/******************************************************************************
 *
 * Project:  GDAL Core
 * Purpose:  Python plugin loader
 * Author:   Even Rouault, <even dot rouault at spatialys dot com>
 *
 ******************************************************************************
 * Copyright (c) 2017-2019, Even Rouault, <even dot rouault at spatialys dot
 *com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "cpl_conv.h"
#include "cpl_string.h"
#include "gdal_priv.h"
#include "ogrsf_frmts.h"
#include "gdalpython.h"

#include <algorithm>
#include <memory>
#include <mutex>

using namespace GDALPy;

#ifdef GDAL_NO_AUTOLOAD
void GDALDriverManager::AutoLoadPythonDrivers()
{
}

void GDALDriverManager::CleanupPythonDrivers()
{
}

#else

static PyObject *layer_featureCount(PyObject *m, PyObject *args,
                                    PyObject *kwargs);

static const PyMethodDef gdal_python_driver_methods[] = {
    {"layer_featureCount", layer_featureCount, METH_VARARGS | METH_KEYWORDS,
     nullptr},
    {nullptr, nullptr, 0, nullptr}};

static PyObject *Py_None = nullptr;

static PyObject *gpoGDALPythonDriverModule = nullptr;

/************************************************************************/
/*                         IncRefAndReturn()                            */
/************************************************************************/

static PyObject *IncRefAndReturn(PyObject *obj)
{
    Py_IncRef(obj);
    return obj;
}

/************************************************************************/
/*                            CallPython()                              */
/************************************************************************/

static PyObject *CallPython(PyObject *function)
{
    PyObject *pyArgs = PyTuple_New(0);
    PyObject *pRet = PyObject_Call(function, pyArgs, nullptr);
    Py_DecRef(pyArgs);
    return pRet;
}

/************************************************************************/
/*                            CallPython()                              */
/************************************************************************/

static PyObject *CallPython(PyObject *function, int nVal)
{
    PyObject *pyArgs = PyTuple_New(1);
    PyTuple_SetItem(pyArgs, 0, PyLong_FromLong(nVal));
    PyObject *pRet = PyObject_Call(function, pyArgs, nullptr);
    Py_DecRef(pyArgs);
    return pRet;
}

/************************************************************************/
/*                InitializePythonAndLoadGDALPythonDriverModule() */
/************************************************************************/

static bool InitializePythonAndLoadGDALPythonDriverModule()
{
    if (!GDALPythonInitialize())
        return false;

    static std::mutex gMutex;
    static bool gbAlreadyInitialized = false;
    std::lock_guard<std::mutex> guard(gMutex);

    if (gbAlreadyInitialized)
        return true;
    gbAlreadyInitialized = true;

    GIL_Holder oHolder(false);

    static PyModuleDef gdal_python_driver_moduledef = {
        PyModuleDef_HEAD_INIT,
        "_gdal_python_driver",
        nullptr,
        static_cast<Py_ssize_t>(-1),  // sizeof(struct module_state),
        gdal_python_driver_methods,
        nullptr,
        nullptr,
        nullptr,
        nullptr};

    PyObject *module =
        PyModule_Create2(&gdal_python_driver_moduledef, PYTHON_API_VERSION);
    // Add module to importable modules
    PyObject *sys = PyImport_ImportModule("sys");
    PyObject *sys_modules = PyObject_GetAttrString(sys, "modules");
    PyDict_SetItemString(sys_modules, "_gdal_python_driver", module);
    Py_DecRef(sys_modules);
    Py_DecRef(sys);
    Py_DecRef(module);

    PyObject *poCompiledString = Py_CompileString(
        "import _gdal_python_driver\n"
        "import json\n"
        "import inspect\n"
        "import sys\n"
        "class BaseLayer(object):\n"
        "   RandomRead='RandomRead'\n"
        "   FastSpatialFilter='FastSpatialFilter'\n"
        "   FastFeatureCount='FastFeatureCount'\n"
        "   FastGetExtent='FastGetExtent'\n"
        "   StringsAsUTF8='StringsAsUTF8'\n"
        "\n"
        "   def __init__(self):\n"
        "       pass\n"
        "\n"
        "   def feature_count(self, force):\n"
        "       assert isinstance(self, BaseLayer), 'self not instance of "
        "BaseLayer'\n"
        "       return _gdal_python_driver.layer_featureCount(self, force)\n"
        "\n"
        "class BaseDataset(object):\n"
        "   def __init__(self):\n"
        "       pass\n"
        "\n"
        "class BaseDriver(object):\n"
        "   def __init__(self):\n"
        "       pass\n"
        "\n"
        "def _gdal_returnNone():\n"
        "  return None"
        "\n"
        "def _gdal_json_serialize(d):\n"
        "  return json.dumps(d)\n"
        "\n"
        "def _instantiate_plugin(plugin_module):\n"
        "   candidate = None\n"
        "   for key in dir(plugin_module):\n"
        "       elt = getattr(plugin_module, key)\n"
        "       if inspect.isclass(elt) and sys.modules[elt.__module__] == "
        "plugin_module and issubclass(elt, BaseDriver):\n"
        "           if candidate:\n"
        "               raise Exception(\"several classes in \" + "
        "plugin_module.__name__ + \" deriving from "
        "gdal_python_driver.BaseDriver\")\n"
        "           candidate = elt\n"
        "   if candidate:\n"
        "       return candidate()\n"
        "   raise Exception(\"cannot find class in \" + plugin_module.__name__ "
        "+ \" deriving from gdal_python_driver.BaseDriver\")\n",
        "gdal_python_driver", Py_file_input);
    gpoGDALPythonDriverModule =
        PyImport_ExecCodeModule("gdal_python_driver", poCompiledString);
    Py_DecRef(poCompiledString);

    // Initialize Py_None
    PyObject *returnNone =
        PyObject_GetAttrString(gpoGDALPythonDriverModule, "_gdal_returnNone");
    Py_None = CallPython(returnNone);
    Py_DecRef(returnNone);

    return true;
}

/************************************************************************/
/*                           GetIntRes()                                */
/************************************************************************/

static int GetIntRes(PyObject *poObj, const char *pszFunctionName)
{
    PyObject *poMethod = PyObject_GetAttrString(poObj, pszFunctionName);
    if (poMethod == nullptr || PyErr_Occurred())
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s",
                 GetPyExceptionString().c_str());
        return 0;
    }

    PyObject *poMethodRes = CallPython(poMethod);
    if (ErrOccurredEmitCPLError())
    {
        Py_DecRef(poMethod);
        return 0;
    }
    Py_DecRef(poMethod);

    int nRes = static_cast<int>(PyLong_AsLong(poMethodRes));
    if (ErrOccurredEmitCPLError())
    {
        Py_DecRef(poMethodRes);
        return 0;
    }

    Py_DecRef(poMethodRes);
    return nRes;
}

/************************************************************************/
/*                           GetDict()                                  */
/************************************************************************/

static char **GetDict(PyObject *poDict)
{
    PyObject *key, *value;
    size_t pos = 0;

    char **papszRes = nullptr;
    while (PyDict_Next(poDict, &pos, &key, &value))
    {
        if (ErrOccurredEmitCPLError())
        {
            break;
        }
        CPLString osKey = GetString(key);
        if (ErrOccurredEmitCPLError())
        {
            break;
        }
        CPLString osValue = GetString(value);
        if (ErrOccurredEmitCPLError())
        {
            break;
        }
        papszRes = CSLSetNameValue(papszRes, osKey, osValue);
    }
    return papszRes;
}

/************************************************************************/
/*                          GetStringRes()                              */
/************************************************************************/

static CPLString GetStringRes(PyObject *poObj, const char *pszFunctionName,
                              bool bOptionalMethod = false)
{
    PyObject *poMethod = PyObject_GetAttrString(poObj, pszFunctionName);
    if (poMethod == nullptr || PyErr_Occurred())
    {
        if (bOptionalMethod)
        {
            PyErr_Clear();
        }
        else
        {
            CPLError(CE_Failure, CPLE_AppDefined, "%s",
                     GetPyExceptionString().c_str());
        }
        return CPLString();
    }

    PyObject *poMethodRes = CallPython(poMethod);

    if (ErrOccurredEmitCPLError())
    {
        Py_DecRef(poMethod);
        return CPLString();
    }
    Py_DecRef(poMethod);

    CPLString osRes = GetString(poMethodRes);
    if (ErrOccurredEmitCPLError())
    {
        Py_DecRef(poMethodRes);
        return CPLString();
    }

    Py_DecRef(poMethodRes);
    return osRes;
}

/************************************************************************/
/*                          PythonPluginLayer                           */
/************************************************************************/

class PythonPluginLayer final : public OGRLayer
{
    PyObject *m_poLayer = nullptr;
    OGRFeatureDefn *m_poFeatureDefn = nullptr;
    CPLString m_osName{};
    CPLString m_osFIDColumn{};
    bool m_bHasFIDColumn = false;
    std::map<CPLString, CPLStringList> m_oMapMD{};
    PyObject *m_pyFeatureByIdMethod = nullptr;
    bool m_bIteratorHonourSpatialFilter = false;
    bool m_bIteratorHonourAttributeFilter = false;
    bool m_bFeatureCountHonourSpatialFilter = false;
    bool m_bFeatureCountHonourAttributeFilter = false;
    PyObject *m_pyIterator = nullptr;
    bool m_bStopIteration = false;

    void RefreshHonourFlags();
    void StoreSpatialFilter();

    void GetFields();
    void GetGeomFields();
    OGRFeature *TranslateToOGRFeature(PyObject *poObj);

    PythonPluginLayer(const PythonPluginLayer &) = delete;
    PythonPluginLayer &operator=(const PythonPluginLayer &) = delete;

  public:
    explicit PythonPluginLayer(PyObject *poLayer);
    ~PythonPluginLayer();

    const char *GetName() override;
    void ResetReading() override;
    OGRFeature *GetNextFeature() override;
    OGRFeature *GetFeature(GIntBig nFID) override;
    int TestCapability(const char *) override;
    OGRFeatureDefn *GetLayerDefn() override;

    GIntBig GetFeatureCount(int bForce) override;
    const char *GetFIDColumn() override;
    OGRErr SetAttributeFilter(const char *) override;

    void SetSpatialFilter(OGRGeometry *) override;
    void SetSpatialFilter(int iGeomField, OGRGeometry *) override;

    OGRErr GetExtent(OGREnvelope *psExtent, int bForce) override;

    OGRErr GetExtent(int iGeomField, OGREnvelope *psExtent, int bForce) override
    {
        return OGRLayer::GetExtent(iGeomField, psExtent, bForce);
    }

    char **GetMetadata(const char *pszDomain = "") override;
};

/************************************************************************/
/*                          PythonPluginLayer()                         */
/************************************************************************/

PythonPluginLayer::PythonPluginLayer(PyObject *poLayer)
    : m_poLayer(poLayer), m_poFeatureDefn(nullptr)
{
    SetDescription(PythonPluginLayer::GetName());
    const char *pszPtr = CPLSPrintf("%p", this);
    PyObject *ptr = PyUnicode_FromString(pszPtr);
    PyObject_SetAttrString(m_poLayer, "_gdal_pointer", ptr);
    Py_DecRef(ptr);
    PyObject_SetAttrString(m_poLayer, "spatial_filter_extent", Py_None);
    PyObject_SetAttrString(m_poLayer, "spatial_filter", Py_None);
    PyObject_SetAttrString(m_poLayer, "attribute_filter", Py_None);
    auto poFalse = PyBool_FromLong(false);
    if (!PyObject_HasAttrString(m_poLayer, "iterator_honour_attribute_filter"))
    {
        PyObject_SetAttrString(m_poLayer, "iterator_honour_attribute_filter",
                               poFalse);
    }
    if (!PyObject_HasAttrString(m_poLayer, "iterator_honour_spatial_filter"))
    {
        PyObject_SetAttrString(m_poLayer, "iterator_honour_spatial_filter",
                               poFalse);
    }
    if (!PyObject_HasAttrString(m_poLayer,
                                "feature_count_honour_attribute_filter"))
    {
        PyObject_SetAttrString(
            m_poLayer, "feature_count_honour_attribute_filter", poFalse);
    }
    if (!PyObject_HasAttrString(m_poLayer,
                                "feature_count_honour_spatial_filter"))
    {
        PyObject_SetAttrString(m_poLayer, "feature_count_honour_spatial_filter",
                               poFalse);
    }
    Py_DecRef(poFalse);
    RefreshHonourFlags();

    if (PyObject_HasAttrString(m_poLayer, "feature_by_id"))
    {
        m_pyFeatureByIdMethod =
            PyObject_GetAttrString(m_poLayer, "feature_by_id");
    }
}

/************************************************************************/
/*                          ~PythonPluginLayer()                        */
/************************************************************************/

PythonPluginLayer::~PythonPluginLayer()
{
    GIL_Holder oHolder(false);
    if (m_poFeatureDefn)
        m_poFeatureDefn->Release();
    Py_DecRef(m_pyFeatureByIdMethod);
    Py_DecRef(m_poLayer);
    Py_DecRef(m_pyIterator);
}

/************************************************************************/
/*                        RefreshHonourFlags()               */
/************************************************************************/

void PythonPluginLayer::RefreshHonourFlags()
{
    if (PyObject_HasAttrString(m_poLayer, "iterator_honour_attribute_filter"))
    {
        auto poObj = PyObject_GetAttrString(m_poLayer,
                                            "iterator_honour_attribute_filter");
        m_bIteratorHonourAttributeFilter = PyLong_AsLong(poObj) != 0;
        Py_DecRef(poObj);
    }
    if (PyObject_HasAttrString(m_poLayer, "iterator_honour_spatial_filter"))
    {
        auto poObj =
            PyObject_GetAttrString(m_poLayer, "iterator_honour_spatial_filter");
        m_bIteratorHonourSpatialFilter = PyLong_AsLong(poObj) != 0;
        Py_DecRef(poObj);
    }
    if (PyObject_HasAttrString(m_poLayer,
                               "feature_count_honour_attribute_filter"))
    {
        auto poObj = PyObject_GetAttrString(
            m_poLayer, "feature_count_honour_attribute_filter");
        m_bFeatureCountHonourAttributeFilter = PyLong_AsLong(poObj) != 0;
        Py_DecRef(poObj);
    }
    if (PyObject_HasAttrString(m_poLayer,
                               "feature_count_honour_spatial_filter"))
    {
        auto poObj = PyObject_GetAttrString(
            m_poLayer, "feature_count_honour_spatial_filter");
        m_bFeatureCountHonourSpatialFilter = PyLong_AsLong(poObj) != 0;
        Py_DecRef(poObj);
    }
}

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

OGRErr PythonPluginLayer::SetAttributeFilter(const char *pszFilter)
{
    GIL_Holder oHolder(false);
    PyObject *str =
        pszFilter ? PyUnicode_FromString(pszFilter) : IncRefAndReturn(Py_None);
    PyObject_SetAttrString(m_poLayer, "attribute_filter", str);
    Py_DecRef(str);

    if (PyObject_HasAttrString(m_poLayer, "attribute_filter_changed"))
    {
        auto poObj =
            PyObject_GetAttrString(m_poLayer, "attribute_filter_changed");
        Py_DecRef(CallPython(poObj));
        Py_DecRef(poObj);
    }

    return OGRLayer::SetAttributeFilter(pszFilter);
}

/************************************************************************/
/*                          StoreSpatialFilter()                        */
/************************************************************************/

void PythonPluginLayer::StoreSpatialFilter()
{
    GIL_Holder oHolder(false);
    if (m_poFilterGeom && !m_poFilterGeom->IsEmpty())
    {
        PyObject *list = PyList_New(4);
        PyList_SetItem(list, 0, PyFloat_FromDouble(m_sFilterEnvelope.MinX));
        PyList_SetItem(list, 1, PyFloat_FromDouble(m_sFilterEnvelope.MinY));
        PyList_SetItem(list, 2, PyFloat_FromDouble(m_sFilterEnvelope.MaxX));
        PyList_SetItem(list, 3, PyFloat_FromDouble(m_sFilterEnvelope.MaxY));
        PyObject_SetAttrString(m_poLayer, "spatial_filter_extent", list);
        Py_DecRef(list);

        char *pszWKT = nullptr;
        m_poFilterGeom->exportToWkt(&pszWKT);
        PyObject *str = PyUnicode_FromString(pszWKT);
        PyObject_SetAttrString(m_poLayer, "spatial_filter", str);
        Py_DecRef(str);
        CPLFree(pszWKT);
    }
    else
    {
        PyObject_SetAttrString(m_poLayer, "spatial_filter_extent", Py_None);
        PyObject_SetAttrString(m_poLayer, "spatial_filter", Py_None);
    }

    if (PyObject_HasAttrString(m_poLayer, "spatial_filter_changed"))
    {
        auto poObj =
            PyObject_GetAttrString(m_poLayer, "spatial_filter_changed");
        Py_DecRef(CallPython(poObj));
        Py_DecRef(poObj);
    }
}

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

void PythonPluginLayer::SetSpatialFilter(OGRGeometry *poGeom)
{
    OGRLayer::SetSpatialFilter(poGeom);
    StoreSpatialFilter();
}

void PythonPluginLayer::SetSpatialFilter(int iGeomField, OGRGeometry *poGeom)
{
    OGRLayer::SetSpatialFilter(iGeomField, poGeom);
    StoreSpatialFilter();
}

/************************************************************************/
/*                           GetName()                                  */
/************************************************************************/

const char *PythonPluginLayer::GetName()
{
    if (m_osName.empty())
    {
        GIL_Holder oHolder(false);

        PyObject *poObj = PyObject_GetAttrString(m_poLayer, "name");
        if (ErrOccurredEmitCPLError())
            return m_osName;
        if (PyCallable_Check(poObj))
        {
            m_osName = GetStringRes(m_poLayer, "name");
        }
        else
        {
            m_osName = GetString(poObj);
            CPL_IGNORE_RET_VAL(ErrOccurredEmitCPLError());
        }
        Py_DecRef(poObj);
    }
    return m_osName;
}

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

int PythonPluginLayer::TestCapability(const char *pszCap)
{
    GIL_Holder oHolder(false);
    if (PyObject_HasAttrString(m_poLayer, "test_capability"))
    {
        PyObject *poObj = PyObject_GetAttrString(m_poLayer, "test_capability");
        if (ErrOccurredEmitCPLError())
            return 0;
        PyObject *pyArgs = PyTuple_New(1);
        PyTuple_SetItem(pyArgs, 0, PyUnicode_FromString(pszCap));
        PyObject *pRet = PyObject_Call(poObj, pyArgs, nullptr);
        Py_DecRef(pyArgs);
        Py_DecRef(poObj);
        if (ErrOccurredEmitCPLError())
        {
            Py_DecRef(pRet);
            return 0;
        }
        int nRes = static_cast<int>(PyLong_AsLong(pRet));
        Py_DecRef(pRet);
        if (ErrOccurredEmitCPLError())
        {
            return 0;
        }
        return nRes;
    }
    return 0;
}

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

const char *PythonPluginLayer::GetFIDColumn()
{
    if (!m_bHasFIDColumn)
    {
        m_bHasFIDColumn = true;
        GIL_Holder oHolder(false);
        PyObject *poObj = PyObject_GetAttrString(m_poLayer, "fid_name");
        if (PyErr_Occurred())
        {
            PyErr_Clear();
        }
        else
        {
            if (PyCallable_Check(poObj))
            {
                m_osFIDColumn = GetStringRes(m_poLayer, "fid_name", true);
            }
            else
            {
                m_osFIDColumn = GetString(poObj);
                CPL_IGNORE_RET_VAL(ErrOccurredEmitCPLError());
            }
            Py_DecRef(poObj);
        }
    }
    return m_osFIDColumn;
}

/************************************************************************/
/*                        layer_featureCount()                           */
/************************************************************************/

static PyObject *layer_featureCount(PyObject * /*m*/, PyObject *args,
                                    PyObject * /*kwargs*/)
{
    PyObject *poPyLayer = nullptr;
    int bForce = 0;
    if (PyArg_ParseTuple(args, "O|i", &poPyLayer, &bForce))
    {
        PyObject *poPointer =
            PyObject_GetAttrString(poPyLayer, "_gdal_pointer");
        if (poPointer)
        {
            CPLString osPtr = GetString(poPointer);
            Py_DecRef(poPointer);
            void *pPtr = nullptr;
            sscanf(osPtr, "%p", &pPtr);
            PythonPluginLayer *poLayer = static_cast<PythonPluginLayer *>(pPtr);
            return PyLong_FromLongLong(
                poLayer->OGRLayer::GetFeatureCount(bForce));
        }
    }
    Py_IncRef(Py_None);
    return Py_None;
}

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

GIntBig PythonPluginLayer::GetFeatureCount(int bForce)
{
    GIL_Holder oHolder(false);

    if (PyObject_HasAttrString(m_poLayer, "feature_count") &&
        (m_bFeatureCountHonourAttributeFilter || m_poAttrQuery == nullptr) &&
        (m_bFeatureCountHonourSpatialFilter || m_poFilterGeom == nullptr))
    {
        auto poMethod = PyObject_GetAttrString(m_poLayer, "feature_count");
        PyObject *poRet = CallPython(poMethod, bForce);
        if (ErrOccurredEmitCPLError())
        {
            Py_DecRef(poRet);
            return OGRLayer::GetFeatureCount(bForce);
        }

        GIntBig nRet = PyLong_AsLongLong(poRet);
        if (ErrOccurredEmitCPLError())
        {
            Py_DecRef(poRet);
            return OGRLayer::GetFeatureCount(bForce);
        }

        Py_DecRef(poRet);
        return nRet;
    }
    return OGRLayer::GetFeatureCount(bForce);
}

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

OGRErr PythonPluginLayer::GetExtent(OGREnvelope *psExtent, int bForce)
{
    GIL_Holder oHolder(false);
    if (PyObject_HasAttrString(m_poLayer, "extent"))
    {
        PyObject *poMethod = PyObject_GetAttrString(m_poLayer, "extent");
        if (poMethod != nullptr)
        {
            PyObject *poRet = CallPython(poMethod, bForce);

            if (ErrOccurredEmitCPLError())
            {
                Py_DecRef(poRet);
                return OGRLayer::GetExtent(psExtent, bForce);
            }

            if (poRet == Py_None)
            {
                Py_DecRef(poRet);
                return OGRERR_FAILURE;
            }

            if (PySequence_Size(poRet) == 4)
            {
                PyObject *poMinX = PySequence_GetItem(poRet, 0);
                PyObject *poMinY = PySequence_GetItem(poRet, 1);
                PyObject *poMaxX = PySequence_GetItem(poRet, 2);
                PyObject *poMaxY = PySequence_GetItem(poRet, 3);
                double dfMinX = PyFloat_AsDouble(poMinX);
                double dfMinY = PyFloat_AsDouble(poMinY);
                double dfMaxX = PyFloat_AsDouble(poMaxX);
                double dfMaxY = PyFloat_AsDouble(poMaxY);
                if (ErrOccurredEmitCPLError())
                {
                    Py_DecRef(poRet);
                    return OGRLayer::GetExtent(psExtent, bForce);
                }
                Py_DecRef(poRet);
                psExtent->MinX = dfMinX;
                psExtent->MinY = dfMinY;
                psExtent->MaxX = dfMaxX;
                psExtent->MaxY = dfMaxY;
                return OGRERR_NONE;
            }
            else
            {
                CPLError(CE_Failure, CPLE_AppDefined,
                         "List should have 4 values");
            }

            Py_DecRef(poRet);
        }
    }
    return OGRLayer::GetExtent(psExtent, bForce);
}

/************************************************************************/
/*                      TranslateToOGRFeature()                         */
/************************************************************************/

OGRFeature *PythonPluginLayer::TranslateToOGRFeature(PyObject *poObj)
{
    if (poObj == Py_None)
        return nullptr;

    OGRFeature *poFeature = new OGRFeature(GetLayerDefn());

    PyObject *myBool = PyBool_FromLong(1);
    PyObject *myBoolType = PyObject_Type(myBool);
    PyObject *myInt = PyLong_FromLong(1);
    PyObject *myIntType = PyObject_Type(myInt);
    PyObject *myLong = PyLong_FromLongLong(1);
    PyObject *myLongType = PyObject_Type(myLong);
    PyObject *myFloat = PyFloat_FromDouble(1.0);
    PyObject *myFloatType = PyObject_Type(myFloat);
    PyObject *myStr = PyUnicode_FromString("");
    PyObject *myStrType = PyObject_Type(myStr);

    auto poFields = PyDict_GetItemString(poObj, "fields");
    auto poGeometryFields = PyDict_GetItemString(poObj, "geometry_fields");
    auto poId = PyDict_GetItemString(poObj, "id");
    auto poStyleString = PyDict_GetItemString(poObj, "style");
    PyErr_Clear();

    if (poId && PyObject_IsInstance(poId, myLongType))
    {
        poFeature->SetFID(static_cast<GIntBig>(PyLong_AsLongLong(poId)));
    }
    else if (poId && PyObject_IsInstance(poId, myIntType))
    {
        poFeature->SetFID(static_cast<GIntBig>(PyLong_AsLong(poId)));
    }

    if (poStyleString && poStyleString != Py_None)
    {
        CPLString osValue = GetString(poStyleString);
        if (!ErrOccurredEmitCPLError())
        {
            poFeature->SetStyleString(osValue);
        }
    }

    if (poGeometryFields && poGeometryFields != Py_None)
    {
        PyObject *key = nullptr;
        PyObject *value = nullptr;
        size_t pos = 0;
        while (PyDict_Next(poGeometryFields, &pos, &key, &value))
        {
            CPLString osKey = GetString(key);
            if (ErrOccurredEmitCPLError())
            {
                break;
            }
            if (value != Py_None)
            {
                const int idx = m_poFeatureDefn->GetGeomFieldIndex(osKey);
                if (idx >= 0)
                {
                    OGRGeometry *poGeom = nullptr;
                    if (PyObject_IsInstance(value, myStrType))
                    {
                        // WKT
                        CPLString osValue = GetString(value);
                        if (ErrOccurredEmitCPLError())
                        {
                            break;
                        }
                        OGRGeometryFactory::createFromWkt(osValue.c_str(),
                                                          nullptr, &poGeom);
                    }
                    else
                    {
                        // WKB (from bytes, bytearray, memoryview)
                        PyObject *poBytes = PyBytes_FromObject(value);
                        if (ErrOccurredEmitCPLError())
                        {
                            break;
                        }
                        char *buffer = nullptr;
                        size_t length = 0;
                        PyBytes_AsStringAndSize(poBytes, &buffer, &length);
                        if (ErrOccurredEmitCPLError())
                        {
                            break;
                        }

                        OGRGeometryFactory::createFromWkb(
                            buffer, nullptr, &poGeom, length, wkbVariantIso);
                    }

                    if (poGeom)
                    {
                        const auto poGeomFieldDefn =
                            m_poFeatureDefn->GetGeomFieldDefn(idx);
                        if (poGeomFieldDefn)
                            poGeom->assignSpatialReference(
                                poGeomFieldDefn->GetSpatialRef());
                    }
                    poFeature->SetGeomFieldDirectly(idx, poGeom);
                }
            }
        }
    }

    PyObject *key = nullptr;
    PyObject *value = nullptr;
    size_t pos = 0;
    while (poFields && poFields != Py_None &&
           PyDict_Next(poFields, &pos, &key, &value))
    {
        CPLString osKey = GetString(key);
        if (ErrOccurredEmitCPLError())
        {
            break;
        }

        if (value == Py_None)
        {
            int idx = m_poFeatureDefn->GetFieldIndex(osKey);
            if (idx >= 0)
            {
                poFeature->SetFieldNull(idx);
            }
        }
        else if (PyObject_IsInstance(value, myLongType))
        {
            int idx = m_poFeatureDefn->GetFieldIndex(osKey);
            if (idx >= 0)
            {
                poFeature->SetField(
                    idx, static_cast<GIntBig>(PyLong_AsLongLong(value)));
            }
        }
        else if (PyObject_IsInstance(value, myBoolType) ||
                 PyObject_IsInstance(value, myIntType))
        {
            int idx = m_poFeatureDefn->GetFieldIndex(osKey);
            if (idx >= 0)
            {
                poFeature->SetField(idx,
                                    static_cast<GIntBig>(PyLong_AsLong(value)));
            }
        }
        else if (PyObject_IsInstance(value, myFloatType))
        {
            int idx = m_poFeatureDefn->GetFieldIndex(osKey);
            if (idx >= 0)
            {
                poFeature->SetField(idx, PyFloat_AsDouble(value));
            }
        }
        else
        {
            int idx = m_poFeatureDefn->GetFieldIndex(osKey);
            if (idx >= 0 &&
                m_poFeatureDefn->GetFieldDefn(idx)->GetType() == OFTBinary)
            {
                Py_ssize_t nSize = PyBytes_Size(value);
                const char *pszBytes = PyBytes_AsString(value);
                poFeature->SetField(
                    idx, static_cast<int>(nSize),
                    const_cast<GByte *>(
                        reinterpret_cast<const GByte *>(pszBytes)));
                continue;
            }

            CPLString osValue = GetString(value);
            if (ErrOccurredEmitCPLError())
            {
                break;
            }
            if (idx >= 0)
            {
                poFeature->SetField(idx, osValue);
            }
        }
    }

    Py_DecRef(myBoolType);
    Py_DecRef(myBool);
    Py_DecRef(myIntType);
    Py_DecRef(myInt);
    Py_DecRef(myLongType);
    Py_DecRef(myLong);
    Py_DecRef(myFloatType);
    Py_DecRef(myFloat);
    Py_DecRef(myStr);
    Py_DecRef(myStrType);

    return poFeature;
}

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

OGRFeature *PythonPluginLayer::GetFeature(GIntBig nFID)
{
    GIL_Holder oHolder(false);

    if (m_pyFeatureByIdMethod)
    {
        PyObject *pyArgs = PyTuple_New(1);
        PyTuple_SetItem(pyArgs, 0, PyLong_FromLongLong(nFID));
        PyObject *pRet = PyObject_Call(m_pyFeatureByIdMethod, pyArgs, nullptr);
        Py_DecRef(pyArgs);
        if (ErrOccurredEmitCPLError())
        {
            Py_DecRef(pRet);
            return nullptr;
        }
        auto poFeature = TranslateToOGRFeature(pRet);
        Py_DecRef(pRet);
        if (ErrOccurredEmitCPLError())
        {
            return nullptr;
        }
        return poFeature;
    }
    return OGRLayer::GetFeature(nFID);
}

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

void PythonPluginLayer::ResetReading()
{
    m_bStopIteration = false;

    GIL_Holder oHolder(false);

    Py_DecRef(m_pyIterator);
    m_pyIterator = PyObject_GetIter(m_poLayer);
    CPL_IGNORE_RET_VAL(ErrOccurredEmitCPLError());
}

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

OGRFeature *PythonPluginLayer::GetNextFeature()
{
    GIL_Holder oHolder(false);

    if (m_bStopIteration)
        return nullptr;

    if (m_pyIterator == nullptr)
    {
        ResetReading();
        if (m_pyIterator == nullptr)
        {
            return nullptr;
        }
    }

    while (true)
    {
        PyObject *poRet = PyIter_Next(m_pyIterator);
        if (poRet == nullptr)
        {
            m_bStopIteration = true;
            CPL_IGNORE_RET_VAL(ErrOccurredEmitCPLError());
            return nullptr;
        }

        auto poFeature = TranslateToOGRFeature(poRet);
        Py_DecRef(poRet);
        if (poFeature == nullptr)
        {
            return nullptr;
        }

        if ((m_bIteratorHonourSpatialFilter || m_poFilterGeom == nullptr ||
             FilterGeometry(poFeature->GetGeomFieldRef(m_iGeomFieldFilter))) &&
            (m_bIteratorHonourAttributeFilter || m_poAttrQuery == nullptr ||
             m_poAttrQuery->Evaluate(poFeature)))
        {
            return poFeature;
        }

        delete poFeature;
    }
}

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

OGRFeatureDefn *PythonPluginLayer::GetLayerDefn()
{
    if (m_poFeatureDefn)
        return m_poFeatureDefn;

    GIL_Holder oHolder(false);
    m_poFeatureDefn = new OGRFeatureDefn(GetName());
    m_poFeatureDefn->Reference();
    m_poFeatureDefn->SetGeomType(wkbNone);

    GetFields();
    GetGeomFields();
    return m_poFeatureDefn;
}

/************************************************************************/
/*                           GetFields()                                */
/************************************************************************/

void PythonPluginLayer::GetFields()
{
    PyObject *poFields = PyObject_GetAttrString(m_poLayer, "fields");
    if (ErrOccurredEmitCPLError())
        return;
    if (PyCallable_Check(poFields))
    {
        PyObject *poFieldsRes = CallPython(poFields);
        if (ErrOccurredEmitCPLError())
        {
            Py_DecRef(poFields);

            return;
        }
        Py_DecRef(poFields);
        poFields = poFieldsRes;
    }

    size_t nSize = PySequence_Size(poFields);
    if (ErrOccurredEmitCPLError())
    {
        Py_DecRef(poFields);

        return;
    }
    for (size_t i = 0; i < nSize; i++)
    {
        PyObject *poItem = PySequence_GetItem(poFields, i);
        if (poItem == nullptr || PyErr_Occurred())
        {
            CPLError(CE_Failure, CPLE_AppDefined, "%s",
                     GetPyExceptionString().c_str());
            Py_DecRef(poFields);

            return;
        }

        PyObject *key, *value;
        size_t pos = 0;
        CPLString osFieldName;
        OGRFieldType eType = OFTString;
        OGRFieldSubType eSubType = OFSTNone;
        while (PyDict_Next(poItem, &pos, &key, &value))
        {
            if (ErrOccurredEmitCPLError())
            {
                Py_DecRef(poFields);

                return;
            }
            CPLString osKey = GetString(key);
            if (ErrOccurredEmitCPLError())
            {
                Py_DecRef(poFields);

                return;
            }
            if (strcmp(osKey, "name") == 0)
            {
                osFieldName = GetString(value);
                if (ErrOccurredEmitCPLError())
                {
                    Py_DecRef(poFields);

                    return;
                }
            }
            else if (strcmp(osKey, "type") == 0)
            {
                PyObject *myInt = PyLong_FromLong(1);
                PyObject *myIntType = PyObject_Type(myInt);
                if (PyObject_IsInstance(value, myIntType))
                {
                    int nType = static_cast<int>(PyLong_AsLong(value));
                    if (nType < 0 || nType > OFTMaxType)
                    {
                        CPLError(CE_Failure, CPLE_AppDefined, "Wrong type: %d",
                                 nType);
                    }
                    else
                    {
                        eType = static_cast<OGRFieldType>(nType);
                        if (ErrOccurredEmitCPLError())
                        {
                            Py_DecRef(poFields);

                            return;
                        }
                    }
                }
                else
                {
                    CPLString osValue = GetString(value);
                    if (ErrOccurredEmitCPLError())
                    {
                        Py_DecRef(poFields);

                        return;
                    }
                    if (EQUAL(osValue, "String"))
                        eType = OFTString;
                    else if (EQUAL(osValue, "Integer") ||
                             EQUAL(osValue, "Integer32") ||
                             EQUAL(osValue, "Int32"))
                        eType = OFTInteger;
                    else if (EQUAL(osValue, "Boolean"))
                    {
                        eType = OFTInteger;
                        eSubType = OFSTBoolean;
                    }
                    else if (EQUAL(osValue, "Integer16") ||
                             EQUAL(osValue, "Int16"))
                    {
                        eType = OFTInteger;
                        eSubType = OFSTInt16;
                    }
                    else if (EQUAL(osValue, "Integer64") ||
                             EQUAL(osValue, "Int64"))
                        eType = OFTInteger64;
                    else if (EQUAL(osValue, "Real"))
                        eType = OFTReal;
                    else if (EQUAL(osValue, "Float") ||
                             EQUAL(osValue, "Float32"))
                    {
                        eType = OFTReal;
                        eSubType = OFSTFloat32;
                    }
                    else if (EQUAL(osValue, "Binary"))
                        eType = OFTBinary;
                    else if (EQUAL(osValue, "DateTime"))
                        eType = OFTDateTime;
                    else if (EQUAL(osValue, "Date"))
                        eType = OFTDate;
                    else if (EQUAL(osValue, "Time"))
                        eType = OFTTime;
                    else
                    {
                        CPLError(CE_Failure, CPLE_AppDefined, "Wrong type: %s",
                                 osValue.c_str());
                    }
                }
                Py_DecRef(myInt);
                Py_DecRef(myIntType);
            }
            else
            {
                CPLDebug("GDAL", "Unknown field property: %s", osKey.c_str());
            }
        }

        if (!osFieldName.empty())
        {
            OGRFieldDefn oFieldDefn(osFieldName, eType);
            oFieldDefn.SetSubType(eSubType);
            m_poFeatureDefn->AddFieldDefn(&oFieldDefn);
        }
    }

    Py_DecRef(poFields);
}

/************************************************************************/
/*                         GetGeomFields()                              */
/************************************************************************/

void PythonPluginLayer::GetGeomFields()
{
    PyObject *poFields = PyObject_GetAttrString(m_poLayer, "geometry_fields");
    if (ErrOccurredEmitCPLError())
        return;
    if (PyCallable_Check(poFields))
    {
        PyObject *poFieldsRes = CallPython(poFields);
        if (ErrOccurredEmitCPLError())
        {
            Py_DecRef(poFields);

            return;
        }
        Py_DecRef(poFields);
        poFields = poFieldsRes;
    }

    size_t nSize = PySequence_Size(poFields);
    if (ErrOccurredEmitCPLError())
    {
        Py_DecRef(poFields);

        return;
    }
    for (size_t i = 0; i < nSize; i++)
    {
        PyObject *poItem = PySequence_GetItem(poFields, i);
        if (poItem == nullptr || PyErr_Occurred())
        {
            CPLError(CE_Failure, CPLE_AppDefined, "%s",
                     GetPyExceptionString().c_str());
            Py_DecRef(poFields);

            return;
        }

        PyObject *key, *value;
        size_t pos = 0;
        CPLString osFieldName, osSRS;
        OGRwkbGeometryType eType = wkbUnknown;
        while (PyDict_Next(poItem, &pos, &key, &value))
        {
            if (ErrOccurredEmitCPLError())
            {
                Py_DecRef(poFields);

                return;
            }
            CPLString osKey = GetString(key);
            if (ErrOccurredEmitCPLError())
            {
                Py_DecRef(poFields);

                return;
            }
            if (strcmp(osKey, "name") == 0)
            {
                osFieldName = GetString(value);
                if (ErrOccurredEmitCPLError())
                {
                    Py_DecRef(poFields);

                    return;
                }
            }
            else if (strcmp(osKey, "type") == 0)
            {
                PyObject *myInt = PyLong_FromLong(1);
                PyObject *myIntType = PyObject_Type(myInt);
                if (PyObject_IsInstance(value, myIntType))
                {
                    eType =
                        static_cast<OGRwkbGeometryType>(PyLong_AsLong(value));
                    if (ErrOccurredEmitCPLError())
                    {
                        Py_DecRef(poFields);

                        return;
                    }
                }
                else
                {
                    CPLString osValue = GetString(value);
                    if (ErrOccurredEmitCPLError())
                    {
                        Py_DecRef(poFields);

                        return;
                    }
                    eType = OGRFromOGCGeomType(osValue);
                    if (eType == wkbUnknown && !EQUAL(osValue, "Geometry"))
                    {
                        CPLError(CE_Failure, CPLE_AppDefined, "Wrong type: %s",
                                 osValue.c_str());
                    }
                }
                Py_DecRef(myInt);
                Py_DecRef(myIntType);
            }
            else if (strcmp(osKey, "srs") == 0)
            {
                if (value != Py_None)
                {
                    osSRS = GetString(value);
                    if (ErrOccurredEmitCPLError())
                    {
                        Py_DecRef(poFields);

                        return;
                    }
                }
            }
            else
            {
                CPLDebug("GDAL", "Unknown geometry field property: %s",
                         osKey.c_str());
            }
        }

        OGRGeomFieldDefn oFieldDefn(osFieldName, eType);
        if (!osSRS.empty())
        {
            OGRSpatialReference *poSRS = new OGRSpatialReference();
            poSRS->SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER);
            poSRS->SetFromUserInput(
                osSRS, OGRSpatialReference::SET_FROM_USER_INPUT_LIMITATIONS);
            oFieldDefn.SetSpatialRef(poSRS);
            poSRS->Release();
        }
        m_poFeatureDefn->AddGeomFieldDefn(&oFieldDefn);
    }

    Py_DecRef(poFields);
}

/************************************************************************/
/*                          GetMetadata()                               */
/************************************************************************/

static char **GetMetadata(PyObject *obj, const char *pszDomain)
{
    if (!PyObject_HasAttrString(obj, "metadata"))
        return nullptr;
    PyObject *poMetadata = PyObject_GetAttrString(obj, "metadata");
    CPLAssert(poMetadata);
    PyObject *poMethodRes;
    if (PyCallable_Check(poMetadata))
    {
        PyObject *pyArgs = PyTuple_New(1);
        PyTuple_SetItem(pyArgs, 0,
                        pszDomain && pszDomain[0]
                            ? PyUnicode_FromString(pszDomain)
                            : IncRefAndReturn(Py_None));
        poMethodRes = PyObject_Call(poMetadata, pyArgs, nullptr);
        Py_DecRef(pyArgs);
        Py_DecRef(poMetadata);

        if (ErrOccurredEmitCPLError())
        {
            return nullptr;
        }
    }
    else
    {
        poMethodRes = poMetadata;
    }

    if (poMethodRes == Py_None)
    {
        Py_DecRef(poMethodRes);
        return nullptr;
    }
    char **papszMD = GetDict(poMethodRes);
    Py_DecRef(poMethodRes);
    return papszMD;
}

/************************************************************************/
/*                          GetMetadata()                               */
/************************************************************************/

char **PythonPluginLayer::GetMetadata(const char *pszDomain)
{
    GIL_Holder oHolder(false);
    if (pszDomain == nullptr)
        pszDomain = "";
    m_oMapMD[pszDomain] = CPLStringList(::GetMetadata(m_poLayer, pszDomain));
    return m_oMapMD[pszDomain].List();
}

/************************************************************************/
/*                         PythonPluginDataset                          */
/************************************************************************/

class PythonPluginDataset final : public GDALDataset
{
    PyObject *m_poDataset = nullptr;
    std::map<int, std::unique_ptr<OGRLayer>> m_oMapLayer{};
    std::map<CPLString, CPLStringList> m_oMapMD{};
    bool m_bHasLayersMember = false;

    PythonPluginDataset(const PythonPluginDataset &) = delete;
    PythonPluginDataset &operator=(const PythonPluginDataset &) = delete;

  public:
    PythonPluginDataset(GDALOpenInfo *poOpenInfo, PyObject *poDataset);
    ~PythonPluginDataset();

    int GetLayerCount() override;
    OGRLayer *GetLayer(int) override;
    char **GetMetadata(const char *pszDomain = "") override;
};

/************************************************************************/
/*                         PythonPluginDataset()                        */
/************************************************************************/

PythonPluginDataset::PythonPluginDataset(GDALOpenInfo *poOpenInfo,
                                         PyObject *poDataset)
    : m_poDataset(poDataset)
{
    SetDescription(poOpenInfo->pszFilename);

    GIL_Holder oHolder(false);

    const auto poLayers = PyObject_GetAttrString(m_poDataset, "layers");
    PyErr_Clear();
    if (poLayers)
    {
        if (PySequence_Check(poLayers))
        {
            m_bHasLayersMember = true;
            const int nSize = static_cast<int>(PySequence_Size(poLayers));
            for (int i = 0; i < nSize; i++)
            {
                const auto poLayer = PySequence_GetItem(poLayers, i);
                Py_IncRef(poLayer);
                m_oMapLayer[i] = std::unique_ptr<PythonPluginLayer>(
                    new PythonPluginLayer(poLayer));
            }
        }
        Py_DecRef(poLayers);
    }
}

/************************************************************************/
/*                        ~PythonPluginDataset()                        */
/************************************************************************/

PythonPluginDataset::~PythonPluginDataset()
{
    GIL_Holder oHolder(false);

    if (m_poDataset && PyObject_HasAttrString(m_poDataset, "close"))
    {
        PyObject *poClose = PyObject_GetAttrString(m_poDataset, "close");
        PyObject *pyArgs = PyTuple_New(0);
        Py_DecRef(PyObject_Call(poClose, pyArgs, nullptr));
        Py_DecRef(pyArgs);
        Py_DecRef(poClose);

        CPL_IGNORE_RET_VAL(ErrOccurredEmitCPLError());
    }
    Py_DecRef(m_poDataset);
}

/************************************************************************/
/*                          GetLayerCount()                             */
/************************************************************************/

int PythonPluginDataset::GetLayerCount()
{
    if (m_bHasLayersMember)
        return static_cast<int>(m_oMapLayer.size());

    GIL_Holder oHolder(false);
    return GetIntRes(m_poDataset, "layer_count");
}

/************************************************************************/
/*                            GetLayer()                                */
/************************************************************************/

OGRLayer *PythonPluginDataset::GetLayer(int idx)
{
    if (idx < 0)
        return nullptr;

    auto oIter = m_oMapLayer.find(idx);
    if (oIter != m_oMapLayer.end())
        return m_oMapLayer[idx].get();

    if (m_bHasLayersMember)
        return nullptr;

    GIL_Holder oHolder(false);

    PyObject *poMethod = PyObject_GetAttrString(m_poDataset, "layer");
    if (poMethod == nullptr || PyErr_Occurred())
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s",
                 GetPyExceptionString().c_str());
        return nullptr;
    }

    PyObject *poMethodRes = CallPython(poMethod, idx);
    if (ErrOccurredEmitCPLError())
    {
        Py_DecRef(poMethod);
        return nullptr;
    }
    Py_DecRef(poMethod);

    if (poMethodRes == Py_None)
    {
        m_oMapLayer[idx] = nullptr;
        Py_DecRef(poMethodRes);
        return nullptr;
    }
    m_oMapLayer[idx] =
        std::unique_ptr<PythonPluginLayer>(new PythonPluginLayer(poMethodRes));
    return m_oMapLayer[idx].get();
}

/************************************************************************/
/*                          GetMetadata()                               */
/************************************************************************/

char **PythonPluginDataset::GetMetadata(const char *pszDomain)
{
    GIL_Holder oHolder(false);
    if (pszDomain == nullptr)
        pszDomain = "";
    m_oMapMD[pszDomain] = CPLStringList(::GetMetadata(m_poDataset, pszDomain));
    return m_oMapMD[pszDomain].List();
}

/************************************************************************/
/*                          PythonPluginDriver                          */
/************************************************************************/

class PythonPluginDriver : public GDALDriver
{
    CPLMutex *m_hMutex = nullptr;
    CPLString m_osFilename;
    PyObject *m_poPlugin = nullptr;

    PythonPluginDriver(const PythonPluginDriver &) = delete;
    PythonPluginDriver &operator=(const PythonPluginDriver &) = delete;

    bool LoadPlugin();

    int Identify(GDALOpenInfo *);
    static int IdentifyEx(GDALDriver *, GDALOpenInfo *);

    GDALDataset *Open(GDALOpenInfo *);
    static GDALDataset *OpenEx(GDALDriver *, GDALOpenInfo *);

  public:
    PythonPluginDriver(const char *pszFilename, const char *pszPluginName,
                       char **papszMD);
    ~PythonPluginDriver();
};

/************************************************************************/
/*                            LoadPlugin()                              */
/************************************************************************/

bool PythonPluginDriver::LoadPlugin()
{
    CPLMutexHolder oMutexHolder(&m_hMutex);
    if (m_poPlugin)
        return true;
    if (!InitializePythonAndLoadGDALPythonDriverModule())
        return false;
    GIL_Holder oHolder(false);

    CPLString osStr;
    VSILFILE *fp = VSIFOpenL(m_osFilename, "rb");
    VSIFSeekL(fp, 0, SEEK_END);
    auto nSize = VSIFTellL(fp);
    if (nSize > 10 * 1024 * 1024)
    {
        VSIFCloseL(fp);
        return false;
    }
    VSIFSeekL(fp, 0, SEEK_SET);
    osStr.resize(static_cast<size_t>(nSize));
    VSIFReadL(&osStr[0], 1, static_cast<size_t>(nSize), fp);
    VSIFCloseL(fp);
    PyObject *poCompiledString =
        Py_CompileString(osStr, m_osFilename, Py_file_input);
    if (poCompiledString == nullptr || PyErr_Occurred())
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Couldn't compile code:\n%s",
                 GetPyExceptionString().c_str());
        return false;
    }
    const CPLString osPluginModuleName(CPLGetBasename(m_osFilename));
    PyObject *poModule =
        PyImport_ExecCodeModule(osPluginModuleName, poCompiledString);
    Py_DecRef(poCompiledString);

    if (poModule == nullptr || PyErr_Occurred())
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s",
                 GetPyExceptionString().c_str());
        return false;
    }

    PyObject *poInstantiate = PyObject_GetAttrString(gpoGDALPythonDriverModule,
                                                     "_instantiate_plugin");
    CPLAssert(poInstantiate);

    PyObject *pyArgs = PyTuple_New(1);
    PyTuple_SetItem(pyArgs, 0, poModule);
    PyObject *poPlugin = PyObject_Call(poInstantiate, pyArgs, nullptr);
    Py_DecRef(pyArgs);
    Py_DecRef(poInstantiate);

    if (ErrOccurredEmitCPLError())
    {
        return false;
    }
    else
    {
        m_poPlugin = poPlugin;
        return true;
    }
}

/************************************************************************/
/*                       BuildIdentifyOpenArgs()                        */
/************************************************************************/

static void BuildIdentifyOpenArgs(GDALOpenInfo *poOpenInfo, PyObject *&pyArgs,
                                  PyObject *&pyKwargs)
{
    pyArgs = PyTuple_New(3);
    PyTuple_SetItem(pyArgs, 0, PyUnicode_FromString(poOpenInfo->pszFilename));
    PyTuple_SetItem(pyArgs, 1,
                    PyBytes_FromStringAndSize(poOpenInfo->pabyHeader,
                                              poOpenInfo->nHeaderBytes));
    PyTuple_SetItem(pyArgs, 2, PyLong_FromLong(poOpenInfo->nOpenFlags));
    pyKwargs = PyDict_New();
    PyObject *pyOpenOptions = PyDict_New();
    PyDict_SetItemString(pyKwargs, "open_options", pyOpenOptions);
    if (poOpenInfo->papszOpenOptions)
    {
        for (char **papszIter = poOpenInfo->papszOpenOptions; *papszIter;
             ++papszIter)
        {
            char *pszKey = nullptr;
            const char *pszValue = CPLParseNameValue(*papszIter, &pszKey);
            if (pszKey && pszValue)
            {
                auto pyValue = PyUnicode_FromString(pszValue);
                PyDict_SetItemString(pyOpenOptions, pszKey, pyValue);
                Py_DecRef(pyValue);
            }
            CPLFree(pszKey);
        }
    }
    Py_DecRef(pyOpenOptions);
}

/************************************************************************/
/*                            Identify()                                */
/************************************************************************/

int PythonPluginDriver::Identify(GDALOpenInfo *poOpenInfo)
{
    if (m_poPlugin == nullptr)
    {
        if (!LoadPlugin())
            return FALSE;
    }

    GIL_Holder oHolder(false);

    PyObject *poMethod = PyObject_GetAttrString(m_poPlugin, "identify");
    if (poMethod == nullptr || PyErr_Occurred())
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s",
                 GetPyExceptionString().c_str());
        return 0;
    }

    PyObject *pyArgs = nullptr;
    PyObject *pyKwargs = nullptr;
    BuildIdentifyOpenArgs(poOpenInfo, pyArgs, pyKwargs);
    PyObject *poMethodRes = PyObject_Call(poMethod, pyArgs, pyKwargs);
    Py_DecRef(pyArgs);
    Py_DecRef(pyKwargs);

    if (ErrOccurredEmitCPLError())
    {
        Py_DecRef(poMethod);
        return 0;
    }
    Py_DecRef(poMethod);

    int nRes = static_cast<int>(PyLong_AsLong(poMethodRes));
    if (ErrOccurredEmitCPLError())
    {
        Py_DecRef(poMethodRes);
        return 0;
    }

    Py_DecRef(poMethodRes);
    return nRes;
}

/************************************************************************/
/*                            IdentifyEx()                              */
/************************************************************************/

int PythonPluginDriver::IdentifyEx(GDALDriver *poDrv, GDALOpenInfo *poOpenInfo)
{
    return reinterpret_cast<PythonPluginDriver *>(poDrv)->Identify(poOpenInfo);
}

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

GDALDataset *PythonPluginDriver::Open(GDALOpenInfo *poOpenInfo)
{
    if (m_poPlugin == nullptr)
    {
        if (!LoadPlugin())
            return nullptr;
    }

    GIL_Holder oHolder(false);

    PyObject *poMethod = PyObject_GetAttrString(m_poPlugin, "open");
    if (poMethod == nullptr || PyErr_Occurred())
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s",
                 GetPyExceptionString().c_str());
        return nullptr;
    }

    PyObject *pyArgs = nullptr;
    PyObject *pyKwargs = nullptr;
    BuildIdentifyOpenArgs(poOpenInfo, pyArgs, pyKwargs);
    PyObject *poMethodRes = PyObject_Call(poMethod, pyArgs, pyKwargs);
    Py_DecRef(pyArgs);
    Py_DecRef(pyKwargs);

    if (ErrOccurredEmitCPLError())
    {
        Py_DecRef(poMethod);
        return nullptr;
    }
    Py_DecRef(poMethod);

    if (poMethodRes == Py_None)
    {
        Py_DecRef(poMethodRes);
        return nullptr;
    }
    return new PythonPluginDataset(poOpenInfo, poMethodRes);
}

/************************************************************************/
/*                              OpenEx()                                */
/************************************************************************/

GDALDataset *PythonPluginDriver::OpenEx(GDALDriver *poDrv,
                                        GDALOpenInfo *poOpenInfo)
{
    return reinterpret_cast<PythonPluginDriver *>(poDrv)->Open(poOpenInfo);
}

/************************************************************************/
/*                        PythonPluginDriver()                          */
/************************************************************************/

PythonPluginDriver::PythonPluginDriver(const char *pszFilename,
                                       const char *pszPluginName,
                                       char **papszMD)
    : m_hMutex(nullptr), m_osFilename(pszFilename), m_poPlugin(nullptr)
{
    SetDescription(pszPluginName);
    SetMetadata(papszMD);
    pfnIdentifyEx = IdentifyEx;
    pfnOpenWithDriverArg = OpenEx;
}

/************************************************************************/
/*                       ~PythonPluginDriver()                          */
/************************************************************************/

PythonPluginDriver::~PythonPluginDriver()
{
    if (m_hMutex)
        CPLDestroyMutex(m_hMutex);

    if (m_poPlugin)
    {
        GIL_Holder oHolder(false);
        Py_DecRef(m_poPlugin);
    }
}

/************************************************************************/
/*                         LoadPythonDriver()                           */
/************************************************************************/

static void LoadPythonDriver(const char *pszFilename)
{
    char **papszLines = CSLLoad2(pszFilename, 1000, 1000, nullptr);
    if (papszLines == nullptr)
    {
        return;
    }
    CPLString osPluginName;
    char **papszMD = nullptr;
    bool bAPIOK = false;
    constexpr int CURRENT_API_VERSION = 1;
    for (int i = 0; papszLines[i] != nullptr; i++)
    {
        const char *pszLine = papszLines[i];
        if (!STARTS_WITH_CI(pszLine, "# gdal: DRIVER_"))
            continue;
        pszLine += strlen("# gdal: DRIVER_");

        const char *pszEqual = strchr(pszLine, '=');
        if (pszEqual == nullptr)
            continue;

        CPLString osKey(pszLine);
        osKey.resize(pszEqual - pszLine);
        osKey.Trim();

        CPLString osValue(pszEqual + 1);
        osValue.Trim();

        char chQuote = 0;
        if (!osValue.empty() && (osValue[0] == '"' || osValue[0] == '\''))
        {
            chQuote = osValue[0];
            osValue = osValue.substr(1);
        }
        if (!osValue.empty() && osValue[osValue.size() - 1] == chQuote)
            osValue.resize(osValue.size() - 1);
        if (EQUAL(osKey, "NAME"))
        {
            osPluginName = std::move(osValue);
        }
        else if (EQUAL(osKey, "SUPPORTED_API_VERSION"))
        {
            const CPLStringList aosTokens(
                CSLTokenizeString2(osValue, "[, ]", 0));
            for (int j = 0; j < aosTokens.size(); ++j)
            {
                if (atoi(aosTokens[j]) == CURRENT_API_VERSION)
                {
                    bAPIOK = true;
                    break;
                }
            }
        }
        else
        {
            papszMD = CSLSetNameValue(papszMD, osKey.c_str(), osValue);
        }
    }
    papszMD = CSLSetNameValue(papszMD, "DRIVER_LANGUAGE", "PYTHON");
    CSLDestroy(papszLines);

    if (osPluginName.empty())
    {
        CPLError(CE_Warning, CPLE_AppDefined,
                 "Missing global # gdal: DRIVER_NAME declaration in %s",
                 pszFilename);
    }
    else if (!bAPIOK)
    {
        CPLDebug(
            "GDAL",
            "Plugin %s does not declare # gdal: DRIVER_SUPPORTED_API_VERSION "
            "or not at version %d",
            osPluginName.c_str(), CURRENT_API_VERSION);
    }
    else if (GDALGetDriverByName(osPluginName) == nullptr)
    {
        GDALDriver *poDriver =
            new PythonPluginDriver(pszFilename, osPluginName, papszMD);
        GetGDALDriverManager()->RegisterDriver(poDriver);
    }
    CSLDestroy(papszMD);
}

/************************************************************************/
/*                        AutoLoadPythonDrivers()                       */
/************************************************************************/

/**
 * \brief Auto-load GDAL drivers from Python scripts.
 *
 * This function will automatically load drivers from Python scripts.
 * It searches them first from the directory pointed by the
 * GDAL_PYTHON_DRIVER_PATH configuration option. If not defined, it will
 * use GDAL_DRIVER_PATH. If not defined, it will use the path for
 * drivers hardcoded at build time.
 * Scripts must begin with gdal_ or ogr_ and end up with .py
 *
 * @since GDAL 3.1
 */

void GDALDriverManager::AutoLoadPythonDrivers()
{
    const char *pszPythonDriverPath =
        CPLGetConfigOption("GDAL_PYTHON_DRIVER_PATH", nullptr);
    if (pszPythonDriverPath == nullptr)
    {
        pszPythonDriverPath = CPLGetConfigOption("GDAL_DRIVER_PATH", nullptr);
    }
    char **papszSearchPaths = GetSearchPaths(pszPythonDriverPath);

    /* -------------------------------------------------------------------- */
    /*      Format the ABI version specific subdirectory to look in.        */
    /* -------------------------------------------------------------------- */
    CPLString osABIVersion;

    osABIVersion.Printf("%d.%d", GDAL_VERSION_MAJOR, GDAL_VERSION_MINOR);

    /* -------------------------------------------------------------------- */
    /*      Scan each directory                                             */
    /* -------------------------------------------------------------------- */
    std::vector<CPLString> aosPythonFiles;
    const int nSearchPaths = CSLCount(papszSearchPaths);
    for (int iDir = 0; iDir < nSearchPaths; ++iDir)
    {
        CPLString osABISpecificDir =
            CPLFormFilename(papszSearchPaths[iDir], osABIVersion, nullptr);

        VSIStatBufL sStatBuf;
        if (VSIStatL(osABISpecificDir, &sStatBuf) != 0)
            osABISpecificDir = papszSearchPaths[iDir];

        char **papszFiles = CPLReadDir(osABISpecificDir);
        for (int i = 0; papszFiles && papszFiles[i]; i++)
        {
            if ((STARTS_WITH_CI(papszFiles[i], "gdal_") ||
                 STARTS_WITH_CI(papszFiles[i], "ogr_")) &&
                EQUAL(CPLGetExtension(papszFiles[i]), "py"))
            {
                aosPythonFiles.push_back(
                    CPLFormFilename(osABISpecificDir, papszFiles[i], nullptr));
            }
        }
        CSLDestroy(papszFiles);
    }
    CSLDestroy(papszSearchPaths);

    for (const auto &osPythonFile : aosPythonFiles)
    {
        LoadPythonDriver(osPythonFile);
    }
}

/************************************************************************/
/*                        CleanupPythonDrivers()                        */
/************************************************************************/

void GDALDriverManager::CleanupPythonDrivers()
{
    if (gpoGDALPythonDriverModule)
    {
        // On Windows, with pytest, GDALDestroy() can call this after having
        // stopped Python, so do not attempt any Python related action.
        if (Py_IsInitialized())
        {
            GIL_Holder oHolder(false);
            Py_DecRef(Py_None);
            Py_DecRef(gpoGDALPythonDriverModule);
        }
        Py_None = nullptr;
        gpoGDALPythonDriverModule = nullptr;
    }
}

#endif
