#!/usr/bin/python
# Copyright (C) 2016 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/>.
#
# File: query-config
# Purpose: Extracts field values a flat JSON file,
#          for use in languages that can't handle JSON easily,
#          (I'm looking at you, Bourne shell!)


import sys
import json

import defaults
import util

if len(sys.argv) < 3:
    print("Usage: {0} <flat JSON file> <config field name>".format(sys.argv[0]))
    sys.exit(1)

# Note: lack of error handling is deliberate, if some field is expected to be there
#       but isn't, it's better if the failure will be obvious and spectacular

file = sys.argv[1]
key = sys.argv[2]

with open(file, 'r') as f:
     json_data = json.load(f)

print(json_data[key])