# Copyright (C) 1998-2011 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/>.

"""Something which claims
X-Mailer: <SMTP32 vXXXXXX>

What the heck is this thing?  Here's a recent host:

% telnet 207.51.255.218 smtp
Trying 207.51.255.218...
Connected to 207.51.255.218.
Escape character is '^]'.
220 X1 NT-ESMTP Server 208.24.118.205 (IMail 6.00 45595-15)

"""

from __future__ import absolute_import, unicode_literals

__metaclass__ = type
__all__ = [
    'SMTP32',
    ]


import re

from email.iterators import body_line_iterator
from zope.interface import implements

from mailman.interfaces.bounce import IBounceDetector


ecre = re.compile('original message follows', re.IGNORECASE)
acre = re.compile(r'''
    (                                             # several different prefixes
    user\ mailbox[^:]*:                           # have been spotted in the
    |delivery\ failed[^:]*:                       # wild...
    |unknown\ user[^:]*:
    |undeliverable\ +to
    |delivery\ userid[^:]*:
    )
    \s*                                           # space separator
    (?P<addr>[^\s]*)                              # and finally, the address
    ''', re.IGNORECASE | re.VERBOSE)



class SMTP32:
    """Something which claims

    X-Mailer: <SMTP32 vXXXXXX>
    """

    implements(IBounceDetector)

    def process(self, msg):
        mailer = msg.get('x-mailer', '')
        if not mailer.startswith('<SMTP32 v'):
            return None
        addrs = set()
        for line in body_line_iterator(msg):
            if ecre.search(line):
                break
            mo = acre.search(line)
            if mo:
                addrs.add(mo.group('addr'))
        return list(addrs)