#!/usr/bin/env python3
#
# Copyright (C) 2019 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 argparse

from sys import exit
from subprocess import Popen, PIPE, STDOUT

def _cmd(cmd):
    p = Popen(cmd, stdout=PIPE, stderr=STDOUT, shell=True)
    tmp = p.communicate()[0].strip()
    return tmp.decode()

parser = argparse.ArgumentParser()
parser.add_argument("--validate", action="store", help="Check if timezone is valid")

if __name__ == '__main__':
    args = parser.parse_args()

    if args.validate:
        tz_data = _cmd('find /usr/share/zoneinfo/posix -type f -or -type l | sed -e s:/usr/share/zoneinfo/posix/::')
        tz_data = tz_data.split('\n')
        # if timezone can't be found in list it's invalid
        if args.validate not in tz_data:
            exit(1)
    else:
        parser.print_help()
        exit(1)

    exit(0)