# This file is part of Tryton.  The COPYRIGHT file at the top level of
# this repository contains the full copyright notices and license terms.
import logging
import ssl
import urllib.parse

import ldap3
from ldap3.core.exceptions import LDAPException

from trytond.config import config, parse_uri
from trytond.exceptions import LoginException
from trytond.i18n import gettext
from trytond.model.exceptions import AccessError
from trytond.pool import PoolMeta
from trytond.transaction import without_check_access

logger = logging.getLogger(__name__)
section = 'ldap_authentication'

# Old version of urlparse doesn't parse query for ldap
# see http://bugs.python.org/issue9374
if 'ldap' not in urllib.parse.uses_query:
    urllib.parse.uses_query.append('ldap')


def parse_ldap_url(uri):
    unquote = urllib.parse.unquote
    uri = parse_uri(uri)
    dn = unquote(uri.path)[1:]
    attributes, scope, filter_, extensions = (
        uri.query.split('?') + [''] * 4)[:4]
    if not scope:
        scope = 'base'
    extensions = urllib.parse.parse_qs(extensions)
    return (uri, dn, unquote(attributes), unquote(scope), unquote(filter_),
        extensions)


def ldap_server():
    uri = config.get(section, 'uri')
    if not uri:
        return
    uri, _, _, _, _, extensions = parse_ldap_url(uri)
    if uri.scheme.startswith('ldaps'):
        scheme, port = 'ldaps', 636
        tls = ldap3.Tls(validate=ssl.CERT_REQUIRED)
    else:
        scheme, port = 'ldap', 389
        tls = None
        if 'tls' in uri.scheme:
            tls = ldap3.Tls(validate=ssl.CERT_REQUIRED)
    return ldap3.Server('%s://%s:%s' % (
            scheme, uri.hostname, uri.port or port), tls=tls)


class User(metaclass=PoolMeta):
    __name__ = 'res.user'

    @staticmethod
    def ldap_search_user(login, server, attrs=None):
        '''
        Return the result of a ldap search for the login using the ldap
        server.
        The attributes values defined in attrs will be return.
        '''
        _, dn, _, scope, filter_, extensions = parse_ldap_url(
            config.get(section, 'uri'))
        scope = {
            'base': ldap3.BASE,
            'onelevel': ldap3.LEVEL,
            'one': ldap3.LEVEL,
            'subtree': ldap3.SUBTREE,
            'sub': ldap3.SUBTREE,
            }[scope]
        uid = config.get(section, 'uid', default='uid')
        if filter_:
            filter_ = '(&(%s=%s)%s)' % (uid, login, filter_)
        else:
            filter_ = '(%s=%s)' % (uid, login)

        bindpass = None
        bindname, = extensions.get('bindname', [None])
        if not bindname:
            bindname, = extensions.get('!bindname', [None])
        if bindname:
            # XXX find better way to get the password
            bindpass = config.get(section, 'bind_pass')

        bind_method = ldap3.AUTO_BIND_DEFAULT
        if server.ssl is False and server.tls is not None:
            bind_method = ldap3.AUTO_BIND_TLS_BEFORE_BIND

        with ldap3.Connection(
                server, bindname, bindpass, auto_bind=bind_method) as con:
            con.search(dn, filter_, search_scope=scope, attributes=attrs)
            result = con.entries
            if result and len(result) > 1:
                logger.info('ldap_search_user found more than 1 user')
            return [(e.entry_dn, e.entry_attributes_as_dict)
                for e in result]

    @classmethod
    @without_check_access
    def _check_passwd_ldap_user(cls, logins):
        find = False
        try:
            server = ldap_server()
            if not server:
                return
            for login in logins:
                if cls.ldap_search_user(login, server, attrs=[]):
                    find = True
                    break
        except LDAPException:
            logger.error('LDAPError when checking password', exc_info=True)
        if find:
            raise AccessError(
                gettext('ldap_authentication.msg_ldap_user_change_password',
                    user=login))

    @classmethod
    def create(cls, vlist):
        tocheck = []
        for values in vlist:
            if values.get('password') and 'login' in values:
                tocheck.append(values['login'])
        if tocheck:
            cls._check_passwd_ldap_user(tocheck)
        return super(User, cls).create(vlist)

    @classmethod
    def write(cls, *args):
        actions = iter(args)
        for users, values in zip(actions, actions):
            if values.get('password'):
                logins = [x.login for x in users]
                cls._check_passwd_ldap_user(logins)
        super(User, cls).write(*args)

    @classmethod
    def _login_ldap(cls, login, parameters):
        if 'password' not in parameters:
            msg = gettext('res.msg_user_password', login=login)
            raise LoginException('password', msg, type='password')
        password = parameters['password']
        try:
            server = ldap_server()
            if server:
                uid = config.get(section, 'uid', default='uid')
                users = cls.ldap_search_user(login, server, attrs=[uid])
                if users and len(users) == 1:
                    [(dn, attrs)] = users
                    with ldap3.Connection(
                            server, dn, password,
                            auto_bind=ldap3.AUTO_BIND_NONE) as con:
                        if server.ssl is False and server.tls is not None:
                            con.start_tls()
                        if (password and con.bind()):
                            # Use ldap uid so we always get the right case
                            login = attrs.get(uid, [login])[0]
                            user_id = cls._get_login(login)[0]
                            if user_id:
                                return user_id
                            elif config.getboolean(section, 'create_user'):
                                user, = cls.create([{
                                            'name': login,
                                            'login': login,
                                            }])
                                return user.id
        except LDAPException:
            logger.error('LDAPError when login', exc_info=True)