// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#ifndef SBK_CONVERTER_H
#define SBK_CONVERTER_H

#include "sbkpython.h"
#include "sbkmodule.h"
#include "shibokenmacros.h"
#include "sbkenum.h"
#include "basewrapper_p.h"

#include <limits>
#include <string>

struct SbkObject;

/**
 *  This is a convenience macro identical to Python's PyObject_TypeCheck,
 *  except that the arguments have swapped places, for the great convenience
 *  of generator.
 */
#define SbkObject_TypeCheck(tp, ob) \
        (Py_TYPE(ob) == (tp) || PyType_IsSubtype(Py_TYPE(ob), (tp)))

extern "C"
{

/**
 *  SbkConverter is used to perform type conversions from C++
 *  to Python and vice-versa;.and it is also used for type checking.
 *  SbkConverter is a private structure that must be accessed
 *  using the functions provided by the converter API.
 */
struct SbkConverter;
struct SbkArrayConverter;

/**
 *  Given a void pointer to a C++ object, this function must return
 *  the proper Python object. It may be either an existing wrapper
 *  for the C++ object, or a newly create one. Or even the Python
 *  equivalent of the C++ value passed in the argument.
 *
 *  C++ -> Python
 */
using CppToPythonFunc = PyObject *(*)(const void *);

/**
 *  This function converts a Python object to a C++ value, it may be
 *  a pointer, value, class, container or primitive type, passed via
 *  a void pointer, that will be cast properly inside the function.
 *  This function is usually returned by an IsConvertibleToCppFunc
 *  function, or obtained knowing the type of the Python object input,
 *  thus it will not check the Python object type, and will expect
 *  the void pointer to be pointing to a proper variable.
 *
 *  Python -> C++
 */
using PythonToCppFunc = void (*)(PyObject *,void *);

/**
 *  Checks if the Python object passed in the argument is convertible to a
 *  C++ type defined inside the function, it returns the converter function
 *  that will transform a Python argument into a C++ value.
 *  It returns NULL if the Python object is not convertible to the C++ type
 *  that the function represents.
 *
 *  Python -> C++ ?
 */
using IsConvertibleToCppFunc = PythonToCppFunc (*)(PyObject *);

} // extern "C"

namespace Shiboken {
namespace Conversions {


class LIBSHIBOKEN_API SpecificConverter
{
public:
    enum Type
    {
        InvalidConversion,
        CopyConversion,
        PointerConversion,
        ReferenceConversion
    };

    explicit SpecificConverter(const char *typeName);

    inline SbkConverter *converter() { return m_converter; }
    inline operator SbkConverter *() const { return m_converter; }

    inline bool isValid() { return m_type != InvalidConversion; }
    inline operator bool() const { return m_type != InvalidConversion; }

    inline Type conversionType() { return m_type; }

    PyObject *toPython(const void *cppIn);
    void toCpp(PyObject *pyIn, void *cppOut);
private:
    SbkConverter *m_converter;
    Type m_type;
};


/**
 *  Creates a converter for a wrapper type.
 *  \param type                  A Shiboken.ObjectType that will receive the new converter.
 *  \param toCppPointerConvFunc  Function to retrieve the C++ pointer held by a Python wrapper.
 *  \param toCppPointerCheckFunc Check and return the retriever function of the C++ pointer held by a Python wrapper.
 *  \param pointerToPythonFunc   Function to convert a C++ object to a Python \p type wrapper, keeping their identity.
 *  \param copyToPythonFunc      Function to convert a C++ object to a Python \p type, copying the object.
 *  \returns                     The new converter referred by the wrapper \p type.
 */
LIBSHIBOKEN_API SbkConverter *createConverter(PyTypeObject *type,
                                              PythonToCppFunc toCppPointerConvFunc,
                                              IsConvertibleToCppFunc toCppPointerCheckFunc,
                                              CppToPythonFunc pointerToPythonFunc,
                                              CppToPythonFunc copyToPythonFunc = nullptr);

/**
 *  Creates a converter for a non wrapper type (primitive or container type).
 *  \param type         Python type representing to the new converter.
 *  \param toPythonFunc Function to convert a C++ object to a Python \p type.
 *  \returns            A new type converter.
 */
LIBSHIBOKEN_API SbkConverter *createConverter(PyTypeObject *type, CppToPythonFunc toPythonFunc);

LIBSHIBOKEN_API void deleteConverter(SbkConverter *converter);

/// Sets the Python object to C++ pointer conversion function.
LIBSHIBOKEN_API void setCppPointerToPythonFunction(SbkConverter *converter, CppToPythonFunc pointerToPythonFunc);

/// Sets the C++ pointer to Python object conversion functions.
LIBSHIBOKEN_API void setPythonToCppPointerFunctions(SbkConverter *converter,
                                                    PythonToCppFunc toCppPointerConvFunc,
                                                    IsConvertibleToCppFunc toCppPointerCheckFunc);

/**
 *  Adds a new conversion of a Python object to a C++ value.
 *  This is used in copy and implicit conversions.
 */
LIBSHIBOKEN_API void addPythonToCppValueConversion(SbkConverter *converter,
                                                   PythonToCppFunc pythonToCppFunc,
                                                   IsConvertibleToCppFunc isConvertibleToCppFunc);
LIBSHIBOKEN_API void prependPythonToCppValueConversion(SbkConverter *converter,
                                                       PythonToCppFunc pythonToCppFunc,
                                                       IsConvertibleToCppFunc isConvertibleToCppFunc);

LIBSHIBOKEN_API void addPythonToCppValueConversion(PyTypeObject *type,
                                                   PythonToCppFunc pythonToCppFunc,
                                                   IsConvertibleToCppFunc isConvertibleToCppFunc);
LIBSHIBOKEN_API void addPythonToCppValueConversion(Shiboken::Module::TypeInitStruct typeStruct,
                                                   PythonToCppFunc pythonToCppFunc,
                                                   IsConvertibleToCppFunc isConvertibleToCppFunc);

// C++ -> Python ---------------------------------------------------------------------------

/**
 *  Retrieves the Python wrapper object for the given \p cppIn C++ pointer object.
 *  This function is used only for Value and Object Types.
 *  Example usage:
 *      TYPE *var;
 *      PyObject *pyVar = pointerToPython(SBKTYPE, &var);
 */
LIBSHIBOKEN_API PyObject *pointerToPython(PyTypeObject *type, const void *cppIn);
LIBSHIBOKEN_API PyObject *pointerToPython(const SbkConverter *converter, const void *cppIn);

/**
 *  For the given \p cppIn C++ reference it returns the Python wrapper object,
 *  always for Object Types, and when they already exist for reference types;
 *  for when the latter doesn't have an existing wrapper type, the C++ object
 *  is copied to Python.
 *  Example usage:
 *      TYPE &var = SOMETHING;
 *      PyObject *pyVar = referenceToPython(SBKTYPE, &var);
 */
LIBSHIBOKEN_API PyObject *referenceToPython(PyTypeObject *type, const void *cppIn);
LIBSHIBOKEN_API PyObject *referenceToPython(const SbkConverter *converter, const void *cppIn);

/**
 *  Retrieves the Python wrapper object for the given C++ value pointed by \p cppIn.
 *  This function is used only for Value Types.
 *  Example usage:
 *      TYPE var;
 *      PyObject *pyVar = copyToPython(SBKTYPE, &var);
 */
LIBSHIBOKEN_API PyObject *copyToPython(PyTypeObject *type, const void *cppIn);
LIBSHIBOKEN_API PyObject *copyToPython(const SbkConverter *converter, const void *cppIn);

// Python -> C++ ---------------------------------------------------------------------------

struct PythonToCppConversion
{
    enum Type {Invalid, Pointer, Value};

    operator bool() const { return type != Invalid; }

    void operator()(PyObject *po,void *cpp) const { function(po, cpp); }

    bool isValue() const { return type == Value; }

    PythonToCppFunc function = nullptr;
    Type type = Invalid;
};

/**
 *  Returns a Python to C++ conversion function if the Python object is convertible to a C++ pointer.
 *  It returns NULL if the Python object is not convertible to \p type.
 */
LIBSHIBOKEN_API PythonToCppFunc isPythonToCppPointerConvertible(PyTypeObject *type, PyObject *pyIn);
LIBSHIBOKEN_API PythonToCppConversion pythonToCppPointerConversion(PyTypeObject *type, PyObject *pyIn);
LIBSHIBOKEN_API PythonToCppConversion pythonToCppPointerConversion(Module::TypeInitStruct typeStruct, PyObject *pyIn);

/**
 *  Returns a Python to C++ conversion function if the Python object is convertible to a C++ value.
 *  The resulting converter function will create a copy of the Python object in C++, or implicitly
 *  convert the object to the expected \p type.
 *  It returns NULL if the Python object is not convertible to \p type.
 */
LIBSHIBOKEN_API PythonToCppFunc isPythonToCppValueConvertible(PyTypeObject *type, PyObject *pyIn);
LIBSHIBOKEN_API PythonToCppConversion pythonToCppValueConversion(PyTypeObject *type, PyObject *pyIn);

/**
 *  Returns a Python to C++ conversion function if the Python object is convertible to a C++ reference.
 *  The resulting converter function will return the underlying C++ object held by the Python wrapper,
 *  or a new C++ value if it must be a implicit conversion.
 *  It returns NULL if the Python object is not convertible to \p type.
 */
LIBSHIBOKEN_API PythonToCppFunc isPythonToCppReferenceConvertible(PyTypeObject *type, PyObject *pyIn);
LIBSHIBOKEN_API PythonToCppConversion pythonToCppReferenceConversion(PyTypeObject *type, PyObject *pyIn);

/// This is the same as isPythonToCppValueConvertible function.
LIBSHIBOKEN_API PythonToCppFunc isPythonToCppConvertible(const SbkConverter *converter, PyObject *pyIn);
LIBSHIBOKEN_API PythonToCppConversion pythonToCppReferenceConversion(const SbkConverter *converter, PyObject *pyIn);

LIBSHIBOKEN_API PythonToCppConversion pythonToCppConversion(const SbkConverter *converter, PyObject *pyIn);
LIBSHIBOKEN_API PythonToCppFunc isPythonToCppConvertible(const SbkArrayConverter *converter,
                                                         int dim1, int dim2, PyObject *pyIn);
LIBSHIBOKEN_API PythonToCppConversion pythonToCppConversion(const SbkArrayConverter *converter,
                                                                int dim1, int dim2, PyObject *pyIn);

/**
 *  Returns the C++ pointer for the \p pyIn object cast to the type passed via \p desiredType.
 *  It differs from Shiboken::Object::cppPointer because it casts the pointer to a proper
 *  memory offset depending on the desired type.
 */
LIBSHIBOKEN_API void *cppPointer(PyTypeObject *desiredType, SbkObject *pyIn);

/// Converts a Python object \p pyIn to C++ and stores the result in the C++ pointer passed in \p cppOut.
LIBSHIBOKEN_API void pythonToCppPointer(PyTypeObject *type, PyObject *pyIn, void *cppOut);
LIBSHIBOKEN_API void pythonToCppPointer(const SbkConverter *converter, PyObject *pyIn, void *cppOut);

/// Converts a Python object \p pyIn to C++, and copies the result in the C++ variable passed in \p cppOut.
LIBSHIBOKEN_API void pythonToCppCopy(PyTypeObject *type, PyObject *pyIn, void *cppOut);
LIBSHIBOKEN_API void pythonToCppCopy(const SbkConverter *converter, PyObject *pyIn, void *cppOut);

/**
 *  Helper function returned by generated convertible checking functions
 *  that returns a C++ NULL when the input Python object is None.
 */
LIBSHIBOKEN_API void nonePythonToCppNullPtr(PyObject *, void *cppOut);

/**
 *  Returns true if the \p toCpp function passed is an implicit conversion of Python \p type.
 *  It is used when C++ expects a reference argument, so it may be the same object received
 *  from Python, or another created through implicit conversion.
 */
[[deprecated]] LIBSHIBOKEN_API bool isImplicitConversion(PyTypeObject *type, PythonToCppFunc toCpp);

/// Registers a converter with a type name that may be used to retrieve the converter.
/// Use for fully qualified names (main type). This will overwrite existing converters
/// of the same name.
LIBSHIBOKEN_API void registerConverterName(SbkConverter *converter, const char *typeName);

/// Registers a converter with a type name that may be used to retrieve the converter
/// unless there is already a converter for the name. Use for partially qualified names.
LIBSHIBOKEN_API void registerConverterAlias(SbkConverter *converter, const char *typeName);

/// Returns the converter for a given type name, or NULL if it wasn't registered before.
LIBSHIBOKEN_API SbkConverter *getConverter(const char *typeName);

/// Returns the converter for a primitive type.
LIBSHIBOKEN_API SbkConverter *primitiveTypeConverter(int index);

/// Returns true if a Python sequence is comprised of objects of the given \p type.
LIBSHIBOKEN_API bool checkSequenceTypes(PyTypeObject *type, PyObject *pyIn);

/// Returns true if a Python type is iterable and comprised of objects of the
/// given \p type.
LIBSHIBOKEN_API bool checkIterableTypes(PyTypeObject *type, PyObject *pyIn);

/// Returns true if a Python sequence is comprised of objects of a type convertible to the one represented by the given \p converter.
LIBSHIBOKEN_API bool convertibleSequenceTypes(const SbkConverter *converter, PyObject *pyIn);

/// Returns true if a Python sequence is comprised of objects of a type convertible to \p type.
LIBSHIBOKEN_API bool convertibleSequenceTypes(PyTypeObject *type, PyObject *pyIn);

/// Returns true if a Python type is iterable and comprised of objects of a
/// type convertible to the one represented by the given \p converter.
LIBSHIBOKEN_API bool convertibleIterableTypes(const SbkConverter *converter, PyObject *pyIn);

/// Returns true if a Python type is iterable and comprised of objects of a
/// type convertible to \p type.
LIBSHIBOKEN_API bool convertibleIterableTypes(PyTypeObject *type, PyObject *pyIn);

/// Returns true if a Python sequence can be converted to a C++ pair.
LIBSHIBOKEN_API bool checkPairTypes(PyTypeObject *firstType, PyTypeObject *secondType, PyObject *pyIn);

/// Returns true if a Python sequence can be converted to a C++ pair.
LIBSHIBOKEN_API bool convertiblePairTypes(const SbkConverter *firstConverter, bool firstCheckExact,
                                          const SbkConverter *secondConverter, bool secondCheckExact,
                                          PyObject *pyIn);

/// Returns true if a Python dictionary can be converted to a C++ hash or map.
LIBSHIBOKEN_API bool checkDictTypes(PyTypeObject *keyType, PyTypeObject *valueType, PyObject *pyIn);

/// Returns true if a Python dictionary can be converted to a C++ multi hash/map.
/// The Python dictionary is expected to contain lists of values
bool checkMultiDictTypes(PyTypeObject *keyType, PyTypeObject *valueType,
                         PyObject *pyIn);

/// Returns true if a Python dictionary can be converted to a C++ hash or map.
LIBSHIBOKEN_API bool convertibleDictTypes(const SbkConverter *keyConverter, bool keyCheckExact,
                                          const SbkConverter *valueConverter, bool valueCheckExact,
                                          PyObject *pyIn);

/// Returns true if a Python dictionary can be converted to a C++ multi hash/map.
/// The Python dictionary is expected to contain lists of values
LIBSHIBOKEN_API bool convertibleMultiDictTypes(const SbkConverter *keyConverter,
                                               bool keyCheckExact,
                                               const SbkConverter *valueConverter,
                                               bool valueCheckExact,
                                               PyObject *pyIn);

/// Returns the Python type object associated with the given \p converter.
LIBSHIBOKEN_API PyTypeObject *getPythonTypeObject(const SbkConverter *converter);

/// Returns the Python type object for the given \p typeName.
LIBSHIBOKEN_API PyTypeObject *getPythonTypeObject(const char *typeName);

/// Returns true if the Python type associated with the converter is a value type.
LIBSHIBOKEN_API bool pythonTypeIsValueType(const SbkConverter *converter);

/// Returns true if the Python type associated with the converter is an object type.
LIBSHIBOKEN_API bool pythonTypeIsObjectType(const SbkConverter *converter);

/// Returns true if the Python type associated with the converter is a wrapper type.
LIBSHIBOKEN_API bool pythonTypeIsWrapperType(const SbkConverter *converter);

enum  : int {
SBK_PY_LONG_LONG_IDX =             0,
// Qt5: name collision in QtCore after QBool is replaced by bool
SBK_BOOL_IDX_1 =                   1,
SBK_CHAR_IDX =                     2,
SBK_CONSTCHARPTR_IDX =             3,
SBK_DOUBLE_IDX =                   4,
SBK_FLOAT_IDX =                    5,
SBK_INT_IDX =                      6,
SBK_SIGNEDINT_IDX =                6,
SBK_LONG_IDX =                     7,
SBK_SHORT_IDX =                    8,
SBK_SIGNEDCHAR_IDX =               9,
SBK_STD_STRING_IDX =              10,
SBK_STD_WSTRING_IDX =             11,
SBK_UNSIGNEDPY_LONG_LONG_IDX =    12,
SBK_UNSIGNEDCHAR_IDX =            13,
SBK_UNSIGNEDINT_IDX =             14,
SBK_UNSIGNEDLONG_IDX =            15,
SBK_UNSIGNEDSHORT_IDX =           16,
SBK_VOIDPTR_IDX =                 17,
SBK_NULLPTR_T_IDX =               18
};

template<typename T> SbkConverter *PrimitiveTypeConverter() { return nullptr; }
template<> inline SbkConverter *PrimitiveTypeConverter<PY_LONG_LONG>() { return primitiveTypeConverter(SBK_PY_LONG_LONG_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<bool>() { return primitiveTypeConverter(SBK_BOOL_IDX_1); }
template<> inline SbkConverter *PrimitiveTypeConverter<char>() { return primitiveTypeConverter(SBK_CHAR_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<const char *>() { return primitiveTypeConverter(SBK_CONSTCHARPTR_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<double>() { return primitiveTypeConverter(SBK_DOUBLE_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<float>() { return primitiveTypeConverter(SBK_FLOAT_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<int>() { return primitiveTypeConverter(SBK_INT_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<long>() { return primitiveTypeConverter(SBK_LONG_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<short>() { return primitiveTypeConverter(SBK_SHORT_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<signed char>() { return primitiveTypeConverter(SBK_SIGNEDCHAR_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<std::string>() { return primitiveTypeConverter(SBK_STD_STRING_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<std::wstring>() { return primitiveTypeConverter(SBK_STD_WSTRING_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<unsigned PY_LONG_LONG>() { return primitiveTypeConverter(SBK_UNSIGNEDPY_LONG_LONG_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<unsigned char>() { return primitiveTypeConverter(SBK_UNSIGNEDCHAR_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<unsigned int>() { return primitiveTypeConverter(SBK_UNSIGNEDINT_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<unsigned long>() { return primitiveTypeConverter(SBK_UNSIGNEDLONG_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<unsigned short>() { return primitiveTypeConverter(SBK_UNSIGNEDSHORT_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<void *>() { return primitiveTypeConverter(SBK_VOIDPTR_IDX); }
template<> inline SbkConverter *PrimitiveTypeConverter<std::nullptr_t>() { return primitiveTypeConverter(SBK_NULLPTR_T_IDX); }

} // namespace Shiboken::Conversions

/**
*   This function template is used to get the PyTypeObject of a C++ type T.
*   All implementations should be provided by template specializations generated by the generator when
*   T isn't a C++ primitive type.
*   \see SpecialCastFunction
*/
template<typename T> PyTypeObject *SbkType() { return nullptr; }

// Below are the template specializations for C++ primitive types.
template<> inline PyTypeObject *SbkType<PY_LONG_LONG>() { return &PyLong_Type; }
template<> inline PyTypeObject *SbkType<bool>() { return &PyBool_Type; }
template<> inline PyTypeObject *SbkType<char>() { return &PyLong_Type; }
template<> inline PyTypeObject *SbkType<double>() { return &PyFloat_Type; }
template<> inline PyTypeObject *SbkType<float>() { return &PyFloat_Type; }
template<> inline PyTypeObject *SbkType<int>() { return &PyLong_Type; }
template<> inline PyTypeObject *SbkType<long>() { return &PyLong_Type; }
template<> inline PyTypeObject *SbkType<short>() { return &PyLong_Type; }
template<> inline PyTypeObject *SbkType<signed char>() { return &PyLong_Type; }
template<> inline PyTypeObject *SbkType<unsigned PY_LONG_LONG>() { return &PyLong_Type; }
template<> inline PyTypeObject *SbkType<unsigned char>() { return &PyLong_Type; }
template<> inline PyTypeObject *SbkType<unsigned int>() { return &PyLong_Type; }
template<> inline PyTypeObject *SbkType<unsigned long>() { return &PyLong_Type; }
template<> inline PyTypeObject *SbkType<unsigned short>() { return &PyLong_Type; }
template<> inline PyTypeObject *SbkType<std::nullptr_t>() { return Py_TYPE(&_Py_NoneStruct); }

} // namespace Shiboken

#define SbkChar_Check(X) (PyNumber_Check(X) || Shiboken::String::checkChar(X))

struct PySideQFlagsType;
struct SbkQFlagsTypePrivate
{
    SbkConverter *converter;
};

#endif // SBK_CONVERTER_H
