#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Copyright 2014-2015 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.

__author__ = 'Jorge Niedbalski R. <jorge.niedbalski@canonical.com>'

import yaml

from subprocess import check_call

from charmhelpers.core.hookenv import (
    log,
    DEBUG,
    ERROR,
)


def create(sysctl_dict, sysctl_file):
    """Creates a sysctl.conf file from a YAML associative array

    :param sysctl_dict: a YAML-formatted string of sysctl options eg "{ 'kernel.max_pid': 1337 }"
    :type sysctl_dict: str
    :param sysctl_file: path to the sysctl file to be saved
    :type sysctl_file: str or unicode
    :returns: None
    """
    try:
        sysctl_dict_parsed = yaml.safe_load(sysctl_dict)
    except yaml.YAMLError:
        log("Error parsing YAML sysctl_dict: {}".format(sysctl_dict),
            level=ERROR)
        return

    with open(sysctl_file, "w") as fd:
        for key, value in sysctl_dict_parsed.items():
            fd.write("{}={}\n".format(key, value))

    log("Updating sysctl_file: %s values: %s" % (sysctl_file, sysctl_dict_parsed),
        level=DEBUG)

    check_call(["sysctl", "-p", sysctl_file])
