# -*- coding: utf-8 -*-
# vim:set expandtab tabstop=4 shiftwidth=4:
#
# License MIT
# LdapCherry
# Copyright (c) 2014 Carpentier Pierre-Francois

import ldapcherry.backend.backendLdap
import cherrypy
import ldap
import ldap.modlist as modlist
import ldap.filter
import logging
import ldapcherry.backend
from ldapcherry.exceptions import UserDoesntExist, GroupDoesntExist
import os
import re


class CaFileDontExist(Exception):
    def __init__(self, cafile):
        self.cafile = cafile
        self.log = "CA file %(cafile)s don't exist" % {'cafile': cafile}


NO_ATTR = 0
DISPLAYED_ATTRS = 1
LISTED_ATTRS = 2
ALL_ATTRS = 3


# Generated by the followin command:

# samba-tool group list | \
# while read line; \
# do
# ldapsearch -x -h localhost -D "administrator@dc.ldapcherry.org" \
#     -w qwertyP455 -b "dc=dc,dc=ldapcherry,dc=org"  "(cn=$line)" dn; \
# done | grep -e "dn: .*CN=Builtin" | \
# sed "s/dn: CN=\(.*\),CN=.*/'\1',/"

AD_BUILTIN_GROUPS = [
    'Pre-Windows 2000 Compatible Access',
    'Windows Authorization Access Group',
    'Certificate Service DCOM Access',
    'Network Configuration Operators',
    'Terminal Server License Servers',
    'Incoming Forest Trust Builders',
    'Performance Monitor Users',
    'Cryptographic Operators',
    'Distributed COM Users',
    'Performance Log Users',
    'Remote Desktop Users',
    'Account Operators',
    'Event Log Readers',
    'Backup Operators',
    'Server Operators',
    'Print Operators',
    'Administrators',
    'Replicator',
    'IIS_IUSRS',
    'Guests',
    'Users',
]


class Backend(ldapcherry.backend.backendLdap.Backend):

    def __init__(self, config, logger, name, attrslist, key):
        self.config = config
        self._logger = logger
        self.backend_name = name
        self.backend_display_name = self.get_param('display_name')
        self.domain = self.get_param('domain')
        self.login = self.get_param('login')
        basedn = 'dc=' + re.sub(r'\.', ',DC=', self.domain)
        self.binddn = self.get_param('login') + '@' + self.domain
        self.bindpassword = self.get_param('password')
        self.ca = self.get_param('ca', False)
        self.checkcert = self.get_param('checkcert', 'on')
        self.starttls = self.get_param('starttls', 'off')
        self.uri = self.get_param('uri')
        self.timeout = self.get_param('timeout', 1)
        self.userdn = 'CN=Users,' + basedn
        self.groupdn = self.userdn
        self.builtin = 'CN=Builtin,' + basedn
        self.user_filter_tmpl = '(sAMAccountName=%(username)s)'
        self.group_filter_tmpl = '(member=%(userdn)s)'
        self.search_filter_tmpl = '(&(|(sAMAccountName=%(searchstring)s)' \
            '(cn=%(searchstring)s*)' \
            '(name=%(searchstring)s*)' \
            '(sn=%(searchstring)s*)' \
            '(givenName=%(searchstring)s*)' \
            '(cn=%(searchstring)s*))' \
            '(&(objectClass=person)' \
            '(objectClass=user)' \
            '(!(objectClass=computer)))' \
            ')'
        self.dn_user_attr = 'cn'
        self.key = 'sAMAccountName'
        self.objectclasses = [
            'top',
            'person',
            'organizationalPerson',
            'user',
            'posixAccount',
            ]
        self.group_attrs = {
            'member': "%(dn)s"
            }

        self.attrlist = []
        for a in attrslist:
            self.attrlist.append(self._str(a))

    def _search_group(self, searchfilter, groupdn):
        searchfilter = self._str(searchfilter)
        ldap_client = self._bind()
        try:
            r = ldap_client.search_s(
                groupdn,
                ldap.SCOPE_SUBTREE,
                searchfilter,
                attrlist=['CN']
                )
        except Exception as e:
            ldap_client.unbind_s()
            self._exception_handler(e)

        ldap_client.unbind_s()
        return r

    def _build_groupdn(self, groups):
        ad_groups = []
        for group in groups:
            if group in AD_BUILTIN_GROUPS:
                ad_groups.append('cn=' + group + ',' + self.builtin)
            else:
                ad_groups.append('cn=' + group + ',' + self.groupdn)
        return ad_groups

    def add_to_groups(self, username, groups):
        ad_groups = self._build_groupdn(groups)
        super(Backend, self).add_to_groups(username, ad_groups)

    def del_from_groups(self, username, groups):
        ad_groups = self._build_groupdn(groups)
        super(Backend, self).del_from_groups(username, ad_groups)

    def get_groups(self, username):
        username = ldap.filter.escape_filter_chars(username)
        userdn = self._get_user(username, NO_ATTR)

        searchfilter = self.group_filter_tmpl % {
            'userdn': userdn,
            'username': username
        }

        groups = self._search_group(searchfilter, self.groupdn)
        groups = groups + self._search_group(searchfilter, self.builtin)
        ret = []
        self._logger(
            severity=logging.DEBUG,
            msg="%(backend)s: groups of '%(user)s' are %(groups)s" % {
                'user': username,
                'groups': str(groups),
                'backend': self.backend_name
                }
        )

        for entry in groups:
            ret.append(entry[1]['cn'][0])
        return ret

    def auth(self, username, password):

        binddn = username + '@' + self.domain
        if binddn is not None:
            ldap_client = self._connect()
            try:
                ldap_client.simple_bind_s(binddn, password)
            except ldap.INVALID_CREDENTIALS:
                ldap_client.unbind_s()
                return False
            ldap_client.unbind_s()
            return True
        else:
            return False