#!/usr/bin/env python3

import re
import sys

def set(key, value):
    with open("/etc/default/locale", "r+") as f:
        data = f.read()
        f.seek(0)
        f.write(replace(key, value, data))
        f.truncate()

def replace(key, value, content):
    if key in content:
        return re.sub(r"^{}=.*$".format(key), "{}=\"{}\"".format(key, value), content, flags=re.MULTILINE)
    else:
        return "{}\n{}=\"{}\"\n".format(content, key, value)

if __name__ == '__main__':
    if len(sys.argv) != 3:
        print("Required key and value arguments not given")
        sys.exit(1)
    sys.exit(set(sys.argv[1], sys.argv[2]))
