/******************************************************************************
 *
 * Project:  CSV Translator
 * Purpose:  Implements OGRCSVDriver.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 2004, Frank Warmerdam <warmerdam@pobox.com>
 * Copyright (c) 2010-2013, Even Rouault <even dot rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "cpl_port.h"
#include "ogr_csv.h"

#include <cerrno>
#include <cstring>
#include <map>
#include <string>
#include <utility>

#include "cpl_conv.h"
#include "cpl_error.h"
#include "cpl_multiproc.h"
#include "cpl_string.h"
#include "cpl_vsi.h"
#include "gdal.h"
#include "gdal_priv.h"

static CPLMutex *hMutex = nullptr;
static std::map<CPLString, GDALDataset *> *poMap = nullptr;

/************************************************************************/
/*                         OGRCSVDriverIdentify()                       */
/************************************************************************/

static int OGRCSVDriverIdentify(GDALOpenInfo *poOpenInfo)

{
    if (poOpenInfo->fpL != nullptr)
    {
        if (poOpenInfo->IsSingleAllowedDriver("CSV"))
            return TRUE;

        const CPLString osBaseFilename =
            CPLGetFilename(poOpenInfo->pszFilename);
        const CPLString osExt =
            OGRCSVDataSource::GetRealExtension(poOpenInfo->pszFilename);

        if (EQUAL(osBaseFilename, "NfdcFacilities.xls") ||
            EQUAL(osBaseFilename, "NfdcRunways.xls") ||
            EQUAL(osBaseFilename, "NfdcRemarks.xls") ||
            EQUAL(osBaseFilename, "NfdcSchedules.xls"))
        {
            return TRUE;
        }
        else if ((STARTS_WITH_CI(osBaseFilename, "NationalFile_") ||
                  STARTS_WITH_CI(osBaseFilename, "POP_PLACES_") ||
                  STARTS_WITH_CI(osBaseFilename, "HIST_FEATURES_") ||
                  STARTS_WITH_CI(osBaseFilename, "US_CONCISE_") ||
                  STARTS_WITH_CI(osBaseFilename, "AllNames_") ||
                  STARTS_WITH_CI(osBaseFilename,
                                 "Feature_Description_History_") ||
                  STARTS_WITH_CI(osBaseFilename, "ANTARCTICA_") ||
                  STARTS_WITH_CI(osBaseFilename, "GOVT_UNITS_") ||
                  STARTS_WITH_CI(osBaseFilename, "NationalFedCodes_") ||
                  STARTS_WITH_CI(osBaseFilename, "AllStates_") ||
                  STARTS_WITH_CI(osBaseFilename, "AllStatesFedCodes_") ||
                  (osBaseFilename.size() > 2 &&
                   STARTS_WITH_CI(osBaseFilename + 2, "_Features_")) ||
                  (osBaseFilename.size() > 2 &&
                   STARTS_WITH_CI(osBaseFilename + 2, "_FedCodes_"))) &&
                 (EQUAL(osExt, "txt") || EQUAL(osExt, "zip")))
        {
            return TRUE;
        }
        else if (EQUAL(osBaseFilename, "allCountries.txt") ||
                 EQUAL(osBaseFilename, "allCountries.zip"))
        {
            return TRUE;
        }
        else if (EQUAL(osExt, "csv") || EQUAL(osExt, "tsv") ||
                 EQUAL(osExt, "psv"))
        {
            return TRUE;
        }
        else if (STARTS_WITH(poOpenInfo->pszFilename, "/vsizip/") &&
                 EQUAL(osExt, "zip"))
        {
            return -1;  // Unsure.
        }
        else
        {
            return FALSE;
        }
    }
    else if (STARTS_WITH_CI(poOpenInfo->pszFilename, "CSV:"))
    {
        return TRUE;
    }
    else if (poOpenInfo->bIsDirectory)
    {
        if (poOpenInfo->IsSingleAllowedDriver("CSV"))
            return TRUE;

        return -1;  // Unsure.
    }

    return FALSE;
}

/************************************************************************/
/*                        OGRCSVDriverRemoveFromMap()                   */
/************************************************************************/

void OGRCSVDriverRemoveFromMap(const char *pszName, GDALDataset *poDS)
{
    if (poMap == nullptr)
        return;
    CPLMutexHolderD(&hMutex);
    std::map<CPLString, GDALDataset *>::iterator oIter = poMap->find(pszName);
    if (oIter != poMap->end())
    {
        GDALDataset *poOtherDS = oIter->second;
        if (poDS == poOtherDS)
            poMap->erase(oIter);
    }
}

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

static GDALDataset *OGRCSVDriverOpen(GDALOpenInfo *poOpenInfo)

{
    if (!OGRCSVDriverIdentify(poOpenInfo))
        return nullptr;

    if (poMap != nullptr)
    {
        CPLMutexHolderD(&hMutex);
        std::map<CPLString, GDALDataset *>::iterator oIter =
            poMap->find(poOpenInfo->pszFilename);
        if (oIter != poMap->end())
        {
            GDALDataset *poOtherDS = oIter->second;
            poOtherDS->FlushCache(false);
        }
    }

    auto poDSUniquePtr = std::make_unique<OGRCSVDataSource>();

    if (!poDSUniquePtr->Open(poOpenInfo->pszFilename,
                             poOpenInfo->eAccess == GA_Update, false,
                             poOpenInfo->papszOpenOptions,
                             poOpenInfo->IsSingleAllowedDriver("CSV")))
    {
        poDSUniquePtr.reset();
    }

    auto poDS = poDSUniquePtr.release();

    if (poOpenInfo->eAccess == GA_Update && poDS != nullptr)
    {
        CPLMutexHolderD(&hMutex);
        if (poMap == nullptr)
            poMap = new std::map<CPLString, GDALDataset *>();
        if (poMap->find(poOpenInfo->pszFilename) == poMap->end())
        {
            (*poMap)[poOpenInfo->pszFilename] = poDS;
        }
    }

    return poDS;
}

/************************************************************************/
/*                               Create()                               */
/************************************************************************/

static GDALDataset *
OGRCSVDriverCreate(const char *pszName, CPL_UNUSED int nBands,
                   CPL_UNUSED int nXSize, CPL_UNUSED int nYSize,
                   CPL_UNUSED GDALDataType eDT, char **papszOptions)
{
    // First, ensure there isn't any such file yet.
    VSIStatBufL sStatBuf;

    if (strcmp(pszName, "/dev/stdout") == 0)
        pszName = "/vsistdout/";

    if (VSIStatL(pszName, &sStatBuf) == 0)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "It seems a file system object called '%s' already exists.",
                 pszName);

        return nullptr;
    }

    // If the target is not a simple .csv then create it as a directory.
    CPLString osDirName;

    if (EQUAL(CPLGetExtension(pszName), "csv"))
    {
        osDirName = CPLGetPath(pszName);
        if (osDirName == "")
            osDirName = ".";

        // HACK: CPLGetPath("/vsimem/foo.csv") = "/vsimem", but this is not
        // recognized afterwards as a valid directory name.
        if (osDirName == "/vsimem")
            osDirName = "/vsimem/";
    }
    else
    {
        if (STARTS_WITH(pszName, "/vsizip/"))
        {
            // Do nothing.
        }
        else if (!EQUAL(pszName, "/vsistdout/") && VSIMkdir(pszName, 0755) != 0)
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "Failed to create directory %s:\n%s", pszName,
                     VSIStrerror(errno));
            return nullptr;
        }
        osDirName = pszName;
    }

    // Force it to open as a datasource.
    auto poDS = std::make_unique<OGRCSVDataSource>();

    if (EQUAL(CPLGetExtension(pszName), "csv"))
    {
        poDS->CreateForSingleFile(osDirName, pszName);
    }
    else if (!poDS->Open(osDirName, /* bUpdate = */ true,
                         /* bForceAccept = */ true, nullptr,
                         /* bSingleDriver = */ true))
    {
        return nullptr;
    }

    const char *pszGeometry = CSLFetchNameValue(papszOptions, "GEOMETRY");
    if (pszGeometry != nullptr && EQUAL(pszGeometry, "AS_WKT"))
        poDS->EnableGeometryFields();

    return poDS.release();
}

/************************************************************************/
/*                              Delete()                                */
/************************************************************************/

static CPLErr OGRCSVDriverDelete(const char *pszFilename)

{
    return CPLUnlinkTree(pszFilename) == 0 ? CE_None : CE_Failure;
}

/************************************************************************/
/*                           OGRCSVDriverUnload()                       */
/************************************************************************/

static void OGRCSVDriverUnload(GDALDriver *)
{
    if (hMutex != nullptr)
        CPLDestroyMutex(hMutex);
    hMutex = nullptr;
    delete poMap;
    poMap = nullptr;
}

/************************************************************************/
/*                           RegisterOGRCSV()                           */
/************************************************************************/

#define XSTRINGIFY(x) #x
#define STRINGIFY(x) XSTRINGIFY(x)

void RegisterOGRCSV()

{
    if (GDALGetDriverByName("CSV") != nullptr)
        return;

    GDALDriver *poDriver = new GDALDriver();

    poDriver->SetDescription("CSV");
    poDriver->SetMetadataItem(GDAL_DCAP_VECTOR, "YES");
    poDriver->SetMetadataItem(GDAL_DCAP_CREATE_LAYER, "YES");
    poDriver->SetMetadataItem(GDAL_DCAP_DELETE_LAYER, "YES");
    poDriver->SetMetadataItem(GDAL_DCAP_CREATE_FIELD, "YES");
    poDriver->SetMetadataItem(GDAL_DCAP_DELETE_FIELD, "YES");
    poDriver->SetMetadataItem(GDAL_DCAP_REORDER_FIELDS, "YES");
    poDriver->SetMetadataItem(GDAL_DMD_CREATION_FIELD_DEFN_FLAGS,
                              "WidthPrecision");
    poDriver->SetMetadataItem(GDAL_DMD_ALTER_FIELD_DEFN_FLAGS,
                              "Name Type WidthPrecision");

    poDriver->SetMetadataItem(GDAL_DCAP_CURVE_GEOMETRIES, "YES");
    poDriver->SetMetadataItem(GDAL_DCAP_MEASURED_GEOMETRIES, "YES");
    poDriver->SetMetadataItem(GDAL_DCAP_Z_GEOMETRIES, "YES");

    poDriver->SetMetadataItem(GDAL_DMD_LONGNAME,
                              "Comma Separated Value (.csv)");
    poDriver->SetMetadataItem(GDAL_DMD_EXTENSIONS, "csv tsv psv");
    poDriver->SetMetadataItem(GDAL_DMD_HELPTOPIC, "drivers/vector/csv.html");
    poDriver->SetMetadataItem(GDAL_DMD_SUPPORTED_SQL_DIALECTS, "OGRSQL SQLITE");
    poDriver->SetMetadataItem(GDAL_DMD_NUMERIC_FIELD_WIDTH_INCLUDES_SIGN,
                              "YES");
    poDriver->SetMetadataItem(
        GDAL_DMD_NUMERIC_FIELD_WIDTH_INCLUDES_DECIMAL_SEPARATOR, "YES");

    poDriver->SetMetadataItem(GDAL_DMD_CREATIONOPTIONLIST,
                              "<CreationOptionList>"
                              "  <Option name='GEOMETRY' type='string-select' "
                              "description='how to encode geometry fields'>"
                              "    <Value>AS_WKT</Value>"
                              "  </Option>"
                              "</CreationOptionList>");

    poDriver->SetMetadataItem(
        GDAL_DS_LAYER_CREATIONOPTIONLIST,
        "<LayerCreationOptionList>"
        "  <Option name='SEPARATOR' type='string-select' description='field "
        "separator' default='COMMA'>"
        "    <Value>COMMA</Value>"
        "    <Value>SEMICOLON</Value>"
        "    <Value>TAB</Value>"
        "    <Value>SPACE</Value>"
        "  </Option>"
#ifdef _WIN32
        "  <Option name='LINEFORMAT' type='string-select' "
        "description='end-of-line sequence' default='CRLF'>"
#else
        "  <Option name='LINEFORMAT' type='string-select' "
        "description='end-of-line sequence' default='LF'>"
#endif
        "    <Value>CRLF</Value>"
        "    <Value>LF</Value>"
        "  </Option>"
        "  <Option name='GEOMETRY' type='string-select' description='how to "
        "encode geometry fields'>"
        "    <Value>AS_WKT</Value>"
        "    <Value>AS_XYZ</Value>"
        "    <Value>AS_XY</Value>"
        "    <Value>AS_YX</Value>"
        "  </Option>"
        "  <Option name='CREATE_CSVT' type='boolean' description='whether to "
        "create a .csvt file' default='NO'/>"
        "  <Option name='WRITE_BOM' type='boolean' description='whether to "
        "write a UTF-8 BOM prefix' default='NO'/>"
        "  <Option name='GEOMETRY_NAME' type='string' description='Name of "
        "geometry column. Only used if GEOMETRY=AS_WKT' default='WKT'/>"
        "  <Option name='STRING_QUOTING' type='string-select' "
        "description='whether to double-quote strings. IF_AMBIGUOUS means that "
        "string values that look like numbers will be quoted (it also implies "
        "IF_NEEDED).' default='IF_AMBIGUOUS'>"
        "    <Value>IF_NEEDED</Value>"
        "    <Value>IF_AMBIGUOUS</Value>"
        "    <Value>ALWAYS</Value>"
        "  </Option>"
        "</LayerCreationOptionList>");

    poDriver->SetMetadataItem(
        GDAL_DMD_OPENOPTIONLIST,
        "<OpenOptionList>"
        "  <Option name='SEPARATOR' type='string-select' "
        "description='field separator' default='AUTO'>"
        "    <Value>AUTO</Value>"
        "    <Value>COMMA</Value>"
        "    <Value>SEMICOLON</Value>"
        "    <Value>TAB</Value>"
        "    <Value>SPACE</Value>"
        "    <Value>PIPE</Value>"
        "  </Option>"
        "  <Option name='MERGE_SEPARATOR' type='boolean' description='whether "
        "to merge consecutive separators' default='NO'/>"
        "  <Option name='AUTODETECT_TYPE' type='boolean' description='whether "
        "to guess data type from first bytes of the file' default='NO'/>"
        "  <Option name='KEEP_SOURCE_COLUMNS' type='boolean' "
        "description='whether to add original columns whose guessed data type "
        "is not String. Only used if AUTODETECT_TYPE=YES' default='NO'/>"
        "  <Option name='AUTODETECT_WIDTH' type='string-select' "
        "description='whether to auto-detect width/precision. Only used if "
        "AUTODETECT_TYPE=YES' default='NO'>"
        "    <Value>YES</Value>"
        "    <Value>NO</Value>"
        "    <Value>STRING_ONLY</Value>"
        "  </Option>"
        "  <Option name='AUTODETECT_SIZE_LIMIT' type='int' description='number "
        "of bytes to inspect for auto-detection of data type. Only used if "
        "AUTODETECT_TYPE=YES' default='1000000'/>"
        "  <Option name='QUOTED_FIELDS_AS_STRING' type='boolean' "
        "description='Only used if AUTODETECT_TYPE=YES. Whether to enforce "
        "quoted fields as string fields.' default='NO'/>"
        "  <Option name='X_POSSIBLE_NAMES' type='string' description='Comma "
        "separated list of possible names for X/longitude coordinate of a "
        "point.'/>"
        "  <Option name='Y_POSSIBLE_NAMES' type='string' description='Comma "
        "separated list of possible names for Y/latitude coordinate of a "
        "point.'/>"
        "  <Option name='Z_POSSIBLE_NAMES' type='string' description='Comma "
        "separated list of possible names for Z/elevation coordinate of a "
        "point.'/>"
        "  <Option name='GEOM_POSSIBLE_NAMES' type='string' description='Comma "
        "separated list of possible names for geometry columns.' "
        "default='WKT'/>"
        "  <Option name='KEEP_GEOM_COLUMNS' type='boolean' "
        "description='whether to add original x/y/geometry columns as regular "
        "fields.' default='YES'/>"
        "  <Option name='HEADERS' type='string-select' description='Whether "
        "the first line of the file contains column names or not' "
        "default='AUTO'>"
        "    <Value>YES</Value>"
        "    <Value>NO</Value>"
        "    <Value>AUTO</Value>"
        "  </Option>"
        "  <Option name='EMPTY_STRING_AS_NULL' type='boolean' "
        "description='Whether to consider empty strings as null fields on "
        "reading' default='NO'/>"
        "  <Option name='MAX_LINE_SIZE' type='int' description='Maximum number "
        "of bytes for a line (-1=unlimited)' default='" STRINGIFY(
            OGR_CSV_DEFAULT_MAX_LINE_SIZE) "'/>"
                                           "</OpenOptionList>");

    poDriver->SetMetadataItem(GDAL_DCAP_VIRTUALIO, "YES");
    poDriver->SetMetadataItem(GDAL_DMD_CREATIONFIELDDATATYPES,
                              "Integer Integer64 Real String Date DateTime "
                              "Time IntegerList Integer64List RealList "
                              "StringList");
    poDriver->SetMetadataItem(GDAL_DMD_CREATIONFIELDDATASUBTYPES,
                              "Boolean Int16 Float32");
    poDriver->SetMetadataItem(GDAL_DCAP_HONOR_GEOM_COORDINATE_PRECISION, "YES");

    poDriver->pfnOpen = OGRCSVDriverOpen;
    poDriver->pfnIdentify = OGRCSVDriverIdentify;
    poDriver->pfnCreate = OGRCSVDriverCreate;
    poDriver->pfnDelete = OGRCSVDriverDelete;
    poDriver->pfnUnloadDriver = OGRCSVDriverUnload;

    GetGDALDriverManager()->RegisterDriver(poDriver);
}