/******************************************************************************
 *
 * Project:  WFS Translator
 * Purpose:  Implements OGRWFSLayer class.
 * Author:   Even Rouault, <even dot rouault at spatialys.com>
 *
 ******************************************************************************
 * Copyright (c) 2010-2013, Even Rouault <even dot rouault at spatialys.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/

#include "cpl_port.h"
#include "ogr_wfs.h"
#include "ogr_api.h"
#include "cpl_minixml.h"
#include "cpl_http.h"
#include "parsexsd.h"

/************************************************************************/
/*                      OGRWFSRecursiveUnlink()                         */
/************************************************************************/

void OGRWFSRecursiveUnlink(const char *pszName)

{
    char **papszFileList = VSIReadDir(pszName);

    for (int i = 0; papszFileList != nullptr && papszFileList[i] != nullptr;
         i++)
    {
        VSIStatBufL sStatBuf;

        if (EQUAL(papszFileList[i], ".") || EQUAL(papszFileList[i], ".."))
            continue;

        CPLString osFullFilename =
            CPLFormFilename(pszName, papszFileList[i], nullptr);

        if (VSIStatL(osFullFilename, &sStatBuf) == 0)
        {
            if (VSI_ISREG(sStatBuf.st_mode))
            {
                VSIUnlink(osFullFilename);
            }
            else if (VSI_ISDIR(sStatBuf.st_mode))
            {
                OGRWFSRecursiveUnlink(osFullFilename);
            }
        }
    }

    CSLDestroy(papszFileList);

    VSIRmdir(pszName);
}

/************************************************************************/
/*                            OGRWFSLayer()                             */
/************************************************************************/

OGRWFSLayer::OGRWFSLayer(OGRWFSDataSource *poDSIn, OGRSpatialReference *poSRSIn,
                         int bAxisOrderAlreadyInvertedIn,
                         const char *pszBaseURLIn, const char *pszNameIn,
                         const char *pszNSIn, const char *pszNSValIn)
    : poDS(poDSIn), poFeatureDefn(nullptr), bGotApproximateLayerDefn(false),
      poGMLFeatureClass(nullptr),
      bAxisOrderAlreadyInverted(bAxisOrderAlreadyInvertedIn), m_poSRS(poSRSIn),
      pszBaseURL(CPLStrdup(pszBaseURLIn)), pszName(CPLStrdup(pszNameIn)),
      pszNS(pszNSIn ? CPLStrdup(pszNSIn) : nullptr),
      pszNSVal(pszNSValIn ? CPLStrdup(pszNSValIn) : nullptr),
      bStreamingDS(false), poBaseDS(nullptr), poBaseLayer(nullptr),
      bHasFetched(false), bReloadNeeded(false), eGeomType(wkbUnknown),
      nFeatures(-1), bCountFeaturesInGetNextFeature(false),
      poFetchedFilterGeom(nullptr), nExpectedInserts(0), bInTransaction(false),
      bUseFeatureIdAtLayerLevel(false), bPagingActive(false),
      nPagingStartIndex(0), nFeatureRead(0), pszRequiredOutputFormat(nullptr)
{
    SetDescription(pszName);
}

/************************************************************************/
/*                             Clone()                                  */
/************************************************************************/

OGRWFSLayer *OGRWFSLayer::Clone()
{
    OGRWFSLayer *poDupLayer =
        new OGRWFSLayer(poDS, m_poSRS, bAxisOrderAlreadyInverted, pszBaseURL,
                        pszName, pszNS, pszNSVal);
    if (m_poSRS)
        m_poSRS->Reference();
    poDupLayer->poFeatureDefn = GetLayerDefn()->Clone();
    poDupLayer->poFeatureDefn->Reference();
    poDupLayer->bGotApproximateLayerDefn = bGotApproximateLayerDefn;
    poDupLayer->eGeomType = poDupLayer->poFeatureDefn->GetGeomType();
    poDupLayer->pszRequiredOutputFormat =
        pszRequiredOutputFormat ? CPLStrdup(pszRequiredOutputFormat) : nullptr;

    /* Copy existing schema file if already found */
    CPLString osSrcFileName = CPLSPrintf("/vsimem/tempwfs_%p/file.xsd", this);
    CPLString osTargetFileName =
        CPLSPrintf("/vsimem/tempwfs_%p/file.xsd", poDupLayer);
    CPL_IGNORE_RET_VAL(CPLCopyFile(osTargetFileName, osSrcFileName));

    return poDupLayer;
}

/************************************************************************/
/*                            ~OGRWFSLayer()                            */
/************************************************************************/

OGRWFSLayer::~OGRWFSLayer()

{
    if (bInTransaction)
        OGRWFSLayer::CommitTransaction();

    if (m_poSRS != nullptr)
        m_poSRS->Release();

    if (poFeatureDefn != nullptr)
        poFeatureDefn->Release();
    delete poGMLFeatureClass;

    CPLFree(pszBaseURL);
    CPLFree(pszName);
    CPLFree(pszNS);
    CPLFree(pszNSVal);

    GDALClose(poBaseDS);

    delete poFetchedFilterGeom;

    CPLString osTmpDirName = CPLSPrintf("/vsimem/tempwfs_%p", this);
    OGRWFSRecursiveUnlink(osTmpDirName);

    CPLFree(pszRequiredOutputFormat);
}

/************************************************************************/
/*                          SetActiveSRS()                              */
/************************************************************************/

OGRErr OGRWFSLayer::SetActiveSRS(int /*iGeomField*/,
                                 const OGRSpatialReference *poSRS)
{
    if (poSRS == nullptr)
        return OGRERR_FAILURE;
    const char *const apszOptions[] = {
        "IGNORE_DATA_AXIS_TO_SRS_AXIS_MAPPING=YES", nullptr};
    size_t i = 0;
    for (const auto &poSupportedSRS : m_apoSupportedCRSList)
    {
        if (poSupportedSRS->IsSame(poSRS, apszOptions))
        {
            m_osSRSName = m_aosSupportedCRSList[i];
            if (m_poSRS)
                m_poSRS->Release();
            m_poSRS = poSRS->Clone();
            m_poSRS->SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER);
            if (poFeatureDefn)
            {
                auto poGeomFieldDefn = poFeatureDefn->GetGeomFieldDefn(0);
                if (poGeomFieldDefn)
                {
                    poGeomFieldDefn->SetSpatialRef(m_poSRS);
                }
            }
            m_oExtents = OGREnvelope();
            if (m_oWGS84Extents.IsInit())
            {
                OGRSpatialReference oWGS84;
                oWGS84.SetWellKnownGeogCS("WGS84");
                oWGS84.SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER);
                auto poCT = std::unique_ptr<OGRCoordinateTransformation>(
                    OGRCreateCoordinateTransformation(&oWGS84, m_poSRS));
                if (poCT)
                {
                    poCT->TransformBounds(
                        m_oWGS84Extents.MinX, m_oWGS84Extents.MinY,
                        m_oWGS84Extents.MaxX, m_oWGS84Extents.MaxY,
                        &m_oExtents.MinX, &m_oExtents.MinY, &m_oExtents.MaxX,
                        &m_oExtents.MaxY, 20);
                }
            }
            SetSpatialFilter(nullptr);
            ResetReading();
            return OGRERR_NONE;
        }
        ++i;
    }
    return OGRERR_FAILURE;
}

/************************************************************************/
/*                    GetDescribeFeatureTypeURL()                       */
/************************************************************************/

CPLString OGRWFSLayer::GetDescribeFeatureTypeURL(CPL_UNUSED int bWithNS)
{
    CPLString osURL(pszBaseURL);
    osURL = CPLURLAddKVP(osURL, "SERVICE", "WFS");
    osURL = CPLURLAddKVP(osURL, "VERSION", poDS->GetVersion());
    osURL = CPLURLAddKVP(osURL, "REQUEST", "DescribeFeatureType");
    osURL = CPLURLAddKVP(osURL, "TYPENAME", WFS_EscapeURL(pszName));
    osURL = CPLURLAddKVP(osURL, "PROPERTYNAME", nullptr);
    osURL = CPLURLAddKVP(osURL, "MAXFEATURES", nullptr);
    osURL = CPLURLAddKVP(osURL, "COUNT", nullptr);
    osURL = CPLURLAddKVP(osURL, "FILTER", nullptr);
    osURL = CPLURLAddKVP(osURL, "OUTPUTFORMAT",
                         pszRequiredOutputFormat
                             ? WFS_EscapeURL(pszRequiredOutputFormat).c_str()
                             : nullptr);

    if (pszNS && poDS->GetNeedNAMESPACE())
    {
        /* Older Deegree version require NAMESPACE (e.g.
         * http://www.nokis.org/deegree2/ogcwebservice) */
        /* This has been now corrected */
        CPLString osValue("xmlns(");
        osValue += pszNS;
        osValue += "=";
        osValue += pszNSVal;
        osValue += ")";
        osURL = CPLURLAddKVP(osURL, "NAMESPACE", WFS_EscapeURL(osValue));
    }

    return osURL;
}

/************************************************************************/
/*                      DescribeFeatureType()                           */
/************************************************************************/

OGRFeatureDefn *OGRWFSLayer::DescribeFeatureType()
{
    CPLString osURL = GetDescribeFeatureTypeURL(TRUE);

    CPLDebug("WFS", "%s", osURL.c_str());

    CPLHTTPResult *psResult = poDS->HTTPFetch(osURL, nullptr);
    if (psResult == nullptr)
    {
        return nullptr;
    }

    if (strstr((const char *)psResult->pabyData, "<ServiceExceptionReport") !=
        nullptr)
    {
        if (poDS->IsOldDeegree((const char *)psResult->pabyData))
        {
            CPLHTTPDestroyResult(psResult);
            return DescribeFeatureType();
        }
        CPLError(CE_Failure, CPLE_AppDefined, "Error returned by server : %s",
                 psResult->pabyData);
        CPLHTTPDestroyResult(psResult);
        return nullptr;
    }

    CPLXMLNode *psXML = CPLParseXMLString((const char *)psResult->pabyData);
    if (psXML == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Invalid XML content : %s",
                 psResult->pabyData);
        CPLHTTPDestroyResult(psResult);
        return nullptr;
    }
    CPLHTTPDestroyResult(psResult);

    const CPLXMLNode *psSchema = WFSFindNode(psXML, "schema");
    if (psSchema == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find <Schema>");
        CPLDestroyXMLNode(psXML);

        return nullptr;
    }

    OGRFeatureDefn *poFDefn = ParseSchema(psSchema);
    if (poFDefn)
        poDS->SaveLayerSchema(pszName, psSchema);

    CPLDestroyXMLNode(psXML);
    return poFDefn;
}

/************************************************************************/
/*                            ParseSchema()                             */
/************************************************************************/

OGRFeatureDefn *OGRWFSLayer::ParseSchema(const CPLXMLNode *psSchema)
{
    osTargetNamespace = CPLGetXMLValue(psSchema, "targetNamespace", "");

    CPLString osTmpFileName;

    osTmpFileName = CPLSPrintf("/vsimem/tempwfs_%p/file.xsd", this);
    CPLSerializeXMLTreeToFile(psSchema, osTmpFileName);

    std::vector<GMLFeatureClass *> aosClasses;
    bool bFullyUnderstood = false;
    bool bHaveSchema = GMLParseXSD(osTmpFileName, aosClasses, bFullyUnderstood);

    if (bHaveSchema && aosClasses.size() == 1)
    {
        // CPLDebug("WFS", "Creating %s for %s", osTmpFileName.c_str(),
        // GetName());
        return BuildLayerDefnFromFeatureClass(aosClasses[0]);
    }
    else if (bHaveSchema)
    {
        std::vector<GMLFeatureClass *>::const_iterator oIter =
            aosClasses.begin();
        std::vector<GMLFeatureClass *>::const_iterator oEndIter =
            aosClasses.end();
        while (oIter != oEndIter)
        {
            GMLFeatureClass *poClass = *oIter;
            ++oIter;
            delete poClass;
        }
    }

    VSIUnlink(osTmpFileName);

    return nullptr;
}

/************************************************************************/
/*                   BuildLayerDefnFromFeatureClass()                   */
/************************************************************************/

OGRFeatureDefn *
OGRWFSLayer::BuildLayerDefnFromFeatureClass(GMLFeatureClass *poClass)
{
    poGMLFeatureClass = poClass;

    OGRFeatureDefn *poFDefn = new OGRFeatureDefn(pszName);
    poFDefn->SetGeomType(wkbNone);
    if (poGMLFeatureClass->GetGeometryPropertyCount() > 0)
    {
        poFDefn->SetGeomType(
            (OGRwkbGeometryType)poGMLFeatureClass->GetGeometryProperty(0)
                ->GetType());
        poFDefn->GetGeomFieldDefn(0)->SetSpatialRef(m_poSRS);
    }

    /* -------------------------------------------------------------------- */
    /*      Added attributes (properties).                                  */
    /* -------------------------------------------------------------------- */
    if (poDS->ExposeGMLId())
    {
        OGRFieldDefn oField("gml_id", OFTString);
        oField.SetNullable(FALSE);
        poFDefn->AddFieldDefn(&oField);
    }

    for (int iField = 0; iField < poGMLFeatureClass->GetPropertyCount();
         iField++)
    {
        GMLPropertyDefn *poProperty = poGMLFeatureClass->GetProperty(iField);
        OGRFieldSubType eSubType = OFSTNone;
        const OGRFieldType eFType =
            GML_GetOGRFieldType(poProperty->GetType(), eSubType);

        OGRFieldDefn oField(poProperty->GetName(), eFType);
        oField.SetSubType(eSubType);
        if (STARTS_WITH_CI(oField.GetNameRef(), "ogr:"))
            oField.SetName(poProperty->GetName() + 4);
        if (poProperty->GetWidth() > 0)
            oField.SetWidth(poProperty->GetWidth());
        if (poProperty->GetPrecision() > 0)
            oField.SetPrecision(poProperty->GetPrecision());
        if (!poDS->IsEmptyAsNull())
            oField.SetNullable(poProperty->IsNullable());

        poFDefn->AddFieldDefn(&oField);
    }

    if (poGMLFeatureClass->GetGeometryPropertyCount() > 0)
    {
        const char *pszGeometryColumnName =
            poGMLFeatureClass->GetGeometryProperty(0)->GetSrcElement();
        if (pszGeometryColumnName[0] != '\0')
        {
            osGeometryColumnName = pszGeometryColumnName;
            if (poFDefn->GetGeomFieldCount() > 0)
            {
                poFDefn->GetGeomFieldDefn(0)->SetNullable(
                    poGMLFeatureClass->GetGeometryProperty(0)->IsNullable());
                poFDefn->GetGeomFieldDefn(0)->SetName(pszGeometryColumnName);
            }
        }
    }

    return poFDefn;
}

/************************************************************************/
/*                       MakeGetFeatureURL()                            */
/************************************************************************/

CPLString OGRWFSLayer::MakeGetFeatureURL(int nRequestMaxFeatures,
                                         int bRequestHits)
{
    CPLString osURL(pszBaseURL);
    osURL = CPLURLAddKVP(osURL, "SERVICE", "WFS");
    osURL = CPLURLAddKVP(osURL, "VERSION", poDS->GetVersion());
    osURL = CPLURLAddKVP(osURL, "REQUEST", "GetFeature");
    if (atoi(poDS->GetVersion()) >= 2)
        osURL = CPLURLAddKVP(osURL, "TYPENAMES", WFS_EscapeURL(pszName));
    else
        osURL = CPLURLAddKVP(osURL, "TYPENAME", WFS_EscapeURL(pszName));
    if (!m_osSRSName.empty())
        osURL =
            CPLURLAddKVP(osURL, "SRSNAME", WFS_EscapeURL(m_osSRSName.c_str()));
    if (pszRequiredOutputFormat)
        osURL = CPLURLAddKVP(osURL, "OUTPUTFORMAT",
                             WFS_EscapeURL(pszRequiredOutputFormat));

    if (poDS->IsPagingAllowed() && !bRequestHits)
    {
        nRequestMaxFeatures = poDS->GetPageSize();
        /* If the feature count is known and is less than the page size, we don't
         * need to do paging. Skipping the pagination parameters improves compatibility
         * with remote datasources that don't have a primary key.
         * Without a primary key, the WFS server can't support paging, since there
         * is no natural sort order defined. */
        if (nFeatures < 0 ||
            (nRequestMaxFeatures && nFeatures > nRequestMaxFeatures))
        {
            osURL =
                CPLURLAddKVP(osURL, "STARTINDEX",
                             CPLSPrintf("%d", nPagingStartIndex +
                                                  poDS->GetBaseStartIndex()));
            bPagingActive = true;
        }
    }

    if (nRequestMaxFeatures)
    {
        osURL = CPLURLAddKVP(
            osURL, atoi(poDS->GetVersion()) >= 2 ? "COUNT" : "MAXFEATURES",
            CPLSPrintf("%d", nRequestMaxFeatures));
    }
    if (pszNS && poDS->GetNeedNAMESPACE())
    {
        /* Older Deegree version require NAMESPACE (e.g.
         * http://www.nokis.org/deegree2/ogcwebservice) */
        /* This has been now corrected */
        CPLString osValue("xmlns(");
        osValue += pszNS;
        osValue += "=";
        osValue += pszNSVal;
        osValue += ")";
        osURL = CPLURLAddKVP(osURL, "NAMESPACE", WFS_EscapeURL(osValue));
    }

    delete poFetchedFilterGeom;
    poFetchedFilterGeom = nullptr;

    CPLString osGeomFilter;

    if (m_poFilterGeom != nullptr && !osGeometryColumnName.empty())
    {
        OGREnvelope oEnvelope;
        m_poFilterGeom->getEnvelope(&oEnvelope);

        poFetchedFilterGeom = m_poFilterGeom->clone();

        osGeomFilter = "<BBOX>";
        if (atoi(poDS->GetVersion()) >= 2)
            osGeomFilter += "<ValueReference>";
        else
            osGeomFilter += "<PropertyName>";
        if (pszNS)
        {
            osGeomFilter += pszNS;
            osGeomFilter += ":";
        }
        osGeomFilter += osGeometryColumnName;
        if (atoi(poDS->GetVersion()) >= 2)
            osGeomFilter += "</ValueReference>";
        else
            osGeomFilter += "</PropertyName>";

        if (atoi(poDS->GetVersion()) >= 2)
        {
            osGeomFilter += "<gml:Envelope";

            CPLString osSRSName = CPLURLGetValue(pszBaseURL, "SRSNAME");
            if (!osSRSName.empty())
            {
                osGeomFilter += " srsName=\"";
                osGeomFilter += osSRSName;
                osGeomFilter += "\"";
            }

            osGeomFilter += ">";
            if (bAxisOrderAlreadyInverted)
            {
                osGeomFilter +=
                    CPLSPrintf("<gml:lowerCorner>%.16f "
                               "%.16f</gml:lowerCorner><gml:upperCorner>%.16f "
                               "%.16f</gml:upperCorner>",
                               oEnvelope.MinY, oEnvelope.MinX, oEnvelope.MaxY,
                               oEnvelope.MaxX);
            }
            else
                osGeomFilter +=
                    CPLSPrintf("<gml:lowerCorner>%.16f "
                               "%.16f</gml:lowerCorner><gml:upperCorner>%.16f "
                               "%.16f</gml:upperCorner>",
                               oEnvelope.MinX, oEnvelope.MinY, oEnvelope.MaxX,
                               oEnvelope.MaxY);
            osGeomFilter += "</gml:Envelope>";
        }
        else if (poDS->RequiresEnvelopeSpatialFilter())
        {
            osGeomFilter += "<Envelope xmlns=\"http://www.opengis.net/gml\">";
            if (bAxisOrderAlreadyInverted)
            {
                /* We can go here in WFS 1.1 with geographic coordinate systems
                 */
                /* that are natively return in lat,long order, but as we have */
                /* presented long,lat order to the user, we must switch back */
                /* for the server... */
                osGeomFilter +=
                    CPLSPrintf("<coord><X>%.16f</X><Y>%.16f</Y></"
                               "coord><coord><X>%.16f</X><Y>%.16f</Y></coord>",
                               oEnvelope.MinY, oEnvelope.MinX, oEnvelope.MaxY,
                               oEnvelope.MaxX);
            }
            else
                osGeomFilter +=
                    CPLSPrintf("<coord><X>%.16f</X><Y>%.16f</Y></"
                               "coord><coord><X>%.16f</X><Y>%.16f</Y></coord>",
                               oEnvelope.MinX, oEnvelope.MinY, oEnvelope.MaxX,
                               oEnvelope.MaxY);
            osGeomFilter += "</Envelope>";
        }
        else
        {
            osGeomFilter += "<gml:Box>";
            osGeomFilter += "<gml:coordinates>";
            if (bAxisOrderAlreadyInverted)
            {
                /* We can go here in WFS 1.1 with geographic coordinate systems
                 */
                /* that are natively return in lat,long order, but as we have */
                /* presented long,lat order to the user, we must switch back */
                /* for the server... */
                osGeomFilter +=
                    CPLSPrintf("%.16f,%.16f %.16f,%.16f", oEnvelope.MinY,
                               oEnvelope.MinX, oEnvelope.MaxY, oEnvelope.MaxX);
            }
            else
                osGeomFilter +=
                    CPLSPrintf("%.16f,%.16f %.16f,%.16f", oEnvelope.MinX,
                               oEnvelope.MinY, oEnvelope.MaxX, oEnvelope.MaxY);
            osGeomFilter += "</gml:coordinates>";
            osGeomFilter += "</gml:Box>";
        }
        osGeomFilter += "</BBOX>";
    }

    if (!osGeomFilter.empty() || !osWFSWhere.empty())
    {
        CPLString osFilter;
        if (atoi(poDS->GetVersion()) >= 2)
            osFilter = "<Filter xmlns=\"http://www.opengis.net/fes/2.0\"";
        else
            osFilter = "<Filter xmlns=\"http://www.opengis.net/ogc\"";
        if (pszNS)
        {
            osFilter += " xmlns:";
            osFilter += pszNS;
            osFilter += "=\"";
            osFilter += pszNSVal;
            osFilter += "\"";
        }
        if (atoi(poDS->GetVersion()) >= 2)
            osFilter += " xmlns:gml=\"http://www.opengis.net/gml/3.2\">";
        else
            osFilter += " xmlns:gml=\"http://www.opengis.net/gml\">";
        if (!osGeomFilter.empty() && !osWFSWhere.empty())
            osFilter += "<And>";
        osFilter += osWFSWhere;
        osFilter += osGeomFilter;
        if (!osGeomFilter.empty() && !osWFSWhere.empty())
            osFilter += "</And>";
        osFilter += "</Filter>";

        osURL = CPLURLAddKVP(osURL, "FILTER", WFS_EscapeURL(osFilter));
    }

    if (bRequestHits)
    {
        osURL = CPLURLAddKVP(osURL, "RESULTTYPE", "hits");
    }
    else if (!aoSortColumns.empty())
    {
        CPLString osSortBy;
        for (int i = 0; i < (int)aoSortColumns.size(); i++)
        {
            if (i > 0)
                osSortBy += ",";
            osSortBy += aoSortColumns[i].osColumn;
            if (!aoSortColumns[i].bAsc)
            {
                if (atoi(poDS->GetVersion()) >= 2)
                    osSortBy += " DESC";
                else
                    osSortBy += " D";
            }
        }
        osURL = CPLURLAddKVP(osURL, "SORTBY", WFS_EscapeURL(osSortBy));
    }

    /* If no PROPERTYNAME is specified, build one if there are ignored fields */
    CPLString osPropertyName = CPLURLGetValue(osURL, "PROPERTYNAME");
    const char *pszPropertyName = osPropertyName.c_str();
    if (pszPropertyName[0] == 0 && poFeatureDefn != nullptr)
    {
        bool bHasIgnoredField = false;
        osPropertyName.clear();
        for (int iField = 0; iField < poFeatureDefn->GetFieldCount(); iField++)
        {
            if (EQUAL(poFeatureDefn->GetFieldDefn(iField)->GetNameRef(),
                      "gml_id"))
            {
                /* fake field : skip it */
            }
            else if (poFeatureDefn->GetFieldDefn(iField)->IsIgnored())
            {
                bHasIgnoredField = true;
            }
            else
            {
                if (!osPropertyName.empty())
                    osPropertyName += ",";
                osPropertyName +=
                    poFeatureDefn->GetFieldDefn(iField)->GetNameRef();
            }
        }
        if (!osGeometryColumnName.empty())
        {
            if (poFeatureDefn->IsGeometryIgnored())
            {
                bHasIgnoredField = true;
            }
            else
            {
                if (!osPropertyName.empty())
                    osPropertyName += ",";
                osPropertyName += osGeometryColumnName;
            }
        }

        if (bHasIgnoredField && !osPropertyName.empty())
        {
            osURL = CPLURLAddKVP(osURL, "PROPERTYNAME",
                                 WFS_EscapeURL(osPropertyName));
        }
    }

    return osURL;
}

/************************************************************************/
/*               OGRWFSFetchContentDispositionFilename()                */
/************************************************************************/

static const char *OGRWFSFetchContentDispositionFilename(char **papszHeaders)
{
    const char *pszContentDisposition =
        CSLFetchNameValue(papszHeaders, "Content-Disposition");
    if (pszContentDisposition &&
        STARTS_WITH(pszContentDisposition, "attachment; filename="))
    {
        return pszContentDisposition + strlen("attachment; filename=");
    }
    return nullptr;
}

/************************************************************************/
/*                  MustRetryIfNonCompliantServer()                     */
/************************************************************************/

bool OGRWFSLayer::MustRetryIfNonCompliantServer(const char *pszServerAnswer)
{
    bool bRetry = false;

    /* Deegree server does not support PropertyIsNotEqualTo */
    /* We have to turn it into <Not><PropertyIsEqualTo> */
    if (!osWFSWhere.empty() && poDS->PropertyIsNotEqualToSupported() &&
        strstr(pszServerAnswer,
               "Unknown comparison operation: 'PropertyIsNotEqualTo'") !=
            nullptr)
    {
        poDS->SetPropertyIsNotEqualToUnSupported();
        bRetry = true;
    }

    /* Deegree server requires the gml: prefix in GmlObjectId element, but ESRI
     */
    /* doesn't like it at all ! Other servers don't care... */
    if (!osWFSWhere.empty() && !poDS->DoesGmlObjectIdNeedGMLPrefix() &&
        strstr(pszServerAnswer,
               "&lt;GmlObjectId&gt; requires 'gml:id'-attribute!") != nullptr)
    {
        poDS->SetGmlObjectIdNeedsGMLPrefix();
        bRetry = true;
    }

    /* GeoServer can return the error 'Only FeatureIds are supported when
     * encoding id filters to SDE' */
    if (!osWFSWhere.empty() && !bUseFeatureIdAtLayerLevel &&
        strstr(pszServerAnswer, "Only FeatureIds are supported") != nullptr)
    {
        bUseFeatureIdAtLayerLevel = true;
        bRetry = true;
    }

    if (bRetry)
    {
        SetAttributeFilter(osSQLWhere);
        bHasFetched = true;
        bReloadNeeded = false;
    }

    return bRetry;
}

/************************************************************************/
/*                         FetchGetFeature()                            */
/************************************************************************/

GDALDataset *OGRWFSLayer::FetchGetFeature(int nRequestMaxFeatures)
{

    CPLString osURL = MakeGetFeatureURL(nRequestMaxFeatures, FALSE);
    CPLDebug("WFS", "%s", osURL.c_str());

    CPLHTTPResult *psResult = nullptr;

    CPLString osOutputFormat = CPLURLGetValue(osURL, "OUTPUTFORMAT");

    const auto ReadNumberMatched = [this](const char *pszData)
    {
        const char *pszNumberMatched = strstr(pszData, " numberMatched=\"");
        if (!pszNumberMatched)
            pszNumberMatched = strstr(pszData, "\n"
                                               "numberMatched=\"");
        if (pszNumberMatched)
        {
            pszNumberMatched += strlen(" numberMatched=\"");
            if (*pszNumberMatched >= '0' && *pszNumberMatched <= '9')
            {
                m_nNumberMatched = CPLAtoGIntBig(pszNumberMatched);
                CPLDebug("WFS", "numberMatched = " CPL_FRMT_GIB,
                         m_nNumberMatched);
                if (!bCountFeaturesInGetNextFeature)
                    nFeatures = m_nNumberMatched;
            }
        }
    };

    if (CPLTestBool(CPLGetConfigOption("OGR_WFS_USE_STREAMING", "YES")))
    {
        CPLString osStreamingName;
        if (STARTS_WITH(osURL, "/vsimem/") &&
            CPLTestBool(CPLGetConfigOption("CPL_CURL_ENABLE_VSIMEM", "FALSE")))
        {
            osStreamingName = osURL;
        }
        else
        {
            osStreamingName += "/vsicurl_streaming/";
            osStreamingName += osURL;
        }

        /* Try streaming when the output format is GML and that we have a .xsd
         */
        /* that we are able to understand */
        CPLString osXSDFileName =
            CPLSPrintf("/vsimem/tempwfs_%p/file.xsd", this);
        VSIStatBufL sBuf;
        GDALDriver *poDriver = nullptr;
        if ((osOutputFormat.empty() ||
             osOutputFormat.ifind("GML") != std::string::npos) &&
            VSIStatL(osXSDFileName, &sBuf) == 0 &&
            (poDriver = GDALDriver::FromHandle(GDALGetDriverByName("GML"))) !=
                nullptr &&
            poDriver->pfnOpen)
        {
            bStreamingDS = true;
            CPLStringList aosOptions;
            aosOptions.SetNameValue("XSD", osXSDFileName.c_str());
            aosOptions.SetNameValue("EMPTY_AS_NULL",
                                    poDS->IsEmptyAsNull() ? "YES" : "NO");
            if (CPLGetConfigOption("GML_INVERT_AXIS_ORDER_IF_LAT_LONG",
                                   nullptr) == nullptr)
            {
                aosOptions.SetNameValue(
                    "INVERT_AXIS_ORDER_IF_LAT_LONG",
                    poDS->InvertAxisOrderIfLatLong() ? "YES" : "NO");
            }
            if (CPLGetConfigOption("GML_CONSIDER_EPSG_AS_URN", nullptr) ==
                nullptr)
            {
                aosOptions.SetNameValue("CONSIDER_EPSG_AS_URN",
                                        poDS->GetConsiderEPSGAsURN().c_str());
            }
            if (CPLGetConfigOption("GML_EXPOSE_GML_ID", nullptr) == nullptr)
            {
                aosOptions.SetNameValue("EXPOSE_GML_ID",
                                        poDS->ExposeGMLId() ? "YES" : "NO");
                // iGMLOOIdex ++;
            }

            GDALOpenInfo oOpenInfo(osStreamingName.c_str(), GA_ReadOnly);
            if (oOpenInfo.nHeaderBytes && m_nNumberMatched < 0)
            {
                const char *pszData =
                    reinterpret_cast<const char *>(oOpenInfo.pabyHeader);
                ReadNumberMatched(pszData);
            }
            oOpenInfo.papszOpenOptions = aosOptions.List();

            auto poOutputDS = poDriver->Open(&oOpenInfo, true);
            if (poOutputDS)
            {
                return poOutputDS;
            }
        }
        /* Try streaming when the output format is FlatGeobuf */
        else if ((osOutputFormat.empty() ||
                  osOutputFormat.ifind("flatgeobuf") != std::string::npos) &&
                 VSIStatL(osXSDFileName, &sBuf) == 0 &&
                 GDALGetDriverByName("FlatGeobuf") != nullptr)
        {
            bStreamingDS = true;
            const char *const apszAllowedDrivers[] = {"FlatGeobuf", nullptr};

            GDALDataset *poFlatGeobuf_DS =
                (GDALDataset *)GDALOpenEx(osStreamingName, GDAL_OF_VECTOR,
                                          apszAllowedDrivers, nullptr, nullptr);
            if (poFlatGeobuf_DS)
            {
                return poFlatGeobuf_DS;
            }
        }
        else
        {
            bStreamingDS = false;
        }

        if (bStreamingDS)
        {
            /* In case of failure, read directly the content to examine */
            /* it, if it is XML error content */
            char szBuffer[2048];
            int nRead = 0;
            VSILFILE *fp = VSIFOpenL(osStreamingName, "rb");
            if (fp)
            {
                nRead = (int)VSIFReadL(szBuffer, 1, sizeof(szBuffer) - 1, fp);
                szBuffer[nRead] = '\0';
                VSIFCloseL(fp);
            }

            if (nRead != 0)
            {
                if (MustRetryIfNonCompliantServer(szBuffer))
                    return FetchGetFeature(nRequestMaxFeatures);

                if (strstr(szBuffer, "<ServiceExceptionReport") != nullptr ||
                    strstr(szBuffer, "<ows:ExceptionReport") != nullptr)
                {
                    if (poDS->IsOldDeegree(szBuffer))
                    {
                        return FetchGetFeature(nRequestMaxFeatures);
                    }

                    CPLError(CE_Failure, CPLE_AppDefined,
                             "Error returned by server : %s", szBuffer);
                    return nullptr;
                }
            }
        }
    }

    bStreamingDS = false;
    psResult = poDS->HTTPFetch(osURL, nullptr);
    if (psResult == nullptr)
    {
        return nullptr;
    }

    const char *pszContentType = "";
    if (psResult->pszContentType)
        pszContentType = psResult->pszContentType;

    const std::string osTmpDirName = CPLSPrintf("/vsimem/tempwfs_%p", this);
    VSIMkdir(osTmpDirName.c_str(), 0);

    GByte *pabyData = psResult->pabyData;
    int nDataLen = psResult->nDataLen;
    bool bIsMultiPart = false;
    const char *pszAttachmentFilename = nullptr;

    if (strstr(pszContentType, "multipart") &&
        CPLHTTPParseMultipartMime(psResult))
    {
        bIsMultiPart = true;
        OGRWFSRecursiveUnlink(osTmpDirName.c_str());
        VSIMkdir(osTmpDirName.c_str(), 0);
        for (int i = 0; i < psResult->nMimePartCount; i++)
        {
            CPLString osTmpFileName = osTmpDirName + "/";
            pszAttachmentFilename = OGRWFSFetchContentDispositionFilename(
                psResult->pasMimePart[i].papszHeaders);

            if (pszAttachmentFilename)
                osTmpFileName += pszAttachmentFilename;
            else
                osTmpFileName += CPLSPrintf("file_%d", i);

            GByte *pData =
                (GByte *)VSI_MALLOC_VERBOSE(psResult->pasMimePart[i].nDataLen);
            if (pData)
            {
                memcpy(pData, psResult->pasMimePart[i].pabyData,
                       psResult->pasMimePart[i].nDataLen);
                VSILFILE *fp = VSIFileFromMemBuffer(
                    osTmpFileName, pData, psResult->pasMimePart[i].nDataLen,
                    TRUE);
                VSIFCloseL(fp);
            }
        }
    }
    else
        pszAttachmentFilename =
            OGRWFSFetchContentDispositionFilename(psResult->papszHeaders);

    bool bJSON = false;
    bool bCSV = false;
    bool bKML = false;
    bool bKMZ = false;
    bool bFlatGeobuf = false;
    bool bZIP = false;
    bool bGZIP = false;

    const char *pszOutputFormat = osOutputFormat.c_str();

    if (FindSubStringInsensitive(pszContentType, "json") ||
        FindSubStringInsensitive(pszOutputFormat, "json"))
    {
        bJSON = true;
    }
    else if (FindSubStringInsensitive(pszContentType, "csv") ||
             FindSubStringInsensitive(pszOutputFormat, "csv"))
    {
        bCSV = true;
    }
    else if (FindSubStringInsensitive(pszContentType, "kml") ||
             FindSubStringInsensitive(pszOutputFormat, "kml"))
    {
        bKML = true;
    }
    else if (FindSubStringInsensitive(pszContentType, "kmz") ||
             FindSubStringInsensitive(pszOutputFormat, "kmz"))
    {
        bKMZ = true;
    }
    else if (FindSubStringInsensitive(pszContentType, "flatgeobuf") ||
             FindSubStringInsensitive(pszOutputFormat, "flatgeobuf"))
    {
        bFlatGeobuf = true;
    }
    else if (strstr(pszContentType, "application/zip") != nullptr)
    {
        bZIP = true;
    }
    else if (strstr(pszContentType, "application/gzip") != nullptr)
    {
        bGZIP = true;
    }

    const char *pszData = reinterpret_cast<const char *>(pabyData);
    if (MustRetryIfNonCompliantServer(pszData))
    {
        CPLHTTPDestroyResult(psResult);
        return FetchGetFeature(nRequestMaxFeatures);
    }

    if (strstr(pszData, "<ServiceExceptionReport") != nullptr ||
        strstr(pszData, "<ows:ExceptionReport") != nullptr)
    {
        if (poDS->IsOldDeegree(pszData))
        {
            CPLHTTPDestroyResult(psResult);
            return FetchGetFeature(nRequestMaxFeatures);
        }

        CPLError(CE_Failure, CPLE_AppDefined, "Error returned by server : %s",
                 pabyData);
        CPLHTTPDestroyResult(psResult);
        return nullptr;
    }

    if (m_nNumberMatched < 0)
        ReadNumberMatched(pszData);

    CPLString osTmpFileName;

    if (!bIsMultiPart)
    {
        if (bJSON)
            osTmpFileName = osTmpDirName + "/file.geojson";
        else if (bZIP)
            osTmpFileName = osTmpDirName + "/file.zip";
        else if (bCSV)
            osTmpFileName = osTmpDirName + "/file.csv";
        else if (bKML)
            osTmpFileName = osTmpDirName + "/file.kml";
        else if (bKMZ)
            osTmpFileName = osTmpDirName + "/file.kmz";
        else if (bFlatGeobuf)
            osTmpFileName = osTmpDirName + "/file.fgb";
        /* GML is a special case. It needs the .xsd file that has been saved */
        /* as file.xsd, so we cannot used the attachment filename */
        else if (pszAttachmentFilename &&
                 !EQUAL(CPLGetExtension(pszAttachmentFilename), "GML"))
        {
            osTmpFileName = osTmpDirName + "/";
            osTmpFileName += pszAttachmentFilename;
        }
        else
        {
            osTmpFileName = osTmpDirName + "/file.gfs";
            VSIUnlink(osTmpFileName);

            osTmpFileName = osTmpDirName + "/file.gml";
        }

        VSILFILE *fp =
            VSIFileFromMemBuffer(osTmpFileName, pabyData, nDataLen, TRUE);
        VSIFCloseL(fp);
        psResult->pabyData = nullptr;

        if (bZIP)
        {
            osTmpFileName = "/vsizip/" + osTmpFileName;
        }
        else if (bGZIP)
        {
            osTmpFileName = "/vsigzip/" + osTmpFileName;
        }
    }
    else
    {
        pabyData = nullptr;
        nDataLen = 0;
        osTmpFileName = osTmpDirName;
    }

    CPLHTTPDestroyResult(psResult);

    const char *const *papszOpenOptions = nullptr;
    const char *apszGMLOpenOptions[4] = {nullptr, nullptr, nullptr, nullptr};
    int iGMLOOIdex = 0;
    if (CPLGetConfigOption("GML_INVERT_AXIS_ORDER_IF_LAT_LONG", nullptr) ==
        nullptr)
    {
        apszGMLOpenOptions[iGMLOOIdex] =
            CPLSPrintf("INVERT_AXIS_ORDER_IF_LAT_LONG=%s",
                       poDS->InvertAxisOrderIfLatLong() ? "YES" : "NO");
        iGMLOOIdex++;
    }
    if (CPLGetConfigOption("GML_CONSIDER_EPSG_AS_URN", nullptr) == nullptr)
    {
        apszGMLOpenOptions[iGMLOOIdex] = CPLSPrintf(
            "CONSIDER_EPSG_AS_URN=%s", poDS->GetConsiderEPSGAsURN().c_str());
        iGMLOOIdex++;
    }
    if (CPLGetConfigOption("GML_EXPOSE_GML_ID", nullptr) == nullptr)
    {
        apszGMLOpenOptions[iGMLOOIdex] =
            CPLSPrintf("EXPOSE_GML_ID=%s", poDS->ExposeGMLId() ? "YES" : "NO");
        // iGMLOOIdex ++;
    }

    GDALDriverH hDrv = GDALIdentifyDriver(osTmpFileName, nullptr);
    if (hDrv != nullptr && hDrv == GDALGetDriverByName("GML"))
        papszOpenOptions = apszGMLOpenOptions;

    GDALDataset *poPageDS = (GDALDataset *)GDALOpenEx(
        osTmpFileName, GDAL_OF_VECTOR, nullptr, papszOpenOptions, nullptr);
    if (poPageDS == nullptr && (bZIP || bIsMultiPart))
    {
        char **papszFileList = VSIReadDir(osTmpFileName);
        for (int i = 0; papszFileList != nullptr && papszFileList[i] != nullptr;
             i++)
        {
            CPLString osFullFilename =
                CPLFormFilename(osTmpFileName, papszFileList[i], nullptr);
            hDrv = GDALIdentifyDriver(osFullFilename, nullptr);
            if (hDrv != nullptr && hDrv == GDALGetDriverByName("GML"))
                papszOpenOptions = apszGMLOpenOptions;
            poPageDS =
                (GDALDataset *)GDALOpenEx(osFullFilename, GDAL_OF_VECTOR,
                                          nullptr, papszOpenOptions, nullptr);
            if (poPageDS != nullptr)
                break;
        }

        CSLDestroy(papszFileList);
    }

    if (poPageDS == nullptr)
    {
        if (pabyData != nullptr && !bJSON && !bZIP &&
            strstr((const char *)pabyData, "<wfs:FeatureCollection") ==
                nullptr &&
            strstr((const char *)pabyData, "<gml:FeatureCollection") == nullptr)
        {
            if (nDataLen > 1000)
                pabyData[1000] = 0;
            CPLError(CE_Failure, CPLE_AppDefined, "Error: cannot parse %s",
                     pabyData);
        }
        return nullptr;
    }

    OGRLayer *poLayer = poPageDS->GetLayer(0);
    if (poLayer == nullptr)
    {
        GDALClose(poPageDS);
        return nullptr;
    }

    return poPageDS;
}

/************************************************************************/
/*                            GetLayerDefn()                            */
/************************************************************************/

OGRFeatureDefn *OGRWFSLayer::GetLayerDefn()
{
    if (poFeatureDefn)
        return poFeatureDefn;

    if (poDS->GetLayerCount() > 1)
    {
        poDS->LoadMultipleLayerDefn(GetName(), pszNS, pszNSVal);

        if (poFeatureDefn)
            return poFeatureDefn;
    }

    return BuildLayerDefn();
}

/************************************************************************/
/*                          BuildLayerDefn()                            */
/************************************************************************/

OGRFeatureDefn *OGRWFSLayer::BuildLayerDefn(OGRFeatureDefn *poSrcFDefn)
{
    bool bUnsetWidthPrecision = false;

    poFeatureDefn = new OGRFeatureDefn(pszName);
    poFeatureDefn->GetGeomFieldDefn(0)->SetSpatialRef(m_poSRS);
    poFeatureDefn->Reference();

    GDALDataset *l_poDS = nullptr;

    if (poSrcFDefn == nullptr)
        poSrcFDefn = DescribeFeatureType();
    if (poSrcFDefn == nullptr)
    {
        l_poDS = FetchGetFeature(1);
        if (l_poDS == nullptr)
        {
            return poFeatureDefn;
        }
        OGRLayer *l_poLayer = l_poDS->GetLayer(0);
        if (l_poLayer == nullptr)
        {
            return poFeatureDefn;
        }
        poSrcFDefn = l_poLayer->GetLayerDefn();
        bGotApproximateLayerDefn = true;
        /* We cannot trust width and precision based on a single feature */
        bUnsetWidthPrecision = true;
    }

    const CPLStringList aosPropertyName(CSLTokenizeString2(
        CPLURLGetValue(pszBaseURL, "PROPERTYNAME"), "(,)", 0));

    poFeatureDefn->SetGeomType(poSrcFDefn->GetGeomType());
    if (poSrcFDefn->GetGeomFieldCount() > 0)
        poFeatureDefn->GetGeomFieldDefn(0)->SetName(
            poSrcFDefn->GetGeomFieldDefn(0)->GetNameRef());
    for (int i = 0; i < poSrcFDefn->GetFieldCount(); i++)
    {
        if (!aosPropertyName.empty())
        {
            if (aosPropertyName.FindString(
                    poSrcFDefn->GetFieldDefn(i)->GetNameRef()) >= 0)
                poFeatureDefn->AddFieldDefn(poSrcFDefn->GetFieldDefn(i));
            else
                bGotApproximateLayerDefn = true;
        }
        else
        {
            OGRFieldDefn oFieldDefn(poSrcFDefn->GetFieldDefn(i));
            if (bUnsetWidthPrecision)
            {
                oFieldDefn.SetWidth(0);
                oFieldDefn.SetPrecision(0);
            }
            poFeatureDefn->AddFieldDefn(&oFieldDefn);
        }
    }

    if (l_poDS)
        GDALClose(l_poDS);
    else
        delete poSrcFDefn;

    return poFeatureDefn;
}

/************************************************************************/
/*                            ResetReading()                            */
/************************************************************************/

void OGRWFSLayer::ResetReading()

{
    if (poFeatureDefn == nullptr)
        return;
    if (bPagingActive)
        bReloadNeeded = true;
    nPagingStartIndex = 0;
    nFeatureRead = 0;
    m_nNumberMatched = -1;
    m_bHasReadAtLeastOneFeatureInThisPage = false;
    if (bReloadNeeded)
    {
        GDALClose(poBaseDS);
        poBaseDS = nullptr;
        poBaseLayer = nullptr;
        bHasFetched = false;
        bReloadNeeded = false;
    }
    if (poBaseLayer)
        poBaseLayer->ResetReading();
}

/************************************************************************/
/*                         SetIgnoredFields()                           */
/************************************************************************/

OGRErr OGRWFSLayer::SetIgnoredFields(CSLConstList papszFields)
{
    bReloadNeeded = true;
    ResetReading();
    return OGRLayer::SetIgnoredFields(papszFields);
}

/************************************************************************/
/*                           GetNextFeature()                           */
/************************************************************************/

OGRFeature *OGRWFSLayer::GetNextFeature()
{
    GetLayerDefn();

    while (true)
    {
        if (bReloadNeeded)
        {
            m_bHasReadAtLeastOneFeatureInThisPage = false;
            GDALClose(poBaseDS);
            poBaseDS = nullptr;
            poBaseLayer = nullptr;
            bHasFetched = false;
            bReloadNeeded = false;
        }
        if (poBaseDS == nullptr && !bHasFetched)
        {
            bHasFetched = true;
            poBaseDS = FetchGetFeature(0);
            poBaseLayer = nullptr;
            if (poBaseDS)
            {
                poBaseLayer = poBaseDS->GetLayer(0);
                if (poBaseLayer == nullptr)
                    return nullptr;
                poBaseLayer->ResetReading();

                /* Check that the layer field definition is consistent with the
                 * one */
                /* we got in BuildLayerDefn() */
                if (poFeatureDefn->GetFieldCount() !=
                    poBaseLayer->GetLayerDefn()->GetFieldCount())
                    bGotApproximateLayerDefn = true;
                else
                {
                    for (int iField = 0;
                         iField < poFeatureDefn->GetFieldCount(); iField++)
                    {
                        OGRFieldDefn *poFDefn1 =
                            poFeatureDefn->GetFieldDefn(iField);
                        OGRFieldDefn *poFDefn2 =
                            poBaseLayer->GetLayerDefn()->GetFieldDefn(iField);
                        if (strcmp(poFDefn1->GetNameRef(),
                                   poFDefn2->GetNameRef()) != 0 ||
                            poFDefn1->GetType() != poFDefn2->GetType())
                        {
                            bGotApproximateLayerDefn = true;
                            break;
                        }
                    }
                }
            }
        }
        if (poBaseDS == nullptr || poBaseLayer == nullptr)
            return nullptr;

        OGRFeature *poSrcFeature = poBaseLayer->GetNextFeature();
        if (poSrcFeature == nullptr)
        {
            if (bPagingActive && m_bHasReadAtLeastOneFeatureInThisPage &&
                (m_nNumberMatched < 0 || nFeatureRead < m_nNumberMatched))
            {
                bReloadNeeded = true;
                nPagingStartIndex = nFeatureRead;
                continue;
            }
            return nullptr;
        }
        nFeatureRead++;
        m_bHasReadAtLeastOneFeatureInThisPage = true;
        if (bCountFeaturesInGetNextFeature)
            nFeatures++;

        OGRGeometry *poGeom = poSrcFeature->GetGeometryRef();
        if (m_poFilterGeom != nullptr && poGeom != nullptr &&
            !FilterGeometry(poGeom))
        {
            delete poSrcFeature;
            continue;
        }

        /* Client-side attribute filtering with underlying layer defn */
        /* identical to exposed layer defn. */
        if (!bGotApproximateLayerDefn && osWFSWhere.empty() &&
            m_poAttrQuery != nullptr && !m_poAttrQuery->Evaluate(poSrcFeature))
        {
            delete poSrcFeature;
            continue;
        }

        OGRFeature *poNewFeature = new OGRFeature(poFeatureDefn);
        if (bGotApproximateLayerDefn)
        {
            poNewFeature->SetFrom(poSrcFeature);

            /* Client-side attribute filtering. */
            if (m_poAttrQuery != nullptr && osWFSWhere.empty() &&
                !m_poAttrQuery->Evaluate(poNewFeature))
            {
                delete poSrcFeature;
                delete poNewFeature;
                continue;
            }
        }
        else
        {
            for (int iField = 0; iField < poFeatureDefn->GetFieldCount();
                 iField++)
            {
                poNewFeature->SetField(iField,
                                       poSrcFeature->GetRawFieldRef(iField));
            }
            poNewFeature->SetStyleString(poSrcFeature->GetStyleString());
            poNewFeature->SetGeometryDirectly(poSrcFeature->StealGeometry());
        }
        poNewFeature->SetFID(poSrcFeature->GetFID());
        poGeom = poNewFeature->GetGeometryRef();

        /* FIXME? I don't really know what we should do with WFS 1.1.0 */
        /* and non-GML format !!! I guess 50% WFS servers must do it wrong
         * anyway */
        /* GeoServer does currently axis inversion for non GML output, but */
        /* apparently this is not correct :
         * http://jira.codehaus.org/browse/GEOS-3657 */
        if (poGeom != nullptr && bAxisOrderAlreadyInverted &&
            strcmp(poBaseDS->GetDriverName(), "GML") != 0)
        {
            poGeom->swapXY();
        }

        if (poGeom && m_poSRS)
            poGeom->assignSpatialReference(m_poSRS);
        delete poSrcFeature;
        return poNewFeature;
    }
}

/************************************************************************/
/*                         SetSpatialFilter()                           */
/************************************************************************/

void OGRWFSLayer::SetSpatialFilter(OGRGeometry *poGeom)
{
    if (bStreamingDS)
    {
        bReloadNeeded = true;
    }
    else if (poFetchedFilterGeom == nullptr && poBaseDS != nullptr)
    {
        /* If there was no filter set, and that we set one */
        /* the new result set can only be a subset of the whole */
        /* so no need to reload from source */
        bReloadNeeded = false;
    }
    else if (poFetchedFilterGeom != nullptr && poGeom != nullptr &&
             poBaseDS != nullptr)
    {
        OGREnvelope oOldEnvelope, oNewEnvelope;
        poFetchedFilterGeom->getEnvelope(&oOldEnvelope);
        poGeom->getEnvelope(&oNewEnvelope);
        /* Optimization : we don't need to request the server */
        /* if the new BBOX is inside the old BBOX as we have */
        /* already all the features */
        bReloadNeeded = !oOldEnvelope.Contains(oNewEnvelope);
    }
    else
    {
        bReloadNeeded = true;
    }
    nFeatures = -1;
    OGRLayer::SetSpatialFilter(poGeom);
    ResetReading();
}

/************************************************************************/
/*                        SetAttributeFilter()                          */
/************************************************************************/

OGRErr OGRWFSLayer::SetAttributeFilter(const char *pszFilter)
{
    if (pszFilter != nullptr && pszFilter[0] == 0)
        pszFilter = nullptr;

    CPLString osOldWFSWhere(osWFSWhere);

    CPLFree(m_pszAttrQueryString);
    m_pszAttrQueryString = (pszFilter) ? CPLStrdup(pszFilter) : nullptr;

    delete m_poAttrQuery;
    m_poAttrQuery = nullptr;

    if (pszFilter != nullptr)
    {
        m_poAttrQuery = new OGRFeatureQuery();

        OGRErr eErr = m_poAttrQuery->Compile(GetLayerDefn(), pszFilter, TRUE,
                                             WFSGetCustomFuncRegistrar());
        if (eErr != OGRERR_NONE)
        {
            delete m_poAttrQuery;
            m_poAttrQuery = nullptr;
            return eErr;
        }
    }

    if (poDS->HasMinOperators() && m_poAttrQuery != nullptr)
    {
        swq_expr_node *poNode = (swq_expr_node *)m_poAttrQuery->GetSWQExpr();
        poNode->ReplaceBetweenByGEAndLERecurse();

        int bNeedsNullCheck = FALSE;
        int nVersion = (strcmp(poDS->GetVersion(), "1.0.0") == 0) ? 100
                       : (atoi(poDS->GetVersion()) >= 2)          ? 200
                                                                  : 110;
        if (poNode->field_type != SWQ_BOOLEAN)
            osWFSWhere = "";
        else
            osWFSWhere = WFS_TurnSQLFilterToOGCFilter(
                poNode, nullptr, GetLayerDefn(), nVersion,
                poDS->PropertyIsNotEqualToSupported(),
                poDS->UseFeatureId() || bUseFeatureIdAtLayerLevel,
                poDS->DoesGmlObjectIdNeedGMLPrefix(), "", &bNeedsNullCheck);
        if (bNeedsNullCheck && !poDS->HasNullCheck())
            osWFSWhere = "";
    }
    else
        osWFSWhere = "";

    if (m_poAttrQuery != nullptr && osWFSWhere.empty())
    {
        CPLDebug("WFS", "Using client-side only mode for filter \"%s\"",
                 pszFilter);
        OGRErr eErr = OGRLayer::SetAttributeFilter(pszFilter);
        if (eErr != OGRERR_NONE)
            return eErr;
    }
    ResetReading();

    osSQLWhere = (pszFilter) ? pszFilter : "";

    if (osWFSWhere != osOldWFSWhere)
        bReloadNeeded = true;
    else
        bReloadNeeded = false;
    nFeatures = -1;

    return OGRERR_NONE;
}

/************************************************************************/
/*                           TestCapability()                           */
/************************************************************************/

int OGRWFSLayer::TestCapability(const char *pszCap)

{
    if (EQUAL(pszCap, OLCFastFeatureCount))
    {
        if (nFeatures >= 0)
            return TRUE;

        return poBaseLayer != nullptr && m_poFilterGeom == nullptr &&
               m_poAttrQuery == nullptr &&
               poBaseLayer->TestCapability(pszCap) &&
               (!poDS->IsPagingAllowed() &&
                poBaseLayer->GetFeatureCount() < poDS->GetPageSize());
    }

    else if (EQUAL(pszCap, OLCFastGetExtent))
    {
        if (m_oExtents.IsInit())
            return TRUE;

        return poBaseLayer != nullptr && poBaseLayer->TestCapability(pszCap);
    }

    else if (EQUAL(pszCap, OLCStringsAsUTF8))
        return poBaseLayer != nullptr && poBaseLayer->TestCapability(pszCap);

    else if (EQUAL(pszCap, OLCSequentialWrite) ||
             EQUAL(pszCap, OLCDeleteFeature) || EQUAL(pszCap, OLCRandomWrite))
    {
        GetLayerDefn();
        return poDS->SupportTransactions() && poDS->UpdateMode() &&
               poFeatureDefn->GetFieldIndex("gml_id") == 0;
    }
    else if (EQUAL(pszCap, OLCTransactions))
    {
        return poDS->SupportTransactions() && poDS->UpdateMode();
    }
    else if (EQUAL(pszCap, OLCIgnoreFields))
    {
        return TRUE;
    }

    return FALSE;
}

/************************************************************************/
/*                  ExecuteGetFeatureResultTypeHits()                   */
/************************************************************************/

GIntBig OGRWFSLayer::ExecuteGetFeatureResultTypeHits()
{
    char *pabyData = nullptr;
    CPLString osURL = MakeGetFeatureURL(0, TRUE);
    if (pszRequiredOutputFormat)
        osURL = CPLURLAddKVP(osURL, "OUTPUTFORMAT",
                             WFS_EscapeURL(pszRequiredOutputFormat));
    CPLDebug("WFS", "%s", osURL.c_str());

    CPLHTTPResult *psResult = poDS->HTTPFetch(osURL, nullptr);
    if (psResult == nullptr)
    {
        return -1;
    }

    /* http://demo.snowflakesoftware.com:8080/Obstacle_AIXM_ZIP/GOPublisherWFS
     * returns */
    /* zip content, including for RESULTTYPE=hits */
    if (psResult->pszContentType != nullptr &&
        strstr(psResult->pszContentType, "application/zip") != nullptr)
    {
        CPLString osTmpFileName;
        osTmpFileName.Printf("/vsimem/wfstemphits_%p.zip", this);
        VSILFILE *fp = VSIFileFromMemBuffer(osTmpFileName, psResult->pabyData,
                                            psResult->nDataLen, FALSE);
        VSIFCloseL(fp);

        CPLString osZipTmpFileName("/vsizip/" + osTmpFileName);

        char **papszDirContent = VSIReadDir(osZipTmpFileName);
        if (CSLCount(papszDirContent) != 1)
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "Cannot parse result of RESULTTYPE=hits request : more "
                     "than one file in zip");
            CSLDestroy(papszDirContent);
            CPLHTTPDestroyResult(psResult);
            VSIUnlink(osTmpFileName);
            return -1;
        }

        CPLString osFileInZipTmpFileName = osZipTmpFileName + "/";
        osFileInZipTmpFileName += papszDirContent[0];

        fp = VSIFOpenL(osFileInZipTmpFileName.c_str(), "rb");
        VSIStatBufL sBuf;
        if (fp == nullptr ||
            VSIStatL(osFileInZipTmpFileName.c_str(), &sBuf) != 0)
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "Cannot parse result of RESULTTYPE=hits request : cannot "
                     "open one file in zip");
            CSLDestroy(papszDirContent);
            CPLHTTPDestroyResult(psResult);
            VSIUnlink(osTmpFileName);
            if (fp)
                VSIFCloseL(fp);
            return -1;
        }
        pabyData = (char *)CPLMalloc((size_t)(sBuf.st_size + 1));
        pabyData[sBuf.st_size] = 0;
        VSIFReadL(pabyData, 1, (size_t)sBuf.st_size, fp);
        VSIFCloseL(fp);

        CSLDestroy(papszDirContent);
        VSIUnlink(osTmpFileName);
    }
    else
    {
        pabyData = (char *)psResult->pabyData;
        psResult->pabyData = nullptr;
    }

    if (strstr(pabyData, "<ServiceExceptionReport") != nullptr ||
        strstr(pabyData, "<ows:ExceptionReport") != nullptr)
    {
        if (poDS->IsOldDeegree(pabyData))
        {
            CPLHTTPDestroyResult(psResult);
            return ExecuteGetFeatureResultTypeHits();
        }
        CPLError(CE_Failure, CPLE_AppDefined, "Error returned by server : %s",
                 pabyData);
        CPLHTTPDestroyResult(psResult);
        CPLFree(pabyData);
        return -1;
    }

    CPLXMLNode *psXML = CPLParseXMLString(pabyData);
    if (psXML == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Invalid XML content : %s",
                 pabyData);
        CPLHTTPDestroyResult(psResult);
        CPLFree(pabyData);
        return -1;
    }

    CPLStripXMLNamespace(psXML, nullptr, TRUE);
    CPLXMLNode *psRoot = CPLGetXMLNode(psXML, "=FeatureCollection");
    if (psRoot == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Cannot find <FeatureCollection>");
        CPLDestroyXMLNode(psXML);
        CPLHTTPDestroyResult(psResult);
        CPLFree(pabyData);
        return -1;
    }

    const char *pszValue = CPLGetXMLValue(psRoot, "numberOfFeatures", nullptr);
    if (pszValue == nullptr)
        pszValue =
            CPLGetXMLValue(psRoot, "numberMatched", nullptr); /* WFS 2.0.0 */
    if (pszValue == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find numberOfFeatures");
        CPLDestroyXMLNode(psXML);
        CPLHTTPDestroyResult(psResult);
        CPLFree(pabyData);

        poDS->DisableSupportHits();
        return -1;
    }

    GIntBig l_nFeatures = CPLAtoGIntBig(pszValue);
    /* Hum,
     * http://deegree3-testing.deegree.org:80/deegree-inspire-node/services?MAXFEATURES=10&SERVICE=WFS&VERSION=1.1.0&REQUEST=GetFeature&TYPENAME=ad:Address&OUTPUTFORMAT=text/xml;%20subtype=gml/3.2.1&RESULTTYPE=hits
     */
    /* returns more than MAXFEATURES features... So truncate to MAXFEATURES */
    CPLString osMaxFeatures = CPLURLGetValue(
        osURL, atoi(poDS->GetVersion()) >= 2 ? "COUNT" : "MAXFEATURES");
    if (!osMaxFeatures.empty())
    {
        GIntBig nMaxFeatures = CPLAtoGIntBig(osMaxFeatures);
        if (l_nFeatures > nMaxFeatures)
        {
            CPLDebug("WFS",
                     "Truncating result from " CPL_FRMT_GIB " to " CPL_FRMT_GIB,
                     l_nFeatures, nMaxFeatures);
            l_nFeatures = nMaxFeatures;
        }
    }

    CPLDestroyXMLNode(psXML);
    CPLHTTPDestroyResult(psResult);
    CPLFree(pabyData);

    return l_nFeatures;
}

/************************************************************************/
/*              CanRunGetFeatureCountAndGetExtentTogether()             */
/************************************************************************/

int OGRWFSLayer::CanRunGetFeatureCountAndGetExtentTogether()
{
    /* In some cases, we can evaluate the result of GetFeatureCount() */
    /* and GetExtent() with the same data */
    CPLString osRequestURL = MakeGetFeatureURL(0, FALSE);
    return (!m_oExtents.IsInit() && nFeatures < 0 &&
            osRequestURL.ifind("FILTER") == std::string::npos &&
            osRequestURL.ifind("MAXFEATURES") == std::string::npos &&
            osRequestURL.ifind("COUNT") == std::string::npos &&
            !(GetLayerDefn()->IsGeometryIgnored()));
}

/************************************************************************/
/*                           GetFeatureCount()                          */
/************************************************************************/

GIntBig OGRWFSLayer::GetFeatureCount(int bForce)
{
    if (nFeatures >= 0)
        return nFeatures;

    if (TestCapability(OLCFastFeatureCount))
        return poBaseLayer->GetFeatureCount(bForce);

    if ((m_poAttrQuery == nullptr || !osWFSWhere.empty()) &&
        poDS->GetFeatureSupportHits())
    {
        nFeatures = ExecuteGetFeatureResultTypeHits();
        if (nFeatures >= 0)
            return nFeatures;
    }

    /* If we have not yet the base layer, try to read one */
    /* feature, and then query again OLCFastFeatureCount on the */
    /* base layer. In case the WFS response would contain the */
    /* number of features */
    if (poBaseLayer == nullptr)
    {
        ResetReading();
        OGRFeature *poFeature = GetNextFeature();
        delete poFeature;
        ResetReading();

        if (TestCapability(OLCFastFeatureCount))
            return poBaseLayer->GetFeatureCount(bForce);
    }

    /* In some cases, we can evaluate the result of GetFeatureCount() */
    /* and GetExtent() with the same data */
    if (CanRunGetFeatureCountAndGetExtentTogether())
    {
        OGREnvelope sDummy;
        GetExtent(&sDummy);
    }

    if (nFeatures < 0)
        nFeatures = OGRLayer::GetFeatureCount(bForce);

    return nFeatures;
}

/************************************************************************/
/*                              SetExtents()                            */
/************************************************************************/

void OGRWFSLayer::SetExtents(double dfMinXIn, double dfMinYIn, double dfMaxXIn,
                             double dfMaxYIn)
{
    m_oExtents.MinX = dfMinXIn;
    m_oExtents.MinY = dfMinYIn;
    m_oExtents.MaxX = dfMaxXIn;
    m_oExtents.MaxY = dfMaxYIn;
}

/************************************************************************/
/*                            SetWGS84Extents()                         */
/************************************************************************/

void OGRWFSLayer::SetWGS84Extents(double dfMinXIn, double dfMinYIn,
                                  double dfMaxXIn, double dfMaxYIn)
{
    m_oWGS84Extents.MinX = dfMinXIn;
    m_oWGS84Extents.MinY = dfMinYIn;
    m_oWGS84Extents.MaxX = dfMaxXIn;
    m_oWGS84Extents.MaxY = dfMaxYIn;
}

/************************************************************************/
/*                              GetExtent()                             */
/************************************************************************/

OGRErr OGRWFSLayer::GetExtent(OGREnvelope *psExtent, int bForce)
{
    if (m_oExtents.IsInit())
    {
        *psExtent = m_oExtents;
        return OGRERR_NONE;
    }

    /* If we have not yet the base layer, try to read one */
    /* feature, and then query again OLCFastGetExtent on the */
    /* base layer. In case the WFS response would contain the */
    /* global extent */
    if (poBaseLayer == nullptr)
    {
        ResetReading();
        OGRFeature *poFeature = GetNextFeature();
        delete poFeature;
        ResetReading();
    }

    if (TestCapability(OLCFastGetExtent))
        return poBaseLayer->GetExtent(psExtent, bForce);

    /* In some cases, we can evaluate the result of GetFeatureCount() */
    /* and GetExtent() with the same data */
    if (CanRunGetFeatureCountAndGetExtentTogether())
    {
        bCountFeaturesInGetNextFeature = true;
        nFeatures = 0;
    }

    OGRErr eErr = OGRLayer::GetExtent(psExtent, bForce);

    if (bCountFeaturesInGetNextFeature)
    {
        if (eErr == OGRERR_NONE)
        {
            m_oExtents = *psExtent;
        }
        else
        {
            nFeatures = -1;
        }
        bCountFeaturesInGetNextFeature = false;
    }

    return eErr;
}

/************************************************************************/
/*                          GetShortName()                              */
/************************************************************************/

const char *OGRWFSLayer::GetShortName()
{
    const char *pszShortName = strchr(pszName, ':');
    if (pszShortName == nullptr)
        pszShortName = pszName;
    else
        pszShortName++;
    return pszShortName;
}

/************************************************************************/
/*                          GetPostHeader()                             */
/************************************************************************/

CPLString OGRWFSLayer::GetPostHeader()
{
    CPLString osPost;
    osPost += "<?xml version=\"1.0\"?>\n";
    osPost += "<wfs:Transaction xmlns:wfs=\"http://www.opengis.net/wfs\"\n";
    osPost += "                 "
              "xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"\n";
    osPost += "                 service=\"WFS\" version=\"";
    osPost += poDS->GetVersion();
    osPost += "\"\n";
    osPost += "                 xmlns:gml=\"http://www.opengis.net/gml\"\n";
    osPost += "                 xmlns:ogc=\"http://www.opengis.net/ogc\"\n";
    osPost +=
        "                 xsi:schemaLocation=\"http://www.opengis.net/wfs "
        "http://schemas.opengis.net/wfs/";
    osPost += poDS->GetVersion();
    osPost += "/wfs.xsd ";
    osPost += osTargetNamespace;
    osPost += " ";

    char *pszXMLEncoded =
        CPLEscapeString(GetDescribeFeatureTypeURL(FALSE), -1, CPLES_XML);
    osPost += pszXMLEncoded;
    CPLFree(pszXMLEncoded);

    osPost += "\">\n";

    return osPost;
}

/************************************************************************/
/*                          ICreateFeature()                             */
/************************************************************************/

OGRErr OGRWFSLayer::ICreateFeature(OGRFeature *poFeature)
{
    if (!TestCapability(OLCSequentialWrite))
    {
        if (!poDS->SupportTransactions())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "CreateFeature() not supported: no WMS-T features "
                     "advertized by server");
        else if (!poDS->UpdateMode())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "CreateFeature() not supported: datasource opened as "
                     "read-only");
        return OGRERR_FAILURE;
    }

    if (poGMLFeatureClass == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Cannot insert feature because we didn't manage to parse the "
                 ".XSD schema");
        return OGRERR_FAILURE;
    }

    if (poFeatureDefn->GetFieldIndex("gml_id") != 0)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find gml_id field");
        return OGRERR_FAILURE;
    }

    if (poFeature->IsFieldSetAndNotNull(0))
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Cannot insert a feature when gml_id field is already set");
        return OGRERR_FAILURE;
    }

    CPLString osPost;

    const char *pszShortName = GetShortName();

    if (!bInTransaction)
    {
        osPost += GetPostHeader();
        osPost += "  <wfs:Insert>\n";
    }
    osPost += "    <feature:";
    osPost += pszShortName;
    osPost += " xmlns:feature=\"";
    osPost += osTargetNamespace;
    osPost += "\">\n";

    for (int i = 1; i <= poFeature->GetFieldCount(); i++)
    {
        if (poGMLFeatureClass->GetGeometryPropertyCount() == 1 &&
            poGMLFeatureClass->GetGeometryProperty(0)->GetAttributeIndex() ==
                i - 1)
        {
            OGRGeometry *poGeom = poFeature->GetGeometryRef();
            if (poGeom != nullptr && !osGeometryColumnName.empty())
            {
                if (poGeom->getSpatialReference() == nullptr)
                    poGeom->assignSpatialReference(m_poSRS);
                char *pszGML = nullptr;
                if (strcmp(poDS->GetVersion(), "1.1.0") == 0 ||
                    atoi(poDS->GetVersion()) >= 2)
                {
                    char **papszOptions = CSLAddString(nullptr, "FORMAT=GML3");
                    pszGML =
                        OGR_G_ExportToGMLEx((OGRGeometryH)poGeom, papszOptions);
                    CSLDestroy(papszOptions);
                }
                else
                    pszGML = OGR_G_ExportToGML((OGRGeometryH)poGeom);
                osPost += "      <feature:";
                osPost += osGeometryColumnName;
                osPost += ">";
                osPost += pszGML;
                osPost += "</feature:";
                osPost += osGeometryColumnName;
                osPost += ">\n";
                CPLFree(pszGML);
            }
        }
        if (i == poFeature->GetFieldCount())
            break;

#ifdef notdef
        if (poFeature->IsFieldNull(i))
        {
            OGRFieldDefn *poFDefn = poFeature->GetFieldDefnRef(i);
            osPost += "      <feature:";
            osPost += poFDefn->GetNameRef();
            osPost += " xsi:nil=\"true\" />\n";
        }
        else
#endif
            if (poFeature->IsFieldSet(i) && !poFeature->IsFieldNull(i))
        {
            OGRFieldDefn *poFDefn = poFeature->GetFieldDefnRef(i);
            osPost += "      <feature:";
            osPost += poFDefn->GetNameRef();
            osPost += ">";
            if (poFDefn->GetType() == OFTInteger)
                osPost += CPLSPrintf("%d", poFeature->GetFieldAsInteger(i));
            else if (poFDefn->GetType() == OFTInteger64)
                osPost +=
                    CPLSPrintf(CPL_FRMT_GIB, poFeature->GetFieldAsInteger64(i));
            else if (poFDefn->GetType() == OFTReal)
                osPost += CPLSPrintf("%.16g", poFeature->GetFieldAsDouble(i));
            else
            {
                char *pszXMLEncoded = CPLEscapeString(
                    poFeature->GetFieldAsString(i), -1, CPLES_XML);
                osPost += pszXMLEncoded;
                CPLFree(pszXMLEncoded);
            }
            osPost += "</feature:";
            osPost += poFDefn->GetNameRef();
            osPost += ">\n";
        }
    }

    osPost += "    </feature:";
    osPost += pszShortName;
    osPost += ">\n";

    if (!bInTransaction)
    {
        osPost += "  </wfs:Insert>\n";
        osPost += "</wfs:Transaction>\n";
    }
    else
    {
        osGlobalInsert += osPost;
        nExpectedInserts++;
        return OGRERR_NONE;
    }

    CPLDebug("WFS", "Post : %s", osPost.c_str());

    char **papszOptions = nullptr;
    papszOptions = CSLAddNameValue(papszOptions, "POSTFIELDS", osPost.c_str());
    papszOptions =
        CSLAddNameValue(papszOptions, "HEADERS",
                        "Content-Type: application/xml; charset=UTF-8");

    CPLHTTPResult *psResult =
        poDS->HTTPFetch(poDS->GetPostTransactionURL(), papszOptions);
    CSLDestroy(papszOptions);

    if (psResult == nullptr)
    {
        return OGRERR_FAILURE;
    }

    if (strstr((const char *)psResult->pabyData, "<ServiceExceptionReport") !=
            nullptr ||
        strstr((const char *)psResult->pabyData, "<ows:ExceptionReport") !=
            nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Error returned by server : %s",
                 psResult->pabyData);
        CPLHTTPDestroyResult(psResult);
        return OGRERR_FAILURE;
    }

    CPLDebug("WFS", "Response: %s", psResult->pabyData);

    CPLXMLNode *psXML = CPLParseXMLString((const char *)psResult->pabyData);
    if (psXML == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Invalid XML content : %s",
                 psResult->pabyData);
        CPLHTTPDestroyResult(psResult);
        return OGRERR_FAILURE;
    }

    CPLStripXMLNamespace(psXML, nullptr, TRUE);
    bool bUse100Schema = false;
    CPLXMLNode *psRoot = CPLGetXMLNode(psXML, "=TransactionResponse");
    if (psRoot == nullptr)
    {
        psRoot = CPLGetXMLNode(psXML, "=WFS_TransactionResponse");
        if (psRoot)
            bUse100Schema = true;
    }

    if (psRoot == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Cannot find <TransactionResponse>");
        CPLDestroyXMLNode(psXML);
        CPLHTTPDestroyResult(psResult);
        return OGRERR_FAILURE;
    }

    CPLXMLNode *psFeatureID = nullptr;

    if (bUse100Schema)
    {
        if (CPLGetXMLNode(psRoot, "TransactionResult.Status.FAILED"))
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Insert failed : %s",
                     psResult->pabyData);
            CPLDestroyXMLNode(psXML);
            CPLHTTPDestroyResult(psResult);
            return OGRERR_FAILURE;
        }

        psFeatureID = CPLGetXMLNode(psRoot, "InsertResult.FeatureId");
        if (psFeatureID == nullptr)
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "Cannot find InsertResult.FeatureId");
            CPLDestroyXMLNode(psXML);
            CPLHTTPDestroyResult(psResult);
            return OGRERR_FAILURE;
        }
    }
    else
    {
        const char *pszFeatureIdElt = atoi(poDS->GetVersion()) >= 2
                                          ? "InsertResults.Feature.ResourceId"
                                          : "InsertResults.Feature.FeatureId";
        psFeatureID = CPLGetXMLNode(psRoot, pszFeatureIdElt);
        if (psFeatureID == nullptr)
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s",
                     pszFeatureIdElt);
            CPLDestroyXMLNode(psXML);
            CPLHTTPDestroyResult(psResult);
            return OGRERR_FAILURE;
        }
    }

    const char *pszFIDAttr = atoi(poDS->GetVersion()) >= 2 ? "rid" : "fid";
    const char *pszFID = CPLGetXMLValue(psFeatureID, pszFIDAttr, nullptr);
    if (pszFID == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s", pszFIDAttr);
        CPLDestroyXMLNode(psXML);
        CPLHTTPDestroyResult(psResult);
        return OGRERR_FAILURE;
    }

    poFeature->SetField("gml_id", pszFID);

    /* If the returned fid is of the form layer_name.num, then use */
    /* num as the OGR FID */
    if (strncmp(pszFID, pszShortName, strlen(pszShortName)) == 0 &&
        pszFID[strlen(pszShortName)] == '.')
    {
        GIntBig nFID = CPLAtoGIntBig(pszFID + strlen(pszShortName) + 1);
        poFeature->SetFID(nFID);
    }

    CPLDebug("WFS", "Got FID = " CPL_FRMT_GIB, poFeature->GetFID());

    CPLDestroyXMLNode(psXML);
    CPLHTTPDestroyResult(psResult);

    /* Invalidate layer */
    bReloadNeeded = true;
    nFeatures = -1;
    m_oExtents = OGREnvelope();

    return OGRERR_NONE;
}

/************************************************************************/
/*                             ISetFeature()                             */
/************************************************************************/

OGRErr OGRWFSLayer::ISetFeature(OGRFeature *poFeature)
{
    if (!TestCapability(OLCRandomWrite))
    {
        if (!poDS->SupportTransactions())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "SetFeature() not supported: no WMS-T features advertized "
                     "by server");
        else if (!poDS->UpdateMode())
            CPLError(
                CE_Failure, CPLE_AppDefined,
                "SetFeature() not supported: datasource opened as read-only");
        return OGRERR_FAILURE;
    }

    if (poFeatureDefn->GetFieldIndex("gml_id") != 0)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find gml_id field");
        return OGRERR_FAILURE;
    }

    if (poFeature->IsFieldSetAndNotNull(0) == FALSE)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Cannot update a feature when gml_id field is not set");
        return OGRERR_FAILURE;
    }

    if (bInTransaction)
    {
        CPLError(
            CE_Warning, CPLE_AppDefined,
            "SetFeature() not yet dealt in transaction. Issued immediately");
    }

    const char *pszShortName = GetShortName();

    CPLString osPost;
    osPost += GetPostHeader();

    osPost += "  <wfs:Update typeName=\"feature:";
    osPost += pszShortName;
    osPost += "\" xmlns:feature=\"";
    osPost += osTargetNamespace;
    osPost += "\">\n";

    OGRGeometry *poGeom = poFeature->GetGeometryRef();
    if (!osGeometryColumnName.empty())
    {
        osPost += "    <wfs:Property>\n";
        osPost += "      <wfs:Name>";
        osPost += osGeometryColumnName;
        osPost += "</wfs:Name>\n";
        if (poGeom != nullptr)
        {
            if (poGeom->getSpatialReference() == nullptr)
                poGeom->assignSpatialReference(m_poSRS);
            char *pszGML = nullptr;
            if (strcmp(poDS->GetVersion(), "1.1.0") == 0 ||
                atoi(poDS->GetVersion()) >= 2)
            {
                char **papszOptions = CSLAddString(nullptr, "FORMAT=GML3");
                pszGML =
                    OGR_G_ExportToGMLEx((OGRGeometryH)poGeom, papszOptions);
                CSLDestroy(papszOptions);
            }
            else
                pszGML = OGR_G_ExportToGML((OGRGeometryH)poGeom);
            osPost += "      <wfs:Value>";
            osPost += pszGML;
            osPost += "</wfs:Value>\n";
            CPLFree(pszGML);
        }
        osPost += "    </wfs:Property>\n";
    }

    for (int i = 1; i < poFeature->GetFieldCount(); i++)
    {
        OGRFieldDefn *poFDefn = poFeature->GetFieldDefnRef(i);

        osPost += "    <wfs:Property>\n";
        osPost += "      <wfs:Name>";
        osPost += poFDefn->GetNameRef();
        osPost += "</wfs:Name>\n";
        if (poFeature->IsFieldSetAndNotNull(i))
        {
            osPost += "      <wfs:Value>";
            if (poFDefn->GetType() == OFTInteger)
                osPost += CPLSPrintf("%d", poFeature->GetFieldAsInteger(i));
            else if (poFDefn->GetType() == OFTInteger64)
                osPost +=
                    CPLSPrintf(CPL_FRMT_GIB, poFeature->GetFieldAsInteger64(i));
            else if (poFDefn->GetType() == OFTReal)
                osPost += CPLSPrintf("%.16g", poFeature->GetFieldAsDouble(i));
            else
            {
                char *pszXMLEncoded = CPLEscapeString(
                    poFeature->GetFieldAsString(i), -1, CPLES_XML);
                osPost += pszXMLEncoded;
                CPLFree(pszXMLEncoded);
            }
            osPost += "</wfs:Value>\n";
        }
        osPost += "    </wfs:Property>\n";
    }
    osPost += "    <ogc:Filter>\n";
    if (poDS->UseFeatureId() || bUseFeatureIdAtLayerLevel)
        osPost += "      <ogc:FeatureId fid=\"";
    else if (atoi(poDS->GetVersion()) >= 2)
        osPost += "      <ogc:ResourceId rid=\"";
    else
        osPost += "      <ogc:GmlObjectId gml:id=\"";
    osPost += poFeature->GetFieldAsString(0);
    osPost += "\"/>\n";
    osPost += "    </ogc:Filter>\n";
    osPost += "  </wfs:Update>\n";
    osPost += "</wfs:Transaction>\n";

    CPLDebug("WFS", "Post : %s", osPost.c_str());

    char **papszOptions = nullptr;
    papszOptions = CSLAddNameValue(papszOptions, "POSTFIELDS", osPost.c_str());
    papszOptions =
        CSLAddNameValue(papszOptions, "HEADERS",
                        "Content-Type: application/xml; charset=UTF-8");

    CPLHTTPResult *psResult =
        poDS->HTTPFetch(poDS->GetPostTransactionURL(), papszOptions);
    CSLDestroy(papszOptions);

    if (psResult == nullptr)
    {
        return OGRERR_FAILURE;
    }

    if (strstr((const char *)psResult->pabyData, "<ServiceExceptionReport") !=
            nullptr ||
        strstr((const char *)psResult->pabyData, "<ows:ExceptionReport") !=
            nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Error returned by server : %s",
                 psResult->pabyData);
        CPLHTTPDestroyResult(psResult);
        return OGRERR_FAILURE;
    }

    CPLDebug("WFS", "Response: %s", psResult->pabyData);

    CPLXMLNode *psXML = CPLParseXMLString((const char *)psResult->pabyData);
    if (psXML == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Invalid XML content : %s",
                 psResult->pabyData);
        CPLHTTPDestroyResult(psResult);
        return OGRERR_FAILURE;
    }

    CPLStripXMLNamespace(psXML, nullptr, TRUE);
    int bUse100Schema = false;
    CPLXMLNode *psRoot = CPLGetXMLNode(psXML, "=TransactionResponse");
    if (psRoot == nullptr)
    {
        psRoot = CPLGetXMLNode(psXML, "=WFS_TransactionResponse");
        if (psRoot)
            bUse100Schema = true;
    }
    if (psRoot == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Cannot find <TransactionResponse>");
        CPLDestroyXMLNode(psXML);
        CPLHTTPDestroyResult(psResult);
        return OGRERR_FAILURE;
    }

    if (bUse100Schema)
    {
        if (CPLGetXMLNode(psRoot, "TransactionResult.Status.FAILED"))
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Update failed : %s",
                     psResult->pabyData);
            CPLDestroyXMLNode(psXML);
            CPLHTTPDestroyResult(psResult);
            return OGRERR_FAILURE;
        }
    }

    CPLDestroyXMLNode(psXML);
    CPLHTTPDestroyResult(psResult);

    /* Invalidate layer */
    bReloadNeeded = true;
    nFeatures = -1;
    m_oExtents = OGREnvelope();

    return OGRERR_NONE;
}

/************************************************************************/
/*                               GetFeature()                           */
/************************************************************************/

OGRFeature *OGRWFSLayer::GetFeature(GIntBig nFID)
{
    GetLayerDefn();
    if (poBaseLayer == nullptr && poFeatureDefn->GetFieldIndex("gml_id") == 0)
    {
        /* This is lovely hackish. We assume that then gml_id will be */
        /* layer_name.number. This is actually what we can observe with */
        /* GeoServer and TinyOWS */
        CPLString osVal =
            CPLSPrintf("gml_id = '%s." CPL_FRMT_GIB "'", GetShortName(), nFID);
        CPLString osOldSQLWhere(osSQLWhere);
        SetAttributeFilter(osVal);
        OGRFeature *poFeature = GetNextFeature();
        const char *pszOldFilter =
            osOldSQLWhere.size() ? osOldSQLWhere.c_str() : nullptr;
        SetAttributeFilter(pszOldFilter);
        if (poFeature)
            return poFeature;
    }

    return OGRLayer::GetFeature(nFID);
}

/************************************************************************/
/*                         DeleteFromFilter()                           */
/************************************************************************/

OGRErr OGRWFSLayer::DeleteFromFilter(const std::string &osOGCFilter)
{
    if (!TestCapability(OLCDeleteFeature))
    {
        if (!poDS->SupportTransactions())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "DeleteFromFilter() not supported: no WMS-T features "
                     "advertized by server");
        else if (!poDS->UpdateMode())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "DeleteFromFilter() not supported: datasource opened as "
                     "read-only");
        return OGRERR_FAILURE;
    }

    if (poFeatureDefn->GetFieldIndex("gml_id") != 0)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find gml_id field");
        return OGRERR_FAILURE;
    }
    const char *pszShortName = GetShortName();

    CPLString osPost;
    osPost += GetPostHeader();

    osPost += "  <wfs:Delete xmlns:feature=\"";
    osPost += osTargetNamespace;
    osPost += "\" typeName=\"feature:";
    osPost += pszShortName;
    osPost += "\">\n";
    osPost += "    <ogc:Filter>\n";
    osPost += osOGCFilter;
    osPost += "    </ogc:Filter>\n";
    osPost += "  </wfs:Delete>\n";
    osPost += "</wfs:Transaction>\n";

    CPLDebug("WFS", "Post : %s", osPost.c_str());

    char **papszOptions = nullptr;
    papszOptions = CSLAddNameValue(papszOptions, "POSTFIELDS", osPost.c_str());
    papszOptions =
        CSLAddNameValue(papszOptions, "HEADERS",
                        "Content-Type: application/xml; charset=UTF-8");

    CPLHTTPResult *psResult =
        poDS->HTTPFetch(poDS->GetPostTransactionURL(), papszOptions);
    CSLDestroy(papszOptions);

    if (psResult == nullptr)
    {
        return OGRERR_FAILURE;
    }

    if (strstr((const char *)psResult->pabyData, "<ServiceExceptionReport") !=
            nullptr ||
        strstr((const char *)psResult->pabyData, "<ows:ExceptionReport") !=
            nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Error returned by server : %s",
                 psResult->pabyData);
        CPLHTTPDestroyResult(psResult);
        return OGRERR_FAILURE;
    }

    CPLDebug("WFS", "Response: %s", psResult->pabyData);

    CPLXMLNode *psXML = CPLParseXMLString((const char *)psResult->pabyData);
    if (psXML == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Invalid XML content : %s",
                 psResult->pabyData);
        CPLHTTPDestroyResult(psResult);
        return OGRERR_FAILURE;
    }

    CPLStripXMLNamespace(psXML, nullptr, TRUE);
    bool bUse100Schema = false;
    CPLXMLNode *psRoot = CPLGetXMLNode(psXML, "=TransactionResponse");
    if (psRoot == nullptr)
    {
        psRoot = CPLGetXMLNode(psXML, "=WFS_TransactionResponse");
        if (psRoot)
            bUse100Schema = true;
    }
    if (psRoot == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Cannot find <TransactionResponse>");
        CPLDestroyXMLNode(psXML);
        CPLHTTPDestroyResult(psResult);
        return OGRERR_FAILURE;
    }

    if (bUse100Schema)
    {
        if (CPLGetXMLNode(psRoot, "TransactionResult.Status.FAILED"))
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Delete failed : %s",
                     psResult->pabyData);
            CPLDestroyXMLNode(psXML);
            CPLHTTPDestroyResult(psResult);
            return OGRERR_FAILURE;
        }
    }

    CPLDestroyXMLNode(psXML);
    CPLHTTPDestroyResult(psResult);

    /* Invalidate layer */
    bReloadNeeded = true;
    nFeatures = -1;
    m_oExtents = OGREnvelope();

    return OGRERR_NONE;
}

/************************************************************************/
/*                            DeleteFeature()                           */
/************************************************************************/

OGRErr OGRWFSLayer::DeleteFeature(GIntBig nFID)
{
    if (!TestCapability(OLCDeleteFeature))
    {
        if (!poDS->SupportTransactions())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "DeleteFeature() not supported: no WMS-T features "
                     "advertized by server");
        else if (!poDS->UpdateMode())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "DeleteFeature() not supported: datasource opened as "
                     "read-only");
        return OGRERR_FAILURE;
    }

    if (poFeatureDefn->GetFieldIndex("gml_id") != 0)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Cannot find gml_id field");
        return OGRERR_FAILURE;
    }

    OGRFeature *poFeature = GetFeature(nFID);
    if (poFeature == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Cannot find feature " CPL_FRMT_GIB, nFID);
        return OGRERR_FAILURE;
    }

    const char *pszGMLID = poFeature->GetFieldAsString("gml_id");
    if (pszGMLID == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Cannot delete a feature with gml_id unset");
        delete poFeature;
        return OGRERR_FAILURE;
    }

    if (bInTransaction)
    {
        CPLError(
            CE_Warning, CPLE_AppDefined,
            "DeleteFeature() not yet dealt in transaction. Issued immediately");
    }

    CPLString osGMLID = pszGMLID;
    pszGMLID = nullptr;
    delete poFeature;
    poFeature = nullptr;

    CPLString osFilter;
    osFilter = "<ogc:FeatureId fid=\"";
    osFilter += osGMLID;
    osFilter += "\"/>\n";
    return DeleteFromFilter(osFilter);
}

/************************************************************************/
/*                         StartTransaction()                           */
/************************************************************************/

OGRErr OGRWFSLayer::StartTransaction()
{
    if (!TestCapability(OLCTransactions))
    {
        if (!poDS->SupportTransactions())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "StartTransaction() not supported: no WMS-T features "
                     "advertized by server");
        else if (!poDS->UpdateMode())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "StartTransaction() not supported: datasource opened as "
                     "read-only");
        return OGRERR_FAILURE;
    }

    if (bInTransaction)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "StartTransaction() has already been called");
        return OGRERR_FAILURE;
    }

    bInTransaction = true;
    osGlobalInsert = "";
    nExpectedInserts = 0;
    aosFIDList.resize(0);

    return OGRERR_NONE;
}

/************************************************************************/
/*                        CommitTransaction()                           */
/************************************************************************/

OGRErr OGRWFSLayer::CommitTransaction()
{
    if (!TestCapability(OLCTransactions))
    {
        if (!poDS->SupportTransactions())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "CommitTransaction() not supported: no WMS-T features "
                     "advertized by server");
        else if (!poDS->UpdateMode())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "CommitTransaction() not supported: datasource opened as "
                     "read-only");
        return OGRERR_FAILURE;
    }

    if (!bInTransaction)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "StartTransaction() has not yet been called");
        return OGRERR_FAILURE;
    }

    if (!osGlobalInsert.empty())
    {
        CPLString osPost = GetPostHeader();
        osPost += "  <wfs:Insert>\n";
        osPost += osGlobalInsert;
        osPost += "  </wfs:Insert>\n";
        osPost += "</wfs:Transaction>\n";

        bInTransaction = false;
        osGlobalInsert = "";
        int l_nExpectedInserts = nExpectedInserts;
        nExpectedInserts = 0;

        CPLDebug("WFS", "Post : %s", osPost.c_str());

        char **papszOptions = nullptr;
        papszOptions =
            CSLAddNameValue(papszOptions, "POSTFIELDS", osPost.c_str());
        papszOptions =
            CSLAddNameValue(papszOptions, "HEADERS",
                            "Content-Type: application/xml; charset=UTF-8");

        CPLHTTPResult *psResult =
            poDS->HTTPFetch(poDS->GetPostTransactionURL(), papszOptions);
        CSLDestroy(papszOptions);

        if (psResult == nullptr)
        {
            return OGRERR_FAILURE;
        }

        if (strstr((const char *)psResult->pabyData,
                   "<ServiceExceptionReport") != nullptr ||
            strstr((const char *)psResult->pabyData, "<ows:ExceptionReport") !=
                nullptr)
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "Error returned by server : %s", psResult->pabyData);
            CPLHTTPDestroyResult(psResult);
            return OGRERR_FAILURE;
        }

        CPLDebug("WFS", "Response: %s", psResult->pabyData);

        CPLXMLNode *psXML = CPLParseXMLString((const char *)psResult->pabyData);
        if (psXML == nullptr)
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Invalid XML content : %s",
                     psResult->pabyData);
            CPLHTTPDestroyResult(psResult);
            return OGRERR_FAILURE;
        }

        CPLStripXMLNamespace(psXML, nullptr, TRUE);
        bool bUse100Schema = false;
        CPLXMLNode *psRoot = CPLGetXMLNode(psXML, "=TransactionResponse");
        if (psRoot == nullptr)
        {
            psRoot = CPLGetXMLNode(psXML, "=WFS_TransactionResponse");
            if (psRoot)
                bUse100Schema = true;
        }

        if (psRoot == nullptr)
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "Cannot find <TransactionResponse>");
            CPLDestroyXMLNode(psXML);
            CPLHTTPDestroyResult(psResult);
            return OGRERR_FAILURE;
        }

        if (bUse100Schema)
        {
            if (CPLGetXMLNode(psRoot, "TransactionResult.Status.FAILED"))
            {
                CPLError(CE_Failure, CPLE_AppDefined, "Insert failed : %s",
                         psResult->pabyData);
                CPLDestroyXMLNode(psXML);
                CPLHTTPDestroyResult(psResult);
                return OGRERR_FAILURE;
            }

            /* TODO */
        }
        else
        {
            int nGotInserted = atoi(
                CPLGetXMLValue(psRoot, "TransactionSummary.totalInserted", ""));
            if (nGotInserted != l_nExpectedInserts)
            {
                CPLError(
                    CE_Failure, CPLE_AppDefined,
                    "Only %d features were inserted whereas %d where expected",
                    nGotInserted, l_nExpectedInserts);
                CPLDestroyXMLNode(psXML);
                CPLHTTPDestroyResult(psResult);
                return OGRERR_FAILURE;
            }

            CPLXMLNode *psInsertResults =
                CPLGetXMLNode(psRoot, "InsertResults");
            if (psInsertResults == nullptr)
            {
                CPLError(CE_Failure, CPLE_AppDefined,
                         "Cannot find node InsertResults");
                CPLDestroyXMLNode(psXML);
                CPLHTTPDestroyResult(psResult);
                return OGRERR_FAILURE;
            }

            aosFIDList.resize(0);

            CPLXMLNode *psChild = psInsertResults->psChild;
            while (psChild)
            {
                const char *pszFID =
                    CPLGetXMLValue(psChild, "FeatureId.fid", nullptr);
                if (pszFID == nullptr)
                {
                    CPLError(CE_Failure, CPLE_AppDefined, "Cannot find fid");
                    CPLDestroyXMLNode(psXML);
                    CPLHTTPDestroyResult(psResult);
                    return OGRERR_FAILURE;
                }
                aosFIDList.push_back(pszFID);

                psChild = psChild->psNext;
            }

            if ((int)aosFIDList.size() != nGotInserted)
            {
                CPLError(CE_Failure, CPLE_AppDefined,
                         "Inconsistent InsertResults: did not get expected FID "
                         "count");
                CPLDestroyXMLNode(psXML);
                CPLHTTPDestroyResult(psResult);
                return OGRERR_FAILURE;
            }
        }

        CPLDestroyXMLNode(psXML);
        CPLHTTPDestroyResult(psResult);
    }

    bInTransaction = false;
    osGlobalInsert = "";
    nExpectedInserts = 0;

    return OGRERR_NONE;
}

/************************************************************************/
/*                      RollbackTransaction()                           */
/************************************************************************/

OGRErr OGRWFSLayer::RollbackTransaction()
{
    if (!TestCapability(OLCTransactions))
    {
        if (!poDS->SupportTransactions())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "RollbackTransaction() not supported: no WMS-T features "
                     "advertized by server");
        else if (!poDS->UpdateMode())
            CPLError(CE_Failure, CPLE_AppDefined,
                     "RollbackTransaction() not supported: datasource opened "
                     "as read-only");
        return OGRERR_FAILURE;
    }

    if (!bInTransaction)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "StartTransaction() has not yet been called");
        return OGRERR_FAILURE;
    }

    bInTransaction = false;
    osGlobalInsert = "";
    nExpectedInserts = 0;

    return OGRERR_NONE;
}

/************************************************************************/
/*                    SetRequiredOutputFormat()                         */
/************************************************************************/

void OGRWFSLayer::SetRequiredOutputFormat(const char *pszRequiredOutputFormatIn)
{
    CPLFree(pszRequiredOutputFormat);
    if (pszRequiredOutputFormatIn)
    {
        pszRequiredOutputFormat = CPLStrdup(pszRequiredOutputFormatIn);
    }
    else
    {
        pszRequiredOutputFormat = nullptr;
    }
}

/************************************************************************/
/*                            SetOrderBy()                              */
/************************************************************************/

void OGRWFSLayer::SetOrderBy(const std::vector<OGRWFSSortDesc> &aoSortColumnsIn)
{
    aoSortColumns = aoSortColumnsIn;
}
