#     Copyright 2019, 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.
#
""" Code generation for locals dict handling.

These are variable handling for classes and partially also Python2 exec
statements.
"""

from nuitka.nodes.shapes.BuiltinTypeShapes import ShapeTypeDict

from .CodeHelpers import generateExpressionCode, withObjectCodeTemporaryAssignment
from .Emission import SourceCodeCollector
from .ErrorCodes import (
    getErrorExitBoolCode,
    getErrorExitCode,
    getNameReferenceErrorCode,
)
from .Indentation import indented
from .PythonAPICodes import getReferenceExportCode
from .templates.CodeTemplatesVariables import (
    template_read_locals_dict_with_fallback,
    template_read_locals_dict_without_fallback,
    template_read_locals_mapping_with_fallback,
    template_read_locals_mapping_without_fallback,
)


def generateSetLocalsDictCode(statement, emit, context):
    new_locals_name = context.allocateTempName("set_locals")

    generateExpressionCode(
        to_name=new_locals_name,
        expression=statement.getNewLocals(),
        emit=emit,
        context=context,
    )

    locals_declaration = context.addLocalsDictName(
        statement.getLocalsScope().getCodeName()
    )

    emit(
        """\
%(locals_dict)s = %(locals_value)s;"""
        % {"locals_dict": locals_declaration, "locals_value": new_locals_name}
    )

    getReferenceExportCode(new_locals_name, emit, context)

    if context.needsCleanup(new_locals_name):
        context.removeCleanupTempName(new_locals_name)


def generateReleaseLocalsDictCode(statement, emit, context):
    locals_declaration = context.addLocalsDictName(
        statement.getLocalsScope().getCodeName()
    )

    emit(
        """\
Py_DECREF( %(locals_dict)s );
%(locals_dict)s = NULL;"""
        % {"locals_dict": locals_declaration}
    )


def generateLocalsDictSetCode(statement, emit, context):
    value_arg_name = context.allocateTempName("dictset_value", unique=True)
    generateExpressionCode(
        to_name=value_arg_name,
        expression=statement.subnode_value,
        emit=emit,
        context=context,
    )

    context.setCurrentSourceCodeReference(statement.getSourceReference())

    locals_scope = statement.getLocalsDictScope()

    locals_declaration = context.addLocalsDictName(locals_scope.getCodeName())

    is_dict = locals_scope.getTypeShape() is ShapeTypeDict

    res_name = context.getIntResName()

    if is_dict:
        emit(
            "%s = PyDict_SetItem( %s, %s, %s );"
            % (
                res_name,
                locals_declaration,
                context.getConstantCode(statement.getVariableName()),
                value_arg_name,
            )
        )
    else:
        emit(
            "%s = PyObject_SetItem( %s, %s, %s );"
            % (
                res_name,
                locals_declaration,
                context.getConstantCode(statement.getVariableName()),
                value_arg_name,
            )
        )

    getErrorExitBoolCode(
        condition="%s != 0" % res_name,
        release_name=value_arg_name,
        needs_check=statement.mayRaiseException(BaseException),
        emit=emit,
        context=context,
    )


def generateLocalsDictDelCode(statement, emit, context):
    locals_scope = statement.getLocalsDictScope()

    dict_arg_name = locals_scope.getCodeName()

    is_dict = locals_scope.getTypeShape() is ShapeTypeDict

    context.setCurrentSourceCodeReference(statement.getSourceReference())

    if is_dict:
        res_name = context.getBoolResName()

        emit(
            "%s = DICT_REMOVE_ITEM( %s, %s );"
            % (
                res_name,
                dict_arg_name,
                context.getConstantCode(statement.getVariableName()),
            )
        )

        getErrorExitBoolCode(
            condition="%s == false" % res_name,
            needs_check=statement.mayRaiseException(BaseException),
            emit=emit,
            context=context,
        )
    else:
        res_name = context.getIntResName()

        emit(
            "%s = PyObject_DelItem( %s, %s );"
            % (
                res_name,
                dict_arg_name,
                context.getConstantCode(statement.getVariableName()),
            )
        )

        getErrorExitBoolCode(
            condition="%s == -1" % res_name,
            needs_check=statement.mayRaiseException(BaseException),
            emit=emit,
            context=context,
        )


def generateLocalsDictVariableRefOrFallbackCode(to_name, expression, emit, context):
    variable_name = expression.getVariableName()

    fallback_emit = SourceCodeCollector()

    with withObjectCodeTemporaryAssignment(
        to_name, "locals_lookup_value", expression, emit, context
    ) as value_name:

        generateExpressionCode(
            to_name=value_name,
            expression=expression.subnode_fallback,
            emit=fallback_emit,
            context=context,
        )

        locals_scope = expression.getLocalsDictScope()
        locals_declaration = context.addLocalsDictName(locals_scope.getCodeName())

        is_dict = locals_scope.getTypeShape() is ShapeTypeDict

        assert not context.needsCleanup(value_name)

        if is_dict:
            template = template_read_locals_dict_with_fallback
        else:
            template = template_read_locals_mapping_with_fallback
            # If the fallback took no reference, then make it do it
            # anyway.
            context.addCleanupTempName(value_name)

        emit(
            template
            % {
                "to_name": value_name,
                "locals_dict": locals_declaration,
                "fallback": indented(fallback_emit.codes),
                "var_name": context.getConstantCode(constant=variable_name),
            }
        )


def generateLocalsDictVariableRefCode(to_name, expression, emit, context):
    variable_name = expression.getVariableName()
    locals_scope = expression.getLocalsDictScope()

    locals_declaration = context.addLocalsDictName(locals_scope.getCodeName())

    is_dict = locals_scope.getTypeShape() is ShapeTypeDict

    if is_dict:
        template = template_read_locals_dict_without_fallback
    else:
        template = template_read_locals_mapping_without_fallback

    with withObjectCodeTemporaryAssignment(
        to_name, "locals_lookup_value", expression, emit, context
    ) as value_name:

        emit(
            template
            % {
                "to_name": value_name,
                "locals_dict": locals_declaration,
                "var_name": context.getConstantCode(constant=variable_name),
            }
        )

        getNameReferenceErrorCode(
            variable_name=variable_name,
            condition="%s == NULL && CHECK_AND_CLEAR_KEY_ERROR_OCCURRED()" % value_name,
            emit=emit,
            context=context,
        )

        getErrorExitCode(check_name=value_name, emit=emit, context=context)

        if not is_dict:
            context.addCleanupTempName(value_name)


def generateLocalsDictVariableCheckCode(to_name, expression, emit, context):
    variable_name = expression.getVariableName()

    locals_scope = expression.getLocalsDictScope()

    locals_declaration = context.addLocalsDictName(locals_scope.getCodeName())

    is_dict = locals_scope.getTypeShape() is ShapeTypeDict

    if is_dict:
        to_name.getCType().emitAssignmentCodeFromBoolCondition(
            to_name=to_name,
            condition="PyDict_GetItem( %(locals_dict)s, %(var_name)s )"
            % {
                "locals_dict": locals_declaration,
                "var_name": context.getConstantCode(constant=variable_name),
            },
            emit=emit,
        )
    else:
        tmp_name = context.getIntResName()

        template = """\
%(tmp_name)s = MAPPING_HAS_ITEM( %(locals_dict)s, %(var_name)s );
"""

        emit(
            template
            % {
                "locals_dict": locals_declaration,
                "var_name": context.getConstantCode(constant=variable_name),
                "tmp_name": tmp_name,
            }
        )

        getErrorExitBoolCode(
            condition="%s == -1" % tmp_name,
            needs_check=expression.mayRaiseException(BaseException),
            emit=emit,
            context=context,
        )

        to_name.getCType().emitAssignmentCodeFromBoolCondition(
            to_name=to_name, condition="%s == 1" % tmp_name, emit=emit
        )
