#!/usr/bin/env python3
#
# Copyright VyOS maintainers and contributors <maintainers@vyos.io>
#
# 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
import re
import sys
from tempfile import NamedTemporaryFile
from argparse import ArgumentParser

from vyos.config import Config
from vyos.remote import urlc
from vyos.component_version import add_system_version_string
from vyos.defaults import directories
from vyos.utils.file import write_file
from vyos.utils.file import write_file_sync
from vyos.utils.file import write_file_atomic
from vyos.utils.file import file_is_persistent

DEFAULT_CONFIG_PATH = os.path.join(directories['config'], 'config.boot')
remote_save = None

parser = ArgumentParser(description='Save configuration')
parser.add_argument('file', type=str, nargs='?', help='Save configuration to file')
parser.add_argument(
    '--write-json-file', type=str, help='Save JSON of configuration to file'
)

args = parser.parse_args()
file = args.file
json_file = args.write_json_file

if file is not None:
    save_file = file
else:
    save_file = DEFAULT_CONFIG_PATH

if re.match(r'\w+:/', save_file):
    try:
        remote_save = urlc(save_file)
    except ValueError as e:
        sys.exit(e)


config = Config()
ct = config.get_config_tree(effective=True)

# The effective config is None before boot configuration is complete.
# Nothing to write, nor do we want to invite saving an empty string:
# exit gracefully.
if ct is None:
    sys.exit()

config_str = ct.to_string()
versioned_config_str = add_system_version_string(config_str)

# pylint: disable=consider-using-with
file_to_write = (
    save_file if remote_save is None else NamedTemporaryFile(delete=False).name
)

if file_is_persistent(file_to_write):
    if os.geteuid() == 0:
        try:
            write_file_atomic(file_to_write, versioned_config_str)
        except OSError as e:
            print(f'failed to write config file, write_file_atomic: {e}')
            sys.exit(1)
    else:
        try:
            write_file_sync(file_to_write, versioned_config_str)
        except OSError as e:
            print(f'failed to write config file, write_file_sync: {e}')
            sys.exit(1)
else:
    try:
        write_file(file_to_write, versioned_config_str)
    except Exception as e:  # pylint: disable=broad-exception-caught
        print(f'failed to write config file, write_file: {e}')
        sys.exit(1)

if json_file is not None and ct is not None:
    try:
        with open(json_file, 'w') as f:
            f.write(ct.to_json())
    except OSError as e:
        print(f'failed to write JSON file: {e}')

if remote_save is not None:
    try:
        remote_save.upload(file_to_write)
    finally:
        os.remove(file_to_write)