#!/usr/bin/python3 -tt
# -*- coding: utf-8 -*-

"""Munin plugin to monitor chrony NTP daemon status.

Copyright 2014, Kim B. Heino, b@bbbs.net, Foobar Oy
License GPLv2+

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

import os
import subprocess
import sys


FIELDS = {
    'stratum': 'Stratum',
    'systime': 'System time',
    'delay': 'Root delay',
    'frequency': 'Frequency',
}


def get_values():
    """Run "chronyc tracking" and parse it's output.

    Return: list of (label, value, description)
    """
    try:
        output = subprocess.run(['/usr/bin/chronyc', 'tracking'],
                                stdout=subprocess.PIPE, check=False,
                                encoding='utf-8', errors='ignore')
    except FileNotFoundError:
        return {}
    lines = output.stdout.splitlines()
    ret = {}
    for label in FIELDS:
        for line in lines:
            if line.startswith(FIELDS[label]):
                value = float(line.split(':', 1)[1].split()[0])
                if ' slow' in line:
                    value = -value
                ret[label] = value
    return ret


def config():
    """Print plugin config."""
    print('multigraph chrony_stratum')
    print('graph_title Chrony stratum')
    print('graph_vlabel stratum')
    print('graph_category time')
    print('graph_args --base 1000 --lower-limit 0')
    print('stratum.label Stratum')
    print('stratum.warning 1:9')

    print('multigraph chrony_systime')
    print('graph_title Chrony system time offset')
    print('graph_vlabel seconds')
    print('graph_category time')
    print('graph_args --base 1000')
    print('systime.label System time offset to NTP time')

    print('multigraph chrony_delay')
    print('graph_title Chrony network delay')
    print('graph_vlabel seconds')
    print('graph_category time')
    print('graph_args --base 1000')
    print('delay.label Network path delay')

    print('multigraph chrony_frequency')
    print('graph_title Chrony clock frequency error')
    print('graph_vlabel ppm')
    print('graph_category time')
    print('graph_args --base 1000')
    print('frequency.label Local clock frequency error')

    if os.environ.get('MUNIN_CAP_DIRTYCONFIG') == '1':
        fetch()


def fetch():
    """Print values."""
    values = get_values()
    for key in FIELDS:
        print('multigraph chrony_{}'.format(key))
        if key == 'stratum' and values[key] == 0:
            print('{}.value U'.format(key))
        else:
            print('{}.value {:.8f}'.format(key, values[key]))


if __name__ == '__main__':
    if len(sys.argv) > 1 and sys.argv[1] == 'autoconf':
        print('yes' if get_values() else 'no')
    elif len(sys.argv) > 1 and sys.argv[1] == 'config':
        config()
    else:
        fetch()