# 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.

# Sometimes the same address gets subscribed to a list as both an address and
# as a user. This causes various issues. This script finds those cases and
# unsubscribes the address, leaving the user subscribed.
#
# This is run with
# mailman shell -r delete_dup_sub xxx
# after saving it as
# /opt/mailman/mm/venv/bin/delete_dup_sub.py
# xxx is Yes to actually do the unsubscribe, anything else or nothing
# only reports.

from mailman.database.transaction import transactional
from mailman.interfaces.listmanager import IListManager
from mailman.model.address import Address
from mailman.model.user import User
from zope.component import getUtility

listmanager = getUtility(IListManager)

@transactional
def unsubscribe(doit, member):
    print(f'Unsubscribing {member}')
    if doit:
        member.unsubscribe()

def do_dup(doit, mlist, val):
    if type(val[0].subscriber) is Address:
        if type(val[1].subscriber) is User:
            unsubscribe(doit, val[0])
        else:
            print(f'Anomalous types: '
                  f'{mlist.list_id} {val[0].subscriber} {val[1].subscriber}')
    elif type(val[0].subscriber) is User:
        if type(val[1].subscriber) is Address:
            unsubscribe(doit, val[1])
        else:
            print(f'Anomalous types: '
                  f'{mlist.list_id} {val[0].subscriber} {val[1].subscriber}')
    else:
        print(f'Anomalous types: '
              f'{mlist.list_id} {val[0].subscriber} {val[1].subscriber}')

def delete_dup_sub(*arg):
    if len(arg) == 1 and arg[0] == 'Yes':
        doit = True
    else:
        doit = False
    for mlist in listmanager.mailing_lists:
        membs = dict()
        for memb in mlist.members.members:
            membs.setdefault(memb.address.email, []).append(memb)
        for key, val in membs.items():
            if len(val) == 1:
                continue
            elif len(val) != 2:
                print(f'How can this be: {mlist.list_id} {key} {val}')
                continue
            else:
                do_dup(doit, mlist, val)