# Copyright (C) 2011 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/>.

"""Ban manager."""

from __future__ import absolute_import, unicode_literals

__metaclass__ = type
__all__ = [
    'BanManager',
    ]


import re

from storm.locals import Int, Unicode
from zope.interface import implements

from mailman.config import config
from mailman.database.model import Model
from mailman.interfaces.bans import IBan, IBanManager



class Ban(Model):
    implements(IBan)

    id = Int(primary=True)
    email = Unicode()
    mailing_list = Unicode()

    def __init__(self, email, mailing_list):
        super(Ban, self).__init__()
        self.email = email
        self.mailing_list = mailing_list



class BanManager:
    implements(IBanManager)

    def ban(self, email, mailing_list=None):
        """See `IBanManager`."""
        bans = config.db.store.find(
            Ban, email=email, mailing_list=mailing_list)
        if bans.count() == 0:
            ban = Ban(email, mailing_list)
            config.db.store.add(ban)

    def unban(self, email, mailing_list=None):
        """See `IBanManager`."""
        ban = config.db.store.find(
            Ban, email=email, mailing_list=mailing_list).one()
        if ban is not None:
            config.db.store.remove(ban)

    def is_banned(self, email, mailing_list=None):
        """See `IBanManager`."""
        # A specific mailing list ban is being checked, however the email
        # address could be banned specifically, or globally.
        if mailing_list is not None:
            # Try specific bans first.
            bans = config.db.store.find(
                Ban, email=email, mailing_list=mailing_list)
            if bans.count() > 0:
                return True
            # Try global bans next.
            bans = config.db.store.find(Ban, email=email, mailing_list=None)
            if bans.count() > 0:
                return True
            # Now try specific mailing list bans, but with a pattern.
            bans = config.db.store.find(Ban, mailing_list=mailing_list)
            for ban in bans:
                if (ban.email.startswith('^') and
                    re.match(ban.email, email, re.IGNORECASE) is not None):
                    return True
            # And now try global pattern bans.
            bans = config.db.store.find(Ban, mailing_list=None)
            for ban in bans:
                if (ban.email.startswith('^') and
                    re.match(ban.email, email, re.IGNORECASE) is not None):
                    return True
        else:
            # The client is asking for global bans.  Look up bans on the
            # specific email address first.
            bans = config.db.store.find(
                Ban, email=email, mailing_list=None)
            if bans.count() > 0:
                return True
            # And now look for global pattern bans.
            bans = config.db.store.find(Ban, mailing_list=None)
            for ban in bans:
                if (ban.email.startswith('^') and
                    re.match(ban.email, email, re.IGNORECASE) is not None):
                    return True
        return False