# This file is part of Tryton.  The COPYRIGHT file at the top level of
# this repository contains the full copyright notices and license terms.
try:
    import crypt
except ImportError:
    pass

from trytond.pool import Pool
from trytond.config import config
from trytond.transaction import Transaction
from trytond import backend


def _get_pool(dbname):
    database_list = Pool.database_list()
    pool = Pool(dbname)
    if dbname not in database_list:
        pool.init()
    return pool


def login(dbname, loginname, password, cache=True):
    with Transaction().start(dbname, 0):
        pool = _get_pool(dbname)
        User = pool.get('res.user')
        user_id = User.get_login(loginname, password)
    if user_id:
        if not cache:
            return user_id
        with Transaction().start(dbname, user_id):
            Session = pool.get('ir.session')
            session, = Session.create([{}])
            return user_id, session.key
    return


def logout(dbname, user, session):
    with Transaction().start(dbname, 0):
        pool = _get_pool(dbname)
        Session = pool.get('ir.session')
        sessions = Session.search([
                ('key', '=', session),
                ])
        if not sessions:
            return
        session, = sessions
        name = session.create_uid.login
        Session.delete(sessions)
    return name


def check_super(passwd):
    cryptedpasswd = config.get('session', 'super_pwd')
    if cryptedpasswd and crypt.crypt(passwd, cryptedpasswd) == cryptedpasswd:
        return True
    raise Exception('AccessDenied')


def check(dbname, user, session):
    DatabaseOperationalError = backend.get('DatabaseOperationalError')
    for count in range(config.getint('database', 'retry'), -1, -1):
        with Transaction().start(dbname, user) as transaction:
            pool = _get_pool(dbname)
            Session = pool.get('ir.session')
            try:
                if not Session.check(user, session):
                    return
                else:
                    return user
            except DatabaseOperationalError:
                if count:
                    continue
                raise
            finally:
                transaction.commit()