#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# Copyright 2019 ScyllaDB
#

#
# This file is part of Scylla.
#
# Scylla is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Scylla 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 Scylla.  If not, see <http://www.gnu.org/licenses/>.

import os
import sys
import argparse
from scylla_util import *

if __name__ == '__main__':
    if os.getuid() > 0:
        print('Requires root permission.')
        sys.exit(1)
    parser = argparse.ArgumentParser(description='Configure memory for Scylla.')
    parser.add_argument('--lock-memory',
                        help='lock all memory', action='store_true')
    parser.add_argument('--memory',
                        help='memory to use, in bytes (ex: 4G, default=all)')
    parser.add_argument('--reserve-memory',
                        help='memory reserved to OS (if --memory not specified)')
    args = parser.parse_args()
    if not args.lock_memory and not args.memory and not args.reserve_memory:
        parser.print_help()
        sys.exit(1)

    conf_args=[]
    if args.lock_memory:
        conf_args.append('--lock-memory=1')
    if args.memory:
        conf_args.append('--memory={}'.format(args.memory))
    if args.reserve_memory:
        conf_args.append('--reserve-memory={}'.format(args.reserve_memory))
    conf = 'MEM_CONF="{}"\n'.format(' '.join(conf_args))

    with open(str(etcdir_p() / 'scylla.d' / 'memory.conf'), 'w') as f:
        f.write(conf)