# Copyright (C) 2009-2012 by the Free Software Foundation, Inc.
#
# This file is part of GNU Mailman.
#
# GNU Mailman 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.
#
# GNU Mailman 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
# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.

"""Module stuff."""

from __future__ import absolute_import, unicode_literals

__metaclass__ = type
__all__ = [
    'makedirs',
    'umask',
    ]


import os
import errno



class umask:
    """Manage the umask for the with statement."""

    def __init__(self, umask):
        self._umask = umask
        self._old_umask = None

    def __enter__(self):
        assert self._old_umask is None, 'Unexpected existing umask'
        self._old_umask = os.umask(self._umask)

    def __exit__(self, *exc_info):
        assert self._old_umask is not None, 'No previous umask'
        os.umask(self._old_umask)
        # Do not suppress exceptions.
        return False



def makedirs(path, mode=02775):
    """Create a directory hierarchy, ensuring permissions.

    Other than just calling os.makedirs(), this ensures that the umask is
    reset so that the makedirs mode will be honored.

    :param path: The directory path to create.
    :type path: string
    :param mode: The numeric permission mode to use.
    :type mode: int
    """
    try:
        with umask(0):
            os.makedirs(path, mode)
    except OSError as error:
        # Ignore the exceptions if the directory already exists.
        if error.errno != errno.EEXIST:
            raise
    # Some systems such as FreeBSD ignore mkdir's mode, so walk the just
    # created directories and try to set the mode, ignoring any OSErrors that
    # occur here.
    for dirpath, dirnames, filenames in os.walk(path):
        try:
            os.chmod(dirpath, mode)
        except OSError:
            pass