mia-accounting/src/accounting/utils/random_id.py

# The Mia! Accounting Project.
# Author: imacat@mail.imacat.idv.tw (imacat), 2023/1/30

#  Copyright (c) 2023 imacat.
#
#  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.
"""The random ID utility for the data models.

This module should not import any other module from the application.

"""
from secrets import randbelow
from typing import Type

from accounting import db


def new_id(cls: Type[db.Model]):
    """Generates and returns a new, unused random ID for the data model.

    :param cls: The data model.
    :return: The newly-generated, unused random ID.
    """
    while True:
        obj_id: int = 100000000 + randbelow(900000000)
        if db.session.get(cls, obj_id) is None:
            return obj_id