#!/usr/bin/python

import sys
import ldap
import subprocess

LDAP_URI = 'ldap://db.cluster.univ.kiev.ua:389/'
LDAP_BASEDN = 'ou=People,dc=cluster,dc=univ,dc=kiev,dc=ua'
MAILMAN_BIN_PATH = '/usr/lib/mailman/bin/'
MAILMAN_LIST = 'knu-hpc-users'

def get_ldap_emails ():
    try:
        ldap_conn = ldap.initialize(LDAP_URI)
        ldap_conn.protocol_version = ldap.VERSION3
        ldap_list = ldap_conn.search_st(LDAP_BASEDN, ldap.SCOPE_SUBTREE, attrlist=['mail'], timeout=10)

        ldap_emails = []
        for (dn, attrs_list) in ldap_list:
            if 'mail' in attrs_list:
                ldap_emails.extend(attrs_list['mail'])

        ldap_conn.unbind()
        return [ email.lower() for email in ldap_emails ]
    except ldap.LDAPError as e:
        print e
        sys.exit(1)

def get_mailman_emails ():
    try:
        output = subprocess.check_output([MAILMAN_BIN_PATH + 'list_members', MAILMAN_LIST])
        return output.split()
    except subprocess.CalledProcessError as e:
        print e
        sys.exit(1)

def mailman_user_add (email):
    cmd = MAILMAN_BIN_PATH + 'add_members -w n -a n -r - ' + MAILMAN_LIST
    proc = subprocess.Popen(cmd,shell=True,stdin=subprocess.PIPE)
    proc.communicate(email)

def mailman_user_del (email):
    cmd = MAILMAN_BIN_PATH + 'remove_members -n -N -f - ' + MAILMAN_LIST
    proc = subprocess.Popen(cmd,shell=True,stdin=subprocess.PIPE)
    proc.communicate(email)
    if not proc.returncode:
        print 'Unsubscribed: ' + email
    else:
        print 'Failed to unsubscribe: ' + email

def main():
    ldap_emails = get_ldap_emails()
    if not ldap_emails:
        print 'LDAP bind is successfull, but query returns no e-mails.'
        print 'Skipping mailman database manipulation.'
        sys.exit(0)

    mailman_emails = get_mailman_emails()

    for email in ldap_emails:
        if email in mailman_emails:
            mailman_emails.remove(email)
            continue
        else:
            mailman_user_add(email)

    for email in mailman_emails:
        mailman_user_del(email)

main()