#!/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 unittest

from vyos.utils.process import cmdl
from vyos.utils.config import read_saved_value
from vyos.defaults import directories

from base_vyostest_shim import VyOSUnitTestSHIM

class TestConfigDep(VyOSUnitTestSHIM.TestCase):
    def test_disk_resident(self):
        config_file = os.path.join(directories['config'], 'config.boot')

        evict_cmd = ['vmtouch', '-e', config_file]
        page_count_cmd = ['fincore', '-o', 'PAGES', '-n', config_file]

        test_value = 'test_disk_resident'
        test_path = ['interfaces', 'ethernet', 'eth3', 'description']

        self.cli_set(test_path, value=test_value)
        self.cli_commit()
        self.cli_save(config_file)

        cmdl(evict_cmd)
        # pages may be paged back into memory by the time the above
        # completes (man vmtouch); either way, we read what is resident on
        # disk. The following is just for curiosity:
        pages = cmdl(page_count_cmd)

        saved_value = read_saved_value(test_path)

        if self.debug:
            print(f'vm pages on read config: {int(pages)}')

        self.assertEqual(test_value, saved_value)

        # clean up remaining
        self.cli_delete(test_path)
        self.cli_commit()
        self.cli_save(config_file)

    def test_disk_resident_atomic(self):
        config_file = os.path.join(directories['config'], 'config.boot')

        # save config will only call write_file_atomic if euid == 0:
        # below is the command as invoked by CLI 'save'
        save_cmd = [
            'sg', 'vyattacfg',
            'umask 0002; /usr/libexec/vyos/vyos-save-config.py',
        ]

        evict_cmd = ['vmtouch', '-e', config_file]
        page_count_cmd = ['fincore', '-o', 'PAGES', '-n', config_file]

        test_value = 'test_disk_resident'
        test_path = ['interfaces', 'ethernet', 'eth3', 'description']

        self.cli_set(test_path, value=test_value)
        self.cli_commit()
        cmdl(save_cmd, sudo=True)

        cmdl(evict_cmd)
        # pages may be paged back into memory by the time the above
        # completes (man vmtouch); either way, we read what is resident on
        # disk. The following is just for curiosity:
        pages = cmdl(page_count_cmd)

        saved_value = read_saved_value(test_path)

        if self.debug:
            print(f'vm pages on read config: {int(pages)}')

        # check that we have at the least sync'd config;
        # checking actual atomicity is a different matter ...
        self.assertEqual(test_value, saved_value)

        # clean up remaining
        self.cli_delete(test_path)
        self.cli_commit()
        cmdl(save_cmd, sudo=True)


if __name__ == '__main__':
    unittest.main(verbosity=2, failfast=VyOSUnitTestSHIM.TestCase.debug_on())