1C_T30TXT_A007999_20170102T111441/IMG_DATA/T30TXT_20170102T111442_B12
            // --> GRANULE/L1C_T30TXT_A007999_20170102T111441/MTD_TL.xml
            oDesc.osMTDTLPath = osDirname + chSeparator +
                                CPLGetDirname(CPLGetDirname(pszImageFile)) +
                                chSeparator + "MTD_TL.xml";
            osList.push_back(oDesc);
        }
    }

    return true;
}

/************************************************************************/
/*                 SENTINEL2GetGranuleList_L2ASafeCompact()             */
/************************************************************************/

static bool SENTINEL2GetGranuleList_L2ASafeCompact(
    CPLXMLNode *psMainMTD, const char *pszFilename,
    std::vector<L1CSafeCompatGranuleDescription> &osList)
{
    const char *pszNodePath =
        "=Level-2A_User_Product.General_Info.Product_Info";
    CPLXMLNode *psProductInfo = CPLGetXMLNode(psMainMTD, pszNodePath);
    if (psProductInfo == nullptr)
    {
        pszNodePath = "=Level-2A_User_Product.General_Info.L2A_Product_Info";
        psProductInfo = CPLGetXMLNode(psMainMTD, pszNodePath);
    }
    if (psProductInfo == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s", pszNodePath);
        return false;
    }

    CPLXMLNode *psProductOrganisation =
        CPLGetXMLNode(psProductInfo, "Product_Organisation");
    if (psProductOrganisation == nullptr)
    {
        psProductOrganisation =
            CPLGetXMLNode(psProductInfo, "L2A_Product_Organisation");
        if (psProductOrganisation == nullptr)
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s",
                     "Product_Organisation");
            return false;
        }
    }

    CPLString osDirname(CPLGetDirname(pszFilename));
#ifdef HAVE_READLINK
    char szPointerFilename[2048];
    int nBytes = static_cast<int>(
        readlink(pszFilename, szPointerFilename, sizeof(szPointerFilename)));
    if (nBytes != -1)
    {
        const int nOffset =
            std::min(nBytes, static_cast<int>(sizeof(szPointerFilename) - 1));
        szPointerFilename[nOffset] = '\0';
        osDirname = CPLGetDirname(szPointerFilename);
    }
#endif

    const char chSeparator = SENTINEL2GetPathSeparator(osDirname);
    for (CPLXMLNode *psIter = psProductOrganisation->psChild; psIter != nullptr;
         psIter = psIter->psNext)
    {
        if (psIter->eType != CXT_Element ||
            !EQUAL(psIter->pszValue, "Granule_List"))
        {
            continue;
        }
        for (CPLXMLNode *psIter2 = psIter->psChild; psIter2 != nullptr;
             psIter2 = psIter2->psNext)
        {
            if (psIter2->eType != CXT_Element ||
                !EQUAL(psIter2->pszValue, "Granule"))
            {
                continue;
            }

            const char *pszImageFile =
                CPLGetXMLValue(psIter2, "IMAGE_FILE", nullptr);
            if (pszImageFile == nullptr)
            {
                pszImageFile =
                    CPLGetXMLValue(psIter2, "IMAGE_FILE_2A", nullptr);
                if (pszImageFile == nullptr || strlen(pszImageFile) < 3)
                {
                    CPLDebug("SENTINEL2", "Missing IMAGE_FILE element");
                    continue;
                }
            }
            L1CSafeCompatGranuleDescription oDesc;
            oDesc.osBandPrefixPath = osDirname + chSeparator + pszImageFile;
            if (oDesc.osBandPrefixPath.size() < 36)
            {
                CPLDebug("SENTINEL2", "Band prefix path too short");
                continue;
            }
            oDesc.osBandPrefixPath.resize(oDesc.osBandPrefixPath.size() - 36);
            // GRANULE/L1C_T30TXT_A007999_20170102T111441/IMG_DATA/T30TXT_20170102T111442_B12_60m
            // --> GRANULE/L1C_T30TXT_A007999_20170102T111441/MTD_TL.xml
            oDesc.osMTDTLPath = osDirname + chSeparator +
                                CPLGetDirname(CPLGetDirname(pszImageFile));
            if (oDesc.osMTDTLPath.size() < 9)
            {
                CPLDebug("SENTINEL2", "MTDTL path too short");
                continue;
            }
            oDesc.osMTDTLPath.resize(oDesc.osMTDTLPath.size() - 9);
            oDesc.osMTDTLPath = oDesc.osMTDTLPath + chSeparator + "MTD_TL.xml";
            osList.push_back(oDesc);
        }
    }

    return true;
}

/************************************************************************/
/*                           OpenL1C_L2A()                              */
/************************************************************************/

GDALDataset *SENTINEL2Dataset::OpenL1C_L2A(const char *pszFilename,
                                           SENTINEL2Level eLevel)
{
    CPLXMLNode *psRoot = CPLParseXMLFile(pszFilename);
    if (psRoot == nullptr)
    {
        CPLDebug("SENTINEL2", "Cannot XML parse %s", pszFilename);
        return nullptr;
    }

    char *pszOriginalXML = CPLSerializeXMLTree(psRoot);
    CPLString osOriginalXML;
    if (pszOriginalXML)
        osOriginalXML = pszOriginalXML;
    CPLFree(pszOriginalXML);

    SENTINEL2_CPLXMLNodeHolder oXMLHolder(psRoot);
    CPLStripXMLNamespace(psRoot, nullptr, TRUE);

    const char *pszNodePath =
        (eLevel == SENTINEL2_L1C)
            ? "=Level-1C_User_Product.General_Info.Product_Info"
            : "=Level-2A_User_Product.General_Info.Product_Info";
    CPLXMLNode *psProductInfo = CPLGetXMLNode(psRoot, pszNodePath);
    if (psProductInfo == nullptr && eLevel == SENTINEL2_L2A)
    {
        pszNodePath = "=Level-2A_User_Product.General_Info.L2A_Product_Info";
        psProductInfo = CPLGetXMLNode(psRoot, pszNodePath);
    }
    if (psProductInfo == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s", pszNodePath);
        return nullptr;
    }

    const bool bIsSafeCompact =
        EQUAL(CPLGetXMLValue(psProductInfo, "Query_Options.PRODUCT_FORMAT", ""),
              "SAFE_COMPACT");

    std::set<int> oSetResolutions;
    std::map<int, std::set<CPLString>> oMapResolutionsToBands;
    if (bIsSafeCompact)
    {
        for (unsigned int i = 0; i < NB_BANDS; ++i)
        {
            // L2 does not contain B10
            if (i == 10 && eLevel == SENTINEL2_L2A)
                continue;
            const SENTINEL2BandDescription *psBandDesc = &asBandDesc[i];
            oSetResolutions.insert(psBandDesc->nResolution);
            CPLString osName =
                psBandDesc->pszBandName + 1; /* skip B character */
            if (atoi(osName) < 10)
                osName = "0" + osName;
            oMapResolutionsToBands[psBandDesc->nResolution].insert(osName);
        }
        if (eLevel == SENTINEL2_L2A)
        {
            for (const auto &sL2ABandDesc : asL2ABandDesc)
            {
                oSetResolutions.insert(sL2ABandDesc.nResolution);
                oMapResolutionsToBands[sL2ABandDesc.nResolution].insert(
                    sL2ABandDesc.pszBandName);
            }
        }
    }
    else if (eLevel == SENTINEL2_L1C &&
             !SENTINEL2GetResolutionSet(psProductInfo, oSetResolutions,
                                        oMapResolutionsToBands))
    {
        CPLDebug("SENTINEL2", "Failed to get resolution set");
        return nullptr;
    }

    std::vector<CPLString> aosGranuleList;
    if (bIsSafeCompact)
    {
        std::vector<L1CSafeCompatGranuleDescription>
            aoL1CSafeCompactGranuleList;
        if (eLevel == SENTINEL2_L1C &&
            !SENTINEL2GetGranuleList_L1CSafeCompact(
                psRoot, pszFilename, aoL1CSafeCompactGranuleList))
        {
            CPLDebug("SENTINEL2", "Failed to get granule list");
            return nullptr;
        }
        else if (eLevel == SENTINEL2_L2A &&
                 !SENTINEL2GetGranuleList_L2ASafeCompact(
                     psRoot, pszFilename, aoL1CSafeCompactGranuleList))
        {
            CPLDebug("SENTINEL2", "Failed to get granule list");
            return nullptr;
        }
        for (size_t i = 0; i < aoL1CSafeCompactGranuleList.size(); ++i)
        {
            aosGranuleList.push_back(
                aoL1CSafeCompactGranuleList[i].osMTDTLPath);
        }
    }
    else if (!SENTINEL2GetGranuleList(
                 psRoot, eLevel, pszFilename, aosGranuleList,
                 (eLevel == SENTINEL2_L1C) ? nullptr : &oSetResolutions,
                 (eLevel == SENTINEL2_L1C) ? nullptr : &oMapResolutionsToBands))
    {
        CPLDebug("SENTINEL2", "Failed to get granule list");
        return nullptr;
    }
    if (oSetResolutions.empty())
    {
        CPLDebug("SENTINEL2", "Resolution set is empty");
        return nullptr;
    }

    std::set<int> oSetEPSGCodes;
    for (size_t i = 0; i < aosGranuleList.size(); i++)
    {
        int nEPSGCode = 0;
        if (SENTINEL2GetGranuleInfo(eLevel, aosGranuleList[i],
                                    *(oSetResolutions.begin()), &nEPSGCode))
        {
            oSetEPSGCodes.insert(nEPSGCode);
        }
    }

    SENTINEL2DatasetContainer *poDS = new SENTINEL2DatasetContainer();
    char **papszMD = SENTINEL2GetUserProductMetadata(
        psRoot, (eLevel == SENTINEL2_L1C) ? "Level-1C_User_Product"
                                          : "Level-2A_User_Product");
    poDS->GDALDataset::SetMetadata(papszMD);
    CSLDestroy(papszMD);

    if (!osOriginalXML.empty())
    {
        char *apszXMLMD[2];
        apszXMLMD[0] = const_cast<char *>(osOriginalXML.c_str());
        apszXMLMD[1] = nullptr;
        poDS->GDALDataset::SetMetadata(apszXMLMD, "xml:SENTINEL2");
    }

    const char *pszPrefix =
        (eLevel == SENTINEL2_L1C) ? "SENTINEL2_L1C" : "SENTINEL2_L2A";

    /* Create subdatsets per resolution (10, 20, 60m) and EPSG codes */
    int iSubDSNum = 1;
    for (std::set<int>::const_iterator oIterRes = oSetResolutions.begin();
         oIterRes != oSetResolutions.end(); ++oIterRes)
    {
        const int nResolution = *oIterRes;

        for (std::set<int>::const_iterator oIterEPSG = oSetEPSGCodes.begin();
             oIterEPSG != oSetEPSGCodes.end(); ++oIterEPSG)
        {
            const int nEPSGCode = *oIterEPSG;
            poDS->GDALDataset::SetMetadataItem(
                CPLSPrintf("SUBDATASET_%d_NAME", iSubDSNum),
                CPLSPrintf("%s:%s:%dm:EPSG_%d", pszPrefix, pszFilename,
                           nResolution, nEPSGCode),
                "SUBDATASETS");

            CPLString osBandNames = SENTINEL2GetBandListForResolution(
                oMapResolutionsToBands[nResolution]);

            CPLString osDesc(CPLSPrintf("Bands %s with %dm resolution",
                                        osBandNames.c_str(), nResolution));
            if (nEPSGCode >= 32601 && nEPSGCode <= 32660)
                osDesc += CPLSPrintf(", UTM %dN", nEPSGCode - 32600);
            else if (nEPSGCode >= 32701 && nEPSGCode <= 32760)
                osDesc += CPLSPrintf(", UTM %dS", nEPSGCode - 32700);
            else
                osDesc += CPLSPrintf(", EPSG:%d", nEPSGCode);
            poDS->GDALDataset::SetMetadataItem(
                CPLSPrintf("SUBDATASET_%d_DESC", iSubDSNum), osDesc.c_str(),
                "SUBDATASETS");

            iSubDSNum++;
        }
    }

    /* Expose TCI or PREVIEW subdatasets */
    if (bIsSafeCompact)
    {
        for (std::set<int>::const_iterator oIterEPSG = oSetEPSGCodes.begin();
             oIterEPSG != oSetEPSGCodes.end(); ++oIterEPSG)
        {
            const int nEPSGCode = *oIterEPSG;
            poDS->GDALDataset::SetMetadataItem(
                CPLSPrintf("SUBDATASET_%d_NAME", iSubDSNum),
                CPLSPrintf("%s:%s:TCI:EPSG_%d", pszPrefix, pszFilename,
                           nEPSGCode),
                "SUBDATASETS");

            CPLString osDesc("True color image");
            if (nEPSGCode >= 32601 && nEPSGCode <= 32660)
                osDesc += CPLSPrintf(", UTM %dN", nEPSGCode - 32600);
            else if (nEPSGCode >= 32701 && nEPSGCode <= 32760)
                osDesc += CPLSPrintf(", UTM %dS", nEPSGCode - 32700);
            else
                osDesc += CPLSPrintf(", EPSG:%d", nEPSGCode);
            poDS->GDALDataset::SetMetadataItem(
                CPLSPrintf("SUBDATASET_%d_DESC", iSubDSNum), osDesc.c_str(),
                "SUBDATASETS");

            iSubDSNum++;
        }
    }
    else
    {
        for (std::set<int>::const_iterator oIterEPSG = oSetEPSGCodes.begin();
             oIterEPSG != oSetEPSGCodes.end(); ++oIterEPSG)
        {
            const int nEPSGCode = *oIterEPSG;
            poDS->GDALDataset::SetMetadataItem(
                CPLSPrintf("SUBDATASET_%d_NAME", iSubDSNum),
                CPLSPrintf("%s:%s:PREVIEW:EPSG_%d", pszPrefix, pszFilename,
                           nEPSGCode),
                "SUBDATASETS");

            CPLString osDesc("RGB preview");
            if (nEPSGCode >= 32601 && nEPSGCode <= 32660)
                osDesc += CPLSPrintf(", UTM %dN", nEPSGCode - 32600);
            else if (nEPSGCode >= 32701 && nEPSGCode <= 32760)
                osDesc += CPLSPrintf(", UTM %dS", nEPSGCode - 32700);
            else
                osDesc += CPLSPrintf(", EPSG:%d", nEPSGCode);
            poDS->GDALDataset::SetMetadataItem(
                CPLSPrintf("SUBDATASET_%d_DESC", iSubDSNum), osDesc.c_str(),
                "SUBDATASETS");

            iSubDSNum++;
        }
    }

    pszNodePath =
        (eLevel == SENTINEL2_L1C)
            ? "=Level-1C_User_Product.Geometric_Info.Product_Footprint."
              "Product_Footprint.Global_Footprint.EXT_POS_LIST"
            : "=Level-2A_User_Product.Geometric_Info.Product_Footprint."
              "Product_Footprint.Global_Footprint.EXT_POS_LIST";
    const char *pszPosList = CPLGetXMLValue(psRoot, pszNodePath, nullptr);
    if (pszPosList != nullptr)
    {
        CPLString osPolygon = SENTINEL2GetPolygonWKTFromPosList(pszPosList);
        if (!osPolygon.empty())
            poDS->GDALDataset::SetMetadataItem("FOOTPRINT", osPolygon.c_str());
    }

    return poDS;
}

/************************************************************************/
/*                    SENTINEL2GetL1BCTileMetadata()                    */
/************************************************************************/

static char **SENTINEL2GetL1BCTileMetadata(CPLXMLNode *psMainMTD)
{
    CPLStringList aosList;

    CPLXMLNode *psRoot = CPLGetXMLNode(psMainMTD, "=Level-1C_Tile_ID");
    if (psRoot == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find =Level-1C_Tile_ID");
        return nullptr;
    }
    CPLXMLNode *psGeneralInfo = CPLGetXMLNode(psRoot, "General_Info");
    for (CPLXMLNode *psIter =
             (psGeneralInfo ? psGeneralInfo->psChild : nullptr);
         psIter != nullptr; psIter = psIter->psNext)
    {
        if (psIter->eType != CXT_Element)
            continue;
        const char *pszValue = CPLGetXMLValue(psIter, nullptr, nullptr);
        if (pszValue != nullptr)
        {
            aosList.AddNameValue(psIter->pszValue, pszValue);
        }
    }

    CPLXMLNode *psQII = CPLGetXMLNode(psRoot, "Quality_Indicators_Info");
    if (psQII != nullptr)
    {
        CPLXMLNode *psICCQI = CPLGetXMLNode(psQII, "Image_Content_QI");
        for (CPLXMLNode *psIter = (psICCQI ? psICCQI->psChild : nullptr);
             psIter != nullptr; psIter = psIter->psNext)
        {
            if (psIter->eType != CXT_Element)
                continue;
            if (psIter->psChild != nullptr &&
                psIter->psChild->eType == CXT_Text)
            {
                aosList.AddNameValue(psIter->pszValue,
                                     psIter->psChild->pszValue);
            }
        }
    }

    return aosList.StealList();
}

/************************************************************************/
/*                              OpenL1CTile()                           */
/************************************************************************/

GDALDataset *SENTINEL2Dataset::OpenL1CTile(const char *pszFilename,
                                           CPLXMLNode **ppsRootMainMTD,
                                           int nResolutionOfInterest,
                                           std::set<CPLString> *poBandSet)
{
    CPLXMLNode *psRoot = CPLParseXMLFile(pszFilename);
    if (psRoot == nullptr)
    {
        CPLDebug("SENTINEL2", "Cannot XML parse %s", pszFilename);
        return nullptr;
    }

    char *pszOriginalXML = CPLSerializeXMLTree(psRoot);
    CPLString osOriginalXML;
    if (pszOriginalXML)
        osOriginalXML = pszOriginalXML;
    CPLFree(pszOriginalXML);

    SENTINEL2_CPLXMLNodeHolder oXMLHolder(psRoot);
    CPLStripXMLNamespace(psRoot, nullptr, TRUE);

    std::set<int> oSetResolutions;
    std::map<int, std::set<CPLString>> oMapResolutionsToBands;
    char **papszMD = nullptr;
    SENTINEL2GetResolutionSetAndMainMDFromGranule(
        pszFilename, "Level-1C_User_Product", nResolutionOfInterest,
        oSetResolutions, oMapResolutionsToBands, papszMD, ppsRootMainMTD);
    if (poBandSet != nullptr)
        *poBandSet = oMapResolutionsToBands[nResolutionOfInterest];

    SENTINEL2DatasetContainer *poDS = new SENTINEL2DatasetContainer();

    char **papszGranuleMD = SENTINEL2GetL1BCTileMetadata(psRoot);
    papszMD = CSLMerge(papszMD, papszGranuleMD);
    CSLDestroy(papszGranuleMD);

    // Remove CLOUD_COVERAGE_ASSESSMENT that comes from main metadata, if
    // granule CLOUDY_PIXEL_PERCENTAGE is present.
    if (CSLFetchNameValue(papszMD, "CLOUDY_PIXEL_PERCENTAGE") != nullptr &&
        CSLFetchNameValue(papszMD, "CLOUD_COVERAGE_ASSESSMENT") != nullptr)
    {
        papszMD =
            CSLSetNameValue(papszMD, "CLOUD_COVERAGE_ASSESSMENT", nullptr);
    }

    poDS->GDALDataset::SetMetadata(papszMD);
    CSLDestroy(papszMD);

    if (!osOriginalXML.empty())
    {
        char *apszXMLMD[2];
        apszXMLMD[0] = const_cast<char *>(osOriginalXML.c_str());
        apszXMLMD[1] = nullptr;
        poDS->GDALDataset::SetMetadata(apszXMLMD, "xml:SENTINEL2");
    }

    /* Create subdatsets per resolution (10, 20, 60m) */
    int iSubDSNum = 1;
    for (std::set<int>::const_iterator oIterRes = oSetResolutions.begin();
         oIterRes != oSetResolutions.end(); ++oIterRes)
    {
        const int nResolution = *oIterRes;

        poDS->GDALDataset::SetMetadataItem(
            CPLSPrintf("SUBDATASET_%d_NAME", iSubDSNum),
            CPLSPrintf("%s:%s:%dm", "SENTINEL2_L1C_TILE", pszFilename,
                       nResolution),
            "SUBDATASETS");

        CPLString osBandNames = SENTINEL2GetBandListForResolution(
            oMapResolutionsToBands[nResolution]);

        CPLString osDesc(CPLSPrintf("Bands %s with %dm resolution",
                                    osBandNames.c_str(), nResolution));
        poDS->GDALDataset::SetMetadataItem(
            CPLSPrintf("SUBDATASET_%d_DESC", iSubDSNum), osDesc.c_str(),
            "SUBDATASETS");

        iSubDSNum++;
    }

    /* Expose PREVIEW subdataset */
    poDS->GDALDataset::SetMetadataItem(
        CPLSPrintf("SUBDATASET_%d_NAME", iSubDSNum),
        CPLSPrintf("%s:%s:PREVIEW", "SENTINEL2_L1C_TILE", pszFilename),
        "SUBDATASETS");

    CPLString osDesc("RGB preview");
    poDS->GDALDataset::SetMetadataItem(
        CPLSPrintf("SUBDATASET_%d_DESC", iSubDSNum), osDesc.c_str(),
        "SUBDATASETS");

    return poDS;
}

/************************************************************************/
/*                         SENTINEL2GetOption()                         */
/************************************************************************/

static const char *SENTINEL2GetOption(GDALOpenInfo *poOpenInfo,
                                      const char *pszName,
                                      const char *pszDefaultVal)
{
#ifdef GDAL_DMD_OPENOPTIONLIST
    const char *pszVal =
        CSLFetchNameValue(poOpenInfo->papszOpenOptions, pszName);
    if (pszVal != nullptr)
        return pszVal;
#else
    (void)poOpenInfo;
#endif
    return CPLGetConfigOption(CPLSPrintf("SENTINEL2_%s", pszName),
                              pszDefaultVal);
}

/************************************************************************/
/*                            LaunderUnit()                             */
/************************************************************************/

static CPLString LaunderUnit(const char *pszUnit)
{
    CPLString osUnit;
    for (int i = 0; pszUnit[i] != '\0';)
    {
        if (strncmp(pszUnit + i,
                    "\xC2"
                    "\xB2",
                    2) == 0) /* square / 2 */
        {
            i += 2;
            osUnit += "2";
        }
        else if (strncmp(pszUnit + i,
                         "\xC2"
                         "\xB5",
                         2) == 0) /* micro */
        {
            i += 2;
            osUnit += "u";
        }
        else
        {
            osUnit += pszUnit[i];
            i++;
        }
    }
    return osUnit;
}

/************************************************************************/
/*                       SENTINEL2GetTileInfo()                         */
/************************************************************************/

static bool SENTINEL2GetTileInfo(const char *pszFilename, int *pnWidth,
                                 int *pnHeight, int *pnBits)
{
    static const unsigned char jp2_box_jp[] = {0x6a, 0x50, 0x20,
                                               0x20}; /* 'jP  ' */
    VSILFILE *fp = VSIFOpenL(pszFilename, "rb");
    if (fp == nullptr)
        return false;
    GByte abyHeader[8];
    if (VSIFReadL(abyHeader, 8, 1, fp) != 1)
    {
        VSIFCloseL(fp);
        return false;
    }
    if (memcmp(abyHeader + 4, jp2_box_jp, 4) == 0)
    {
        bool bRet = false;
        /* Just parse the ihdr box instead of doing a full dataset opening */
        GDALJP2Box oBox(fp);
        if (oBox.ReadFirst())
        {
            while (strlen(oBox.GetType()) > 0)
            {
                if (EQUAL(oBox.GetType(), "jp2h"))
                {
                    GDALJP2Box oChildBox(fp);
                    if (!oChildBox.ReadFirstChild(&oBox))
                        break;

                    while (strlen(oChildBox.GetType()) > 0)
                    {
                        if (EQUAL(oChildBox.GetType(), "ihdr"))
                        {
                            GByte *pabyData = oChildBox.ReadBoxData();
                            GIntBig nLength = oChildBox.GetDataLength();
                            if (pabyData != nullptr && nLength >= 4 + 4 + 2 + 1)
                            {
                                bRet = true;
                                if (pnHeight)
                                {
                                    memcpy(pnHeight, pabyData, 4);
                                    CPL_MSBPTR32(pnHeight);
                                }
                                if (pnWidth != nullptr)
                                {
                                    // cppcheck-suppress nullPointer
                                    memcpy(pnWidth, pabyData + 4, 4);
                                    CPL_MSBPTR32(pnWidth);
                                }
                                if (pnBits)
                                {
                                    GByte byPBC = pabyData[4 + 4 + 2];
                                    if (byPBC != 255)
                                    {
                                        *pnBits = 1 + (byPBC & 0x7f);
                                    }
                                    else
                                        *pnBits = 0;
                                }
                            }
                            CPLFree(pabyData);
                            break;
                        }
                        if (!oChildBox.ReadNextChild(&oBox))
                            break;
                    }
                    break;
                }

                if (!oBox.ReadNext())
                    break;
            }
        }
        VSIFCloseL(fp);
        return bRet;
    }
    else /* for unit tests, we use TIFF */
    {
        VSIFCloseL(fp);
        GDALDataset *poDS = (GDALDataset *)GDALOpen(pszFilename, GA_ReadOnly);
        bool bRet = false;
        if (poDS != nullptr)
        {
            if (poDS->GetRasterCount() != 0)
            {
                bRet = true;
                if (pnWidth)
                    *pnWidth = poDS->GetRasterXSize();
                if (pnHeight)
                    *pnHeight = poDS->GetRasterYSize();
                if (pnBits)
                {
                    const char *pszNBits =
                        poDS->GetRasterBand(1)->GetMetadataItem(
                            "NBITS", "IMAGE_STRUCTURE");
                    if (pszNBits == nullptr)
                    {
                        GDALDataType eDT =
                            poDS->GetRasterBand(1)->GetRasterDataType();
                        pszNBits = CPLSPrintf("%d", GDALGetDataTypeSize(eDT));
                    }
                    *pnBits = atoi(pszNBits);
                }
            }
            GDALClose(poDS);
        }
        return bRet;
    }
}

/************************************************************************/
/*                         OpenL1C_L2ASubdataset()                      */
/************************************************************************/

GDALDataset *SENTINEL2Dataset::OpenL1C_L2ASubdataset(GDALOpenInfo *poOpenInfo,
                                                     SENTINEL2Level eLevel)
{
    CPLString osFilename;
    const char *pszPrefix =
        (eLevel == SENTINEL2_L1C) ? "SENTINEL2_L1C" : "SENTINEL2_L2A";
    CPLAssert(STARTS_WITH_CI(poOpenInfo->pszFilename, pszPrefix));
    osFilename = poOpenInfo->pszFilename + strlen(pszPrefix) + 1;
    const char *pszEPSGCode = strrchr(osFilename.c_str(), ':');
    if (pszEPSGCode == nullptr || pszEPSGCode == osFilename.c_str())
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Invalid syntax for %s:", pszPrefix);
        return nullptr;
    }
    osFilename[(size_t)(pszEPSGCode - osFilename.c_str())] = '\0';
    const char *pszPrecision = strrchr(osFilename.c_str(), ':');
    if (pszPrecision == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Invalid syntax for %s:", pszPrefix);
        return nullptr;
    }

    if (!STARTS_WITH_CI(pszEPSGCode + 1, "EPSG_"))
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Invalid syntax for %s:", pszPrefix);
        return nullptr;
    }

    const int nSubDSEPSGCode = atoi(pszEPSGCode + 1 + strlen("EPSG_"));
    const bool bIsPreview = STARTS_WITH_CI(pszPrecision + 1, "PREVIEW");
    const bool bIsTCI = STARTS_WITH_CI(pszPrecision + 1, "TCI");
    const int nSubDSPrecision = (bIsPreview) ? 320
                                : (bIsTCI)   ? 10
                                             : atoi(pszPrecision + 1);
    if (!bIsTCI && !bIsPreview && nSubDSPrecision != 10 &&
        nSubDSPrecision != 20 && nSubDSPrecision != 60)
    {
        CPLError(CE_Failure, CPLE_NotSupported, "Unsupported precision: %d",
                 nSubDSPrecision);
        return nullptr;
    }

    osFilename.resize(pszPrecision - osFilename.c_str());
    std::vector<CPLString> aosNonJP2Files;
    aosNonJP2Files.push_back(osFilename);

    CPLXMLNode *psRoot = CPLParseXMLFile(osFilename);
    if (psRoot == nullptr)
    {
        CPLDebug("SENTINEL2", "Cannot XML parse %s", osFilename.c_str());
        return nullptr;
    }

    char *pszOriginalXML = CPLSerializeXMLTree(psRoot);
    CPLString osOriginalXML;
    if (pszOriginalXML)
        osOriginalXML = pszOriginalXML;
    CPLFree(pszOriginalXML);

    SENTINEL2_CPLXMLNodeHolder oXMLHolder(psRoot);
    CPLStripXMLNamespace(psRoot, nullptr, TRUE);

    CPLXMLNode *psProductInfo =
        eLevel == SENTINEL2_L1C
            ? CPLGetXMLNode(psRoot,
                            "=Level-1C_User_Product.General_Info.Product_Info")
            : CPLGetXMLNode(psRoot,
                            "=Level-2A_User_Product.General_Info.Product_Info");
    if (psProductInfo == nullptr && eLevel == SENTINEL2_L2A)
    {
        psProductInfo = CPLGetXMLNode(
            psRoot, "=Level-2A_User_Product.General_Info.L2A_Product_Info");
    }
    if (psProductInfo == nullptr)
    {
        CPLDebug("SENTINEL2", "Product Info not found");
        return nullptr;
    }

    const bool bIsSafeCompact =
        EQUAL(CPLGetXMLValue(psProductInfo, "Query_Options.PRODUCT_FORMAT", ""),
              "SAFE_COMPACT");

    const char *pszProductURI =
        CPLGetXMLValue(psProductInfo, "PRODUCT_URI", nullptr);
    SENTINEL2ProductType pType = MSI2A;
    if (pszProductURI == nullptr)
    {
        pszProductURI =
            CPLGetXMLValue(psProductInfo, "PRODUCT_URI_2A", nullptr);
        pType = MSI2Ap;
    }
    if (pszProductURI == nullptr)
        pszProductURI = "";

    std::vector<CPLString> aosGranuleList;
    std::map<int, std::set<CPLString>> oMapResolutionsToBands;
    std::vector<L1CSafeCompatGranuleDescription> aoL1CSafeCompactGranuleList;
    if (bIsSafeCompact)
    {
        for (unsigned int i = 0; i < NB_BANDS; ++i)
        {
            // L2 does not contain B10
            if (i == 10 && eLevel == SENTINEL2_L2A)
                continue;
            const SENTINEL2BandDescription *psBandDesc = &asBandDesc[i];
            CPLString osName =
                psBandDesc->pszBandName + 1; /* skip B character */
            if (atoi(osName) < 10)
                osName = "0" + osName;
            oMapResolutionsToBands[psBandDesc->nResolution].insert(osName);
        }
        if (eLevel == SENTINEL2_L2A)
        {
            for (const auto &sL2ABandDesc : asL2ABandDesc)
            {
                oMapResolutionsToBands[sL2ABandDesc.nResolution].insert(
                    sL2ABandDesc.pszBandName);
            }
        }
        if (eLevel == SENTINEL2_L1C &&
            !SENTINEL2GetGranuleList_L1CSafeCompact(
                psRoot, osFilename, aoL1CSafeCompactGranuleList))
        {
            CPLDebug("SENTINEL2", "Failed to get granule list");
            return nullptr;
        }
        if (eLevel == SENTINEL2_L2A &&
            !SENTINEL2GetGranuleList_L2ASafeCompact(
                psRoot, osFilename, aoL1CSafeCompactGranuleList))
        {
            CPLDebug("SENTINEL2", "Failed to get granule list");
            return nullptr;
        }
        for (size_t i = 0; i < aoL1CSafeCompactGranuleList.size(); ++i)
        {
            aosGranuleList.push_back(
                aoL1CSafeCompactGranuleList[i].osMTDTLPath);
        }
    }
    else if (!SENTINEL2GetGranuleList(
                 psRoot, eLevel, osFilename, aosGranuleList, nullptr,
                 (eLevel == SENTINEL2_L1C) ? nullptr : &oMapResolutionsToBands))
    {
        CPLDebug("SENTINEL2", "Failed to get granule list");
        return nullptr;
    }

    std::vector<CPLString> aosBands;
    std::set<CPLString> oSetBands;
    if (bIsPreview || bIsTCI)
    {
        aosBands.push_back("04");
        aosBands.push_back("03");
        aosBands.push_back("02");
    }
    else if (eLevel == SENTINEL2_L1C && !bIsSafeCompact)
    {
        CPLXMLNode *psBandList =
            CPLGetXMLNode(psRoot, "=Level-1C_User_Product.General_Info.Product_"
                                  "Info.Query_Options.Band_List");
        if (psBandList == nullptr)
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s",
                     "Query_Options.Band_List");
            return nullptr;
        }

        for (CPLXMLNode *psIter = psBandList->psChild; psIter != nullptr;
             psIter = psIter->psNext)
        {
            if (psIter->eType != CXT_Element ||
                !EQUAL(psIter->pszValue, "BAND_NAME"))
                continue;
            const char *pszBandName = CPLGetXMLValue(psIter, nullptr, "");
            const SENTINEL2BandDescription *psBandDesc =
                SENTINEL2GetBandDesc(pszBandName);
            if (psBandDesc == nullptr)
            {
                CPLDebug("SENTINEL2", "Unknown band name %s", pszBandName);
                continue;
            }
            if (psBandDesc->nResolution != nSubDSPrecision)
                continue;
            CPLString osName =
                psBandDesc->pszBandName + 1; /* skip B character */
            if (atoi(osName) < 10)
                osName = "0" + osName;
            oSetBands.insert(osName);
        }
        if (oSetBands.empty())
        {
            CPLDebug("SENTINEL2", "Band set is empty");
            return nullptr;
        }
    }
    else
    {
        oSetBands = oMapResolutionsToBands[nSubDSPrecision];
    }

    if (aosBands.empty())
    {
        for (std::set<CPLString>::const_iterator oIterBandnames =
                 oSetBands.begin();
             oIterBandnames != oSetBands.end(); ++oIterBandnames)
        {
            aosBands.push_back(*oIterBandnames);
        }
        /* Put 2=Blue, 3=Green, 4=Band bands in RGB order for conveniency */
        if (aosBands.size() >= 3 && aosBands[0] == "02" &&
            aosBands[1] == "03" && aosBands[2] == "04")
        {
            aosBands[0] = "04";
            aosBands[2] = "02";
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Create dataset.                                                 */
    /* -------------------------------------------------------------------- */

    char **papszMD = SENTINEL2GetUserProductMetadata(
        psRoot, (eLevel == SENTINEL2_L1C) ? "Level-1C_User_Product"
                                          : "Level-2A_User_Product");

    const int nSaturatedVal =
        atoi(CSLFetchNameValueDef(papszMD, "SPECIAL_VALUE_SATURATED", "-1"));
    const int nNodataVal =
        atoi(CSLFetchNameValueDef(papszMD, "SPECIAL_VALUE_NODATA", "-1"));

    const bool bAlpha =
        CPLTestBool(SENTINEL2GetOption(poOpenInfo, "ALPHA", "FALSE"));

    SENTINEL2Dataset *poDS = CreateL1CL2ADataset(
        eLevel, pType, bIsSafeCompact, aosGranuleList,
        aoL1CSafeCompactGranuleList, aosNonJP2Files, nSubDSPrecision,
        bIsPreview, bIsTCI, nSubDSEPSGCode, bAlpha, aosBands, nSaturatedVal,
        nNodataVal, CPLString(pszProductURI));
    if (poDS == nullptr)
    {
        CSLDestroy(papszMD);
        return nullptr;
    }

    if (!osOriginalXML.empty())
    {
        char *apszXMLMD[2] = {nullptr};
        apszXMLMD[0] = const_cast<char *>(osOriginalXML.c_str());
        apszXMLMD[1] = nullptr;
        poDS->GDALDataset::SetMetadata(apszXMLMD, "xml:SENTINEL2");
    }

    poDS->GDALDataset::SetMetadata(papszMD);
    CSLDestroy(papszMD);

    /* -------------------------------------------------------------------- */
    /*      Add extra band metadata.                                        */
    /* -------------------------------------------------------------------- */
    poDS->AddL1CL2ABandMetadata(eLevel, psRoot, aosBands);

    /* -------------------------------------------------------------------- */
    /*      Initialize overview information.                                */
    /* -------------------------------------------------------------------- */
    poDS->SetDescription(poOpenInfo->pszFilename);
    CPLString osOverviewFile;
    if (bIsPreview)
        osOverviewFile = CPLSPrintf("%s_PREVIEW_EPSG_%d.tif.ovr",
                                    osFilename.c_str(), nSubDSEPSGCode);
    else if (bIsTCI)
        osOverviewFile = CPLSPrintf("%s_TCI_EPSG_%d.tif.ovr",
                                    osFilename.c_str(), nSubDSEPSGCode);
    else
        osOverviewFile =
            CPLSPrintf("%s_%dm_EPSG_%d.tif.ovr", osFilename.c_str(),
                       nSubDSPrecision, nSubDSEPSGCode);
    poDS->SetMetadataItem("OVERVIEW_FILE", osOverviewFile, "OVERVIEWS");
    poDS->oOvManager.Initialize(poDS, ":::VIRTUAL:::");

    return poDS;
}

/************************************************************************/
/*                         AddL1CL2ABandMetadata()                      */
/************************************************************************/

void SENTINEL2Dataset::AddL1CL2ABandMetadata(
    SENTINEL2Level eLevel, CPLXMLNode *psRoot,
    const std::vector<CPLString> &aosBands)
{
    CPLXMLNode *psIC =
        CPLGetXMLNode(psRoot, (eLevel == SENTINEL2_L1C)
                                  ? "=Level-1C_User_Product.General_Info."
                                    "Product_Image_Characteristics"
                                  : "=Level-2A_User_Product.General_Info."
                                    "Product_Image_Characteristics");
    if (psIC == nullptr)
    {
        psIC = CPLGetXMLNode(psRoot, "=Level-2A_User_Product.General_Info.L2A_"
                                     "Product_Image_Characteristics");
    }
    if (psIC != nullptr)
    {
        CPLXMLNode *psSIL =
            CPLGetXMLNode(psIC, "Reflectance_Conversion.Solar_Irradiance_List");
        if (psSIL != nullptr)
        {
            for (CPLXMLNode *psIter = psSIL->psChild; psIter != nullptr;
                 psIter = psIter->psNext)
            {
                if (psIter->eType != CXT_Element ||
                    !EQUAL(psIter->pszValue, "SOLAR_IRRADIANCE"))
                {
                    continue;
                }
                const char *pszBandId =
                    CPLGetXMLValue(psIter, "bandId", nullptr);
                const char *pszUnit = CPLGetXMLValue(psIter, "unit", nullptr);
                const char *pszValue = CPLGetXMLValue(psIter, nullptr, nullptr);
                if (pszBandId != nullptr && pszUnit != nullptr &&
                    pszValue != nullptr)
                {
                    int nIdx = atoi(pszBandId);
                    if (nIdx >= 0 && nIdx < (int)NB_BANDS)
                    {
                        for (int i = 0; i < nBands; i++)
                        {
                            GDALRasterBand *poBand = GetRasterBand(i + 1);
                            const char *pszBandName =
                                poBand->GetMetadataItem("BANDNAME");
                            if (pszBandName != nullptr &&
                                EQUAL(asBandDesc[nIdx].pszBandName,
                                      pszBandName))
                            {
                                poBand->GDALRasterBand::SetMetadataItem(
                                    "SOLAR_IRRADIANCE", pszValue);
                                poBand->GDALRasterBand::SetMetadataItem(
                                    "SOLAR_IRRADIANCE_UNIT",
                                    LaunderUnit(pszUnit));
                                break;
                            }
                        }
                    }
                }
            }
        }

        CPLXMLNode *psOL = CPLGetXMLNode(
            psIC, (eLevel == SENTINEL2_L1C) ? "Radiometric_Offset_List"
                                            : "BOA_ADD_OFFSET_VALUES_LIST");
        if (psOL != nullptr)
        {
            for (CPLXMLNode *psIter = psOL->psChild; psIter != nullptr;
                 psIter = psIter->psNext)
            {
                if (psIter->eType != CXT_Element ||
                    !EQUAL(psIter->pszValue, (eLevel == SENTINEL2_L1C)
                                                 ? "RADIO_ADD_OFFSET"
                                                 : "BOA_ADD_OFFSET"))
                {
                    continue;
                }
                const char *pszBandId =
                    CPLGetXMLValue(psIter, "band_id", nullptr);
                const char *pszValue = CPLGetXMLValue(psIter, nullptr, nullptr);
                if (pszBandId != nullptr && pszValue != nullptr)
                {
                    int nIdx = atoi(pszBandId);
                    if (nIdx >= 0 && nIdx < (int)NB_BANDS)
                    {
                        for (int i = 0; i < nBands; i++)
                        {
                            GDALRasterBand *poBand = GetRasterBand(i + 1);
                            const char *pszBandName =
                                poBand->GetMetadataItem("BANDNAME");
                            if (pszBandName != nullptr &&
                                EQUAL(asBandDesc[nIdx].pszBandName,
                                      pszBandName))
                            {
                                poBand->GDALRasterBand::SetMetadataItem(
                                    (eLevel == SENTINEL2_L1C)
                                        ? "RADIO_ADD_OFFSET"
                                        : "BOA_ADD_OFFSET",
                                    pszValue);
                                break;
                            }
                        }
                    }
                }
            }
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Add Scene Classification category values (L2A)                  */
    /* -------------------------------------------------------------------- */
    CPLXMLNode *psSCL = CPLGetXMLNode(
        psRoot, "=Level-2A_User_Product.General_Info."
                "Product_Image_Characteristics.Scene_Classification_List");
    if (psSCL == nullptr)
    {
        psSCL = CPLGetXMLNode(
            psRoot,
            "=Level-2A_User_Product.General_Info."
            "L2A_Product_Image_Characteristics.L2A_Scene_Classification_List");
    }
    int nSCLBand = 0;
    for (int nBand = 1; nBand <= static_cast<int>(aosBands.size()); nBand++)
    {
        if (EQUAL(aosBands[nBand - 1], "SCL"))
        {
            nSCLBand = nBand;
            break;
        }
    }
    if (psSCL != nullptr && nSCLBand > 0)
    {
        std::vector<CPLString> osCategories;
        for (CPLXMLNode *psIter = psSCL->psChild; psIter != nullptr;
             psIter = psIter->psNext)
        {
            if (psIter->eType != CXT_Element ||
                (!EQUAL(psIter->pszValue, "L2A_Scene_Classification_ID") &&
                 !EQUAL(psIter->pszValue, "Scene_Classification_ID")))
            {
                continue;
            }
            const char *pszText =
                CPLGetXMLValue(psIter, "SCENE_CLASSIFICATION_TEXT", nullptr);
            if (pszText == nullptr)
                pszText = CPLGetXMLValue(
                    psIter, "L2A_SCENE_CLASSIFICATION_TEXT", nullptr);
            const char *pszIdx =
                CPLGetXMLValue(psIter, "SCENE_CLASSIFICATION_INDEX", nullptr);
            if (pszIdx == nullptr)
                pszIdx = CPLGetXMLValue(
                    psIter, "L2A_SCENE_CLASSIFICATION_INDEX", nullptr);
            if (pszText && pszIdx && atoi(pszIdx) >= 0 && atoi(pszIdx) < 100)
            {
                int nIdx = atoi(pszIdx);
                if (nIdx >= (int)osCategories.size())
                    osCategories.resize(nIdx + 1);
                if (STARTS_WITH_CI(pszText, "SC_"))
                    osCategories[nIdx] = pszText + 3;
                else
                    osCategories[nIdx] = pszText;
            }
        }
        char **papszCategories =
            (char **)CPLCalloc(osCategories.size() + 1, sizeof(char *));
        for (size_t i = 0; i < osCategories.size(); i++)
            papszCategories[i] = CPLStrdup(osCategories[i]);
        GetRasterBand(nSCLBand)->SetCategoryNames(papszCategories);
        CSLDestroy(papszCategories);
    }
}

/************************************************************************/
/*                         CreateL1CL2ADataset()                        */
/************************************************************************/

SENTINEL2Dataset *SENTINEL2Dataset::CreateL1CL2ADataset(
    SENTINEL2Level eLevel, SENTINEL2ProductType pType, bool bIsSafeCompact,
    const std::vector<CPLString> &aosGranuleList,
    const std::vector<L1CSafeCompatGranuleDescription>
        &aoL1CSafeCompactGranuleList,
    std::vector<CPLString> &aosNonJP2Files, int nSubDSPrecision,
    bool bIsPreview, bool bIsTCI,
    int nSubDSEPSGCode, /* or -1 if not known at this point */
    bool bAlpha, const std::vector<CPLString> &aosBands, int nSaturatedVal,
    int nNodataVal, const CPLString &osProductURI)
{

    /* Iterate over granule metadata to know the layer extent */
    /* and the location of each granule */
    double dfMinX = 1.0e20;
    double dfMinY = 1.0e20;
    double dfMaxX = -1.0e20;
    double dfMaxY = -1.0e20;
    std::vector<SENTINEL2GranuleInfo> aosGranuleInfoList;
    const int nDesiredResolution = (bIsPreview || bIsTCI) ? 0 : nSubDSPrecision;

    if (bIsSafeCompact)
    {
        CPLAssert(aosGranuleList.size() == aoL1CSafeCompactGranuleList.size());
    }

    for (size_t i = 0; i < aosGranuleList.size(); i++)
    {
        int nEPSGCode = 0;
        double dfULX = 0.0;
        double dfULY = 0.0;
        int nResolution = 0;
        int nWidth = 0;
        int nHeight = 0;
        if (SENTINEL2GetGranuleInfo(eLevel, aosGranuleList[i],
                                    nDesiredResolution, &nEPSGCode, &dfULX,
                                    &dfULY, &nResolution, &nWidth, &nHeight) &&
            (nSubDSEPSGCode == nEPSGCode || nSubDSEPSGCode < 0) &&
            nResolution != 0)
        {
            nSubDSEPSGCode = nEPSGCode;
            aosNonJP2Files.push_back(aosGranuleList[i]);

            if (dfULX < dfMinX)
                dfMinX = dfULX;
            if (dfULY > dfMaxY)
                dfMaxY = dfULY;
            const double dfLRX = dfULX + nResolution * nWidth;
            const double dfLRY = dfULY - nResolution * nHeight;
            if (dfLRX > dfMaxX)
                dfMaxX = dfLRX;
            if (dfLRY < dfMinY)
                dfMinY = dfLRY;

            SENTINEL2GranuleInfo oGranuleInfo;
            oGranuleInfo.osPath = CPLGetPath(aosGranuleList[i]);
            if (bIsSafeCompact)
            {
                oGranuleInfo.osBandPrefixPath =
                    aoL1CSafeCompactGranuleList[i].osBandPrefixPath;
            }
            oGranuleInfo.dfMinX = dfULX;
            oGranuleInfo.dfMinY = dfLRY;
            oGranuleInfo.dfMaxX = dfLRX;
            oGranuleInfo.dfMaxY = dfULY;
            oGranuleInfo.nWidth = nWidth / (nSubDSPrecision / nResolution);
            oGranuleInfo.nHeight = nHeight / (nSubDSPrecision / nResolution);
            aosGranuleInfoList.push_back(oGranuleInfo);
        }
    }
    if (dfMinX > dfMaxX)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "No granule found for EPSG code %d", nSubDSEPSGCode);
        return nullptr;
    }

    const int nRasterXSize =
        static_cast<int>((dfMaxX - dfMinX) / nSubDSPrecision + 0.5);
    const int nRasterYSize =
        static_cast<int>((dfMaxY - dfMinY) / nSubDSPrecision + 0.5);
    SENTINEL2Dataset *poDS = new SENTINEL2Dataset(nRasterXSize, nRasterYSize);

#if defined(__GNUC__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wnull-dereference"
#endif
    poDS->aosNonJP2Files = aosNonJP2Files;
#if defined(__GNUC__)
#pragma GCC diagnostic pop
#endif

    OGRSpatialReference oSRS;
    char *pszProjection = nullptr;
    if (oSRS.importFromEPSG(nSubDSEPSGCode) == OGRERR_NONE &&
        oSRS.exportToWkt(&pszProjection) == OGRERR_NONE)
    {
        poDS->SetProjection(pszProjection);
        CPLFree(pszProjection);
    }
    else
    {
        CPLDebug("SENTINEL2", "Invalid EPSG code %d", nSubDSEPSGCode);
    }

    double adfGeoTransform[6] = {0};
    adfGeoTransform[0] = dfMinX;
    adfGeoTransform[1] = nSubDSPrecision;
    adfGeoTransform[2] = 0;
    adfGeoTransform[3] = dfMaxY;
    adfGeoTransform[4] = 0;
    adfGeoTransform[5] = -nSubDSPrecision;
    poDS->SetGeoTransform(adfGeoTransform);
    poDS->GDALDataset::SetMetadataItem("COMPRESSION", "JPEG2000",
                                       "IMAGE_STRUCTURE");
    if (bIsPreview || bIsTCI)
        poDS->GDALDataset::SetMetadataItem("INTERLEAVE", "PIXEL",
                                           "IMAGE_STRUCTURE");

    int nBits = (bIsPreview || bIsTCI) ? 8 : 0 /* 0 = unknown yet*/;
    int nValMax = (bIsPreview || bIsTCI) ? 255 : 0 /* 0 = unknown yet*/;
    const int nBands =
        (bIsPreview || bIsTCI)
            ? 3
            : ((bAlpha) ? 1 : 0) + static_cast<int>(aosBands.size());
    const int nAlphaBand = (bIsPreview || bIsTCI || !bAlpha) ? 0 : nBands;
    const GDALDataType eDT = (bIsPreview || bIsTCI) ? GDT_Byte : GDT_UInt16;

    for (int nBand = 1; nBand <= nBands; nBand++)
    {
        VRTSourcedRasterBand *poBand = nullptr;

        if (nBand != nAlphaBand)
        {
            poBand = new VRTSourcedRasterBand(
                poDS, nBand, eDT, poDS->nRasterXSize, poDS->nRasterYSize);
        }
        else
        {
            poBand = new SENTINEL2AlphaBand(
                poDS, nBand, eDT, poDS->nRasterXSize, poDS->nRasterYSize,
                nSaturatedVal, nNodataVal);
        }

        poDS->SetBand(nBand, poBand);
        if (nBand == nAlphaBand)
            poBand->SetColorInterpretation(GCI_AlphaBand);

        CPLString osBandName;
        if (nBand != nAlphaBand)
        {
            osBandName = aosBands[nBand - 1];
            SENTINEL2SetBandMetadata(poBand, osBandName);
        }
        else
            osBandName = aosBands[0];

        for (size_t iSrc = 0; iSrc < aosGranuleInfoList.size(); iSrc++)
        {
            const SENTINEL2GranuleInfo &oGranuleInfo = aosGranuleInfoList[iSrc];
            CPLString osTile;

            if (bIsSafeCompact && eLevel != SENTINEL2_L2A)
            {
                if (bIsTCI)
                {
                    osTile = oGranuleInfo.osBandPrefixPath + "TCI.jp2";
                }
                else
                {
                    osTile = oGranuleInfo.osBandPrefixPath + "B";
                    if (osBandName.size() == 1)
                        osTile += "0" + osBandName;
                    else if (osBandName.size() == 3)
                        osTile += osBandName.substr(1);
                    else
                        osTile += osBandName;
                    osTile += ".jp2";
                }
            }
            else
            {
                osTile = SENTINEL2GetTilename(
                    oGranuleInfo.osPath, CPLGetFilename(oGranuleInfo.osPath),
                    osBandName, osProductURI, bIsPreview,
                    (eLevel == SENTINEL2_L1C) ? 0 : nSubDSPrecision);
                if (bIsSafeCompact && eLevel == SENTINEL2_L2A &&
                    pType == MSI2Ap && osTile.size() >= 34 &&
                    osTile.substr(osTile.size() - 18, 3) != "MSK")
                {
                    osTile.insert(osTile.size() - 34, "L2A_");
                }
                if (bIsTCI && osTile.size() >= 14)
                {
                    osTile.replace(osTile.size() - 11, 3, "TCI");
                }
            }

            bool bTileFound = false;
            if (nValMax == 0)
            {
                /* It is supposed to be 12 bits, but some products have 15 bits
                 */
                if (SENTINEL2GetTileInfo(osTile, nullptr, nullptr, &nBits))
                {
                    bTileFound = true;
                    if (nBits <= 16)
                        nValMax = (1 << nBits) - 1;
                    else
                    {
                        CPLDebug("SENTINEL2", "Unexpected bit depth %d", nBits);
                        nValMax = 65535;
                    }
                }
            }
            else
            {
                VSIStatBufL sStat;
                if (VSIStatExL(osTile, &sStat, VSI_STAT_EXISTS_FLAG) == 0)
                    bTileFound = true;
            }
            if (!bTileFound)
            {
                CPLError(CE_Warning, CPLE_AppDefined,
                         "Tile %s not found on filesystem. Skipping it",
                         osTile.c_str());
                continue;
            }

            const int nDstXOff = static_cast<int>(
                (oGranuleInfo.dfMinX - dfMinX) / nSubDSPrecision + 0.5);
            const int nDstYOff = static_cast<int>(
                (dfMaxY - oGranuleInfo.dfMaxY) / nSubDSPrecision + 0.5);

            if (nBand != nAlphaBand)
            {
                poBand->AddSimpleSource(
                    osTile, (bIsPreview || bIsTCI) ? nBand : 1, 0, 0,
                    oGranuleInfo.nWidth, oGranuleInfo.nHeight, nDstXOff,
                    nDstYOff, oGranuleInfo.nWidth, oGranuleInfo.nHeight);
            }
            else
            {
                poBand->AddComplexSource(
                    osTile, 1, 0, 0, oGranuleInfo.nWidth, oGranuleInfo.nHeight,
                    nDstXOff, nDstYOff, oGranuleInfo.nWidth,
                    oGranuleInfo.nHeight, nValMax /* offset */, 0 /* scale */);
            }
        }

        if ((nBits % 8) != 0)
        {
            poBand->SetMetadataItem("NBITS", CPLSPrintf("%d", nBits),
                                    "IMAGE_STRUCTURE");
        }
    }

    return poDS;
}

/************************************************************************/
/*                      OpenL1CTileSubdataset()                         */
/************************************************************************/

GDALDataset *SENTINEL2Dataset::OpenL1CTileSubdataset(GDALOpenInfo *poOpenInfo)
{
    CPLString osFilename;
    CPLAssert(STARTS_WITH_CI(poOpenInfo->pszFilename, "SENTINEL2_L1C_TILE:"));
    osFilename = poOpenInfo->pszFilename + strlen("SENTINEL2_L1C_TILE:");
    const char *pszPrecision = strrchr(osFilename.c_str(), ':');
    if (pszPrecision == nullptr || pszPrecision == osFilename.c_str())
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Invalid syntax for SENTINEL2_L1C_TILE:");
        return nullptr;
    }
    const bool bIsPreview = STARTS_WITH_CI(pszPrecision + 1, "PREVIEW");
    const int nSubDSPrecision = (bIsPreview) ? 320 : atoi(pszPrecision + 1);
    if (!bIsPreview && nSubDSPrecision != 10 && nSubDSPrecision != 20 &&
        nSubDSPrecision != 60)
    {
        CPLError(CE_Failure, CPLE_NotSupported, "Unsupported precision: %d",
                 nSubDSPrecision);
        return nullptr;
    }
    osFilename.resize(pszPrecision - osFilename.c_str());

    std::set<CPLString> oSetBands;
    CPLXMLNode *psRootMainMTD = nullptr;
    GDALDataset *poTmpDS =
        OpenL1CTile(osFilename, &psRootMainMTD, nSubDSPrecision, &oSetBands);
    SENTINEL2_CPLXMLNodeHolder oXMLHolder(psRootMainMTD);
    if (poTmpDS == nullptr)
        return nullptr;

    std::vector<CPLString> aosBands;
    if (bIsPreview)
    {
        aosBands.push_back("04");
        aosBands.push_back("03");
        aosBands.push_back("02");
    }
    else
    {
        for (std::set<CPLString>::const_iterator oIterBandnames =
                 oSetBands.begin();
             oIterBandnames != oSetBands.end(); ++oIterBandnames)
        {
            aosBands.push_back(*oIterBandnames);
        }
        /* Put 2=Blue, 3=Green, 4=Band bands in RGB order for conveniency */
        if (aosBands.size() >= 3 && aosBands[0] == "02" &&
            aosBands[1] == "03" && aosBands[2] == "04")
        {
            aosBands[0] = "04";
            aosBands[2] = "02";
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Create dataset.                                                 */
    /* -------------------------------------------------------------------- */

    std::vector<CPLString> aosGranuleList;
    aosGranuleList.push_back(osFilename);

    const int nSaturatedVal = atoi(CSLFetchNameValueDef(
        poTmpDS->GetMetadata(), "SPECIAL_VALUE_SATURATED", "-1"));
    const int nNodataVal = atoi(CSLFetchNameValueDef(
        poTmpDS->GetMetadata(), "SPECIAL_VALUE_NODATA", "-1"));

    const bool bAlpha =
        CPLTestBool(SENTINEL2GetOption(poOpenInfo, "ALPHA", "FALSE"));

    std::vector<CPLString> aosNonJP2Files;
    SENTINEL2Dataset *poDS = CreateL1CL2ADataset(
        SENTINEL2_L1C, MSI2A,
        false,  // bIsSafeCompact
        aosGranuleList, std::vector<L1CSafeCompatGranuleDescription>(),
        aosNonJP2Files, nSubDSPrecision, bIsPreview,
        false,  // bIsTCI
        -1 /*nSubDSEPSGCode*/, bAlpha, aosBands, nSaturatedVal, nNodataVal,
        CPLString());
    if (poDS == nullptr)
    {
        delete poTmpDS;
        return nullptr;
    }

    // Transfer metadata
    poDS->GDALDataset::SetMetadata(poTmpDS->GetMetadata());
    poDS->GDALDataset::SetMetadata(poTmpDS->GetMetadata("xml:SENTINEL2"),
                                   "xml:SENTINEL2");

    delete poTmpDS;

    /* -------------------------------------------------------------------- */
    /*      Add extra band metadata.                                        */
    /* -------------------------------------------------------------------- */
    if (psRootMainMTD != nullptr)
        poDS->AddL1CL2ABandMetadata(SENTINEL2_L1C, psRootMainMTD, aosBands);

    /* -------------------------------------------------------------------- */
    /*      Initialize overview information.                                */
    /* -------------------------------------------------------------------- */
    poDS->SetDescription(poOpenInfo->pszFilename);
    CPLString osOverviewFile;
    if (bIsPreview)
        osOverviewFile = CPLSPrintf("%s_PREVIEW.tif.ovr", osFilename.c_str());
    else
        osOverviewFile =
            CPLSPrintf("%s_%dm.tif.ovr", osFilename.c_str(), nSubDSPrecision);
    poDS->SetMetadataItem("OVERVIEW_FILE", osOverviewFile, "OVERVIEWS");
    poDS->oOvManager.Initialize(poDS, ":::VIRTUAL:::");

    return poDS;
}

/************************************************************************/
/*                      GDALRegister_SENTINEL2()                        */
/************************************************************************/

void GDALRegister_SENTINEL2()
{
    if (GDALGetDriverByName("SENTINEL2") != nullptr)
        return;

    GDALDriver *poDriver = new GDALDriver();

    poDriver->SetDescription("SENTINEL2");
#ifdef GDAL_DCAP_RASTER
    poDriver->SetMetadataItem(GDAL_DCAP_RASTER, "YES");
#endif
    poDriver->SetMetadataItem(GDAL_DCAP_VIRTUALIO, "YES");
    poDriver->SetMetadataItem(GDAL_DMD_LONGNAME, "Sentinel 2");
    poDriver->SetMetadataItem(GDAL_DMD_HELPTOPIC,
                              "drivers/raster/sentinel2.html");
    poDriver->SetMetadataItem(GDAL_DMD_SUBDATASETS, "YES");

#ifdef GDAL_DMD_OPENOPTIONLIST
    poDriver->SetMetadataItem(
        GDAL_DMD_OPENOPTIONLIST,
        "<OpenOptionList>"
        "  <Option name='ALPHA' type='boolean' description='Whether to expose "
        "an alpha band' default='NO'/>"
        "</OpenOptionList>");
#endif

    poDriver->pfnOpen = SENTINEL2Dataset::Open;
    poDriver->pfnIdentify = SENTINEL2Dataset::Identify;

    GetGDALDriverManager()->RegisterDriver(poDriver);
}
