# gp_centrify_sudoers_ext samba gpo policy
# Copyright (C) David Mulder <dmulder@suse.com> 2022
#
# 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 3 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, see <http://www.gnu.org/licenses/>.

import os
from samba.gp.gpclass import gp_pol_ext
from base64 import b64encode
from tempfile import NamedTemporaryFile
from subprocess import Popen, PIPE
from samba.gp.gp_sudoers_ext import visudo, intro
from samba.gp.util.logging import log

def ext_enabled(entries):
    section = 'Software\\Policies\\Centrify\\UnixSettings'
    for e in entries:
        if e.keyname == section and e.valuename == 'sudo.enabled':
            return e.data == 1
    return False

class gp_centrify_sudoers_ext(gp_pol_ext):
    def __str__(self):
        return 'Centrify/Sudo Rights'

    def process_group_policy(self, deleted_gpo_list, changed_gpo_list,
            sdir='/etc/sudoers.d'):
        for guid, settings in deleted_gpo_list:
            self.gp_db.set_guid(guid)
            if str(self) in settings:
                for attribute, sudoers in settings[str(self)].items():
                    if os.path.exists(sudoers):
                        os.unlink(sudoers)
                    self.gp_db.delete(str(self), attribute)
            self.gp_db.commit()

        for gpo in changed_gpo_list:
            if gpo.file_sys_path:
                section = 'Software\\Policies\\Centrify\\UnixSettings\\SuDo'
                self.gp_db.set_guid(gpo.name)
                pol_file = 'MACHINE/Registry.pol'
                path = os.path.join(gpo.file_sys_path, pol_file)
                pol_conf = self.parse(path)
                if not pol_conf or not ext_enabled(pol_conf.entries):
                    continue
                for e in pol_conf.entries:
                    if e.keyname == section and e.data.strip():
                        if '**delvals.' in e.valuename:
                            continue
                        attribute = b64encode(e.data.encode()).decode()
                        old_val = self.gp_db.retrieve(str(self), attribute)
                        if not old_val:
                            contents = intro
                            contents += '%s\n' % e.data
                            with NamedTemporaryFile() as f:
                                with open(f.name, 'w') as w:
                                    w.write(contents)
                                sudo_validation = \
                                        Popen([visudo, '-c', '-f', f.name],
                                            stdout=PIPE, stderr=PIPE).wait()
                            if sudo_validation == 0:
                                with NamedTemporaryFile(prefix='gp_',
                                                        delete=False,
                                                        dir=sdir) as f:
                                    with open(f.name, 'w') as w:
                                        w.write(contents)
                                    self.gp_db.store(str(self),
                                                     attribute,
                                                     f.name)
                            else:
                                log.error('Sudoers apply failed', e.data)
                        self.gp_db.commit()

    def rsop(self, gpo):
        output = {}
        section = 'Software\\Policies\\Centrify\\UnixSettings\\SuDo'
        pol_file = 'MACHINE/Registry.pol'
        if gpo.file_sys_path:
            path = os.path.join(gpo.file_sys_path, pol_file)
            pol_conf = self.parse(path)
            if not pol_conf:
                return output
            for e in pol_conf.entries:
                if e.keyname == section and e.data.strip():
                    if '**delvals.' in e.valuename:
                        continue
                    if str(self) not in output.keys():
                        output[str(self)] = []
                    output[str(self)].append(e.data)
        return output