# Copyright 2022-2023 ETSI TeraFlowSDN - TFS OSG (https://tfs.etsi.org/)
#
# 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.

import re
from enum import Enum
from typing import Optional

# Enumeration classes are redundant with gRPC classes, but gRPC does not provide a programmatical method to retrieve
# the values it expects from strings containing the desired value symbol or its integer value, so a kind of mapping is
# required. Besides, ORM Models expect Enum classes in EnumeratedFields; we create specific and conveniently defined
# Enum classes to serve both purposes.

def grpc_to_enum(grpc_enum_class, orm_enum_class : Enum, grpc_enum_value, grpc_enum_prefix : Optional[str] = None):
    enum_name = grpc_enum_class.Name(grpc_enum_value)

    if grpc_enum_prefix is None:
        grpc_enum_prefix = orm_enum_class.__name__.upper()
        #grpc_enum_prefix = re.sub(r'^ORM_(.+)$', r'\1', grpc_enum_prefix)
        #grpc_enum_prefix = re.sub(r'^(.+)ENUM$', r'\1', grpc_enum_prefix)
        #grpc_enum_prefix = grpc_enum_prefix + '_'
        grpc_enum_prefix = re.sub(r'^ORM_(.+)ENUM$', r'\1_', grpc_enum_prefix)

    if len(grpc_enum_prefix) > 0:
        enum_name = enum_name.replace(grpc_enum_prefix, '')

    orm_enum_value = orm_enum_class._member_map_.get(enum_name)
    return orm_enum_value
