Source code for ats_utilities.factory_type

# -*- coding: UTF-8 -*-

'''
Module
    factory_type.py
Copyright
    Copyright (C) 2017 - 2026 Vladimir Roncevic <elektron.ronca@gmail.com>
    ats_utilities is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
    Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    ats_utilities is distributed in the hope that it will be useful, but
    WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    See the GNU General Public License for more details.
    You should have received a copy of the GNU General Public License along
    with this program. If not, see <http://www.gnu.org/licenses/>.
Info
    Defines factory type utility functions.
'''

from __future__ import annotations

from typing import Any, get_origin, Union
from types import UnionType

from ats_utilities.factory_context_error import raise_context_error
from ats_utilities.exceptions import ATSTypeError

__author__ = r'Vladimir Roncevic'
__copyright__ = r'(C) 2026, https://vroncevic.github.io/ats_utilities'
__credits__ = [r'Vladimir Roncevic', r'Python Software Foundation']
__license__ = r'https://github.com/vroncevic/ats_utilities/blob/dev/LICENSE'
__version__ = r'3.4.2'
__maintainer__ = r'Vladimir Roncevic'
__email__ = r'elektron.ronca@gmail.com'
__status__ = r'Updated'




def _resolve_type(type_to_resolve: Any) -> Any:
    '''
        Resolves nested Union types.
        Handles cases like Union[int, float] by flattening them 
        into a tuple of concrete types (int, float).

        :param type_to_resolve: Type to resolve.
        :type type_to_resolve: <Any>
        :return: Resolved type.
        :rtype: <Any>
        :exceptions: None.
    '''
    origin = get_origin(type_to_resolve)

    if origin in (Union, UnionType):
        args = getattr(type_to_resolve, '__args__', ())
        resolved_args = []

        for arg in args:
            res = _resolve_type(arg)

            if isinstance(res, tuple):
                resolved_args.extend(res)
            else:
                resolved_args.append(res)

        return tuple(resolved_args)

    return origin or type_to_resolve





def check_type(
    instance: object,
    class_or_tuple: type[Any] | tuple[type[Any], ...],
    exc_message_path: str | None = None,
    exception_class: type[Exception] = ATSTypeError
) -> None:
    '''
        Checks if an instance is of a specified type.

        :param instance: Instance to check.
        :type instance: <any>
        :param class_or_tuple: Type or tuple of types to check against.
        :type class_or_tuple: <type | tuple[type, ...]>
        :param exc_message_path: Path and details to include in the exception message.
        :type exc_message_path: <str | None>
        :param exception_class: The exception class to raise if instance is not of the specified type.
        :type exception_class: <type[Exception]> (default ATSTypeError)
        :exceptions:
            | Dynamically raises the provided exception_class (e.g., ATSTypeError).
    '''
    if isinstance(class_or_tuple, tuple):
        check_types = []

        for type_to_check in class_or_tuple:
            res = _resolve_type(type_to_check)

            if isinstance(res, tuple):
                check_types.extend(res)
            else:
                check_types.append(res)

        check_types = tuple(check_types)

    else:
        check_types = _resolve_type(class_or_tuple)

    if not isinstance(instance, check_types):
        raise_context_error(
            fallback_prefix=r'factory_type::check_type(..)',
            fallback_msg=f'expected {class_or_tuple} for instance, got {type(instance).__name__}',
            exc_message_path=exc_message_path,
            exception_class=exception_class,
            depth=3
        )