#     Copyright 2020, Kay Hayen, mailto:kay.hayen@gmail.com
#
#     Part of "Nuitka", an optimizing Python compiler that is compatible and
#     integrates with CPython, but also works on its own.
#
#     Licensed under the Apache License, Version 2.0 (the "License");
#     you may not use this file except in compliance with the License.
#     You may obtain a copy of the License at
#
#        http://www.apache.org/licenses/LICENSE-2.0
#
#     Unless required by applicable law or agreed to in writing, software
#     distributed under the License is distributed on an "AS IS" BASIS,
#     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#     See the License for the specific language governing permissions and
#     limitations under the License.
#
""" Templates for calling functions with positional args only very quickly.

"""

template_call_function_with_args_decl = """\
extern PyObject *CALL_FUNCTION_WITH_ARGS%(args_count)d(PyObject *called, PyObject **args);"""

template_call_function_with_args_impl = """\
PyObject *CALL_FUNCTION_WITH_ARGS%(args_count)d(PyObject *called, PyObject **args) {
    CHECK_OBJECT(called);

    // Check if arguments are valid objects in debug mode.
#ifndef __NUITKA_NO_ASSERT__
    for (size_t i = 0; i < %(args_count)d; i++) {
        CHECK_OBJECT(args[i]);
    }
#endif

    if (Nuitka_Function_Check(called)) {
        if (unlikely(Py_EnterRecursiveCall((char *)" while calling a Python object"))) {
            return NULL;
        }

        struct Nuitka_FunctionObject *function = (struct Nuitka_FunctionObject *)called;
        PyObject *result;

        if (function->m_args_simple && %(args_count)d == function->m_args_positional_count){
            for (Py_ssize_t i = 0; i < %(args_count)d; i++) {
                Py_INCREF(args[i]);
            }

            result = function->m_c_code(function, args);
        } else if (function->m_args_simple && %(args_count)d + function->m_defaults_given == function->m_args_positional_count) {
#ifdef _MSC_VER
            PyObject **python_pars = (PyObject **)_alloca(sizeof(PyObject *) * function->m_args_positional_count);
#else
            PyObject *python_pars[function->m_args_positional_count];
#endif
            memcpy(python_pars, args, %(args_count)d * sizeof(PyObject *));
            memcpy(python_pars + %(args_count)d, &PyTuple_GET_ITEM(function->m_defaults, 0), function->m_defaults_given * sizeof(PyObject *));

            for (Py_ssize_t i = 0; i < function->m_args_positional_count; i++) {
                Py_INCREF(python_pars[i]);
            }

            result = function->m_c_code(function, python_pars);
        } else {
#ifdef _MSC_VER
            PyObject **python_pars = (PyObject **)_alloca(sizeof(PyObject *) * function->m_args_overall_count);
#else
            PyObject *python_pars[function->m_args_overall_count];
#endif
            memset(python_pars, 0, function->m_args_overall_count * sizeof(PyObject *));

            if (parseArgumentsPos(function, python_pars, args, %(args_count)d)) {
                result = function->m_c_code(function, python_pars);
            } else {
                result = NULL;
            }
        }

        Py_LeaveRecursiveCall();

        return result;
    } else if (Nuitka_Method_Check(called)) {
        struct Nuitka_MethodObject *method = (struct Nuitka_MethodObject *)called;

        // Unbound method without arguments, let the error path be slow.
        if (method->m_object != NULL) {
            if (unlikely(Py_EnterRecursiveCall((char *)" while calling a Python object"))) {
                return NULL;
            }

            struct Nuitka_FunctionObject *function = method->m_function;

            PyObject *result;

            if (function->m_args_simple && %(args_count)d + 1 == function->m_args_positional_count) {
#ifdef _MSC_VER
                PyObject **python_pars = (PyObject **)_alloca(sizeof(PyObject *) * function->m_args_positional_count);
#else
                PyObject *python_pars[function->m_args_positional_count];
#endif
                python_pars[0] = method->m_object;
                Py_INCREF(method->m_object);

                for (Py_ssize_t i = 0; i < %(args_count)d; i++) {
                    python_pars[i+1] = args[i];
                    Py_INCREF(args[i]);
                }

                result = function->m_c_code(function, python_pars);
            } else if ( function->m_args_simple && %(args_count)d + 1 + function->m_defaults_given == function->m_args_positional_count ) {
#ifdef _MSC_VER
                PyObject **python_pars = (PyObject **)_alloca(sizeof(PyObject *) * function->m_args_positional_count);
#else
                PyObject *python_pars[function->m_args_positional_count];
#endif
                python_pars[0] = method->m_object;
                Py_INCREF(method->m_object);

                memcpy(python_pars+1, args, %(args_count)d * sizeof(PyObject *));
                memcpy(python_pars+1 + %(args_count)d, &PyTuple_GET_ITEM(function->m_defaults, 0), function->m_defaults_given * sizeof(PyObject *));

                for (Py_ssize_t i = 1; i < function->m_args_overall_count; i++) {
                    Py_INCREF(python_pars[i]);
                }

                result = function->m_c_code(function, python_pars);
            } else {
#ifdef _MSC_VER
                PyObject **python_pars = (PyObject **)_alloca(sizeof(PyObject *) * function->m_args_overall_count);
#else
                PyObject *python_pars[function->m_args_overall_count];
#endif
                memset(python_pars, 0, function->m_args_overall_count * sizeof(PyObject *));

                if (parseArgumentsMethodPos(function, python_pars, method->m_object, args, %(args_count)d)) {
                    result = function->m_c_code(function, python_pars);
                } else {
                    result = NULL;
                }
            }

            Py_LeaveRecursiveCall();

            return result;
        }
    } else if (PyCFunction_Check(called)) {
        // Try to be fast about wrapping the arguments.
        int flags = PyCFunction_GET_FLAGS(called) & ~(METH_CLASS | METH_STATIC | METH_COEXIST);

        if (flags & METH_NOARGS) {
#if %(args_count)d == 0
            PyCFunction method = PyCFunction_GET_FUNCTION(called);
            PyObject *self = PyCFunction_GET_SELF(called);

            // Recursion guard is not strictly necessary, as we already have
            // one on our way to here.
#ifdef _NUITKA_FULL_COMPAT
            if (unlikely(Py_EnterRecursiveCall((char *)" while calling a Python object"))) {
                return NULL;
            }
#endif

            PyObject *result = (*method)( self, NULL );

#ifdef _NUITKA_FULL_COMPAT
            Py_LeaveRecursiveCall();
#endif

            if (result != NULL) {
            // Some buggy C functions do set an error, but do not indicate it
            // and Nuitka inner workings can get upset/confused from it.
                DROP_ERROR_OCCURRED();

                return result;
            } else {
                // Other buggy C functions do this, return NULL, but with
                // no error set, not allowed.
                if (unlikely(!ERROR_OCCURRED())) {
                    SET_CURRENT_EXCEPTION_TYPE0_STR(
                        PyExc_SystemError,
                        "NULL result without error in PyObject_Call"
                    );
                }

                return NULL;
            }
#else
            PyErr_Format(
                PyExc_TypeError,
                "%%s() takes no arguments (%(args_count)d given)",
                ((PyCFunctionObject *)called)->m_ml->ml_name
            );
            return NULL;
#endif
        } else if (flags & METH_O) {
#if %(args_count)d == 1
            PyCFunction method = PyCFunction_GET_FUNCTION(called);
            PyObject *self = PyCFunction_GET_SELF(called);

            // Recursion guard is not strictly necessary, as we already have
            // one on our way to here.
#ifdef _NUITKA_FULL_COMPAT
            if (unlikely(Py_EnterRecursiveCall((char *)" while calling a Python object"))) {
                return NULL;
            }
#endif

            PyObject *result = (*method)( self, args[0] );

#ifdef _NUITKA_FULL_COMPAT
            Py_LeaveRecursiveCall();
#endif

            if (result != NULL) {
            // Some buggy C functions do set an error, but do not indicate it
            // and Nuitka inner workings can get upset/confused from it.
                DROP_ERROR_OCCURRED();

                return result;
            } else {
                // Other buggy C functions do this, return NULL, but with
                // no error set, not allowed.
                if (unlikely(!ERROR_OCCURRED())) {
                    SET_CURRENT_EXCEPTION_TYPE0_STR(
                        PyExc_SystemError,
                        "NULL result without error in PyObject_Call"
                    );
                }

                return NULL;
            }
#else
            PyErr_Format(PyExc_TypeError,
                "%%s() takes exactly one argument (%(args_count)d given)",
                 ((PyCFunctionObject *)called)->m_ml->ml_name
            );
            return NULL;
#endif
        } else if (flags & METH_VARARGS) {
            PyCFunction method = PyCFunction_GET_FUNCTION(called);
            PyObject *self = PyCFunction_GET_SELF(called);

            PyObject *pos_args = MAKE_TUPLE(args, %(args_count)d);

            PyObject *result;

            // Recursion guard is not strictly necessary, as we already have
            // one on our way to here.
#ifdef _NUITKA_FULL_COMPAT
            if (unlikely(Py_EnterRecursiveCall((char *)" while calling a Python object"))) {
                return NULL;
            }
#endif

#if PYTHON_VERSION < 360
            if (flags & METH_KEYWORDS) {
                result = (*(PyCFunctionWithKeywords)method)(self, pos_args, NULL);
            } else {
                result = (*method)(self, pos_args);
            }
#else
            if (flags == (METH_VARARGS|METH_KEYWORDS)) {
                result = (*(PyCFunctionWithKeywords)method)(self, pos_args, NULL);
            } else if (flags == METH_FASTCALL) {
#if PYTHON_VERSION < 370
                result = (*(_PyCFunctionFast)method)(self, &PyTuple_GET_ITEM(pos_args, 0), %(args_count)d, NULL);
#else
                result = (*(_PyCFunctionFast)method)(self, &pos_args, %(args_count)d);
#endif
            } else {
                result = (*method)(self, pos_args);
            }
#endif

#ifdef _NUITKA_FULL_COMPAT
            Py_LeaveRecursiveCall();
#endif

            if (result != NULL) {
                // Some buggy C functions do set an error, but do not indicate it
                // and Nuitka inner workings can get upset/confused from it.
                DROP_ERROR_OCCURRED();

                Py_DECREF(pos_args);
                return result;
            } else {
                // Other buggy C functions do this, return NULL, but with
                // no error set, not allowed.
                if (unlikely(!ERROR_OCCURRED())) {
                    SET_CURRENT_EXCEPTION_TYPE0_STR(
                        PyExc_SystemError,
                        "NULL result without error in PyObject_Call"
                    );
                }

                Py_DECREF(pos_args);
                return NULL;
            }
        }
    } else if (PyFunction_Check(called)) {
        return callPythonFunction(
            called,
            args,
            %(args_count)d
        );
    }

    PyObject *pos_args = MAKE_TUPLE(args, %(args_count)d);

    PyObject *result = CALL_FUNCTION(called, pos_args, NULL);

    Py_DECREF(pos_args);

    return result;
}
"""


template_call_method_with_args_decl = """\
extern PyObject *CALL_METHOD_WITH_ARGS%(args_count)d(PyObject *source, PyObject *attr_name, PyObject **args);\
"""

template_call_method_with_args_impl = """\
PyObject *CALL_METHOD_WITH_ARGS%(args_count)d(PyObject *source, PyObject *attr_name, PyObject **args) {
    CHECK_OBJECT(source);
    CHECK_OBJECT(attr_name);

    // Check if arguments are valid objects in debug mode.
#ifndef __NUITKA_NO_ASSERT__
    for (size_t i = 0; i < %(args_count)d; i++) {
        CHECK_OBJECT(args[i]);
    }
#endif

    PyTypeObject *type = Py_TYPE(source);

    if (type->tp_getattro == PyObject_GenericGetAttr) {
        // Unfortunately this is required, although of cause rarely necessary.
        if (unlikely(type->tp_dict == NULL)) {
            if (unlikely(PyType_Ready(type) < 0)) {
                return NULL;
            }
        }

        PyObject *descr = _PyType_Lookup(type, attr_name);
        descrgetfunc func = NULL;

        if (descr != NULL)
        {
            Py_INCREF(descr);

#if PYTHON_VERSION < 300
            if (PyType_HasFeature(Py_TYPE(descr), Py_TPFLAGS_HAVE_CLASS)) {
#endif
                func = Py_TYPE(descr)->tp_descr_get;

                if (func != NULL && PyDescr_IsData(descr))
                {
                    PyObject *called_object = func(descr, source, (PyObject *)type);
                    Py_DECREF(descr);

                    PyObject *result = CALL_FUNCTION_WITH_ARGS%(args_count)d(
                        called_object,
                        args
                    );
                    Py_DECREF(called_object);
                    return result;
                }
#if PYTHON_VERSION < 300
            }
#endif
        }

        Py_ssize_t dictoffset = type->tp_dictoffset;
        PyObject *dict = NULL;

        if ( dictoffset != 0 )
        {
            // Negative dictionary offsets have special meaning.
            if ( dictoffset < 0 )
            {
                Py_ssize_t tsize;
                size_t size;

                tsize = ((PyVarObject *)source)->ob_size;
                if (tsize < 0)
                    tsize = -tsize;
                size = _PyObject_VAR_SIZE( type, tsize );

                dictoffset += (long)size;
            }

            PyObject **dictptr = (PyObject **) ((char *)source + dictoffset);
            dict = *dictptr;
        }

        if (dict != NULL)
        {
            CHECK_OBJECT(dict);

            Py_INCREF(dict);

            PyObject *called_object = PyDict_GetItem(dict, attr_name);

            if (called_object != NULL)
            {
                Py_INCREF(called_object);
                Py_XDECREF(descr);
                Py_DECREF(dict);

                PyObject *result = CALL_FUNCTION_WITH_ARGS%(args_count)d(
                    called_object,
                    args
                );
                Py_DECREF(called_object);
                return result;
            }

            Py_DECREF(dict);
        }

        if (func != NULL) {
            if (func == Nuitka_Function_Type.tp_descr_get) {
                PyObject *result = Nuitka_CallMethodFunctionPosArgs(
                    (struct Nuitka_FunctionObject const *)descr,
                    source,
                    args,
                    %(args_count)d
                );

                Py_DECREF(descr);

                return result;
            } else {
                PyObject *called_object = func(descr, source, (PyObject *)type);
                CHECK_OBJECT(called_object);

                Py_DECREF(descr);

                PyObject *result = CALL_FUNCTION_WITH_ARGS%(args_count)d(
                    called_object,
                    args
                );
                Py_DECREF(called_object);

                return result;
            }
        }

        if (descr != NULL) {
            CHECK_OBJECT(descr);

            PyObject *result = CALL_FUNCTION_WITH_ARGS%(args_count)d(
                descr,
                args
            );
            Py_DECREF(descr);

            return result;
        }

#if PYTHON_VERSION < 300
        PyErr_Format(
            PyExc_AttributeError,
            "'%%s' object has no attribute '%%s'",
            type->tp_name,
            PyString_AS_STRING( attr_name )
        );
#else
        PyErr_Format(
            PyExc_AttributeError,
            "'%%s' object has no attribute '%%U'",
            type->tp_name,
            attr_name
        );
#endif
        return NULL;
    }
#if PYTHON_VERSION < 300
    else if (type == &PyInstance_Type) {
        PyInstanceObject *source_instance = (PyInstanceObject *)source;

        // The special cases have their own variant on the code generation level
        // as we are called with constants only.
        assert(attr_name != const_str_plain___dict__);
        assert(attr_name != const_str_plain___class__);

        // Try the instance dict first.
        PyObject *called_object = GET_STRING_DICT_VALUE(
            (PyDictObject *)source_instance->in_dict,
            (PyStringObject *)attr_name
        );

        // Note: The "called_object" was found without taking a reference,
        // so we need not release it in this branch.
        if (called_object != NULL) {
            return CALL_FUNCTION_WITH_ARGS%(args_count)d(called_object, args);
        }

        // Then check the class dictionaries.
        called_object = FIND_ATTRIBUTE_IN_CLASS(
            source_instance->in_class,
            attr_name
        );

        // Note: The "called_object" was found without taking a reference,
        // so we need not release it in this branch.
        if (called_object != NULL) {
            descrgetfunc descr_get = Py_TYPE(called_object)->tp_descr_get;

            if (descr_get == Nuitka_Function_Type.tp_descr_get) {
                return Nuitka_CallMethodFunctionPosArgs(
                    (struct Nuitka_FunctionObject const *)called_object,
                    source,
                    args,
                    %(args_count)d
                );
            } else if (descr_get != NULL) {
                PyObject *method = descr_get(
                    called_object,
                    source,
                    (PyObject *)source_instance->in_class
                );

                if (unlikely(method == NULL)) {
                    return NULL;
                }

                PyObject *result = CALL_FUNCTION_WITH_ARGS%(args_count)d(method, args);
                Py_DECREF(method);
                return result;
            } else {
                return CALL_FUNCTION_WITH_ARGS%(args_count)d(called_object, args);
            }

        } else if (unlikely(source_instance->in_class->cl_getattr == NULL)) {
            PyErr_Format(
                PyExc_AttributeError,
                "%%s instance has no attribute '%%s'",
                PyString_AS_STRING( source_instance->in_class->cl_name ),
                PyString_AS_STRING( attr_name )
            );

            return NULL;
        } else {
            // Finally allow the "__getattr__" override to provide it or else
            // it's an error.

            PyObject *args2[] = {
                source,
                attr_name
            };

            called_object = CALL_FUNCTION_WITH_ARGS2(
                source_instance->in_class->cl_getattr,
                args2
            );

            if (unlikely(called_object == NULL))
            {
                return NULL;
            }

            PyObject *result = CALL_FUNCTION_WITH_ARGS%(args_count)d(
                called_object,
                args
            );
            Py_DECREF(called_object);
            return result;
        }
    }
#endif
    else if (type->tp_getattro != NULL) {
        PyObject *called_object = (*type->tp_getattro)(
            source,
            attr_name
        );

        if (unlikely(called_object == NULL)) {
            return NULL;
        }

        PyObject *result = CALL_FUNCTION_WITH_ARGS%(args_count)d(
            called_object,
            args
        );
        Py_DECREF(called_object);
        return result;
    } else if (type->tp_getattr != NULL) {
        PyObject *called_object = (*type->tp_getattr)(
            source,
            (char *)Nuitka_String_AsString_Unchecked(attr_name)
        );

        if (unlikely(called_object == NULL))
        {
            return NULL;
        }

        PyObject *result = CALL_FUNCTION_WITH_ARGS%(args_count)d(
            called_object,
            args
        );
        Py_DECREF(called_object);
        return result;
    } else {
        PyErr_Format(
            PyExc_AttributeError,
            "'%%s' object has no attribute '%%s'",
            type->tp_name,
            Nuitka_String_AsString_Unchecked(attr_name)
        );

        return NULL;
    }
}
"""

from . import TemplateDebugWrapper  # isort:skip

TemplateDebugWrapper.checkDebug(globals())
