/******************************************************************************
 *
 * Project:  Oracle Spatial Driver
 * Purpose:  Implementation of the OGROCILayer class.  This is layer semantics
 *           shared between table accessors and ExecuteSQL() result
 *           pseudo-layers.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 2002, Frank Warmerdam <warmerdam@pobox.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 "ogr_oci.h"
#include "cpl_conv.h"

CPL_CVSID("$Id: ogrocilayer.cpp 22f8ae3bf7bc3cccd970992655c63fc5254d3206 2018-04-08 20:13:05 +0200 Even Rouault $")

/************************************************************************/
/*                           OGROCILayer()                               */
/************************************************************************/

OGROCILayer::OGROCILayer()

{
    poFeatureDefn = nullptr;
    poDS = nullptr;
    poStatement = nullptr;

    pszQueryStatement = nullptr;
    nResultOffset = 0;
    pszGeomName = nullptr;
    iGeomColumn = -1;
    pszFIDName = nullptr;
    iFIDColumn = -1;

    hLastGeom = nullptr;
    hLastGeomInd = nullptr;

    iNextShapeId = 0;
}

/************************************************************************/
/*                            ~OGROCILayer()                             */
/************************************************************************/

OGROCILayer::~OGROCILayer()

{
    if( m_nFeaturesRead > 0 && poFeatureDefn != nullptr )
    {
        CPLDebug( "OCI", "%d features read on layer '%s'.",
                  (int) m_nFeaturesRead,
                  poFeatureDefn->GetName() );
    }

    OGROCILayer::ResetReading();

    CPLFree( pszGeomName );
    pszGeomName = nullptr;

    CPLFree( pszFIDName );
    pszFIDName = nullptr;

    CPLFree( pszQueryStatement );
    pszQueryStatement = nullptr;

    if( poFeatureDefn != nullptr )
        poFeatureDefn->Release();
}

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

void OGROCILayer::ResetReading()

{
    if( poStatement != nullptr )
        delete poStatement;
    poStatement = nullptr;

    iNextShapeId = 0;
}

/************************************************************************/
/*                           GetNextFeature()                           */
/*                                                                      */
/*      By default we implement the full spatial and attribute query    */
/*      semantics manually here.  The table query class will            */
/*      override this method and implement these inline, but the        */
/*      simple SELECT statement evaluator (OGROCISelectLayer) will      */
/*      depend us this code implementing additional spatial or          */
/*      attribute query semantics.                                      */
/************************************************************************/

OGRFeature *OGROCILayer::GetNextFeature()

{
    while( true )
    {
        OGRFeature      *poFeature;

        poFeature = GetNextRawFeature();
        if( poFeature == nullptr )
            return nullptr;

        if( (m_poFilterGeom == nullptr
            || FilterGeometry( poFeature->GetGeometryRef() ) )
            && (m_poAttrQuery == nullptr
                || m_poAttrQuery->Evaluate( poFeature )) )
            return poFeature;

        delete poFeature;
    }
}

/************************************************************************/
/*                         GetNextRawFeature()                          */
/************************************************************************/

OGRFeature *OGROCILayer::GetNextRawFeature()

{
/* -------------------------------------------------------------------- */
/*      Do we need to establish an initial query?                       */
/* -------------------------------------------------------------------- */
    if( iNextShapeId == 0 && poStatement == nullptr )
    {
        if( !ExecuteQuery(pszQueryStatement) )
            return nullptr;
    }

/* -------------------------------------------------------------------- */
/*      Have we run out of query results, such that we have no          */
/*      statement left?                                                 */
/* -------------------------------------------------------------------- */
    if( poStatement == nullptr )
        return nullptr;

/* -------------------------------------------------------------------- */
/*      Are we in some sort of error condition?                         */
/* -------------------------------------------------------------------- */
    hLastGeom = nullptr;

    char **papszResult = poStatement->SimpleFetchRow();

    if( papszResult == nullptr )
    {
        iNextShapeId = MAX(1,iNextShapeId);
        delete poStatement;
        poStatement = nullptr;
        return nullptr;
    }

/* -------------------------------------------------------------------- */
/*      Create a feature from the current result.                       */
/* -------------------------------------------------------------------- */
    int         iField;
    OGRFeature *poFeature = new OGRFeature( poFeatureDefn );

    poFeature->SetFID( iNextShapeId );
    iNextShapeId++;
    m_nFeaturesRead++;

    if( iFIDColumn != -1 && papszResult[iFIDColumn] != nullptr )
        poFeature->SetFID( atoi(papszResult[iFIDColumn]) );

    for( iField = 0; iField < poFeatureDefn->GetFieldCount(); iField++ )
    {
        if( papszResult[iField] != nullptr )
            poFeature->SetField( iField, papszResult[iField] );
        else
            poFeature->SetFieldNull( iField );
    }

/* -------------------------------------------------------------------- */
/*      Translate geometry if we have it.                               */
/* -------------------------------------------------------------------- */
    if( iGeomColumn != -1 )
    {
        poFeature->SetGeometryDirectly( TranslateGeometry() );

        OGROCISession      *poSession = poDS->GetSession();

        if( poFeature->GetGeometryRef() != nullptr && hLastGeom != nullptr )
            poSession->Failed(
                OCIObjectFree(poSession->hEnv, poSession->hError,
                              (dvoid *) hLastGeom,
                              (ub2)OCI_OBJECTFREE_FORCE) );

        hLastGeom = nullptr;
        hLastGeomInd = nullptr;
    }

    nResultOffset++;

    return poFeature;
}

/************************************************************************/
/*                            ExecuteQuery()                            */
/*                                                                      */
/*      This is invoke when the first request for a feature is          */
/*      made.  It executes the query, and binds columns as needed.      */
/*      The OGROCIStatement is used for most of the work.               */
/************************************************************************/

int OGROCILayer::ExecuteQuery( const char *pszReqQuery )

{
    OGROCISession      *poSession = poDS->GetSession();

    CPLAssert( pszReqQuery != nullptr );
    CPLAssert( poStatement == nullptr );

/* -------------------------------------------------------------------- */
/*      Execute the query.                                              */
/* -------------------------------------------------------------------- */
    poStatement = new OGROCIStatement( poSession );
    if( poStatement->Execute( pszReqQuery ) != CE_None )
    {
        delete poStatement;
        poStatement = nullptr;
        return FALSE;
    }
    nResultOffset = 0;

/* -------------------------------------------------------------------- */
/*      Do additional work binding the geometry column.                 */
/* -------------------------------------------------------------------- */
    if( iGeomColumn != -1 )
    {
        OCIDefine *hGDefine = nullptr;

        if( poSession->Failed(
            OCIDefineByPos(poStatement->GetStatement(), &hGDefine,
                           poSession->hError,
                           (ub4) iGeomColumn+1, (dvoid *)nullptr, (sb4)0, SQLT_NTY,
                           (dvoid *)nullptr, (ub2 *)nullptr, (ub2 *)nullptr, (ub4)OCI_DEFAULT),
            "OCIDefineByPos(geometry)") )
            return FALSE;

        if( poSession->Failed(
            OCIDefineObject(hGDefine, poSession->hError,
                            poSession->hGeometryTDO,
                            (dvoid **) &hLastGeom, (ub4 *)nullptr,
                            (dvoid **) &hLastGeomInd, (ub4 *)nullptr ),
            "OCIDefineObject") )
            return FALSE;
    }

    return TRUE;
}

/************************************************************************/
/*                         TranslateGeometry()                          */
/************************************************************************/

OGRGeometry *OGROCILayer::TranslateGeometry()

{
    OGROCISession      *poSession = poDS->GetSession();

/* -------------------------------------------------------------------- */
/*      Is the geometry NULL?                                           */
/* -------------------------------------------------------------------- */
    if( hLastGeom == nullptr || hLastGeomInd == nullptr
        || hLastGeomInd->_atomic == OCI_IND_NULL )
        return nullptr;

/* -------------------------------------------------------------------- */
/*      Get the size of the sdo_elem_info and sdo_ordinates arrays.     */
/* -------------------------------------------------------------------- */
    int nElemCount, nOrdCount;

    if( poSession->Failed(
        OCICollSize( poSession->hEnv, poSession->hError,
                     (OCIColl *)(hLastGeom->sdo_elem_info), &nElemCount),
        "OCICollSize(sdo_elem_info)" ) )
        return nullptr;

    if( poSession->Failed(
        OCICollSize( poSession->hEnv, poSession->hError,
                     (OCIColl *)(hLastGeom->sdo_ordinates), &nOrdCount),
        "OCICollSize(sdo_ordinates)" ) )
        return nullptr;

/* -------------------------------------------------------------------- */
/*      Get the GType.                                                  */
/* -------------------------------------------------------------------- */
    int nGType;

    if( poSession->Failed(
        OCINumberToInt(poSession->hError, &(hLastGeom->sdo_gtype),
                       (uword)sizeof(int), OCI_NUMBER_SIGNED,
                       (dvoid *)&nGType),
        "OCINumberToInt(GType)" ) )
        return nullptr;

/* -------------------------------------------------------------------- */
/*      Establish the dimension.                                        */
/* -------------------------------------------------------------------- */
    int nDimension = MAX(2,(nGType / 1000));

/* -------------------------------------------------------------------- */
/*      Handle point data directly from built-in point info.            */
/* -------------------------------------------------------------------- */
    if( ORA_GTYPE_MATCH(nGType,ORA_GTYPE_POINT)
        && hLastGeomInd->sdo_point._atomic == OCI_IND_NOTNULL
        && hLastGeomInd->sdo_point.x == OCI_IND_NOTNULL
        && hLastGeomInd->sdo_point.y == OCI_IND_NOTNULL )
    {
        double     dfX, dfY, dfZ = 0.0;

        OCINumberToReal(poSession->hError, &(hLastGeom->sdo_point.x),
                        (uword)sizeof(double), (dvoid *)&dfX);
        OCINumberToReal(poSession->hError, &(hLastGeom->sdo_point.y),
                        (uword)sizeof(double), (dvoid *)&dfY);
        if( hLastGeomInd->sdo_point.z == OCI_IND_NOTNULL )
            OCINumberToReal(poSession->hError, &(hLastGeom->sdo_point.z),
                            (uword)sizeof(double), (dvoid *)&dfZ);

        if( nDimension == 3 )
            return new OGRPoint( dfX, dfY, dfZ );
        else
            return new OGRPoint( dfX, dfY );
    }

/* -------------------------------------------------------------------- */
/*      If this is a sort of container geometry, create the             */
/*      container now.                                                  */
/* -------------------------------------------------------------------- */
    OGRGeometryCollection *poCollection = nullptr;
    OGRPolygon *poPolygon = nullptr;

    if( ORA_GTYPE_MATCH(nGType,ORA_GTYPE_POLYGON) )
        poPolygon = new OGRPolygon();
    else if( ORA_GTYPE_MATCH(nGType,ORA_GTYPE_COLLECTION) )
        poCollection = new OGRGeometryCollection();
    else if( ORA_GTYPE_MATCH(nGType,ORA_GTYPE_MULTIPOINT) )
        poCollection = new OGRMultiPoint();
    else if( ORA_GTYPE_MATCH(nGType,ORA_GTYPE_MULTILINESTRING) )
        poCollection = new OGRMultiLineString();
    else if( ORA_GTYPE_MATCH(nGType,ORA_GTYPE_MULTIPOLYGON) )
        poCollection = new OGRMultiPolygon();

/* ==================================================================== */
/*      Loop over the component elements.                               */
/* ==================================================================== */
    for( int iElement = 0; iElement < nElemCount; iElement += 3 )
    {
        int       nInterpretation, nEType;
        int       nStartOrdinal, nElemOrdCount;

        LoadElementInfo( iElement, nElemCount, nOrdCount,
                         &nEType, &nInterpretation,
                         &nStartOrdinal, &nElemOrdCount );

/* -------------------------------------------------------------------- */
/*      Translate this element.                                         */
/* -------------------------------------------------------------------- */
        OGRGeometry *poGeom;

        poGeom = TranslateGeometryElement( &iElement, nGType, nDimension,
                                           nEType, nInterpretation,
                                           nStartOrdinal - 1, nElemOrdCount );

        if( poGeom == nullptr )
            return nullptr;

/* -------------------------------------------------------------------- */
/*      Based on GType do what is appropriate.                          */
/* -------------------------------------------------------------------- */
        if( ORA_GTYPE_MATCH(nGType,ORA_GTYPE_LINESTRING) )
        {
            CPLAssert(wkbFlatten(poGeom->getGeometryType()) == wkbLineString);
            return poGeom;
        }

        else if( ORA_GTYPE_MATCH(nGType,ORA_GTYPE_POINT) )
        {
            CPLAssert(wkbFlatten(poGeom->getGeometryType()) == wkbPoint);
            return poGeom;
        }

        else if( ORA_GTYPE_MATCH(nGType,ORA_GTYPE_POLYGON) )
        {
            CPLAssert(wkbFlatten(poGeom->getGeometryType()) == wkbLineString );
            poPolygon->addRingDirectly( poGeom->toLinearRing() );
        }
        else
        {
            CPLAssert( poCollection != nullptr );
            if( wkbFlatten(poGeom->getGeometryType()) == wkbMultiPoint )
            {
                OGRMultiPoint *poMP = poGeom->toMultiPoint();
                for( auto&& poPoint: *poMP )
                    poCollection->addGeometry(poPoint);
                delete poMP;
            }
            else if( nEType % 1000 == 3 )
            {
                /* its one poly ring, create new poly or add to existing */
                if( nEType == 1003 )
                {
                    if( poPolygon != nullptr
                        && poPolygon->getExteriorRing() != nullptr )
                    {
                        poCollection->addGeometryDirectly( poPolygon );
                        poPolygon = nullptr;
                    }

                    poPolygon = new OGRPolygon();
                }

                if( poPolygon != nullptr )
                    poPolygon->addRingDirectly( poGeom->toLinearRing() );
                else
                {
                    CPLAssert( poPolygon != nullptr );
                }
            }
            else
                poCollection->addGeometryDirectly( poGeom );
        }
    }

    if( poCollection != nullptr
        && poPolygon != nullptr )
        poCollection->addGeometryDirectly( poPolygon );

/* -------------------------------------------------------------------- */
/*      Return resulting collection geometry.                           */
/* -------------------------------------------------------------------- */
    if( poCollection == nullptr )
        return poPolygon;
    else
        return poCollection;
}

/************************************************************************/
/*                          LoadElementInfo()                           */
/*                                                                      */
/*      Fetch the start ordinal, count, EType and interpretation        */
/*      values for a particular element.                                */
/************************************************************************/

int
OGROCILayer::LoadElementInfo( int iElement, int nElemCount, int nTotalOrdCount,
                              int *pnEType, int *pnInterpretation,
                              int *pnStartOrdinal, int *pnElemOrdCount )

{
    OGROCISession      *poSession = poDS->GetSession();
    boolean bExists;
    OCINumber *hNumber;
/* -------------------------------------------------------------------- */
/*      Get the details about element from the elem_info array.         */
/* -------------------------------------------------------------------- */
    OCICollGetElem(poSession->hEnv, poSession->hError,
                   (OCIColl *)(hLastGeom->sdo_elem_info),
                   (sb4)(iElement+0), (boolean *)&bExists,
                   (dvoid **)&hNumber, nullptr );
    OCINumberToInt(poSession->hError, hNumber, (uword)sizeof(ub4),
                   OCI_NUMBER_UNSIGNED, (dvoid *) pnStartOrdinal );

    OCICollGetElem(poSession->hEnv, poSession->hError,
                   (OCIColl *)(hLastGeom->sdo_elem_info),
                   (sb4)(iElement+1), (boolean *)&bExists,
                   (dvoid **)&hNumber, nullptr );
    OCINumberToInt(poSession->hError, hNumber, (uword)sizeof(ub4),
                   OCI_NUMBER_UNSIGNED, (dvoid *) pnEType );

    OCICollGetElem(poSession->hEnv, poSession->hError,
                   (OCIColl *)(hLastGeom->sdo_elem_info),
                   (sb4)(iElement+2), (boolean *)&bExists,
                   (dvoid **)&hNumber, nullptr );
    OCINumberToInt(poSession->hError, hNumber, (uword)sizeof(ub4),
                   OCI_NUMBER_UNSIGNED, (dvoid *) pnInterpretation );

    if( iElement < nElemCount-3 )
    {
        ub4 nNextStartOrdinal;

        OCICollGetElem(poSession->hEnv, poSession->hError,
                       (OCIColl *)(hLastGeom->sdo_elem_info),
                       (sb4)(iElement+3), (boolean *)&bExists,
                       (dvoid **)&hNumber,nullptr);
        OCINumberToInt(poSession->hError, hNumber, (uword)sizeof(ub4),
                       OCI_NUMBER_UNSIGNED, (dvoid *) &nNextStartOrdinal );

        *pnElemOrdCount = nNextStartOrdinal - *pnStartOrdinal;
    }
    else
        *pnElemOrdCount = nTotalOrdCount - *pnStartOrdinal + 1;

    return TRUE;
}

/************************************************************************/
/*                      TranslateGeometryElement()                      */
/************************************************************************/

OGRGeometry *
OGROCILayer::TranslateGeometryElement( int *piElement,
                                       int nGType, int nDimension,
                                       int nEType, int nInterpretation,
                                       int nStartOrdinal, int nElemOrdCount )

{
/* -------------------------------------------------------------------- */
/*      Handle simple point.                                            */
/* -------------------------------------------------------------------- */
    if( nEType == 1 && nInterpretation == 1 )
    {
        OGRPoint *poPoint = new OGRPoint();
        double dfX, dfY, dfZ = 0.0;

        GetOrdinalPoint( nStartOrdinal, nDimension, &dfX, &dfY, &dfZ );

        poPoint->setX( dfX );
        poPoint->setY( dfY );
        if( nDimension == 3 )
            poPoint->setZ( dfZ );

        return poPoint;
    }

/* -------------------------------------------------------------------- */
/*      Handle multipoint.                                              */
/* -------------------------------------------------------------------- */
    else if( nEType == 1 && nInterpretation > 1 )
    {
        OGRMultiPoint *poMP = new OGRMultiPoint();
        double dfX, dfY, dfZ = 0.0;
        int i;

        CPLAssert( nInterpretation == nElemOrdCount / nDimension );

        for( i = 0; i < nInterpretation; i++ )
        {
            GetOrdinalPoint( nStartOrdinal + i*nDimension, nDimension,
                             &dfX, &dfY, &dfZ );

            OGRPoint *poPoint = (nDimension == 3) ? new OGRPoint( dfX, dfY, dfZ ):  new OGRPoint( dfX, dfY );
            poMP->addGeometryDirectly( poPoint );
        }
        return poMP;
    }

/* -------------------------------------------------------------------- */
/*      Discard orientations for oriented points.                       */
/* -------------------------------------------------------------------- */
    else if( nEType == 1 && nInterpretation == 0 )
    {
        CPLDebug( "OCI", "Ignoring orientations for oriented points." );
        return nullptr;
    }

/* -------------------------------------------------------------------- */
/*      Handle line strings consisting of straight segments.            */
/* -------------------------------------------------------------------- */
    else if( nEType == 2 && nInterpretation == 1 )
    {
        OGRLineString *poLS = new OGRLineString();
        int nPointCount = nElemOrdCount / nDimension, i;

        poLS->setNumPoints( nPointCount );

        for( i = 0; i < nPointCount; i++ )
        {
            double dfX, dfY, dfZ = 0.0;

            GetOrdinalPoint( i*nDimension + nStartOrdinal, nDimension,
                             &dfX, &dfY, &dfZ );
            if (nDimension == 3)
                poLS->setPoint( i, dfX, dfY, dfZ );
            else
                poLS->setPoint( i, dfX, dfY );
        }

        return poLS;
    }

/* -------------------------------------------------------------------- */
/*      Handle line strings consisting of circular arcs.                */
/* -------------------------------------------------------------------- */
    else if( nEType == 2 && nInterpretation == 2 )
    {
        OGRLineString *poLS = new OGRLineString();
        int nPointCount = nElemOrdCount / nDimension, i;

        for( i = 0; i < nPointCount-2; i += 2 )
        {
            double dfStartX, dfStartY, dfStartZ = 0.0;
            double dfMidX, dfMidY, dfMidZ = 0.0;
            double dfEndX, dfEndY, dfEndZ = 0.0;

            GetOrdinalPoint( i*nDimension + nStartOrdinal, nDimension,
                             &dfStartX, &dfStartY, &dfStartZ );
            GetOrdinalPoint( (i+1)*nDimension + nStartOrdinal, nDimension,
                             &dfMidX, &dfMidY, &dfMidZ );
            GetOrdinalPoint( (i+2)*nDimension + nStartOrdinal, nDimension,
                             &dfEndX, &dfEndY, &dfEndZ );

            OGROCIStrokeArcToOGRGeometry_Points( dfStartX, dfStartY,
                                                 dfMidX, dfMidY,
                                                 dfEndX, dfEndY,
                                                 6.0, FALSE, poLS );
        }

        return poLS;
    }

/* -------------------------------------------------------------------- */
/*      Handle polygon rings.  Treat curves as if they were             */
/*      linestrings.                                                    */
/* -------------------------------------------------------------------- */
    else if( nEType % 1000 == 3 && nInterpretation == 1 )
    {
        OGRLinearRing *poLS = new OGRLinearRing();
        int nPointCount = nElemOrdCount / nDimension, i;

        poLS->setNumPoints( nPointCount );

        for( i = 0; i < nPointCount; i++ )
        {
            double dfX, dfY, dfZ = 0.0;

            GetOrdinalPoint( i*nDimension + nStartOrdinal, nDimension,
                             &dfX, &dfY, &dfZ );
            if (nDimension == 3)
                poLS->setPoint( i, dfX, dfY, dfZ );
            else
                poLS->setPoint( i, dfX, dfY );
        }

        return poLS;
    }

/* -------------------------------------------------------------------- */
/*      Handle polygon rings made of circular arcs.                     */
/* -------------------------------------------------------------------- */
    else if( nEType % 1000 == 3 && nInterpretation == 2 )
    {
        OGRLineString *poLS = new OGRLinearRing();
        int nPointCount = nElemOrdCount / nDimension, i;

        for( i = 0; i < nPointCount-2; i += 2 )
        {
            double dfStartX, dfStartY, dfStartZ = 0.0;
            double dfMidX, dfMidY, dfMidZ = 0.0;
            double dfEndX, dfEndY, dfEndZ = 0.0;

            GetOrdinalPoint( i*nDimension + nStartOrdinal, nDimension,
                             &dfStartX, &dfStartY, &dfStartZ );
            GetOrdinalPoint( (i+1)*nDimension + nStartOrdinal, nDimension,
                             &dfMidX, &dfMidY, &dfMidZ );
            GetOrdinalPoint( (i+2)*nDimension + nStartOrdinal, nDimension,
                             &dfEndX, &dfEndY, &dfEndZ );

            OGROCIStrokeArcToOGRGeometry_Points( dfStartX, dfStartY,
                                                 dfMidX, dfMidY,
                                                 dfEndX, dfEndY,
                                                 6.0, FALSE, poLS );
        }

        return poLS;
    }

/* -------------------------------------------------------------------- */
/*      Handle rectangle definitions ... translate into a linear ring.  */
/* -------------------------------------------------------------------- */
    else if( nEType % 1000 == 3 && nInterpretation == 3 )
    {
        OGRLinearRing *poLS = new OGRLinearRing();
        double dfX1, dfY1, dfZ1 = 0.0;
        double dfX2, dfY2, dfZ2 = 0.0;

        GetOrdinalPoint( nStartOrdinal, nDimension,
                         &dfX1, &dfY1, &dfZ1 );
        GetOrdinalPoint( nStartOrdinal + nDimension, nDimension,
                         &dfX2, &dfY2, &dfZ2 );

        poLS->setNumPoints( 5 );

        poLS->setPoint( 0, dfX1, dfY1, dfZ1 );
        poLS->setPoint( 1, dfX2, dfY1, dfZ1 );
        poLS->setPoint( 2, dfX2, dfY2, dfZ2 );
        poLS->setPoint( 3, dfX1, dfY2, dfZ2 );
        poLS->setPoint( 4, dfX1, dfY1, dfZ1 );

        return poLS;
    }

/* -------------------------------------------------------------------- */
/*      Handle circle definitions ... translate into a linear ring.     */
/* -------------------------------------------------------------------- */
    else if( nEType % 100 == 3 && nInterpretation == 4 )
    {
        OGRLinearRing *poLS = new OGRLinearRing();
        double dfX1, dfY1, dfZ1 = 0.0;
        double dfX2, dfY2, dfZ2 = 0.0;
        double dfX3, dfY3, dfZ3 = 0.0;

        GetOrdinalPoint( nStartOrdinal, nDimension,
                         &dfX1, &dfY1, &dfZ1 );
        GetOrdinalPoint( nStartOrdinal + nDimension, nDimension,
                         &dfX2, &dfY2, &dfZ2 );
        GetOrdinalPoint( nStartOrdinal + nDimension*2, nDimension,
                         &dfX3, &dfY3, &dfZ3 );

        OGROCIStrokeArcToOGRGeometry_Points( dfX1, dfY1,
                                             dfX2, dfY2,
                                             dfX3, dfY3,
                                             6.0, TRUE, poLS );

        return poLS;
    }

/* -------------------------------------------------------------------- */
/*      Handle compound line strings and polygon rings.                 */
/*                                                                      */
/*      This is quite complicated since we need to consume several      */
/*      following elements, and merge the resulting geometries.         */
/* -------------------------------------------------------------------- */
    else if( nEType == 4  || nEType % 100 == 5 )
    {
        int nSubElementCount = nInterpretation;
        OGRLineString *poLS;
        int nElemCount, nTotalOrdCount;
        OGROCISession      *poSession = poDS->GetSession();

        if( poSession->Failed(
            OCICollSize( poSession->hEnv, poSession->hError,
                         (OCIColl *)(hLastGeom->sdo_elem_info), &nElemCount),
            "OCICollSize(sdo_elem_info)" ) )
            return nullptr;

        if( poSession->Failed(
            OCICollSize( poSession->hEnv, poSession->hError,
                         (OCIColl*)(hLastGeom->sdo_ordinates),&nTotalOrdCount),
            "OCICollSize(sdo_ordinates)" ) )
            return nullptr;

        if( nEType == 4 )
            poLS = new OGRLineString();
        else
            poLS = new OGRLinearRing();

        for( *piElement += 3; nSubElementCount-- > 0;  *piElement += 3 )
        {
            LoadElementInfo( *piElement, nElemCount, nTotalOrdCount,
                             &nEType, &nInterpretation,
                             &nStartOrdinal, &nElemOrdCount );

            // Adjust for repeated end point except for last element.
            if( nSubElementCount > 0 )
                nElemOrdCount += nDimension;

            // translate element.
            OGRGeometry* poGeom =
                TranslateGeometryElement( piElement, nGType, nDimension,
                                          nEType, nInterpretation,
                                          nStartOrdinal - 1, nElemOrdCount );
            OGRLineString* poElemLS = dynamic_cast<OGRLineString *>(poGeom);

            // Try to append to our aggregate linestring/ring
            if( poElemLS )
            {
                if( poLS->getNumPoints() > 0 )
                {
                    CPLAssert(
                        poElemLS->getX(0) == poLS->getX(poLS->getNumPoints()-1)
                        && poElemLS->getY(0) ==poLS->getY(poLS->getNumPoints()-1));

                    poLS->addSubLineString( poElemLS, 1 );
                }
                else
                    poLS->addSubLineString( poElemLS, 0 );
            }
            delete poGeom;
        }

        *piElement -= 3;
        return poLS;
    }

/* -------------------------------------------------------------------- */
/*      Otherwise it is apparently unsupported.                         */
/* -------------------------------------------------------------------- */
    else
    {

        CPLDebug( "OCI", "Geometry with EType=%d, Interp=%d ignored.",
                  nEType, nInterpretation );
    }

    return nullptr;
}

/************************************************************************/
/*                          GetOrdinalPoint()                           */
/************************************************************************/

int OGROCILayer::GetOrdinalPoint( int iOrdinal, int nDimension,
                                  double *pdfX, double *pdfY, double *pdfZ )

{
    OGROCISession      *poSession = poDS->GetSession();
    boolean bExists;
    OCINumber *hNumber;

    OCICollGetElem( poSession->hEnv, poSession->hError,
                    (OCIColl *)(hLastGeom->sdo_ordinates),
                    (sb4)iOrdinal+0, (boolean *)&bExists,
                    (dvoid **)&hNumber, nullptr );
    OCINumberToReal(poSession->hError, hNumber,
                    (uword)sizeof(double), (dvoid *)pdfX);
    OCICollGetElem( poSession->hEnv, poSession->hError,
                    (OCIColl *)(hLastGeom->sdo_ordinates),
                    (sb4)iOrdinal + 1, (boolean *)&bExists,
                    (dvoid **)&hNumber, nullptr );
    OCINumberToReal(poSession->hError, hNumber,
                    (uword)sizeof(double), (dvoid *)pdfY);
    if( nDimension == 3 )
    {
        OCICollGetElem( poSession->hEnv, poSession->hError,
                        (OCIColl *)(hLastGeom->sdo_ordinates),
                        (sb4)iOrdinal + 2, (boolean *)&bExists,
                        (dvoid **)&hNumber, nullptr );
        OCINumberToReal(poSession->hError, hNumber,
                        (uword)sizeof(double), (dvoid *)pdfZ);
    }

    return TRUE;
}

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

int OGROCILayer::TestCapability( const char * pszCap )

{
    if( EQUAL(pszCap,OLCRandomRead) )
        return TRUE;

    else if( EQUAL(pszCap,OLCFastFeatureCount) )
        return m_poFilterGeom == nullptr;

    else if( EQUAL(pszCap,OLCFastSpatialFilter) )
        return TRUE;

    else if( EQUAL(pszCap,OLCTransactions) )
        return TRUE;

    else
        return FALSE;
}

/************************************************************************/
/*                          LookupTableSRID()                           */
/*                                                                      */
/*      Note that the table name may also be prefixed by the owner      */
/*      with a dot separator.                                           */
/************************************************************************/

int OGROCILayer::LookupTableSRID()

{
/* -------------------------------------------------------------------- */
/*      If we don't have a geometry column, there isn't much point      */
/*      in trying.                                                      */
/* -------------------------------------------------------------------- */
    if( pszGeomName == nullptr )
        return -1;

/* -------------------------------------------------------------------- */
/*      Split out the owner if available.                               */
/* -------------------------------------------------------------------- */
    const char *pszTableName = GetLayerDefn()->GetName();
    char *pszOwner = nullptr;

    if( strstr(pszTableName,".") != nullptr )
    {
        pszOwner = CPLStrdup(pszTableName);
        pszTableName = strstr(pszTableName,".") + 1;

        *(strstr(pszOwner,".")) = '\0';
    }

/* -------------------------------------------------------------------- */
/*      Build our query command.                                        */
/* -------------------------------------------------------------------- */
    OGROCIStringBuf oCommand;

    oCommand.Append( "SELECT SRID FROM ALL_SDO_GEOM_METADATA "
                      "WHERE TABLE_NAME = UPPER(:table_name) AND COLUMN_NAME = UPPER(:geometry_name)" );

    if( pszOwner != nullptr )
    {
        oCommand.Append( " AND OWNER = :owner");
    }

/* -------------------------------------------------------------------- */
/*      Execute query command.                                          */
/* -------------------------------------------------------------------- */
    OGROCIStatement oGetTables( poDS->GetSession() );
    int nSRID = -1;
    
    if( oGetTables.Prepare( oCommand.GetString() ) != CE_None )
        return nSRID;
    
    oGetTables.BindString(":table_name", pszTableName);
    oGetTables.BindString(":geometry_name", pszGeomName);
    if( pszOwner != nullptr )
    {
        oGetTables.BindString(":owner", pszOwner);
        CPLFree( pszOwner );
    }

    if( oGetTables.Execute( nullptr ) == CE_None )
    {
        char **papszRow = oGetTables.SimpleFetchRow();

        if( papszRow != nullptr && papszRow[0] != nullptr )
            nSRID = atoi( papszRow[0] );
    }

    return nSRID;
}

/************************************************************************/
/*                            GetFIDColumn()                            */
/************************************************************************/

const char *OGROCILayer::GetFIDColumn()

{
    if( pszFIDName != nullptr )
        return pszFIDName;
    else
        return "";
}

/************************************************************************/
/*                         GetGeometryColumn()                          */
/************************************************************************/

const char *OGROCILayer::GetGeometryColumn()

{
    if( pszGeomName != nullptr )
        return pszGeomName;
    else
        return "";
}