bhgomes/oeis

# -*- coding: utf-8 -*- #
#
# oeis/__init__.py
#
#
# MIT License
#
# Copyright (c) 2019 Brandon Gomes
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#

"""
Interface to the OEIS.

"""

# -------------- Standard Library -------------- #

import sys

# ---------------- oeis Library ---------------- #

from ._version import __version_info__, __version__

from . import generators
from .base import *
from .client import *
from .sequence import *
from .util import value_or


GETATTR_IMPORT_SUPPORT = sys.version_info >= (3, 7)


def _module_getattr_(a_, oeis_, file):
    """Customize Module Import Mechanism."""

    def inner(attribute):
        if attribute == "__all__":
            return __all__
        try:
            return a_.__call__(attribute)
        except MissingID:
            return getattr(oeis_, attribute)
        except Exception:
            raise ImportError(
                "cannot import name '{}' from 'oeis' ({})".format(attribute, file)
            )

    return inner


def get_custom_session():
    """"""
    if REQUESTS_SUPPORT:
        import requests

        session = requests.Session()
        if CACHE_CONTROL_SUPPORT:
            from cachecontrol import CacheControl

            return CacheControl(session)
        return session
    return None


def build_generators(generator_list, oeis_):
    """Register all Included Generators."""
    for generator in map(lambda g: getattr(generators, g), generator_list):
        generator_name = generator.__name__
        if generator_name.startswith("g"):
            oeis_.register(generator_name.strip("g"), generator, meta=True)


def setup_module(generator_list, file, *, a_=None, oeis_=None):
    """"""
    a_ = value_or(a_, SequenceFactory(always_cache=True, session=get_custom_session()))
    oeis_ = value_or(oeis_, Registry.from_factory(a_))

    build_generators(generator_list, oeis_)

    if GETATTR_IMPORT_SUPPORT:
        return a_, oeis_, _module_getattr_(a_, oeis_, file)
    return a_, oeis_, lambda n: None


A, OEIS, __getattr__ = setup_module(generators.__all__, __file__)


__all__ = (
    base.__all__ + client.__all__ + sequence.__all__ + ("A", "OEIS", "GETATTR_IMPORT_SUPPORT")
)