#!/usr/bin/env python3
#
# Copyright (C) 2021 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# 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 sys import exit

from vyos.config import Config
from vyos.template import render
from vyos.utils.process import cmd
from vyos import ConfigError
from vyos import airbag
airbag.enable()

config_file = r'/run/sysctl/99-vyos-sysctl.conf'

def get_config(config=None):
    if config:
        conf = config
    else:
        conf = Config()
    base = ['system', 'sysctl']
    if not conf.exists(base):
        return None

    sysctl = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True,
                                  no_tag_node_value_mangle=True)

    return sysctl

def verify(sysctl):
    return None

def generate(sysctl):
    if not sysctl:
        if os.path.isfile(config_file):
            os.unlink(config_file)
        return None

    render(config_file, 'system/sysctl.conf.j2', sysctl)
    return None

def apply(sysctl):
    if not sysctl:
        return None

    # We silently ignore all errors
    # See: https://bugzilla.redhat.com/show_bug.cgi?id=1264080
    cmd(f'sysctl -f {config_file}')
    return None

if __name__ == '__main__':
    try:
        c = get_config()
        verify(c)
        generate(c)
        apply(c)
    except ConfigError as e:
        print(e)
        exit(1)