#!/usr/bin/python3 -tt
# -*- coding: utf-8 -*-
# pylint: disable=invalid-name
# pylint: enable=invalid-name

"""Munin plugin to monitor systemd service status.
Copyright 2018, Kim B. Heino, b@bbbs.net, Foobar Oy
License GPLv2+

#%# capabilities=autoconf
#%# family=auto
"""

import os
import re
import subprocess
import sys


STATES = (
    'failed',
    'dead',
    'running',
    'exited',
    'active',
    'listening',
    'waiting',
    'plugged',
    'mounted',
)


def config():
    """Autoconfig values."""
    print('graph_title systemd services')
    print('graph_vlabel Services')
    print('graph_category processes')
    print('graph_args --base 1000 --lower-limit 0')
    print('graph_scale no')
    print('graph_info Number of services in given activation state.')
    for state in STATES:
        print('{state}.label Services in {state} state'.format(state=state))
    print('failed.warning 0:0')
    if os.environ.get('MUNIN_CAP_DIRTYCONFIG') == '1':
        fetch()


def fetch():
    """Print runtime values."""
    # Get data
    try:
        output = subprocess.check_output([
            '/bin/systemctl',
            'list-units'])  # deb9/py3.5 doesn't have encoding parameter
    except (OSError, subprocess.CalledProcessError):
        return

    # Parse data
    states = {state: 0 for state in STATES}
    for line in output.splitlines():
        line = line.decode('utf-8').split()
        if len(line) < 4:
            continue
        if len(line[0]) < 3:  # Skip failed-bullet
            line = line[1:]
        if line[0].endswith('.scope'):  # Ignore scopes
            continue
        if re.match(r'user.*@\d+\.service', line[0]):
            continue
        if line[3] in states:
            states[line[3]] = states[line[3]] + 1

    # Output
    for state in STATES:
        print('{}.value {}'.format(state, states[state]))


if __name__ == '__main__':
    if len(sys.argv) > 1 and sys.argv[1] == 'autoconf':
        print('yes')
    elif len(sys.argv) > 1 and sys.argv[1] == 'config':
        config()
    else:
        fetch()