# Copyright (C) 1998-2009 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/>.

"""Parse mystery style generated by MTA at caiwireless.net."""

import re
import email

tcre = re.compile(r'the following recipients did not receive this message:',
                  re.IGNORECASE)
acre = re.compile(r'<(?P<addr>[^>]*)>')



def process(msg):
    if msg.get_content_type() <> 'multipart/mixed':
        return None
    # simple state machine
    #     0 == nothing seen
    #     1 == tag line seen
    state = 0
    # This format thinks it's a MIME, but it really isn't
    for line in email.Iterators.body_line_iterator(msg):
        line = line.strip()
        if state == 0 and tcre.match(line):
            state = 1
        elif state == 1 and line:
            mo = acre.match(line)
            if not mo:
                return None
            return [mo.group('addr')]