# Copyright (C) 2008-2010 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/>.

"""MHonArc archiver."""

from __future__ import absolute_import, unicode_literals

__metaclass__ = type
__all__ = [
    'MHonArc',
    ]


import hashlib
import logging
import subprocess

from base64 import b32encode
from urlparse import urljoin
from zope.interface import implements

from mailman.config import config
from mailman.interfaces.archiver import IArchiver
from mailman.utilities.string import expand


log = logging.getLogger('mailman.archiver')



class MHonArc:
    """Local MHonArc archiver."""

    implements(IArchiver)

    name = 'mhonarc'

    @staticmethod
    def list_url(mlist):
        """See `IArchiver`."""
        # XXX What about private MHonArc archives?
        return expand(config.archiver.mhonarc.base_url,
                      dict(listname=mlist.fqdn_listname,
                           hostname=mlist.domain.url_host,
                           fqdn_listname=mlist.fqdn_listname,
                           ))

    @staticmethod
    def permalink(mlist, msg):
        """See `IArchiver`."""
        # XXX What about private MHonArc archives?
        message_id = msg.get('message-id')
        # It is not the archiver's job to ensure the message has a Message-ID.
        # If no Message-ID is available, there is no permalink.
        if message_id is None:
            return None
        # The angle brackets are not part of the Message-ID.  See RFC 2822.
        if message_id.startswith('<') and message_id.endswith('>'):
            message_id = message_id[1:-1]
        else:
            message_id = message_id.strip()
        sha = hashlib.sha1(message_id)
        message_id_hash = b32encode(sha.digest())
        del msg['x-message-id-hash']
        msg['X-Message-ID-Hash'] = message_id_hash
        return urljoin(MHonArc.list_url(mlist), message_id_hash)

    @staticmethod
    def archive_message(mlist, msg):
        """See `IArchiver`."""
        substitutions = config.__dict__.copy()
        substitutions['listname'] = mlist.fqdn_listname
        command = expand(config.archiver.mhonarc.command, substitutions)
        proc = subprocess.Popen(
            command, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
            shell=True)
        stdout, stderr = proc.communicate(msg.as_string())
        if proc.returncode <> 0:
            log.error('%s: mhonarc subprocess had non-zero exit code: %s' %
                      (msg['message-id'], proc.returncode))
        log.info(stdout)
        log.error(stderr)
