# Copyright (C) 2022 by the Free Software Foundation, Inc.
#
# This program 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 2
# of the License, or (at your option) any later version.
#
# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
# USA.

# Prior to Mailman 3.3.5, some tokens for user confirmations were pended with
# too long a lifetime.  This script removes those pendings based on when they
# were pended and the configured pending_request_life rather than their
# expiration.

# Also prior to Mailman 3.3.5, pended held_message tokens for email handling
# of the message were not removed when the message was handled via REST.  This
# script removes those pendings too.

# This is run with
# mailman shell -r delete_orphans_expireds
# after saving it as
# /opt/mailman/mm/venv/bin/delete_orphans_expireds.py

from datetime import datetime
from lazr.config import as_timedelta
from mailman.config import config
from mailman.database.transaction import transactional
from mailman.interfaces.pending import IPendings
from zope.component import getUtility

pendings = getUtility(IPendings)

def is_request(id):
    if config.db.store.execute(
        'SELECT * FROM _request WHERE id = {};'.format(id)).rowcount > 0:
        return True
    return False

then = datetime.now() - as_timedelta(config.mailman.pending_request_life)
thenm = datetime.now() - as_timedelta(config.mailman.moderator_request_life)

def fromisoformat(x):
    if hasattr(datetime, 'fromisoformat'):
        return datetime.fromisoformat(x)
    try:
        return datetime.strptime(x, '%Y-%m-%dT%H:%M:%S.%f')
    except ValueError:
        return datetime.strptime(x, '%Y-%m-%dT%H:%M:%S')

@transactional
def delete_orphans_expireds():
    count = 0
    for token, data in pendings.find(pend_type='held message'):
        if data and not is_request(data['id']):
            result = pendings.confirm(token, expunge=True)
            count += 1
    print(f'expunged {count} orphaned pended held messages')

    count = 0
    for token, data in pendings.find(pend_type='data'):
        if data and data['_mod_hold_date']:
            when = data['_mod_hold_date']
            if isinstance(when, str):
                when = fromisoformat(when)
            if when < thenm:
                result = pendings.confirm(token, expunge=True)
                count += 1
    print(f'expunged {count} expired held messages')

    pends = list(pendings.find(pend_type='subscription'))
    pends += list(pendings.find(pend_type='unsubscription'))
    count = 0
    for token, values in pends:
        if values and values['token_owner'] == 'subscriber':
            when = values['when']
            if isinstance(when, str):
                when = fromisoformat(when)
            if when < then:
                result = pendings.confirm(token, expunge=True)
                count += 1
    print(f'expunged {count} expired (un)subscription confirmations')