/******************************************************************************
 *
 * Project:  MSSQL Spatial driver
 * Purpose:  Definition of classes for OGR MSSQL Spatial driver.
 * Author:   Tamas Szekeres, szekerest at gmail.com
 *
 ******************************************************************************
 * Copyright (c) 2010, Tamas Szekeres
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "ogr_mssqlspatial.h"

/************************************************************************/
/*                        OGRMSSQLSpatialLayer()                        */
/************************************************************************/

OGRMSSQLSpatialLayer::OGRMSSQLSpatialLayer(OGRMSSQLSpatialDataSource *poDSIn)
    : poDS(poDSIn)

{
}

/************************************************************************/
/*                      ~OGRMSSQLSpatialLayer()                         */
/************************************************************************/

OGRMSSQLSpatialLayer::~OGRMSSQLSpatialLayer()

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

    ClearStatement();

    CPLFree(pszGeomColumn);
    CPLFree(pszFIDColumn);
    CPLFree(panFieldOrdinals);

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

    if (poSRS)
        poSRS->Release();
}

/************************************************************************/
/*                          BuildFeatureDefn()                          */
/*                                                                      */
/*      Build feature definition from a set of column definitions       */
/*      set on a statement.  Sift out geometry and FID fields.          */
/************************************************************************/

void OGRMSSQLSpatialLayer::BuildFeatureDefn(const char *pszLayerName,
                                            CPLODBCStatement *poStmtIn)

{
    bool bShowFidColumn =
        CPLTestBool(CPLGetConfigOption("MSSQLSPATIAL_SHOW_FID_COLUMN", "NO"));

    if (!poFeatureDefn)
    {
        poFeatureDefn = new OGRFeatureDefn(pszLayerName);
        poFeatureDefn->Reference();
    }
    else
    {
        for (int iFieldIdx = poFeatureDefn->GetFieldCount() - 1; iFieldIdx >= 0;
             --iFieldIdx)
        {
            poFeatureDefn->DeleteFieldDefn(iFieldIdx);
        }
        for (int iFieldIdx = poFeatureDefn->GetGeomFieldCount() - 1;
             iFieldIdx >= 0; --iFieldIdx)
        {
            poFeatureDefn->DeleteGeomFieldDefn(iFieldIdx);
        }
        poFeatureDefn->SetName(pszLayerName);
    }

    nRawColumns = poStmtIn->GetColCount();

    CPLFree(panFieldOrdinals);
    panFieldOrdinals = (int *)CPLMalloc(sizeof(int) * nRawColumns);

    for (int iCol = 0; iCol < nRawColumns; iCol++)
    {
        if (pszGeomColumn == nullptr)
        {
            /* need to identify the geometry column */
            if (EQUAL(poStmtIn->GetColTypeName(iCol), "geometry"))
            {
                nGeomColumnType = MSSQLCOLTYPE_GEOMETRY;
                pszGeomColumn = CPLStrdup(poStmtIn->GetColName(iCol));
                if (poFeatureDefn->GetGeomFieldCount() == 1)
                {
                    poFeatureDefn->GetGeomFieldDefn(0)->SetNullable(
                        poStmtIn->GetColNullable(iCol));
                    poFeatureDefn->GetGeomFieldDefn(0)->SetName(pszGeomColumn);
                }
                nGeomColumnIndex = iCol;
                continue;
            }
            else if (EQUAL(poStmtIn->GetColTypeName(iCol), "geography"))
            {
                nGeomColumnType = MSSQLCOLTYPE_GEOGRAPHY;
                pszGeomColumn = CPLStrdup(poStmtIn->GetColName(iCol));
                if (poFeatureDefn->GetGeomFieldCount() == 1)
                {
                    poFeatureDefn->GetGeomFieldDefn(0)->SetNullable(
                        poStmtIn->GetColNullable(iCol));
                    poFeatureDefn->GetGeomFieldDefn(0)->SetName(pszGeomColumn);
                }
                nGeomColumnIndex = iCol;
                continue;
            }
        }
        else
        {
            if (EQUAL(poStmtIn->GetColName(iCol), pszGeomColumn))
            {
                if (poFeatureDefn->GetGeomFieldCount() == 1)
                {
                    poFeatureDefn->GetGeomFieldDefn(0)->SetNullable(
                        poStmtIn->GetColNullable(iCol));
                    poFeatureDefn->GetGeomFieldDefn(0)->SetName(pszGeomColumn);
                }
                nGeomColumnIndex = iCol;
                continue;
            }
        }

        if (pszFIDColumn != nullptr)
        {
            if (EQUAL(poStmtIn->GetColName(iCol), pszFIDColumn))
            {
                bool bIntegerFID = false;
                switch (CPLODBCStatement::GetTypeMapping(
                    poStmtIn->GetColType(iCol)))
                {
                    case SQL_C_SSHORT:
                    case SQL_C_USHORT:
                    case SQL_C_SLONG:
                    case SQL_C_ULONG:
                    case SQL_C_SBIGINT:
                    case SQL_C_UBIGINT:
                        bIntegerFID = true;
                        break;
                    default:
                        break;
                }
                if (!bIntegerFID)
                {
                    CPLDebug(
                        "MSSQL",
                        "Ignoring FID column %s as it is of non integer type",
                        pszFIDColumn);
                    CPLFree(pszFIDColumn);
                    pszFIDColumn = nullptr;
                }
                else
                {
                    if (STARTS_WITH_CI(poStmtIn->GetColTypeName(iCol),
                                       "bigint"))
                        SetMetadataItem(OLMD_FID64, "YES");

                    if (EQUAL(poStmtIn->GetColTypeName(iCol), "int identity") ||
                        EQUAL(poStmtIn->GetColTypeName(iCol),
                              "bigint identity"))
                        bIsIdentityFid = TRUE;

                    nFIDColumnIndex = iCol;

                    if (!bShowFidColumn)
                        continue;
                }
            }
        }
        else
        {
            if (EQUAL(poStmtIn->GetColTypeName(iCol), "int identity"))
            {
                pszFIDColumn = CPLStrdup(poStmtIn->GetColName(iCol));
                bIsIdentityFid = TRUE;
                nFIDColumnIndex = iCol;

                if (!bShowFidColumn)
                    continue;
            }
            else if (EQUAL(poStmtIn->GetColTypeName(iCol), "bigint identity"))
            {
                pszFIDColumn = CPLStrdup(poStmtIn->GetColName(iCol));
                bIsIdentityFid = TRUE;
                SetMetadataItem(OLMD_FID64, "YES");
                nFIDColumnIndex = iCol;

                if (!bShowFidColumn)
                    continue;
            }
        }

        OGRFieldDefn oField(poStmtIn->GetColName(iCol), OFTString);

        switch (CPLODBCStatement::GetTypeMapping(poStmtIn->GetColType(iCol)))
        {
            case SQL_C_SSHORT:
                oField.SetType(OFTInteger);
                oField.SetSubType(OFSTInt16);
                break;

            case SQL_C_USHORT:
            case SQL_C_SLONG:
            case SQL_C_ULONG:
                oField.SetType(OFTInteger);
                break;

            case SQL_C_SBIGINT:
            case SQL_C_UBIGINT:
                oField.SetType(OFTInteger64);
                break;

            case SQL_C_BINARY:
                oField.SetType(OFTBinary);
                oField.SetWidth(MAX(0, poStmtIn->GetColSize(iCol)));
                break;

            case SQL_C_NUMERIC:
                oField.SetType(OFTReal);
                oField.SetPrecision(poStmtIn->GetColPrecision(iCol));
                oField.SetWidth(MAX(0, poStmtIn->GetColSize(iCol)));
                if (oField.GetPrecision() == 0 && oField.GetWidth() <= 9)
                    oField.SetType(OFTInteger);
                else if (oField.GetPrecision() == 0 && oField.GetWidth() <= 18)
                    oField.SetType(OFTInteger64);
                break;

            case SQL_C_FLOAT:
                oField.SetType(OFTReal);
                oField.SetSubType(OFSTFloat32);
                break;

            case SQL_C_DOUBLE:
                oField.SetType(OFTReal);
                break;

            case SQL_C_DATE:
                oField.SetType(OFTDate);
                break;

            case SQL_C_TIME:
                oField.SetType(OFTTime);
                break;

            case SQL_C_TIMESTAMP:
                oField.SetType(OFTDateTime);
                break;

            case SQL_C_GUID:
                m_bHasUUIDColumn = true;
                oField.SetType(OFTString);
                oField.SetSubType(OFSTUUID);
                break;

            default:
                oField.SetWidth(MAX(0, poStmtIn->GetColSize(iCol)));
                /* leave it as OFTString */;
        }

        oField.SetNullable(poStmtIn->GetColNullable(iCol));

        if (poStmtIn->GetColColumnDef(iCol))
        {
            /* process default value specification */
            if (EQUAL(poStmtIn->GetColColumnDef(iCol), "(getdate())"))
                oField.SetDefault("CURRENT_TIMESTAMP");
            else if (STARTS_WITH_CI(poStmtIn->GetColColumnDef(iCol),
                                    "(CONVERT([time],getdate()"))
                oField.SetDefault("CURRENT_TIME");
            else if (STARTS_WITH_CI(poStmtIn->GetColColumnDef(iCol),
                                    "(CONVERT([date],getdate()"))
                oField.SetDefault("CURRENT_DATE");
            else
            {
                char *pszDefault = CPLStrdup(poStmtIn->GetColColumnDef(iCol));
                int nLen = static_cast<int>(strlen(pszDefault));
                if (nLen >= 1 && pszDefault[0] == '(' &&
                    pszDefault[nLen - 1] == ')')
                {
                    // All default values are encapsulated in brackets
                    // by MSSQL server.
                    if (nLen >= 4 && pszDefault[1] == '(' &&
                        pszDefault[nLen - 2] == ')')
                    {
                        /* for numeric values double brackets are used */
                        pszDefault[nLen - 2] = '\0';
                        oField.SetDefault(pszDefault + 2);
                    }
                    else
                    {
                        pszDefault[nLen - 1] = '\0';
                        oField.SetDefault(pszDefault + 1);
                    }
                }
                else
                    oField.SetDefault(pszDefault);

                CPLFree(pszDefault);
            }
        }

        poFeatureDefn->AddFieldDefn(&oField);
        panFieldOrdinals[poFeatureDefn->GetFieldCount() - 1] = iCol;
    }

    /* -------------------------------------------------------------------- */
    /*      If we don't already have an FID, check if there is a special    */
    /*      FID named column available.                                     */
    /* -------------------------------------------------------------------- */
    if (pszFIDColumn == nullptr)
    {
        const char *pszOGR_FID =
            CPLGetConfigOption("MSSQLSPATIAL_OGR_FID", "OGR_FID");
        if (poFeatureDefn->GetFieldIndex(pszOGR_FID) != -1)
            pszFIDColumn = CPLStrdup(pszOGR_FID);
    }

    if (pszFIDColumn != nullptr)
        CPLDebug("OGR_MSSQLSpatial", "Using column %s as FID for table %s.",
                 pszFIDColumn, poFeatureDefn->GetName());
    else
        CPLDebug("OGR_MSSQLSpatial", "Table %s has no identified FID column.",
                 poFeatureDefn->GetName());
}

/************************************************************************/
/*                           ClearStatement()                           */
/************************************************************************/

void OGRMSSQLSpatialLayer::ClearStatement()

{
    if (poStmt != nullptr)
    {
        delete poStmt;
        poStmt = nullptr;
    }
}

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

void OGRMSSQLSpatialLayer::ResetReading()

{
    if (m_bResetNeeded)
    {
        iNextShapeId = 0;
        ClearStatement();
        m_bEOF = false;
        m_bResetNeeded = false;
    }
}

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

OGRFeature *OGRMSSQLSpatialLayer::GetNextFeature()

{
    if (m_bEOF)
        return nullptr;

    while (true)
    {
        OGRFeature *poFeature;

        poFeature = GetNextRawFeature();
        if (poFeature == nullptr)
        {
            m_bEOF = true;
            return nullptr;
        }

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

        delete poFeature;
    }
}

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

OGRFeature *OGRMSSQLSpatialLayer::GetNextRawFeature()

{
    m_bResetNeeded = true;
    if (GetStatement() == nullptr)
        return nullptr;

    /* -------------------------------------------------------------------- */
    /*      If we are marked to restart then do so, and fetch a record.     */
    /* -------------------------------------------------------------------- */
    if (!poStmt->Fetch())
    {
        delete poStmt;
        poStmt = nullptr;
        return nullptr;
    }

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

    const char *pszFID;
    if (pszFIDColumn != nullptr && poStmt->GetColId(pszFIDColumn) > -1 &&
        (pszFID = poStmt->GetColData(poStmt->GetColId(pszFIDColumn))) !=
            nullptr)
        poFeature->SetFID(CPLAtoGIntBig(pszFID));
    else
        poFeature->SetFID(iNextShapeId);

    iNextShapeId++;
    m_nFeaturesRead++;

    /* -------------------------------------------------------------------- */
    /*      Set the fields.                                                 */
    /* -------------------------------------------------------------------- */
    for (int iField = 0; iField < poFeatureDefn->GetFieldCount(); iField++)
    {
        if (poFeatureDefn->GetFieldDefn(iField)->IsIgnored())
            continue;

        int iSrcField = panFieldOrdinals[iField];
        const char *pszValue = poStmt->GetColData(iSrcField);

        if (pszValue == nullptr)
            poFeature->SetFieldNull(iField);
        else if (poFeature->GetFieldDefnRef(iField)->GetType() == OFTBinary)
            poFeature->SetField(iField, poStmt->GetColDataLength(iSrcField),
                                (GByte *)pszValue);
        else
            poFeature->SetField(iField, pszValue);
    }

    /* -------------------------------------------------------------------- */
    /*      Try to extract a geometry.                                      */
    /* -------------------------------------------------------------------- */
    if (pszGeomColumn != nullptr && !poFeatureDefn->IsGeometryIgnored())
    {
        int iField = poStmt->GetColId(pszGeomColumn);
        const char *pszGeomText = poStmt->GetColData(iField);
        OGRGeometry *poGeom = nullptr;
        OGRErr eErr = OGRERR_NONE;

        if (pszGeomText != nullptr)
        {
            int nLength = poStmt->GetColDataLength(iField);

            if (nGeomColumnType == MSSQLCOLTYPE_GEOMETRY ||
                nGeomColumnType == MSSQLCOLTYPE_GEOGRAPHY ||
                nGeomColumnType == MSSQLCOLTYPE_BINARY)
            {
                switch (poDS->GetGeometryFormat())
                {
                    case MSSQLGEOMETRY_NATIVE:
                    {
                        OGRMSSQLGeometryParser oParser(nGeomColumnType);
                        eErr = oParser.ParseSqlGeometry(
                            (unsigned char *)pszGeomText, nLength, &poGeom);
                        nSRSId = oParser.GetSRSId();
                    }
                    break;
                    case MSSQLGEOMETRY_WKB:
                    case MSSQLGEOMETRY_WKBZM:
                        eErr = OGRGeometryFactory::createFromWkb(
                            pszGeomText, nullptr, &poGeom, nLength);
                        break;
                    case MSSQLGEOMETRY_WKT:
                        eErr = OGRGeometryFactory::createFromWkt(
                            pszGeomText, nullptr, &poGeom);
                        break;
                }
            }
            else if (nGeomColumnType == MSSQLCOLTYPE_TEXT)
            {
                eErr = OGRGeometryFactory::createFromWkt(pszGeomText, nullptr,
                                                         &poGeom);
            }
        }

        if (eErr != OGRERR_NONE)
        {
            const char *pszMessage;

            switch (eErr)
            {
                case OGRERR_NOT_ENOUGH_DATA:
                    pszMessage = "Not enough data to deserialize";
                    break;
                case OGRERR_UNSUPPORTED_GEOMETRY_TYPE:
                    pszMessage = "Unsupported geometry type";
                    break;
                case OGRERR_CORRUPT_DATA:
                    pszMessage = "Corrupt data";
                    break;
                default:
                    pszMessage = "Unrecognized error";
            }
            CPLError(CE_Failure, CPLE_AppDefined, "GetNextRawFeature(): %s",
                     pszMessage);
        }

        if (poGeom != nullptr)
        {
            if (GetSpatialRef())
                poGeom->assignSpatialReference(poSRS);

            poFeature->SetGeometryDirectly(poGeom);
        }
    }

    return poFeature;
}

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

OGRFeature *OGRMSSQLSpatialLayer::GetFeature(GIntBig nFeatureId)

{
    /* This should be implemented directly! */

    return OGRLayer::GetFeature(nFeatureId);
}

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

int OGRMSSQLSpatialLayer::TestCapability(CPL_UNUSED const char *pszCap)
{
    return FALSE;
}

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

OGRErr OGRMSSQLSpatialLayer::StartTransaction()

{
    if (!poDS->GetSession()->BeginTransaction())
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Failed to start transaction: %s",
                 poDS->GetSession()->GetLastError());
        return OGRERR_FAILURE;
    }
    return OGRERR_NONE;
}

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

OGRErr OGRMSSQLSpatialLayer::CommitTransaction()

{
    if (!poDS->GetSession()->CommitTransaction())
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Failed to commit transaction: %s",
                 poDS->GetSession()->GetLastError());
        return OGRERR_FAILURE;
    }
    return OGRERR_NONE;
}

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

OGRErr OGRMSSQLSpatialLayer::RollbackTransaction()

{
    if (!poDS->GetSession()->RollbackTransaction())
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Failed to roll back transaction: %s",
                 poDS->GetSession()->GetLastError());
        return OGRERR_FAILURE;
    }
    return OGRERR_NONE;
}

/************************************************************************/
/*                           GetSpatialRef()                            */
/************************************************************************/

OGRSpatialReference *OGRMSSQLSpatialLayer::GetSpatialRef()

{
    if (poSRS == nullptr && nSRSId > 0)
    {
        poSRS = poDS->FetchSRS(nSRSId);
        if (poSRS != nullptr)
            poSRS->Reference();
        else
            nSRSId = 0;
    }

    return poSRS;
}

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

const char *OGRMSSQLSpatialLayer::GetFIDColumn()

{
    GetLayerDefn();

    if (pszFIDColumn != nullptr)
        return pszFIDColumn;
    else
        return "";
}

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

const char *OGRMSSQLSpatialLayer::GetGeometryColumn()

{
    GetLayerDefn();

    if (pszGeomColumn != nullptr)
        return pszGeomColumn;
    else
        return "";
}

/************************************************************************/
/*                        GByteArrayToHexString()                       */
/************************************************************************/

char *OGRMSSQLSpatialLayer::GByteArrayToHexString(const GByte *pabyData,
                                                  int nLen)
{
    char *pszTextBuf;

    const size_t nTextBufLen = nLen * 2 + 3;
    pszTextBuf = (char *)CPLMalloc(nTextBufLen);

    int iSrc, iDst = 0;

    for (iSrc = 0; iSrc < nLen; iSrc++)
    {
        if (iSrc == 0)
        {
            snprintf(pszTextBuf + iDst, nTextBufLen - iDst, "0x%02x",
                     pabyData[iSrc]);
            iDst += 4;
        }
        else
        {
            snprintf(pszTextBuf + iDst, nTextBufLen - iDst, "%02x",
                     pabyData[iSrc]);
            iDst += 2;
        }
    }
    pszTextBuf[iDst] = 0;

    return pszTextBuf;
}

/************************************************************************/
/*                             GetDataset()                             */
/************************************************************************/

GDALDataset *OGRMSSQLSpatialLayer::GetDataset()
{
    return poDS;
}
