/******************************************************************************
 *
 * Project:  SAP HANA Spatial Driver
 * Purpose:  OGRHanaTableLayer class implementation
 * Author:   Maxim Rylov
 *
 ******************************************************************************
 * Copyright (c) 2020, SAP SE
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "ogr_hana.h"
#include "ogrhanafeaturereader.h"
#include "ogrhanautils.h"

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <limits>
#include <sstream>

#include "odbc/Exception.h"
#include "odbc/PreparedStatement.h"
#include "odbc/ResultSet.h"
#include "odbc/Statement.h"
#include "odbc/Types.h"

namespace OGRHANA
{
namespace
{

constexpr const char *UNSUPPORTED_OP_READ_ONLY =
    "%s : unsupported operation on a read-only datasource.";

const char *GetColumnDefaultValue(const OGRFieldDefn &field)
{
    const char *defaultValue = field.GetDefault();
    if (field.GetType() == OFTInteger && field.GetSubType() == OFSTBoolean)
        return (EQUAL(defaultValue, "1") || EQUAL(defaultValue, "'t'"))
                   ? "TRUE"
                   : "FALSE";
    return defaultValue;
}

CPLString FindGeomFieldName(const OGRFeatureDefn &featureDefn)
{
    if (featureDefn.GetGeomFieldCount() == 0)
        return "OGR_GEOMETRY";

    int numGeomFields = featureDefn.GetGeomFieldCount();
    for (int i = 1; i <= 2 * numGeomFields; ++i)
    {
        CPLString name = CPLSPrintf("OGR_GEOMETRY_%d", i);
        if (featureDefn.GetGeomFieldIndex(name) < 0)
            return name;
    }

    return "OGR_GEOMETRY";
}

CPLString GetParameterValue(short type, const CPLString &typeName, bool isArray)
{
    if (isArray)
    {
        CPLString arrayType = "STRING";
        switch (type)
        {
            case QGRHanaDataTypes::TinyInt:
                arrayType = "TINYINT";
                break;
            case QGRHanaDataTypes::SmallInt:
                arrayType = "SMALLINT";
                break;
            case QGRHanaDataTypes::Integer:
                arrayType = "INT";
                break;
            case QGRHanaDataTypes::BigInt:
                arrayType = "BIGINT";
                break;
            case QGRHanaDataTypes::Float:
            case QGRHanaDataTypes::Real:
                arrayType = "REAL";
                break;
            case QGRHanaDataTypes::Double:
                arrayType = "DOUBLE";
                break;
            case QGRHanaDataTypes::WVarChar:
                arrayType = "STRING";
                break;
        }
        return "ARRAY(SELECT * FROM OGR_PARSE_" + arrayType + "_ARRAY(?, '" +
               ARRAY_VALUES_DELIMITER + "'))";
    }
    else if (typeName.compare("NCLOB") == 0)
        return "TO_NCLOB(?)";
    else if (typeName.compare("CLOB") == 0)
        return "TO_CLOB(?)";
    else if (typeName.compare("BLOB") == 0)
        return "TO_BLOB(?)";
    else
        return "?";
}

std::vector<int> ParseIntValues(const std::string &str)
{
    std::vector<int> values;
    try
    {
        std::stringstream stream(str);
        while (stream.good())
        {
            std::string value;
            std::getline(stream, value, ',');
            values.push_back(std::stoi(value.c_str()));
        }
    }
    catch (...)
    {
        values.clear();
    }
    return values;
}

ColumnTypeInfo ParseColumnTypeInfo(const CPLString &typeDef)
{
    auto incorrectFormatErr = [&]()
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Column type '%s' has incorrect format.", typeDef.c_str());
    };

    CPLString typeName;
    std::vector<int> typeSize;

    const size_t posStart = typeDef.find("(");
    if (posStart == std::string::npos)
    {
        typeName = typeDef;
    }
    else
    {
        const size_t posEnd = typeDef.rfind(")");
        if (posEnd != std::string::npos && posEnd > posStart)
        {
            const size_t posLast = typeDef.find_last_not_of(" \n\r\t");
            if (posLast == posEnd)
            {
                typeName = typeDef.substr(0, posStart);
                const std::string values =
                    typeDef.substr(posStart + 1, posEnd - posStart - 1);
                typeSize = ParseIntValues(values);
            }
        }

        if (typeSize.empty() || typeSize.size() > 2)
        {
            incorrectFormatErr();
            return {"", QGRHanaDataTypes::Unknown, 0, 0};
        }
    }

    typeName.Trim();

    if (EQUAL(typeName.c_str(), "BOOLEAN"))
        return {typeName, QGRHanaDataTypes::Boolean, 0, 0};
    else if (EQUAL(typeName.c_str(), "TINYINT"))
        return {typeName, QGRHanaDataTypes::TinyInt, 0, 0};
    else if (EQUAL(typeName.c_str(), "SMALLINT"))
        return {typeName, QGRHanaDataTypes::SmallInt, 0, 0};
    else if (EQUAL(typeName.c_str(), "INTEGER"))
        return {typeName, QGRHanaDataTypes::Integer, 0, 0};
    else if (EQUAL(typeName.c_str(), "DECIMAL"))
    {
        switch (typeSize.size())
        {
            case 0:
                return {typeName, QGRHanaDataTypes::Decimal, 0, 0};
            case 1:
                return {typeName, QGRHanaDataTypes::Decimal, typeSize[0], 0};
            case 2:
                return {typeName, QGRHanaDataTypes::Decimal, typeSize[0],
                        typeSize[1]};
        }
    }
    else if (EQUAL(typeName.c_str(), "FLOAT"))
    {
        switch (typeSize.size())
        {
            case 0:
                return {typeName, QGRHanaDataTypes::Float, 10, 0};
            case 1:
                return {typeName, QGRHanaDataTypes::Float, typeSize[0], 0};
            default:
                incorrectFormatErr();
                return {"", QGRHanaDataTypes::Unknown, 0, 0};
        }
    }
    else if (EQUAL(typeName.c_str(), "REAL"))
        return {typeName, QGRHanaDataTypes::Real, 0, 0};
    else if (EQUAL(typeName.c_str(), "DOUBLE"))
        return {typeName, QGRHanaDataTypes::Double, 0, 0};
    else if (EQUAL(typeName.c_str(), "VARCHAR"))
    {
        switch (typeSize.size())
        {
            case 0:
                return {typeName, QGRHanaDataTypes::VarChar, 1, 0};
            case 1:
                return {typeName, QGRHanaDataTypes::VarChar, typeSize[0], 0};
            default:
                incorrectFormatErr();
                return {"", QGRHanaDataTypes::Unknown, 0, 0};
        }
    }
    else if (EQUAL(typeName.c_str(), "NVARCHAR"))
    {
        switch (typeSize.size())
        {
            case 0:
                return {typeName, QGRHanaDataTypes::WVarChar, 1, 0};
            case 1:
                return {typeName, QGRHanaDataTypes::WVarChar, typeSize[0], 0};
            case 2:
                incorrectFormatErr();
                return {"", QGRHanaDataTypes::Unknown, 0, 0};
        }
    }
    else if (EQUAL(typeName.c_str(), "NCLOB"))
        return {typeName, QGRHanaDataTypes::WLongVarChar, 0, 0};
    else if (EQUAL(typeName.c_str(), "DATE"))
        return {typeName, QGRHanaDataTypes::Date, 0, 0};
    else if (EQUAL(typeName.c_str(), "TIME"))
        return {typeName, QGRHanaDataTypes::Time, 0, 0};
    else if (EQUAL(typeName.c_str(), "TIMESTAMP"))
        return {typeName, QGRHanaDataTypes::Timestamp, 0, 0};
    else if (EQUAL(typeName.c_str(), "VARBINARY"))
    {
        switch (typeSize.size())
        {
            case 0:
                return {typeName, QGRHanaDataTypes::VarBinary, 1, 0};
            case 1:
                return {typeName, QGRHanaDataTypes::VarBinary, typeSize[0], 0};
            case 2:
                incorrectFormatErr();
                return {"", QGRHanaDataTypes::Unknown, 0, 0};
        }
    }
    else if (EQUAL(typeName.c_str(), "BLOB"))
        return {typeName, QGRHanaDataTypes::LongVarBinary, 0, 0};
    else if (EQUAL(typeName.c_str(), "REAL_VECTOR"))
    {
        switch (typeSize.size())
        {
            case 0:
                return {typeName, QGRHanaDataTypes::RealVector, 1, 0};
            case 1:
                return {typeName, QGRHanaDataTypes::RealVector, typeSize[0], 0};
            case 2:
                incorrectFormatErr();
                return {"", QGRHanaDataTypes::Unknown, 0, 0};
        }
    }

    CPLError(CE_Failure, CPLE_NotSupported, "Unknown column type '%s'.",
             typeName.c_str());
    return {std::move(typeName), QGRHanaDataTypes::Unknown, 0, 0};
}

CPLString GetColumnDefinition(const ColumnTypeInfo &typeInfo)
{
    bool isArray = std::strstr(typeInfo.name, "ARRAY") != nullptr;

    if (isArray)
    {
        switch (typeInfo.type)
        {
            case QGRHanaDataTypes::SmallInt:
                return "SMALLINT ARRAY";
            case QGRHanaDataTypes::Integer:
                return "INTEGER ARRAY";
            case QGRHanaDataTypes::BigInt:
                return "BIGINT ARRAY";
            case QGRHanaDataTypes::Real:
                return "REAL ARRAY";
            case QGRHanaDataTypes::Double:
                return "DOUBLE ARRAY";
            case QGRHanaDataTypes::WVarChar:
                return "NVARCHAR(512) ARRAY";
            default:
                return "UNKNOWN";
        }
    }

    switch (typeInfo.type)
    {
        case QGRHanaDataTypes::Boolean:
        case QGRHanaDataTypes::TinyInt:
        case QGRHanaDataTypes::SmallInt:
        case QGRHanaDataTypes::Integer:
        case QGRHanaDataTypes::BigInt:
        case QGRHanaDataTypes::Float:
        case QGRHanaDataTypes::Real:
        case QGRHanaDataTypes::Double:
        case QGRHanaDataTypes::Date:
        case QGRHanaDataTypes::TypeDate:
        case QGRHanaDataTypes::Time:
        case QGRHanaDataTypes::TypeTime:
        case QGRHanaDataTypes::Timestamp:
        case QGRHanaDataTypes::TypeTimestamp:
        case QGRHanaDataTypes::Char:
        case QGRHanaDataTypes::WChar:
        case QGRHanaDataTypes::LongVarChar:
        case QGRHanaDataTypes::LongVarBinary:
            return typeInfo.name;
        case QGRHanaDataTypes::Decimal:
        case QGRHanaDataTypes::Numeric:
            return CPLString().Printf("DECIMAL(%d,%d)", typeInfo.width,
                                      typeInfo.precision);
        case QGRHanaDataTypes::VarChar:
        case QGRHanaDataTypes::WVarChar:
        case QGRHanaDataTypes::Binary:
        case QGRHanaDataTypes::VarBinary:
        case QGRHanaDataTypes::WLongVarChar:
        case QGRHanaDataTypes::RealVector:
            return (typeInfo.width == 0)
                       ? typeInfo.name
                       : CPLString().Printf("%s(%d)", typeInfo.name.c_str(),
                                            typeInfo.width);
        default:
            return "UNKNOWN";
    }
}

void SetFieldDefn(OGRFieldDefn &field, const ColumnTypeInfo &typeInfo)
{
    auto isArray = [&typeInfo]()
    { return std::strstr(typeInfo.name, "ARRAY") != nullptr; };

    switch (typeInfo.type)
    {
        case QGRHanaDataTypes::Bit:
        case QGRHanaDataTypes::Boolean:
            field.SetType(OFTInteger);
            field.SetSubType(OFSTBoolean);
            break;
        case QGRHanaDataTypes::TinyInt:
        case QGRHanaDataTypes::SmallInt:
            field.SetType(isArray() ? OFTIntegerList : OFTInteger);
            field.SetSubType(OFSTInt16);
            break;
        case QGRHanaDataTypes::Integer:
            field.SetType(isArray() ? OFTIntegerList : OFTInteger);
            break;
        case QGRHanaDataTypes::BigInt:
            field.SetType(isArray() ? OFTInteger64List : OFTInteger64);
            break;
        case QGRHanaDataTypes::Double:
        case QGRHanaDataTypes::Real:
        case QGRHanaDataTypes::Float:
            field.SetType(isArray() ? OFTRealList : OFTReal);
            if (typeInfo.type != QGRHanaDataTypes::Double)
                field.SetSubType(OFSTFloat32);
            break;
        case QGRHanaDataTypes::Decimal:
        case QGRHanaDataTypes::Numeric:
            field.SetType(isArray() ? OFTRealList : OFTReal);
            break;
        case QGRHanaDataTypes::Char:
        case QGRHanaDataTypes::VarChar:
        case QGRHanaDataTypes::LongVarChar:
            field.SetType(isArray() ? OFTStringList : OFTString);
            break;
        case QGRHanaDataTypes::WChar:
        case QGRHanaDataTypes::WVarChar:
        case QGRHanaDataTypes::WLongVarChar:
            field.SetType(isArray() ? OFTStringList : OFTString);
            break;
        case QGRHanaDataTypes::Date:
        case QGRHanaDataTypes::TypeDate:
            field.SetType(OFTDate);
            break;
        case QGRHanaDataTypes::Time:
        case QGRHanaDataTypes::TypeTime:
            field.SetType(OFTTime);
            break;
        case QGRHanaDataTypes::Timestamp:
        case QGRHanaDataTypes::TypeTimestamp:
            field.SetType(OFTDateTime);
            break;
        case QGRHanaDataTypes::Binary:
        case QGRHanaDataTypes::VarBinary:
        case QGRHanaDataTypes::LongVarBinary:
        case QGRHanaDataTypes::RealVector:
            field.SetType(OFTBinary);
            break;
        default:
            break;
    }

    field.SetWidth(typeInfo.width);
    field.SetPrecision(typeInfo.precision);
}

}  // anonymous namespace

/************************************************************************/
/*                         OGRHanaTableLayer()                          */
/************************************************************************/

OGRHanaTableLayer::OGRHanaTableLayer(OGRHanaDataSource *datasource,
                                     const char *schemaName,
                                     const char *tableName, int update)
    : OGRHanaLayer(datasource), schemaName_(schemaName), tableName_(tableName),
      updateMode_(update)
{
    rawQuery_ =
        "SELECT * FROM " + GetFullTableNameQuoted(schemaName_, tableName_);
    SetDescription(tableName_.c_str());
}

/************************************************************************/
/*                        ~OGRHanaTableLayer()                          */
/************************************************************************/

OGRHanaTableLayer::~OGRHanaTableLayer()
{
    FlushPendingBatches(true);
}

/* -------------------------------------------------------------------- */
/*                             Initialize()                             */
/* -------------------------------------------------------------------- */

OGRErr OGRHanaTableLayer::Initialize()
{
    if (initialized_)
        return OGRERR_NONE;

    OGRErr err =
        InitFeatureDefinition(schemaName_, tableName_, rawQuery_, tableName_);
    if (err != OGRERR_NONE)
        return err;

    if (fidFieldIndex_ != OGRNullFID)
    {
        CPLDebug("HANA", "table %s has FID column %s.", tableName_.c_str(),
                 fidFieldName_.c_str());

        CPLString sql = CPLString().Printf(
            "SELECT COUNT(*) FROM %s",
            GetFullTableNameQuoted(schemaName_, tableName_).c_str());
        odbc::StatementRef stmt = dataSource_->CreateStatement();
        odbc::ResultSetRef rs = stmt->executeQuery(sql.c_str());
        allowAutoFIDOnCreateFeature_ =
            rs->next() ? (*rs->getLong(1) == 0) : false;
        rs->close();
    }
    else
    {
        CPLDebug("HANA",
                 "table %s has no FID column, FIDs will not be reliable!",
                 tableName_.c_str());

        allowAutoFIDOnCreateFeature_ = true;
    }

    return OGRERR_NONE;
}

/* -------------------------------------------------------------------- */
/*                                 ExecuteUpdate()                      */
/* -------------------------------------------------------------------- */

std::pair<OGRErr, std::size_t>
OGRHanaTableLayer::ExecuteUpdate(odbc::PreparedStatement &statement,
                                 bool withBatch, const char *functionName)
{
    std::size_t ret = 0;

    try
    {
        if (withBatch)
        {
            if (statement.getBatchDataSize() >= batchSize_)
                statement.executeBatch();
            ret = 1;
        }
        else
        {
            ret = statement.executeUpdate();
        }

        if (!dataSource_->IsTransactionStarted())
            dataSource_->Commit();
    }
    catch (odbc::Exception &ex)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Failed to execute %s: %s",
                 functionName, ex.what());
        return {OGRERR_FAILURE, 0};
    }

    return {OGRERR_NONE, ret};
}

/* -------------------------------------------------------------------- */
/*                   CreateDeleteFeatureStatement()                     */
/* -------------------------------------------------------------------- */

odbc::PreparedStatementRef OGRHanaTableLayer::CreateDeleteFeatureStatement()
{
    CPLString sql = CPLString().Printf(
        "DELETE FROM %s WHERE %s = ?",
        GetFullTableNameQuoted(schemaName_, tableName_).c_str(),
        QuotedIdentifier(GetFIDColumn()).c_str());
    return dataSource_->PrepareStatement(sql.c_str());
}

/* -------------------------------------------------------------------- */
/*                   CreateInsertFeatureStatement()                     */
/* -------------------------------------------------------------------- */

odbc::PreparedStatementRef
OGRHanaTableLayer::CreateInsertFeatureStatement(bool withFID)
{
    std::vector<CPLString> columns;
    std::vector<CPLString> values;
    bool hasArray = false;
    for (const AttributeColumnDescription &clmDesc : attrColumns_)
    {
        if (clmDesc.isFeatureID && !withFID)
        {
            if (clmDesc.isAutoIncrement)
                continue;
        }

        columns.push_back(QuotedIdentifier(clmDesc.name));
        values.push_back(
            GetParameterValue(clmDesc.type, clmDesc.typeName, clmDesc.isArray));
        if (clmDesc.isArray)
            hasArray = true;
    }

    for (const GeometryColumnDescription &geomClmDesc : geomColumns_)
    {
        columns.push_back(QuotedIdentifier(geomClmDesc.name));
        values.push_back("ST_GeomFromWKB(? , " +
                         std::to_string(geomClmDesc.srid) + ")");
    }

    if (hasArray && !parseFunctionsChecked_)
    {
        // Create helper functions if needed.
        if (!dataSource_->ParseArrayFunctionsExist(schemaName_.c_str()))
            dataSource_->CreateParseArrayFunctions(schemaName_.c_str());
        parseFunctionsChecked_ = true;
    }

    const CPLString sql = CPLString().Printf(
        "INSERT INTO %s (%s) VALUES(%s)",
        GetFullTableNameQuoted(schemaName_, tableName_).c_str(),
        JoinStrings(columns, ", ").c_str(), JoinStrings(values, ", ").c_str());

    return dataSource_->PrepareStatement(sql.c_str());
}

/* -------------------------------------------------------------------- */
/*                     CreateUpdateFeatureStatement()                   */
/* -------------------------------------------------------------------- */

odbc::PreparedStatementRef OGRHanaTableLayer::CreateUpdateFeatureStatement()
{
    std::vector<CPLString> values;
    values.reserve(attrColumns_.size());
    bool hasArray = false;

    for (const AttributeColumnDescription &clmDesc : attrColumns_)
    {
        if (clmDesc.isFeatureID)
        {
            if (clmDesc.isAutoIncrement)
                continue;
        }
        values.push_back(
            QuotedIdentifier(clmDesc.name) + " = " +
            GetParameterValue(clmDesc.type, clmDesc.typeName, clmDesc.isArray));
        if (clmDesc.isArray)
            hasArray = true;
    }

    for (const GeometryColumnDescription &geomClmDesc : geomColumns_)
    {
        values.push_back(QuotedIdentifier(geomClmDesc.name) + " = " +
                         "ST_GeomFromWKB(?, " +
                         std::to_string(geomClmDesc.srid) + ")");
    }

    if (hasArray && !parseFunctionsChecked_)
    {
        // Create helper functions if needed.
        if (!dataSource_->ParseArrayFunctionsExist(schemaName_.c_str()))
            dataSource_->CreateParseArrayFunctions(schemaName_.c_str());
        parseFunctionsChecked_ = true;
    }

    const CPLString sql = CPLString().Printf(
        "UPDATE %s SET %s WHERE %s = ?",
        GetFullTableNameQuoted(schemaName_, tableName_).c_str(),
        JoinStrings(values, ", ").c_str(),
        QuotedIdentifier(GetFIDColumn()).c_str());

    return dataSource_->PrepareStatement(sql.c_str());
}

/* -------------------------------------------------------------------- */
/*                     ResetPreparedStatements()                        */
/* -------------------------------------------------------------------- */

void OGRHanaTableLayer::ResetPreparedStatements()
{
    if (!currentIdentityValueStmt_.isNull())
        currentIdentityValueStmt_ = nullptr;
    if (!insertFeatureStmtWithFID_.isNull())
        insertFeatureStmtWithFID_ = nullptr;
    if (!insertFeatureStmtWithoutFID_.isNull())
        insertFeatureStmtWithoutFID_ = nullptr;
    if (!deleteFeatureStmt_.isNull())
        deleteFeatureStmt_ = nullptr;
    if (!updateFeatureStmt_.isNull())
        updateFeatureStmt_ = nullptr;
}

/************************************************************************/
/*                        SetStatementParameters()                      */
/************************************************************************/

OGRErr OGRHanaTableLayer::SetStatementParameters(
    odbc::PreparedStatement &statement, OGRFeature *feature, bool newFeature,
    bool withFID, const char *functionName)
{
    OGRHanaFeatureReader featReader(*feature);

    unsigned short paramIndex = 0;
    int fieldIndex = -1;
    for (const AttributeColumnDescription &clmDesc : attrColumns_)
    {
        if (clmDesc.isFeatureID)
        {
            if (!withFID && clmDesc.isAutoIncrement)
                continue;

            ++paramIndex;

            switch (clmDesc.type)
            {
                case QGRHanaDataTypes::Integer:
                    if (feature->GetFID() == OGRNullFID)
                        statement.setInt(paramIndex, odbc::Int());
                    else
                    {
                        if (std::numeric_limits<std::int32_t>::min() >
                                feature->GetFID() ||
                            std::numeric_limits<std::int32_t>::max() <
                                feature->GetFID())
                        {
                            CPLError(CE_Failure, CPLE_AppDefined,
                                     "%s: Feature id with value %s cannot "
                                     "be stored in a column of type INTEGER",
                                     functionName,
                                     std::to_string(feature->GetFID()).c_str());
                            return OGRERR_FAILURE;
                        }

                        statement.setInt(paramIndex,
                                         odbc::Int(static_cast<std::int32_t>(
                                             feature->GetFID())));
                    }
                    break;
                case QGRHanaDataTypes::BigInt:
                    if (feature->GetFID() == OGRNullFID)
                        statement.setLong(paramIndex, odbc::Long());
                    else
                        statement.setLong(paramIndex,
                                          odbc::Long(static_cast<std::int64_t>(
                                              feature->GetFID())));
                    break;
                default:
                    CPLError(CE_Failure, CPLE_AppDefined,
                             "%s: Unexpected type ('%s') in the field "
                             "'%s'",
                             functionName, std::to_string(clmDesc.type).c_str(),
                             clmDesc.name.c_str());
                    return OGRERR_FAILURE;
            }
            continue;
        }
        else
            ++paramIndex;

        ++fieldIndex;

        switch (clmDesc.type)
        {
            case QGRHanaDataTypes::Bit:
            case QGRHanaDataTypes::Boolean:
                statement.setBoolean(paramIndex,
                                     featReader.GetFieldAsBoolean(fieldIndex));
                break;
            case QGRHanaDataTypes::TinyInt:
                if (clmDesc.isArray)
                    statement.setString(
                        paramIndex, featReader.GetFieldAsIntArray(fieldIndex));
                else
                    statement.setByte(paramIndex,
                                      featReader.GetFieldAsByte(fieldIndex));
                break;
            case QGRHanaDataTypes::SmallInt:
                if (clmDesc.isArray)
                    statement.setString(
                        paramIndex, featReader.GetFieldAsIntArray(fieldIndex));
                else
                    statement.setShort(paramIndex,
                                       featReader.GetFieldAsShort(fieldIndex));
                break;
            case QGRHanaDataTypes::Integer:
                if (clmDesc.isArray)
                    statement.setString(
                        paramIndex, featReader.GetFieldAsIntArray(fieldIndex));
                else
                    statement.setInt(paramIndex,
                                     featReader.GetFieldAsInt(fieldIndex));
                break;
            case QGRHanaDataTypes::BigInt:
                if (clmDesc.isArray)
                    statement.setString(
                        paramIndex,
                        featReader.GetFieldAsBigIntArray(fieldIndex));
                else
                    statement.setLong(paramIndex,
                                      featReader.GetFieldAsLong(fieldIndex));
                break;
            case QGRHanaDataTypes::Float:
            case QGRHanaDataTypes::Real:
                if (clmDesc.isArray)
                    statement.setString(
                        paramIndex, featReader.GetFieldAsRealArray(fieldIndex));
                else
                    statement.setFloat(paramIndex,
                                       featReader.GetFieldAsFloat(fieldIndex));
                break;
            case QGRHanaDataTypes::Double:
                if (clmDesc.isArray)
                    statement.setString(
                        paramIndex,
                        featReader.GetFieldAsDoubleArray(fieldIndex));
                else
                    statement.setDouble(
                        paramIndex, featReader.GetFieldAsDouble(fieldIndex));
                break;
            case QGRHanaDataTypes::Decimal:
            case QGRHanaDataTypes::Numeric:
                if ((!feature->IsFieldSet(fieldIndex) ||
                     feature->IsFieldNull(fieldIndex)) &&
                    feature->GetFieldDefnRef(fieldIndex)->GetDefault() ==
                        nullptr)
                    statement.setDecimal(paramIndex, odbc::Decimal());
                else
                    statement.setDouble(
                        paramIndex, featReader.GetFieldAsDouble(fieldIndex));
                break;
            case QGRHanaDataTypes::Char:
            case QGRHanaDataTypes::VarChar:
            case QGRHanaDataTypes::LongVarChar:
                if (clmDesc.isArray)
                    statement.setString(
                        paramIndex,
                        featReader.GetFieldAsStringArray(fieldIndex));
                else
                    statement.setString(paramIndex,
                                        featReader.GetFieldAsString(
                                            fieldIndex, clmDesc.length));
                break;
            case QGRHanaDataTypes::WChar:
            case QGRHanaDataTypes::WVarChar:
            case QGRHanaDataTypes::WLongVarChar:
                if (clmDesc.isArray)
                    statement.setString(
                        paramIndex,
                        featReader.GetFieldAsStringArray(fieldIndex));
                else
                    statement.setString(paramIndex,
                                        featReader.GetFieldAsNString(
                                            fieldIndex, clmDesc.length));
                break;
            case QGRHanaDataTypes::Binary:
            case QGRHanaDataTypes::VarBinary:
            case QGRHanaDataTypes::LongVarBinary:
            case QGRHanaDataTypes::RealVector:
            {
                Binary bin = featReader.GetFieldAsBinary(fieldIndex);
                statement.setBytes(paramIndex, bin.data, bin.size);
            }
            break;
            case QGRHanaDataTypes::DateTime:
            case QGRHanaDataTypes::TypeDate:
                statement.setDate(paramIndex,
                                  featReader.GetFieldAsDate(fieldIndex));
                break;
            case QGRHanaDataTypes::Time:
            case QGRHanaDataTypes::TypeTime:
                statement.setTime(paramIndex,
                                  featReader.GetFieldAsTime(fieldIndex));
                break;
            case QGRHanaDataTypes::Timestamp:
            case QGRHanaDataTypes::TypeTimestamp:
                statement.setTimestamp(
                    paramIndex, featReader.GetFieldAsTimestamp(fieldIndex));
                break;
        }
    }

    for (std::size_t i = 0; i < geomColumns_.size(); ++i)
    {
        ++paramIndex;
        Binary wkb{nullptr, 0};
        OGRErr err = GetGeometryWkb(feature, static_cast<int>(i), wkb);
        if (OGRERR_NONE != err)
            return err;
        statement.setBytes(paramIndex, wkb.data, wkb.size);
    }

    if (!newFeature)
    {
        ++paramIndex;

        statement.setLong(paramIndex, odbc::Long(static_cast<std::int64_t>(
                                          feature->GetFID())));
    }

    return OGRERR_NONE;
}

/* -------------------------------------------------------------------- */
/*                            DropTable()                               */
/* -------------------------------------------------------------------- */

OGRErr OGRHanaTableLayer::DropTable()
{
    CPLString sql =
        "DROP TABLE " + GetFullTableNameQuoted(schemaName_, tableName_);
    try
    {
        dataSource_->ExecuteSQL(sql.c_str());
        CPLDebug("HANA", "Dropped table %s.", GetName());
    }
    catch (const odbc::Exception &ex)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Unable to delete layer '%s': %s",
                 tableName_.c_str(), ex.what());
        return OGRERR_FAILURE;
    }

    return OGRERR_NONE;
}

/* -------------------------------------------------------------------- */
/*                        ExecutePendingBatches()                       */
/* -------------------------------------------------------------------- */

OGRErr OGRHanaTableLayer::ExecutePendingBatches(BatchOperation op)
{
    auto hasFlag = [op](BatchOperation flag) { return (op & flag) == flag; };

    try
    {
        if (!deleteFeatureStmt_.isNull() &&
            deleteFeatureStmt_->getBatchDataSize() > 0 &&
            hasFlag(BatchOperation::DELETE))
            deleteFeatureStmt_->executeBatch();
        if (!insertFeatureStmtWithFID_.isNull() &&
            insertFeatureStmtWithFID_->getBatchDataSize() > 0 &&
            hasFlag(BatchOperation::INSERT))
            insertFeatureStmtWithFID_->executeBatch();
        if (!insertFeatureStmtWithoutFID_.isNull() &&
            insertFeatureStmtWithoutFID_->getBatchDataSize() > 0 &&
            hasFlag(BatchOperation::INSERT))
            insertFeatureStmtWithoutFID_->executeBatch();
        if (!updateFeatureStmt_.isNull() &&
            updateFeatureStmt_->getBatchDataSize() > 0 &&
            hasFlag(BatchOperation::UPDATE))
            updateFeatureStmt_->executeBatch();

        return OGRERR_NONE;
    }
    catch (const odbc::Exception &ex)
    {
        ClearBatches();

        CPLError(CE_Failure, CPLE_AppDefined,
                 "Failed to execute batch commands: %s", ex.what());
        return OGRERR_FAILURE;
    }
}

/* -------------------------------------------------------------------- */
/*                        FlushPendingBatches()                         */
/* -------------------------------------------------------------------- */

void OGRHanaTableLayer::FlushPendingBatches(bool commit)
{
    if (!HasPendingBatches())
        return;

    OGRErr err = ExecutePendingBatches(BatchOperation::ALL);
    if (OGRERR_NONE == err && commit && !dataSource_->IsTransactionStarted())
        dataSource_->Commit();
}

/* -------------------------------------------------------------------- */
/*                        HasPendingBatches()                           */
/* -------------------------------------------------------------------- */

bool OGRHanaTableLayer::HasPendingBatches() const
{
    return (!deleteFeatureStmt_.isNull() &&
            deleteFeatureStmt_->getBatchDataSize() > 0) ||
           (!insertFeatureStmtWithFID_.isNull() &&
            insertFeatureStmtWithFID_->getBatchDataSize() > 0) ||
           (!insertFeatureStmtWithoutFID_.isNull() &&
            insertFeatureStmtWithoutFID_->getBatchDataSize() > 0) ||
           (!updateFeatureStmt_.isNull() &&
            updateFeatureStmt_->getBatchDataSize() > 0);
}

/* -------------------------------------------------------------------- */
/*                            GetColumnTypeInfo()                       */
/* -------------------------------------------------------------------- */

ColumnTypeInfo
OGRHanaTableLayer::GetColumnTypeInfo(const OGRFieldDefn &field) const
{
    for (const auto &clmType : customColumnDefs_)
    {
        if (EQUAL(clmType.name.c_str(), field.GetNameRef()))
            return ParseColumnTypeInfo(clmType.typeDef);
    }

    switch (field.GetType())
    {
        case OFTInteger:
            if (preservePrecision_ && field.GetWidth() > 10)
            {
                return {"DECIMAL", QGRHanaDataTypes::Decimal, field.GetWidth(),
                        0};
            }
            else
            {
                if (field.GetSubType() == OFSTBoolean)
                    return {"BOOLEAN", QGRHanaDataTypes::Boolean,
                            field.GetWidth(), 0};
                else if (field.GetSubType() == OFSTInt16)
                    return {"SMALLINT", QGRHanaDataTypes::SmallInt,
                            field.GetWidth(), 0};
                else
                    return {"INTEGER", QGRHanaDataTypes::Integer,
                            field.GetWidth(), 0};
            }
            break;
        case OFTInteger64:
            if (preservePrecision_ && field.GetWidth() > 20)
            {
                return {"DECIMAL", QGRHanaDataTypes::Decimal, field.GetWidth(),
                        0};
            }
            else
                return {"BIGINT", QGRHanaDataTypes::BigInt, field.GetWidth(),
                        0};
            break;
        case OFTReal:
            if (preservePrecision_ && field.GetWidth() != 0)
            {
                return {"DECIMAL", QGRHanaDataTypes::Decimal, field.GetWidth(),
                        field.GetPrecision()};
            }
            else
            {
                if (field.GetSubType() == OFSTFloat32)
                    return {"REAL", QGRHanaDataTypes::Real, field.GetWidth(),
                            field.GetPrecision()};
                else
                    return {"DOUBLE", QGRHanaDataTypes::Double,
                            field.GetWidth(), field.GetPrecision()};
            }
        case OFTString:
            if (field.GetWidth() == 0 || !preservePrecision_)
            {
                int width = static_cast<int>(defaultStringSize_);
                return {"NVARCHAR", QGRHanaDataTypes::WLongVarChar, width, 0};
            }
            else
            {
                if (field.GetWidth() >= 1 && field.GetWidth() <= 5000)
                    return {"NVARCHAR", QGRHanaDataTypes::WLongVarChar,
                            field.GetWidth(), 0};
                else
                    return {"NCLOB", QGRHanaDataTypes::WLongVarChar, 0, 0};
            }
        case OFTBinary:
            if (field.GetWidth() >= 1 && field.GetWidth() <= 5000)
                return {"VARBINARY", QGRHanaDataTypes::VarBinary,
                        field.GetWidth(), 0};
            else
                return {"BLOB", QGRHanaDataTypes::LongVarBinary,
                        field.GetWidth(), 0};
        case OFTDate:
            return {"DATE", QGRHanaDataTypes::TypeDate, field.GetWidth(), 0};
        case OFTTime:
            return {"TIME", QGRHanaDataTypes::TypeTime, field.GetWidth(), 0};
        case OFTDateTime:
            return {"TIMESTAMP", QGRHanaDataTypes::TypeTimestamp,
                    field.GetWidth(), 0};
        case OFTIntegerList:
            if (field.GetSubType() == OGRFieldSubType::OFSTInt16)
                return {"ARRAY", QGRHanaDataTypes::SmallInt, field.GetWidth(),
                        0};
            else
                return {"ARRAY", QGRHanaDataTypes::Integer, field.GetWidth(),
                        0};
        case OFTInteger64List:
            return {"ARRAY", QGRHanaDataTypes::BigInt, field.GetWidth(), 0};
        case OFTRealList:
            if (field.GetSubType() == OGRFieldSubType::OFSTFloat32)
                return {"ARRAY", QGRHanaDataTypes::Real, field.GetWidth(), 0};
            else
                return {"ARRAY", QGRHanaDataTypes::Double, field.GetWidth(), 0};
            break;
        case OFTStringList:
            return {"ARRAY", QGRHanaDataTypes::WVarChar, 512, 0};
        default:
            break;
    }

    return {"", QGRHanaDataTypes::Unknown, 0, 0};
}

/* -------------------------------------------------------------------- */
/*                           GetGeometryWkb()                           */
/* -------------------------------------------------------------------- */
OGRErr OGRHanaTableLayer::GetGeometryWkb(OGRFeature *feature, int fieldIndex,
                                         Binary &binary)
{
    OGRGeometry *geom = feature->GetGeomFieldRef(fieldIndex);
    if (geom == nullptr || !IsGeometryTypeSupported(geom->getIsoGeometryType()))
        return OGRERR_NONE;

    // Rings must be closed, otherwise HANA throws an exception
    geom->closeRings();
    std::size_t size = static_cast<std::size_t>(geom->WkbSize());
    EnsureBufferCapacity(size);
    unsigned char *data = reinterpret_cast<unsigned char *>(dataBuffer_.data());
    OGRErr err = geom->exportToWkb(OGRwkbByteOrder::wkbNDR, data,
                                   OGRwkbVariant::wkbVariantIso);
    if (OGRERR_NONE == err)
    {
        binary.data = data;
        binary.size = size;
    }
    return err;
}

/************************************************************************/
/*                                IGetExtent()                          */
/************************************************************************/

OGRErr OGRHanaTableLayer::IGetExtent(int geomField, OGREnvelope *extent,
                                     bool force)
{
    if (geomField >= 0 && geomField < GetLayerDefn()->GetGeomFieldCount())
    {
        FlushPendingBatches(false);
    }

    return OGRHanaLayer::IGetExtent(geomField, extent, force);
}

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

GIntBig OGRHanaTableLayer::GetFeatureCount(int force)
{
    FlushPendingBatches(false);

    return OGRHanaLayer::GetFeatureCount(force);
}

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

void OGRHanaTableLayer::ResetReading()
{
    FlushPendingBatches(false);

    if (OGRNullFID != fidFieldIndex_ && nextFeatureId_ > 0)
        allowAutoFIDOnCreateFeature_ = false;

    OGRHanaLayer::ResetReading();
}

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

int OGRHanaTableLayer::TestCapability(const char *capabilities)
{
    if (EQUAL(capabilities, OLCRandomRead))
    {
        EnsureInitialized();
        return fidFieldIndex_ != OGRNullFID;
    }
    if (EQUAL(capabilities, OLCFastFeatureCount))
        return TRUE;
    if (EQUAL(capabilities, OLCFastSpatialFilter))
    {
        EnsureInitialized();
        return !geomColumns_.empty();
    }
    if (EQUAL(capabilities, OLCFastGetExtent))
    {
        EnsureInitialized();
        return IsFastExtentAvailable();
    }
    if (EQUAL(capabilities, OLCCreateField))
        return updateMode_;
    if (EQUAL(capabilities, OLCCreateGeomField) ||
        EQUAL(capabilities, ODsCCreateGeomFieldAfterCreateLayer))
        return updateMode_;
    if (EQUAL(capabilities, OLCDeleteField))
        return updateMode_;
    if (EQUAL(capabilities, OLCDeleteFeature))
    {
        EnsureInitialized();
        return updateMode_ && fidFieldIndex_ != OGRNullFID;
    }
    if (EQUAL(capabilities, OLCAlterFieldDefn))
        return updateMode_;
    if (EQUAL(capabilities, OLCRandomWrite))
        return updateMode_;
    if (EQUAL(capabilities, OLCMeasuredGeometries))
        return TRUE;
    if (EQUAL(capabilities, OLCSequentialWrite))
        return updateMode_;
    if (EQUAL(capabilities, OLCTransactions))
        return updateMode_;
    if (EQUAL(capabilities, OLCStringsAsUTF8))
        return TRUE;

    return FALSE;
}

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

OGRErr OGRHanaTableLayer::ICreateFeature(OGRFeature *feature)
{
    if (!updateMode_)
    {
        CPLError(CE_Failure, CPLE_NotSupported, UNSUPPORTED_OP_READ_ONLY,
                 "CreateFeature");
        return OGRERR_FAILURE;
    }

    if (nullptr == feature)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "NULL pointer to OGRFeature passed to CreateFeature().");
        return OGRERR_FAILURE;
    }

    EnsureInitialized();

    OGRErr err =
        ExecutePendingBatches(BatchOperation::DELETE | BatchOperation::UPDATE);
    if (OGRERR_NONE != err)
        return err;

    bool hasFID = feature->GetFID() != OGRNullFID;
    if (hasFID && OGRNullFID != fidFieldIndex_)
        allowAutoFIDOnCreateFeature_ = false;

    if (!hasFID && allowAutoFIDOnCreateFeature_)
    {
        feature->SetFID(nextFeatureId_++);
        hasFID = true;
    }

    bool useBatch = hasFID && dataSource_->IsTransactionStarted();

    try
    {
        odbc::PreparedStatementRef &stmt =
            hasFID ? insertFeatureStmtWithFID_ : insertFeatureStmtWithoutFID_;

        if (stmt.isNull())
        {
            stmt = CreateInsertFeatureStatement(hasFID);
            if (stmt.isNull())
                return OGRERR_FAILURE;
        }

        err = SetStatementParameters(*stmt, feature, true, hasFID,
                                     "CreateFeature");
        if (OGRERR_NONE != err)
            return err;

        if (useBatch)
            stmt->addBatch();

        auto ret = ExecuteUpdate(*stmt, useBatch, "CreateFeature");

        err = ret.first;
        if (OGRERR_NONE != err)
            return err;

        if (!hasFID && OGRNullFID != fidFieldIndex_)
        {
            const CPLString sql = CPLString().Printf(
                "SELECT CURRENT_IDENTITY_VALUE() \"current identity value\" "
                "FROM %s",
                GetFullTableNameQuoted(schemaName_, tableName_).c_str());

            if (currentIdentityValueStmt_.isNull())
            {
                currentIdentityValueStmt_ =
                    dataSource_->PrepareStatement(sql.c_str());
                if (currentIdentityValueStmt_.isNull())
                    return OGRERR_FAILURE;
            }

            odbc::ResultSetRef rsIdentity =
                currentIdentityValueStmt_->executeQuery();
            if (rsIdentity->next())
            {
                odbc::Long id = rsIdentity->getLong(1);
                if (!id.isNull())
                    feature->SetFID(static_cast<GIntBig>(*id));
            }
            rsIdentity->close();
        }

        return err;
    }
    catch (const std::exception &ex)
    {
        CPLError(CE_Failure, CPLE_NotSupported, "Unable to create feature: %s",
                 ex.what());
        return OGRERR_FAILURE;
    }
    return OGRERR_NONE;
}

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

OGRErr OGRHanaTableLayer::DeleteFeature(GIntBig nFID)
{
    if (!updateMode_)
    {
        CPLError(CE_Failure, CPLE_NotSupported, UNSUPPORTED_OP_READ_ONLY,
                 "DeleteFeature");
        return OGRERR_FAILURE;
    }

    if (nFID == OGRNullFID)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "DeleteFeature(" CPL_FRMT_GIB
                 ") failed.  Unable to delete features "
                 "in tables without\n a recognised FID column.",
                 nFID);
        return OGRERR_FAILURE;
    }

    if (OGRNullFID == fidFieldIndex_)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "DeleteFeature(" CPL_FRMT_GIB
                 ") failed.  Unable to delete features "
                 "in tables without\n a recognised FID column.",
                 nFID);
        return OGRERR_FAILURE;
    }

    EnsureInitialized();

    if (deleteFeatureStmt_.isNull())
    {
        deleteFeatureStmt_ = CreateDeleteFeatureStatement();
        if (deleteFeatureStmt_.isNull())
            return OGRERR_FAILURE;
    }

    OGRErr err =
        ExecutePendingBatches(BatchOperation::INSERT | BatchOperation::UPDATE);
    if (OGRERR_NONE != err)
        return err;

    deleteFeatureStmt_->setLong(1, odbc::Long(static_cast<std::int64_t>(nFID)));
    bool withBatch = dataSource_->IsTransactionStarted();
    if (withBatch)
        deleteFeatureStmt_->addBatch();

    auto ret = ExecuteUpdate(*deleteFeatureStmt_, withBatch, "DeleteFeature");
    return (OGRERR_NONE == ret.first && ret.second != 1)
               ? OGRERR_NON_EXISTING_FEATURE
               : ret.first;
}

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

OGRErr OGRHanaTableLayer::ISetFeature(OGRFeature *feature)
{
    if (!updateMode_)
    {
        CPLError(CE_Failure, CPLE_NotSupported, UNSUPPORTED_OP_READ_ONLY,
                 "SetFeature");
        return OGRERR_FAILURE;
    }

    if (nullptr == feature)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "NULL pointer to OGRFeature passed to SetFeature().");
        return OGRERR_FAILURE;
    }

    if (feature->GetFID() == OGRNullFID)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "FID required on features given to SetFeature().");
        return OGRERR_FAILURE;
    }

    if (OGRNullFID == fidFieldIndex_)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Unable to update features in tables without\n"
                 "a recognised FID column.");
        return OGRERR_FAILURE;
    }

    EnsureInitialized();

    if (updateFeatureStmt_.isNull())
    {
        updateFeatureStmt_ = CreateUpdateFeatureStatement();
        if (updateFeatureStmt_.isNull())
            return OGRERR_FAILURE;
    }

    if (OGRNullFID != fidFieldIndex_)
        allowAutoFIDOnCreateFeature_ = false;

    OGRErr err =
        ExecutePendingBatches(BatchOperation::DELETE | BatchOperation::INSERT);
    if (OGRERR_NONE != err)
        return err;

    try
    {
        err = SetStatementParameters(*updateFeatureStmt_, feature, false, false,
                                     "SetFeature");

        if (OGRERR_NONE != err)
            return err;

        bool withBatch = dataSource_->IsTransactionStarted();
        if (withBatch)
            updateFeatureStmt_->addBatch();

        auto ret = ExecuteUpdate(*updateFeatureStmt_, withBatch, "SetFeature");
        return (OGRERR_NONE == ret.first && ret.second != 1)
                   ? OGRERR_NON_EXISTING_FEATURE
                   : ret.first;
    }
    catch (const std::exception &ex)
    {
        CPLError(CE_Failure, CPLE_NotSupported, "Unable to create feature: %s",
                 ex.what());
        return OGRERR_FAILURE;
    }
}

/************************************************************************/
/*                            CreateField()                             */
/************************************************************************/

OGRErr OGRHanaTableLayer::CreateField(const OGRFieldDefn *srsField,
                                      int approxOK)
{
    if (!updateMode_)
    {
        CPLError(CE_Failure, CPLE_NotSupported, UNSUPPORTED_OP_READ_ONLY,
                 "CreateField");
        return OGRERR_FAILURE;
    }

    if (srsField->GetNameRef() == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Field name cannot be NULL");
        return OGRERR_FAILURE;
    }

    EnsureInitialized();

    OGRFieldDefn dstField(srsField);

    if (launderColumnNames_)
    {
        auto nameRes = dataSource_->LaunderName(dstField.GetNameRef());
        if (nameRes.first != OGRERR_NONE)
            return nameRes.first;
        dstField.SetName(nameRes.second.c_str());
    }

    if (fidFieldIndex_ != OGRNullFID &&
        EQUAL(dstField.GetNameRef(), GetFIDColumn()) &&
        dstField.GetType() != OFTInteger && dstField.GetType() != OFTInteger64)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Wrong field type for %s",
                 dstField.GetNameRef());
        return OGRERR_FAILURE;
    }

    ColumnTypeInfo columnTypeInfo = GetColumnTypeInfo(dstField);
    CPLString columnDef = GetColumnDefinition(columnTypeInfo);

    if (columnTypeInfo.type == QGRHanaDataTypes::Unknown)
    {
        if (columnTypeInfo.name.empty())
            return OGRERR_FAILURE;

        if (approxOK)
        {
            dstField.SetDefault(nullptr);
            CPLError(CE_Warning, CPLE_NotSupported,
                     "Unable to create field %s with type %s on HANA layers. "
                     "Creating as VARCHAR.",
                     dstField.GetNameRef(),
                     OGRFieldDefn::GetFieldTypeName(dstField.GetType()));
            columnTypeInfo.name = "VARCHAR";
            columnTypeInfo.width = static_cast<int>(defaultStringSize_);
            columnDef = "VARCHAR(" + std::to_string(defaultStringSize_) + ")";
        }
        else
        {
            CPLError(CE_Failure, CPLE_NotSupported,
                     "Unable to create field %s with type %s on HANA layers.",
                     dstField.GetNameRef(),
                     OGRFieldDefn::GetFieldTypeName(dstField.GetType()));

            return OGRERR_FAILURE;
        }
    }

    CPLString clmClause =
        QuotedIdentifier(dstField.GetNameRef()) + " " + columnDef;
    if (!dstField.IsNullable())
        clmClause += " NOT NULL";
    if (dstField.GetDefault() != nullptr && !dstField.IsDefaultDriverSpecific())
    {
        if (IsArrayField(dstField.GetType()) ||
            columnTypeInfo.type == QGRHanaDataTypes::LongVarBinary ||
            columnTypeInfo.type == QGRHanaDataTypes::RealVector)
        {
            CPLError(
                CE_Failure, CPLE_NotSupported,
                "Default value cannot be created on column of data type %s: "
                "%s.",
                columnTypeInfo.name.c_str(), dstField.GetNameRef());

            return OGRERR_FAILURE;
        }

        clmClause +=
            CPLString().Printf(" DEFAULT %s", GetColumnDefaultValue(dstField));
    }

    FlushPendingBatches(false);

    const CPLString sql = CPLString().Printf(
        "ALTER TABLE %s ADD(%s)",
        GetFullTableNameQuoted(schemaName_, tableName_).c_str(),
        clmClause.c_str());

    try
    {
        dataSource_->ExecuteSQL(sql.c_str());
    }
    catch (const odbc::Exception &ex)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Failed to execute create attribute field %s: %s",
                 dstField.GetNameRef(), ex.what());
        return OGRERR_FAILURE;
    }

    // columnTypeInfo might contain a different definition due to custom column
    // types
    SetFieldDefn(dstField, columnTypeInfo);

    AttributeColumnDescription clmDesc;
    clmDesc.name = dstField.GetNameRef();
    clmDesc.type = columnTypeInfo.type;
    clmDesc.typeName = columnTypeInfo.name;
    clmDesc.isArray = IsArrayField(dstField.GetType());
    clmDesc.length = columnTypeInfo.width;
    clmDesc.isNullable = dstField.IsNullable();
    clmDesc.isAutoIncrement = false;  // TODO
    clmDesc.scale = static_cast<unsigned short>(columnTypeInfo.precision);
    clmDesc.precision = static_cast<unsigned short>(columnTypeInfo.width);
    if (dstField.GetDefault() != nullptr)
        clmDesc.defaultValue = dstField.GetDefault();

    attrColumns_.push_back(clmDesc);
    featureDefn_->AddFieldDefn(&dstField);

    ColumnsChanged();

    return OGRERR_NONE;
}

/************************************************************************/
/*                          CreateGeomField()                           */
/************************************************************************/

OGRErr OGRHanaTableLayer::CreateGeomField(const OGRGeomFieldDefn *geomField,
                                          int)
{
    if (!updateMode_)
    {
        CPLError(CE_Failure, CPLE_AppDefined, UNSUPPORTED_OP_READ_ONLY,
                 "CreateGeomField");
        return OGRERR_FAILURE;
    }

    if (!IsGeometryTypeSupported(geomField->GetType()))
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Geometry field '%s' in layer '%s' has unsupported type %s",
                 geomField->GetNameRef(), tableName_.c_str(),
                 OGRGeometryTypeToName(geomField->GetType()));
        return OGRERR_FAILURE;
    }

    EnsureInitialized();

    if (featureDefn_->GetGeomFieldIndex(geomField->GetNameRef()) >= 0)
    {
        CPLError(
            CE_Failure, CPLE_AppDefined,
            "CreateGeomField() called with an already existing field name: %s",
            geomField->GetNameRef());
        return OGRERR_FAILURE;
    }

    FlushPendingBatches(false);

    int srid = dataSource_->GetSrsId(geomField->GetSpatialRef());
    if (srid == UNDETERMINED_SRID)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Unable to determine the srs-id for field name: %s",
                 geomField->GetNameRef());
        return OGRERR_FAILURE;
    }

    CPLString clmName(geomField->GetNameRef());
    if (launderColumnNames_)
    {
        auto nameRes = dataSource_->LaunderName(geomField->GetNameRef());
        if (nameRes.first != OGRERR_NONE)
            return nameRes.first;
        clmName.swap(nameRes.second);
    }

    if (clmName.empty())
        clmName = FindGeomFieldName(*featureDefn_);

    CPLString sql = CPLString().Printf(
        "ALTER TABLE %s ADD(%s ST_GEOMETRY(%d))",
        GetFullTableNameQuoted(schemaName_, tableName_).c_str(),
        QuotedIdentifier(clmName).c_str(), srid);

    try
    {
        dataSource_->ExecuteSQL(sql.c_str());
    }
    catch (const odbc::Exception &ex)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Failed to execute CreateGeomField() with field name '%s': %s",
                 geomField->GetNameRef(), ex.what());
        return OGRERR_FAILURE;
    }

    auto newGeomField = std::make_unique<OGRGeomFieldDefn>(
        clmName.c_str(), geomField->GetType());
    newGeomField->SetNullable(geomField->IsNullable());
    newGeomField->SetSpatialRef(geomField->GetSpatialRef());
    geomColumns_.push_back({newGeomField->GetNameRef(), newGeomField->GetType(),
                            srid, newGeomField->IsNullable() == TRUE});
    featureDefn_->AddGeomFieldDefn(std::move(newGeomField));

    ColumnsChanged();

    return OGRERR_NONE;
}

/************************************************************************/
/*                            DeleteField()                             */
/************************************************************************/

OGRErr OGRHanaTableLayer::DeleteField(int field)
{
    if (!updateMode_)
    {
        CPLError(CE_Failure, CPLE_NotSupported, UNSUPPORTED_OP_READ_ONLY,
                 "DeleteField");
        return OGRERR_FAILURE;
    }

    if (field < 0 || field >= featureDefn_->GetFieldCount())
    {
        CPLError(CE_Failure, CPLE_NotSupported, "Field index is out of range");
        return OGRERR_FAILURE;
    }

    EnsureInitialized();

    FlushPendingBatches(false);

    CPLString clmName = featureDefn_->GetFieldDefn(field)->GetNameRef();
    CPLString sql = CPLString().Printf(
        "ALTER TABLE %s DROP (%s)",
        GetFullTableNameQuoted(schemaName_, tableName_).c_str(),
        QuotedIdentifier(clmName).c_str());

    try
    {
        dataSource_->ExecuteSQL(sql.c_str());
    }
    catch (const odbc::Exception &ex)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Failed to drop column %s: %s",
                 clmName.c_str(), ex.what());
        return OGRERR_FAILURE;
    }

    auto it = std::find_if(attrColumns_.begin(), attrColumns_.end(),
                           [&](const AttributeColumnDescription &cd)
                           { return cd.name == clmName; });
    attrColumns_.erase(it);
    OGRErr ret = featureDefn_->DeleteFieldDefn(field);

    ColumnsChanged();

    return ret;
}

/************************************************************************/
/*                            AlterFieldDefn()                          */
/************************************************************************/

OGRErr OGRHanaTableLayer::AlterFieldDefn(int field, OGRFieldDefn *newFieldDefn,
                                         int flagsIn)
{
    if (!updateMode_)
    {
        CPLError(CE_Failure, CPLE_NotSupported, UNSUPPORTED_OP_READ_ONLY,
                 "AlterFieldDefn");
        return OGRERR_FAILURE;
    }

    EnsureInitialized();

    if (field < 0 || field >= featureDefn_->GetFieldCount())
    {
        CPLError(CE_Failure, CPLE_NotSupported, "Field index is out of range");
        return OGRERR_FAILURE;
    }

    OGRFieldDefn *fieldDefn = featureDefn_->GetFieldDefn(field);

    int columnDescIdx = -1;
    for (size_t i = 0; i < attrColumns_.size(); ++i)
    {
        if (EQUAL(attrColumns_[i].name.c_str(), fieldDefn->GetNameRef()))
        {
            columnDescIdx = static_cast<int>(i);
            break;
        }
    }

    if (columnDescIdx < 0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Column description cannot be found");
        return OGRERR_FAILURE;
    }

    CPLString clmName(newFieldDefn->GetNameRef());

    if (launderColumnNames_)
    {
        auto nameRes = dataSource_->LaunderName(newFieldDefn->GetNameRef());
        if (nameRes.first != OGRERR_NONE)
            return nameRes.first;
        clmName.swap(nameRes.second);
    }

    FlushPendingBatches(false);

    ColumnTypeInfo columnTypeInfo = GetColumnTypeInfo(*newFieldDefn);

    try
    {
        if ((flagsIn & ALTER_NAME_FLAG) &&
            (strcmp(fieldDefn->GetNameRef(), newFieldDefn->GetNameRef()) != 0))
        {
            CPLString sql = CPLString().Printf(
                "RENAME COLUMN %s TO %s",
                GetFullColumnNameQuoted(schemaName_, tableName_,
                                        fieldDefn->GetNameRef())
                    .c_str(),
                QuotedIdentifier(clmName).c_str());
            dataSource_->ExecuteSQL(sql.c_str());
        }

        if ((flagsIn & ALTER_TYPE_FLAG) ||
            (flagsIn & ALTER_WIDTH_PRECISION_FLAG) ||
            (flagsIn & ALTER_NULLABLE_FLAG) || (flagsIn & ALTER_DEFAULT_FLAG))
        {
            CPLString fieldTypeDef = GetColumnDefinition(columnTypeInfo);
            if ((flagsIn & ALTER_NULLABLE_FLAG) &&
                fieldDefn->IsNullable() != newFieldDefn->IsNullable())
            {
                if (fieldDefn->IsNullable())
                    fieldTypeDef += " NULL";
                else
                    fieldTypeDef += " NOT NULL";
            }

            if ((flagsIn & ALTER_DEFAULT_FLAG) &&
                ((fieldDefn->GetDefault() == nullptr &&
                  newFieldDefn->GetDefault() != nullptr) ||
                 (fieldDefn->GetDefault() != nullptr &&
                  newFieldDefn->GetDefault() == nullptr) ||
                 (fieldDefn->GetDefault() != nullptr &&
                  newFieldDefn->GetDefault() != nullptr &&
                  strcmp(fieldDefn->GetDefault(), newFieldDefn->GetDefault()) !=
                      0)))
            {
                fieldTypeDef +=
                    " DEFAULT " + ((fieldDefn->GetType() == OFTString)
                                       ? Literal(newFieldDefn->GetDefault())
                                       : CPLString(newFieldDefn->GetDefault()));
            }

            CPLString sql = CPLString().Printf(
                "ALTER TABLE %s ALTER(%s %s)",
                GetFullTableNameQuoted(schemaName_, tableName_).c_str(),
                QuotedIdentifier(clmName).c_str(), fieldTypeDef.c_str());

            dataSource_->ExecuteSQL(sql.c_str());
        }
    }
    catch (const odbc::Exception &ex)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Failed to alter field %s: %s",
                 fieldDefn->GetNameRef(), ex.what());
        return OGRERR_FAILURE;
    }

    // Update field definition and column description

    AttributeColumnDescription &attrClmDesc = attrColumns_[columnDescIdx];

    if (flagsIn & ALTER_NAME_FLAG)
    {
        fieldDefn->SetName(clmName.c_str());
        attrClmDesc.name.assign(clmName.c_str());
    }

    if (flagsIn & ALTER_TYPE_FLAG)
    {
        fieldDefn->SetSubType(OFSTNone);
        fieldDefn->SetType(newFieldDefn->GetType());
        fieldDefn->SetSubType(newFieldDefn->GetSubType());
        attrClmDesc.isArray = IsArrayField(newFieldDefn->GetType());
        attrClmDesc.type = columnTypeInfo.type;
        attrClmDesc.typeName = columnTypeInfo.name;
    }

    if (flagsIn & ALTER_WIDTH_PRECISION_FLAG)
    {
        fieldDefn->SetWidth(newFieldDefn->GetWidth());
        fieldDefn->SetPrecision(newFieldDefn->GetPrecision());
        attrClmDesc.length = newFieldDefn->GetWidth();
        attrClmDesc.scale = newFieldDefn->GetWidth();
        attrClmDesc.precision = newFieldDefn->GetPrecision();
    }

    if (flagsIn & ALTER_NULLABLE_FLAG)
    {
        fieldDefn->SetNullable(newFieldDefn->IsNullable());
        attrClmDesc.isNullable = newFieldDefn->IsNullable();
    }

    if (flagsIn & ALTER_DEFAULT_FLAG)
    {
        fieldDefn->SetDefault(newFieldDefn->GetDefault());
        attrClmDesc.name.assign(newFieldDefn->GetDefault());
    }

    ColumnsChanged();

    return OGRERR_NONE;
}

/************************************************************************/
/*                          ClearBatches()                              */
/************************************************************************/

void OGRHanaTableLayer::ClearBatches()
{
    if (!insertFeatureStmtWithFID_.isNull())
        insertFeatureStmtWithFID_->clearBatch();
    if (!insertFeatureStmtWithoutFID_.isNull())
        insertFeatureStmtWithoutFID_->clearBatch();
    if (!updateFeatureStmt_.isNull())
        updateFeatureStmt_->clearBatch();
}

/************************************************************************/
/*                          ColumnsChanged()                            */
/************************************************************************/

void OGRHanaTableLayer::ColumnsChanged()
{
    ClearQueryStatement();
    ResetReading();
    ResetPreparedStatements();
}

/************************************************************************/
/*                          SetCustomColumnTypes()                      */
/************************************************************************/

void OGRHanaTableLayer::SetCustomColumnTypes(const char *columnTypes)
{
    if (columnTypes == nullptr)
        return;

    const char *ptr = columnTypes;
    const char *start = ptr;
    while (*ptr != '\0')
    {
        if (*ptr == '(')
        {
            // Skip commas inside brackets, for example decimal(20,5)
            while (*ptr != '\0' && *ptr != ')')
            {
                ++ptr;
            }
        }

        ++ptr;

        if (*ptr == ',' || *ptr == '\0')
        {
            std::size_t len = static_cast<std::size_t>(ptr - start);
            const char *sep = std::find(start, start + len, '=');
            if (sep != nullptr)
            {
                std::size_t pos = static_cast<std::size_t>(sep - start);
                customColumnDefs_.push_back(
                    {CPLString(start, pos),
                     CPLString(start + pos + 1, len - pos - 1)});
            }

            start = ptr + 1;
        }
    }
}

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

OGRErr OGRHanaTableLayer::StartTransaction()
{
    return dataSource_->StartTransaction();
}

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

OGRErr OGRHanaTableLayer::CommitTransaction()
{
    if (HasPendingBatches())
    {
        OGRErr err = ExecutePendingBatches(BatchOperation::ALL);
        if (OGRERR_NONE != err)
            return err;
    }

    return dataSource_->CommitTransaction();
}

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

OGRErr OGRHanaTableLayer::RollbackTransaction()
{
    ClearBatches();
    return dataSource_->RollbackTransaction();
}

}  // namespace OGRHANA
