/******************************************************************************

 *

 * Project:  GDAL Core

 * Purpose:  Python interface

 * 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_error.h"

#include "cpl_string.h"

#include "cpl_spawn.h"

#include "gdalpython.h"

#include <algorithm>

#include <mutex>

#include <set>

#include <vector>

using namespace GDALPy;

typedef struct PyThreadState_t PyThreadState;

static PyThreadState *(*PyEval_SaveThread)(void) = nullptr;

static void (*PyEval_RestoreThread)(PyThreadState *) = nullptr;

static void (*Py_Finalize)(void) = nullptr;

static void (*Py_InitializeEx)(int) = nullptr;

static void (*PyEval_InitThreads)(void) = nullptr;

static PyObject *(*Py_CompileStringExFlags)(const char *, const char *, int,

                                            void *, int) = nullptr;

static std::mutex gMutexGDALPython;

static bool gbHasInitializedPython = false;

static PyThreadState *gphThreadState = nullptr;

// Emulate Py_CompileString with Py_CompileStringExFlags

// Probably just a temporary measure for a bug of Python 3.8.0 on Windows

// https://bugs.python.org/issue37633

static PyObject *GDAL_Py_CompileString(const char *str, const char *filename,

                                       int start)

{

    return Py_CompileStringExFlags(str, filename, start, nullptr, -1);

}

namespace GDALPy

{

int (*Py_IsInitialized)(void) = nullptr;

PyGILState_STATE (*PyGILState_Ensure)(void) = nullptr;

void (*PyGILState_Release)(PyGILState_STATE) = nullptr;

void (*Py_SetProgramName)(const wchar_t *) = nullptr;

void (*Py_SetPythonHome)(const wchar_t *) = nullptr;

PyObject *(*PyObject_Type)(PyObject *) = nullptr;

int (*PyObject_IsInstance)(PyObject *, PyObject *) = nullptr;

PyObject *(*PyTuple_New)(size_t) = nullptr;

PyObject *(*PyBool_FromLong)(long) = nullptr;

PyObject *(*PyLong_FromLong)(long) = nullptr;

long (*PyLong_AsLong)(PyObject *) = nullptr;

PyObject *(*PyLong_FromLongLong)(GIntBig) = nullptr;

GIntBig (*PyLong_AsLongLong)(PyObject *) = nullptr;

PyObject *(*PyFloat_FromDouble)(double) = nullptr;

double (*PyFloat_AsDouble)(PyObject *) = nullptr;

PyObject *(*PyObject_Call)(PyObject *, PyObject *, PyObject *) = nullptr;

PyObject *(*PyObject_GetIter)(PyObject *) = nullptr;

PyObject *(*PyIter_Next)(PyObject *) = nullptr;

void (*Py_IncRef)(PyObject *) = nullptr;

void (*Py_DecRef)(PyObject *) = nullptr;

PyObject *(*PyErr_Occurred)(void) = nullptr;

void (*PyErr_Print)(void) = nullptr;

PyObject *(*Py_CompileString)(const char *, const char *, int) = nullptr;

PyObject *(*PyImport_ExecCodeModule)(const char *, PyObject *) = nullptr;

int (*PyObject_HasAttrString)(PyObject *, const char *) = nullptr;

PyObject *(*PyObject_GetAttrString)(PyObject *, const char *) = nullptr;

int (*PyObject_SetAttrString)(PyObject *, const char *, PyObject *) = nullptr;

int (*PyTuple_SetItem)(PyObject *, size_t, PyObject *) = nullptr;

void (*PyObject_Print)(PyObject *, FILE *, int) = nullptr;

Py_ssize_t (*PyBytes_Size)(PyObject *) = nullptr;

const char *(*PyBytes_AsString)(PyObject *) = nullptr;

int *(*PyBytes_AsStringAndSize)(PyObject *, char **, size_t *) = nullptr;

PyObject *(*PyBytes_FromObject)(PyObject *) = nullptr;

PyObject *(*PyBytes_FromStringAndSize)(const void *, size_t) = nullptr;

PyObject *(*PyUnicode_FromString)(const char *) = nullptr;

PyObject *(*PyUnicode_AsUTF8String)(PyObject *) = nullptr;

PyObject *(*PyImport_ImportModule)(const char *) = nullptr;

int (*PyCallable_Check)(PyObject *) = nullptr;

PyObject *(*PyDict_New)(void) = nullptr;

int (*PyDict_SetItemString)(PyObject *p, const char *key,

                            PyObject *val) = nullptr;

int (*PyDict_Next)(PyObject *p, size_t *, PyObject **, PyObject **) = nullptr;

PyObject *(*PyDict_GetItemString)(PyObject *p, const char *key) = nullptr;

PyObject *(*PyList_New)(Py_ssize_t) = nullptr;

int (*PyList_SetItem)(PyObject *, Py_ssize_t, PyObject *) = nullptr;

int (*PyArg_ParseTuple)(PyObject *, const char *, ...) = nullptr;

int (*PySequence_Check)(PyObject *o) = nullptr;

Py_ssize_t (*PySequence_Size)(PyObject *o) = nullptr;

PyObject *(*PySequence_GetItem)(PyObject *o, Py_ssize_t i) = nullptr;

void (*PyErr_Fetch)(PyObject **poPyType, PyObject **poPyValue,

                    PyObject **poPyTraceback) = nullptr;

void (*PyErr_Clear)(void) = nullptr;

const char *(*Py_GetVersion)(void) = nullptr;

int (*PyBuffer_FillInfo)(Py_buffer *view, PyObject *obj, void *buf, size_t len,

                         int readonly, int infoflags) = nullptr;

PyObject *(*PyMemoryView_FromBuffer)(Py_buffer *view) = nullptr;

PyObject *(*PyModule_Create2)(struct PyModuleDef *, int) = nullptr;

}  // namespace GDALPy

/* MinGW32 might define HAVE_DLFCN_H, so skip the unix implementation */

#if defined(HAVE_DLFCN_H) && !defined(_WIN32)

#include <dlfcn.h>

typedef void *LibraryHandle;

#define LOAD_NOCHECK_WITH_NAME(libHandle, x, name)                             \

    do                                                                         \

    {                                                                          \

        void *ptr = dlsym(libHandle, name);                                    \

        memcpy(&x, &ptr, sizeof(void *));                                      \

    } while (0)

#elif defined(_WIN32)

#include <windows.h>

#include <psapi.h>

typedef HMODULE LibraryHandle;

#define LOAD_NOCHECK_WITH_NAME(libHandle, x, name)                             \

    do                                                                         \

    {                                                                          \

        FARPROC ptr = GetProcAddress(libHandle, name);                         \

        memcpy(&x, &ptr, sizeof(void *));                                      \

    } while (0)

#endif

#define STRINGIFY(x) #x

#define LOAD_NOCHECK(libHandle, x)                                             \

    LOAD_NOCHECK_WITH_NAME(libHandle, x, STRINGIFY(x))

#define LOAD_WITH_NAME(libHandle, x, name)                                     \

    do                                                                         \

    {                                                                          \

        LOAD_NOCHECK_WITH_NAME(libHandle, x, name);                            \

        if (!x)                                                                \

        {                                                                      \

            CPLError(CE_Failure, CPLE_AppDefined, "Cannot find %s", name);     \

            return false;                                                      \

        }                                                                      \

    } while (0)

#define LOAD(libHandle, x) LOAD_WITH_NAME(libHandle, x, STRINGIFY(x))

/************************************************************************/

/*                          LoadPythonAPI()                             */

/************************************************************************/

/** Load the subset of the Python C API that we need */

static bool LoadPythonAPI()

{

    static int nInit = -1;

    if (nInit >= 0)

        return nInit == TRUE;

    nInit = FALSE;

#ifdef LOAD_NOCHECK_WITH_NAME

    static LibraryHandle libHandle = nullptr;

    const char *pszPythonSO = CPLGetConfigOption("PYTHONSO", nullptr);

#if defined(HAVE_DLFCN_H) && !defined(_WIN32)

    // First try in the current process in case the python symbols would

    // be already loaded

    libHandle = dlopen(nullptr, RTLD_LAZY);

    if (libHandle != nullptr &&

        dlsym(libHandle, "Py_SetProgramName") != nullptr)

    {

        CPLDebug("GDAL", "Current process has python symbols loaded");

    }

    else

    {

        if (libHandle)

            dlclose(libHandle);

        libHandle = nullptr;

    }

    // Then try the user provided shared object name

    if (libHandle == nullptr && pszPythonSO != nullptr)

    {

        // coverity[tainted_string]

        libHandle = dlopen(pszPythonSO, RTLD_NOW | RTLD_GLOBAL);

        if (libHandle == nullptr)

        {

            CPLError(CE_Failure, CPLE_AppDefined, "Cannot load %s",

                     pszPythonSO);

            return false;

        }

        if (dlsym(libHandle, "Py_SetProgramName") == nullptr)

        {

            CPLError(CE_Failure, CPLE_AppDefined,

                     "Cannot find Py_SetProgramName symbol in %s", pszPythonSO);

            return false;

        }

    }

    // Then try the PYTHONSO_DEFAULT if defined at compile time

#ifdef PYTHONSO_DEFAULT

    if (libHandle == nullptr)

    {

        libHandle = dlopen(PYTHONSO_DEFAULT, RTLD_NOW | RTLD_GLOBAL);

        if (!libHandle)

        {

            CPLDebug("GDAL", "%s found", PYTHONSO_DEFAULT);

        }

    }

#endif

#if defined(__MACH__) && defined(__APPLE__)

#define SO_EXT "dylib"

#else

#define IS_SO_EXT

#define SO_EXT "so"

#endif

    const auto tryDlopen = [](CPLString osPythonSO)

    {

        CPLDebug("GDAL", "Trying %s", osPythonSO.c_str());

        auto l_libHandle = dlopen(osPythonSO.c_str(), RTLD_NOW | RTLD_GLOBAL);

#ifdef IS_SO_EXT

        if (l_libHandle == nullptr)

        {

            osPythonSO += ".1.0";

            CPLDebug("GDAL", "Trying %s", osPythonSO.c_str());

            l_libHandle = dlopen(osPythonSO.c_str(), RTLD_NOW | RTLD_GLOBAL);

        }

#endif

        return l_libHandle;

    };

    // Then try to find the libpython that corresponds to the python binary

    // in the PATH

    if (libHandle == nullptr)

    {

        CPLString osVersion;

        char *pszPath = getenv("PATH");

        if (pszPath != nullptr

#ifdef DEBUG

            // For testing purposes

            && CPLTestBool(CPLGetConfigOption("GDAL_ENABLE_PYTHON_PATH", "YES"))

#endif

        )

        {

            const CPLStringList aosPathParts(

                CSLTokenizeString2(pszPath, ":", 0));

            for (int iTry = 0; iTry < 2; ++iTry)

            {

                for (const char *pszPathPart : aosPathParts)

                {

                    struct stat sStat;

                    std::string osPythonBinary(

                        CPLFormFilenameSafe(pszPathPart, "python", nullptr));

                    if (iTry == 0)

                        osPythonBinary += "3";

                    if (lstat(osPythonBinary.c_str(), &sStat) != 0)

                        continue;

                    CPLDebug("GDAL", "Found %s", osPythonBinary.c_str());

                    if (S_ISLNK(sStat.st_mode)

#ifdef DEBUG

                        // For testing purposes

                        && CPLTestBool(CPLGetConfigOption(

                               "GDAL_ENABLE_PYTHON_SYMLINK", "YES"))

#endif

                    )

                    {

                        std::set<std::string> oSetAlreadyTriedLinks;

                        while (true)

                        {

                            oSetAlreadyTriedLinks.insert(osPythonBinary);

                            // If this is a symlink, hopefully the resolved

                            // name will be like "python3.6"

                            const int nBufSize = 2048;

                            std::vector<char> oFilename(nBufSize);

                            char *szPointerFilename = &oFilename[0];

                            int nBytes = static_cast<int>(

                                readlink(osPythonBinary.c_str(),

                                         szPointerFilename, nBufSize));

                            if (nBytes != -1)

                            {

                                szPointerFilename[std::min(nBytes,

                                                           nBufSize - 1)] = 0;

                                CPLString osFilename(

                                    CPLGetFilename(szPointerFilename));

                                CPLDebug("GDAL", "Which is an alias to: %s",

                                         szPointerFilename);

                                if (STARTS_WITH(osFilename, "python"))

                                {

                                    std::string osResolvedFullLink;

                                    // If the filename is again a symlink,

                                    // resolve it

                                    if (CPLIsFilenameRelative(osFilename))

                                    {

                                        osResolvedFullLink =

                                            CPLFormFilenameSafe(

                                                CPLGetPathSafe(

                                                    osPythonBinary.c_str())

                                                    .c_str(),

                                                osFilename, nullptr);

                                    }

                                    else

                                    {

                                        osResolvedFullLink = osFilename;

                                    }

                                    if (oSetAlreadyTriedLinks.find(

                                            osResolvedFullLink) ==

                                            oSetAlreadyTriedLinks.end() &&

                                        lstat(osResolvedFullLink.c_str(),

                                              &sStat) == 0 &&

                                        S_ISLNK(sStat.st_mode))

                                    {

                                        osPythonBinary =

                                            std::move(osResolvedFullLink);

                                        continue;

                                    }

                                    osVersion =

                                        osFilename.substr(strlen("python"));

                                    CPLDebug(

                                        "GDAL",

                                        "Python version from binary name: %s",

                                        osVersion.c_str());

                                }

                            }

                            else

                            {

                                CPLDebug("GDAL", "realink(%s) failed",

                                         osPythonBinary.c_str());

                            }

                            break;

                        }

                    }

                    // Otherwise, expensive way: start the binary and ask

                    // it for its version...

                    if (osVersion.empty())

                    {

                        const char *pszPrintVersion =

                            "import sys; print(str(sys.version_info[0]) +"

                            "'.' + str(sys.version_info[1]))";

                        const char *const apszArgv[] = {osPythonBinary.c_str(),

                                                        "-c", pszPrintVersion,

                                                        nullptr};

                        const CPLString osTmpFilename(

                            VSIMemGenerateHiddenFilename("out.txt"));

                        VSILFILE *fout = VSIFOpenL(osTmpFilename, "wb+");

                        if (CPLSpawn(apszArgv, nullptr, fout, FALSE) == 0)

                        {

                            char *pszStr =

                                reinterpret_cast<char *>(VSIGetMemFileBuffer(

                                    osTmpFilename, nullptr, FALSE));

                            osVersion = pszStr;

                            if (!osVersion.empty() && osVersion.back() == '\n')

                            {

                                osVersion.resize(osVersion.size() - 1);

                            }

                            CPLDebug("GDAL", "Python version from binary: %s",

                                     osVersion.c_str());

                        }

                        VSIFCloseL(fout);

                        VSIUnlink(osTmpFilename);

                    }

                    break;

                }

                if (!osVersion.empty())

                    break;

            }

        }

        if (!osVersion.empty())

        {

            libHandle = tryDlopen("libpython" + osVersion + "." SO_EXT);

            if (libHandle != nullptr)

            {

                CPLDebug("GDAL", "... success");

            }

            else if (osVersion[0] == '3')

            {

                libHandle = tryDlopen("libpython" + osVersion + "m." SO_EXT);

                if (libHandle != nullptr)

                {

                    CPLDebug("GDAL", "... success");

                }

            }

        }

    }

    // Otherwise probe a few known objects.

    // Note: update doc/source/drivers/raster/vrt.rst if change

    if (libHandle == nullptr)

    {

        const char *const apszPythonSO[] = {

            "libpython3.8." SO_EXT,  "libpython3.9." SO_EXT,

            "libpython3.10." SO_EXT, "libpython3.11." SO_EXT,

            "libpython3.12." SO_EXT, "libpython3.13." SO_EXT,

            "libpython3.7m." SO_EXT, "libpython3.6m." SO_EXT,

            "libpython3.5m." SO_EXT, "libpython3.4m." SO_EXT,

            "libpython3.3." SO_EXT,  "libpython3.2." SO_EXT};

        for (size_t i = 0;

             libHandle == nullptr && i < CPL_ARRAYSIZE(apszPythonSO); ++i)

        {

            libHandle = tryDlopen(apszPythonSO[i]);

            if (libHandle != nullptr)

                CPLDebug("GDAL", "... success");

        }

    }

#elif defined(_WIN32)

    CPLString osPythonBinaryUsed;

    // First try in the current process in case the python symbols would

    // be already loaded

    HANDLE hProcess = GetCurrentProcess();

    std::vector<HMODULE> ahModules;

    // 100 is not large enough when GDAL is loaded from QGIS for example

    ahModules.resize(1000);

    for (int i = 0; i < 2; i++)

    {

        DWORD nSizeNeeded = 0;

        const DWORD nSizeIn =

            static_cast<DWORD>(ahModules.size() * sizeof(HMODULE));

        EnumProcessModules(hProcess, &ahModules[0], nSizeIn, &nSizeNeeded);

        ahModules.resize(static_cast<size_t>(nSizeNeeded) / sizeof(HMODULE));

        if (nSizeNeeded <= nSizeIn)

        {

            break;

        }

    }

    for (size_t i = 0; i < ahModules.size(); i++)

    {

        if (GetProcAddress(ahModules[i], "Py_SetProgramName"))

        {

            libHandle = ahModules[i];

            CPLDebug("GDAL", "Current process has python symbols loaded");

            break;

        }

    }

    // Then try the user provided shared object name

    if (libHandle == nullptr && pszPythonSO != nullptr)

    {

        UINT uOldErrorMode;

        /* Avoid error boxes to pop up (#5211, #5525) */

        uOldErrorMode =

            SetErrorMode(SEM_NOOPENFILEERRORBOX | SEM_FAILCRITICALERRORS);

#if (defined(_WIN32) && _MSC_VER >= 1310) || __MSVCRT_VERSION__ >= 0x0601

        if (CPLTestBool(CPLGetConfigOption("GDAL_FILENAME_IS_UTF8", "YES")))

        {

            wchar_t *pwszFilename =

                CPLRecodeToWChar(pszPythonSO, CPL_ENC_UTF8, CPL_ENC_UCS2);

            libHandle = LoadLibraryW(pwszFilename);

            CPLFree(pwszFilename);

        }

        else

#endif

        {

            libHandle = LoadLibrary(pszPythonSO);

        }

        SetErrorMode(uOldErrorMode);

        if (libHandle == nullptr)

        {

            CPLError(CE_Failure, CPLE_AppDefined, "Cannot load %s",

                     pszPythonSO);

            return false;

        }

        if (GetProcAddress(libHandle, "Py_SetProgramName") == nullptr)

        {

            CPLError(CE_Failure, CPLE_AppDefined,

                     "Cannot find Py_SetProgramName symbol in %s", pszPythonSO);

            return false;

        }

    }

    // Then try the PYTHONSO_DEFAULT if defined at compile time

#ifdef PYTHONSO_DEFAULT

    if (libHandle == nullptr)

    {

        UINT uOldErrorMode;

        uOldErrorMode =

            SetErrorMode(SEM_NOOPENFILEERRORBOX | SEM_FAILCRITICALERRORS);

        libHandle = LoadLibrary(PYTHONSO_DEFAULT);

        SetErrorMode(uOldErrorMode);

        if (!libHandle)

        {

            CPLDebug("GDAL", "%s found", PYTHONSO_DEFAULT);

        }

    }

#endif

    // Then try to find the pythonXY.dll that corresponds to the python binary

    // in the PATH

    if (libHandle == nullptr)

    {

        std::string osDLLName;

        char *pszPath = getenv("PATH");

        if (pszPath != nullptr

#ifdef DEBUG

            // For testing purposes

            && CPLTestBool(CPLGetConfigOption("GDAL_ENABLE_PYTHON_PATH", "YES"))

#endif

        )

        {

            const CPLStringList aosPathParts(

                CSLTokenizeString2(pszPath, ";", 0));

            for (int iTry = 0; iTry < 2; ++iTry)

            {

                for (const char *pszPathPart : aosPathParts)

                {

                    VSIStatBufL sStat;

                    std::string osPythonBinary(CPLFormFilenameSafe(

                        pszPathPart, "python.exe", nullptr));

                    if (iTry == 1)

                        osPythonBinary += "3";

                    if (VSIStatL(osPythonBinary.c_str(), &sStat) != 0)

                        continue;

                    CPLDebug("GDAL", "Found %s", osPythonBinary.c_str());

                    {

                        // Test when dll is in the same directory as the exe

                        const CPLStringList aosFiles(VSIReadDir(pszPathPart));

                        for (const char *pszFilename : aosFiles)

                        {

                            if ((STARTS_WITH_CI(pszFilename, "python") ||

                                 // mingw64 uses libpython3.X.dll naming

                                 STARTS_WITH_CI(pszFilename, "libpython3.")) &&

                                // do not load minimum API dll

                                !EQUAL(pszFilename, "python3.dll") &&

                                EQUAL(CPLGetExtensionSafe(pszFilename).c_str(),

                                      "dll"))

                            {

                                osDLLName = CPLFormFilenameSafe(

                                    pszPathPart, pszFilename, nullptr);

                                osPythonBinaryUsed = osPythonBinary;

                                break;

                            }

                        }

                    }

                    // In python3.2, the dll is in the DLLs subdirectory

                    if (osDLLName.empty())

                    {

                        const std::string osDLLsDir(

                            CPLFormFilenameSafe(pszPathPart, "DLLs", nullptr));

                        const CPLStringList aosFiles(

                            VSIReadDir(osDLLsDir.c_str()));

                        for (const char *pszFilename : aosFiles)

                        {

                            if (STARTS_WITH_CI(pszFilename, "python") &&

                                EQUAL(CPLGetExtensionSafe(pszFilename).c_str(),

                                      "dll"))

                            {

                                osDLLName = CPLFormFilenameSafe(

                                    osDLLsDir.c_str(), pszFilename, nullptr);

                                break;

                            }

                        }

                    }

                    break;

                }

                if (!osDLLName.empty())

                    break;

            }

        }

        if (!osDLLName.empty())

        {

            // CPLDebug("GDAL", "Trying %s", osDLLName.c_str());

            UINT uOldErrorMode;

            uOldErrorMode =

                SetErrorMode(SEM_NOOPENFILEERRORBOX | SEM_FAILCRITICALERRORS);

            libHandle = LoadLibrary(osDLLName.c_str());

            SetErrorMode(uOldErrorMode);

            if (libHandle != nullptr)

            {

                CPLDebug("GDAL", "%s loaded", osDLLName.c_str());

            }

        }

    }

    // Otherwise probe a few known objects

    // Note: update doc/source/drivers/raster/vrt.rst if change

    if (libHandle == nullptr)

    {

        const char *const apszPythonSO[] = {

            "python38.dll",  "python39.dll",  "python310.dll", "python311.dll",

            "python312.dll", "python313.dll", "python37.dll",  "python36.dll",

            "python35.dll",  "python34.dll",  "python33.dll",  "python32.dll"};

        UINT uOldErrorMode;

        uOldErrorMode =

            SetErrorMode(SEM_NOOPENFILEERRORBOX | SEM_FAILCRITICALERRORS);

        for (size_t i = 0;

             libHandle == nullptr && i < CPL_ARRAYSIZE(apszPythonSO); ++i)

        {

            CPLDebug("GDAL", "Trying %s", apszPythonSO[i]);

            libHandle = LoadLibrary(apszPythonSO[i]);

            if (libHandle != nullptr)

                CPLDebug("GDAL", "... success");

        }

        SetErrorMode(uOldErrorMode);

    }

#endif

    if (!libHandle)

    {

        CPLError(

            CE_Failure, CPLE_AppDefined,

            "Cannot find python/libpython. You can set the PYTHONSO "

            "configuration option to point to the a python .so/.dll/.dylib");

        return false;

    }

    LOAD(libHandle, Py_GetVersion);

    CPLString osPythonVersion(Py_GetVersion());

    osPythonVersion.replaceAll("\r\n", ' ');

    osPythonVersion.replaceAll('\n', ' ');

    CPLDebug("GDAL", "Python version used: %s", osPythonVersion.c_str());

    LOAD(libHandle, Py_SetProgramName);

    LOAD(libHandle, Py_SetPythonHome);

#ifdef _WIN32

    if (!osPythonBinaryUsed.empty() && getenv("PYTHONHOME") == nullptr)

    {

        std::string osPythonHome =

            CPLGetDirnameSafe(osPythonBinaryUsed.c_str());

        VSIStatBufL sStat;

        bool bOK = false;

        // Test Windows Conda layout

        std::string osDirEncodings =

            CPLFormFilenameSafe(osPythonHome.c_str(), "lib/encodings", nullptr);

        if (VSIStatL(osDirEncodings.c_str(), &sStat) == 0)

        {

            bOK = true;

        }

        else

        {

            // Test mingw64 layout

            const CPLStringList aosVersionTokens(

                CSLTokenizeString2(osPythonVersion.c_str(), ".", 0));

            if (aosVersionTokens.size() >= 3)

            {

                osPythonHome = CPLGetDirnameSafe(osPythonHome.c_str());

                osDirEncodings = CPLFormFilenameSafe(

                    osPythonHome.c_str(),

                    CPLSPrintf("lib/python%s.%s/encodings", aosVersionTokens[0],

                               aosVersionTokens[1]),

                    nullptr);

                if (VSIStatL(osDirEncodings.c_str(), &sStat) == 0)

                {

                    bOK = true;

                }

            }

        }

        if (bOK)

        {

            static wchar_t wszPythonHome[4096];

            wchar_t *pwszPythonHome = CPLRecodeToWChar(

                osPythonHome.c_str(), CPL_ENC_UTF8, CPL_ENC_UCS2);

            const size_t nLength = wcslen(pwszPythonHome) + 1;

            if (nLength <= sizeof(wszPythonHome))

            {

                CPLDebug("GDAL", "Call Py_SetPythonHome(%s)",

                         osPythonHome.c_str());

                memcpy(wszPythonHome, pwszPythonHome,

                       nLength * sizeof(wchar_t));

                // The string must reside in static storage

                Py_SetPythonHome(wszPythonHome);

            }

            CPLFree(pwszPythonHome);

        }

    }

#endif

    LOAD(libHandle, PyBuffer_FillInfo);

    LOAD(libHandle, PyMemoryView_FromBuffer);

    LOAD(libHandle, PyObject_Type);

    LOAD(libHandle, PyObject_IsInstance);

    LOAD(libHandle, PyTuple_New);

    LOAD(libHandle, PyBool_FromLong);

    LOAD(libHandle, PyLong_FromLong);

    LOAD(libHandle, PyLong_AsLong);

    LOAD(libHandle, PyLong_FromLongLong);

    LOAD(libHandle, PyLong_AsLongLong);

    LOAD(libHandle, PyBytes_Size);

    LOAD(libHandle, PyBytes_AsString);

    LOAD(libHandle, PyBytes_AsStringAndSize);

    LOAD(libHandle, PyBytes_FromObject);

    LOAD(libHandle, PyBytes_FromStringAndSize);

    LOAD(libHandle, PyModule_Create2);

    LOAD_NOCHECK_WITH_NAME(libHandle, PyUnicode_FromString,

                           "PyUnicode_FromString");

    if (PyUnicode_FromString == nullptr)

    {

        LOAD_NOCHECK_WITH_NAME(libHandle, PyUnicode_FromString,

                               "PyUnicodeUCS2_FromString");

    }

    if (PyUnicode_FromString == nullptr)

    {

        LOAD_WITH_NAME(libHandle, PyUnicode_FromString,

                       "PyUnicodeUCS4_FromString");

    }

    LOAD_NOCHECK_WITH_NAME(libHandle, PyUnicode_AsUTF8String,

                           "PyUnicode_AsUTF8String");

    if (PyUnicode_AsUTF8String == nullptr)

    {

        LOAD_NOCHECK_WITH_NAME(libHandle, PyUnicode_AsUTF8String,

                               "PyUnicodeUCS2_AsUTF8String");

    }

    if (PyUnicode_AsUTF8String == nullptr)

    {

        LOAD_WITH_NAME(libHandle, PyUnicode_AsUTF8String,

                       "PyUnicodeUCS4_AsUTF8String");

    }

    LOAD(libHandle, PyFloat_FromDouble);

    LOAD(libHandle, PyFloat_AsDouble);

    LOAD(libHandle, PyObject_Call);

    LOAD(libHandle, PyObject_GetIter);

    LOAD(libHandle, PyIter_Next);

    LOAD(libHandle, Py_IncRef);

    LOAD(libHandle, Py_DecRef);

    LOAD(libHandle, PyErr_Occurred);

    LOAD(libHandle, PyErr_Print);

    LOAD(libHandle, Py_IsInitialized);

    LOAD(libHandle, Py_InitializeEx);

    LOAD(libHandle, PyEval_InitThreads);

    LOAD(libHandle, PyEval_SaveThread);

    LOAD(libHandle, PyEval_RestoreThread);

    LOAD(libHandle, Py_Finalize);

    LOAD_NOCHECK(libHandle, Py_CompileString);

    if (Py_CompileString == nullptr)

    {

        // Probably just a temporary measure for a bug of Python 3.8.0 on

        // Windows https://bugs.python.org/issue37633

        LOAD(libHandle, Py_CompileStringExFlags);

        Py_CompileString = GDAL_Py_CompileString;

    }

    LOAD(libHandle, PyImport_ExecCodeModule);

    LOAD(libHandle, PyObject_HasAttrString);

    LOAD(libHandle, PyObject_GetAttrString);

    LOAD(libHandle, PyObject_SetAttrString);

    LOAD(libHandle, PyTuple_SetItem);

    LOAD(libHandle, PyObject_Print);

    LOAD(libHandle, PyImport_ImportModule);

    LOAD(libHandle, PyCallable_Check);

    LOAD(libHandle, PyDict_New);

    LOAD(libHandle, PyDict_SetItemString);

    LOAD(libHandle, PyDict_Next);

    LOAD(libHandle, PyDict_GetItemString);

    LOAD(libHandle, PyList_New);

    LOAD(libHandle, PyList_SetItem);

    LOAD(libHandle, PySequence_Check);

    LOAD(libHandle, PySequence_Size);

    LOAD(libHandle, PySequence_GetItem);

    LOAD(libHandle, PyArg_ParseTuple);

    LOAD(libHandle, PyGILState_Ensure);

    LOAD(libHandle, PyGILState_Release);

    LOAD(libHandle, PyErr_Fetch);

    LOAD(libHandle, PyErr_Clear);

#else   // LOAD_NOCHECK_WITH_NAME

    CPLError(CE_Failure, CPLE_AppDefined,

             "This platform doesn't support dynamic loading of "

             "libraries");

    return false;

#endif  // LOAD_NOCHECK_WITH_NAME

    nInit = true;

    return true;

}

//! @cond Doxygen_Suppress

/************************************************************************/

/*                        GDALPythonInitialize()                        */

/************************************************************************/

/** Call this to initialize the Python environment.

 */

bool GDALPythonInitialize()

{

    std::lock_guard<std::mutex> guard(gMutexGDALPython);

    if (!LoadPythonAPI())

        return false;

    int bIsInitialized = Py_IsInitialized();

    if (!bIsInitialized)

    {

        gbHasInitializedPython = true;

        CPLDebug("GDAL", "Before Py_Initialize()");

        Py_InitializeEx(0);

        CPLDebug("GDAL", "Py_Initialize()");

        PyEval_InitThreads();

        gphThreadState = PyEval_SaveThread();

    }

    return true;

}

/************************************************************************/

/*                        GDALPythonFinalize()                          */

/************************************************************************/

/** To be called by GDALDestroy() */

void GDALPythonFinalize()

{

    if (gbHasInitializedPython)

    {

        CPLDebug("GDAL", "Py_Finalize() = %p", Py_Finalize);

        PyEval_RestoreThread(gphThreadState);

        Py_Finalize();

        gbHasInitializedPython = false;

        gphThreadState = nullptr;

    }

}

namespace GDALPy

{

/************************************************************************/

/*                            GIL_Holder()                              */

/************************************************************************/

GIL_Holder::GIL_Holder(bool bExclusiveLock) : m_bExclusiveLock(bExclusiveLock)

{

    if (bExclusiveLock)

    {

        gMutexGDALPython.lock();

    }

    m_eState = PyGILState_Ensure();

}

/************************************************************************/

/*                           ~GIL_Holder()                              */

/************************************************************************/

GIL_Holder::~GIL_Holder()

{

    PyGILState_Release(m_eState);

    if (m_bExclusiveLock)

    {

        gMutexGDALPython.unlock();

    }

    else

    {

    }

}

/************************************************************************/

/*                             GetString()                              */

/************************************************************************/

CPLString GetString(PyObject *obj, bool bEmitError)

{

    PyObject *unicode = PyUnicode_AsUTF8String(obj);

    if (PyErr_Occurred())

    {

        if (bEmitError)

        {

            CPLError(CE_Failure, CPLE_AppDefined, "%s",

                     GetPyExceptionString().c_str());

        }

        return CPLString();

    }

    const char *pszRet = PyBytes_AsString(unicode);

    CPLString osRet = pszRet ? pszRet : "";

    Py_DecRef(unicode);

    return osRet;

}

/************************************************************************/

/*                      GetPyExceptionString()                          */

/************************************************************************/

CPLString GetPyExceptionString()

{

    PyObject *poPyType = nullptr;

    PyObject *poPyValue = nullptr;

    PyObject *poPyTraceback = nullptr;

    PyErr_Fetch(&poPyType, &poPyValue, &poPyTraceback);

    if (poPyType)

        Py_IncRef(poPyType);

    if (poPyValue)

        Py_IncRef(poPyValue);

    if (poPyTraceback)

        Py_IncRef(poPyTraceback);

    // This is a mess. traceback.format_exception/format_exception_only

    // sometimes throw exceptions themselves !

    CPLString osPythonCode(

        "import traceback\n"

        "\n"

        "def GDALFormatException2(etype, value):\n"

        "    try:\n"

        "       return ''.join(traceback.format_exception_only(etype, value))\n"

        "    except:\n"

        "       return (str(etype) + ', ' + str(value))\n"

        "\n"

        "def GDALFormatException3(etype, value, tb):\n"

        //"    print(etype, value, tb)\n"

        "    try:\n"

        "       return ''.join(traceback.format_exception(etype, value, tb))\n"

        "    except:\n"

        "       return (str(etype) + ', ' + str(value))\n");

    CPLString osRet("An exception occurred in exception formatting code...");

    static int nCounter = 0;

    CPLString osModuleName(CPLSPrintf("gdal_exception_%d", nCounter));

    PyObject *poCompiledString =

        Py_CompileString(osPythonCode, osModuleName, Py_file_input);

    if (poCompiledString == nullptr || PyErr_Occurred())

    {

        PyErr_Print();

    }

    else

    {

        PyObject *poModule =

            PyImport_ExecCodeModule(osModuleName, poCompiledString);

        CPLAssert(poModule);

        Py_DecRef(poCompiledString);

        PyObject *poPyGDALFormatException2 =

            PyObject_GetAttrString(poModule, "GDALFormatException2");