#!/usr/bin/env python3
# -*- coding: utf-8; py-indent-offset: 4 -*-
#
# Author:  Linuxfabrik GmbH, Zurich, Switzerland
# Contact: info (at) linuxfabrik (dot) ch
#          https://www.linuxfabrik.ch/
# License: The Unlicense, see LICENSE file.

# https://github.com/Linuxfabrik/monitoring-plugins/blob/main/CONTRIBUTING.md

"""See the check's README for more details.
"""

import argparse  # pylint: disable=C0413
import sys  # pylint: disable=C0413

import lib.base  # pylint: disable=C0413
import lib.db_mysql  # pylint: disable=C0413
import lib.human  # pylint: disable=C0413
from lib.globals import STATE_OK, STATE_UNKNOWN  # pylint: disable=C0413

__author__ = 'Linuxfabrik GmbH, Zurich/Switzerland'
__version__ = '2023112901'

DESCRIPTION = """Collects uptime, queries per second, connections and traffic stats for
                 MySQL/MariaDB."""

DEFAULT_DEFAULTS_FILE = '/var/spool/icinga2/.my.cnf'
DEFAULT_DEFAULTS_GROUP = 'client'
DEFAULT_TIMEOUT = 3


def parse_args():
    """Parse command line arguments using argparse.
    """
    parser = argparse.ArgumentParser(description=DESCRIPTION)

    parser.add_argument(
        '-V', '--version',
        action='version',
        version='{0}: v{1} by {2}'.format('%(prog)s', __version__, __author__)
    )

    parser.add_argument(
        '--defaults-file',
        help='Specifies a cnf file to read parameters like user, host and password from '
             '(instead of specifying them on the command line), '
             'for example `/var/spool/icinga2/.my.cnf`. Default: %(default)s',
        dest='DEFAULTS_FILE',
        default=DEFAULT_DEFAULTS_FILE,
    )

    parser.add_argument(
        '--defaults-group',
        help='Group/section to read from in the cnf file. Default: %(default)s',
        dest='DEFAULTS_GROUP',
        default=DEFAULT_DEFAULTS_GROUP,
    )

    parser.add_argument(
        '--timeout',
        help='Network timeout in seconds. Default: %(default)s (seconds)',
        dest='TIMEOUT',
        type=int,
        default=DEFAULT_TIMEOUT,
    )

    return parser.parse_args()


def get_status(conn):
    # Do not implement `get_all_vars()`, just fetch the ones we need for this check.
    # Without the GLOBAL modifier, SHOW STATUS displays the values that are used for
    # the current connection to MariaDB.
    sql = """
        show global status
        where variable_name like 'Bytes_received'
            or variable_name like 'Bytes_sent'
            or variable_name like 'Com_delete'
            or variable_name like 'Com_insert'
            or variable_name like 'Com_replace'
            or variable_name like 'Com_select'
            or variable_name like 'Com_update'
            or variable_name like 'Connections'
            or variable_name like 'Questions'
            or variable_name like 'Uptime'
            ;
          """
    return lib.base.coe(lib.db_mysql.select(conn, sql))


def main():
    """The main function. Hier spielt die Musik.
    """

    # logic taken from mysqltuner.pl:mariadb_stats(), v1.9.8
    # including variable names

    # parse the command line, exit with UNKNOWN if it fails
    try:
        args = parse_args()
    except SystemExit:
        sys.exit(STATE_UNKNOWN)

    mysql_connection = {
        'defaults_file':  args.DEFAULTS_FILE,
        'defaults_group': args.DEFAULTS_GROUP,
        'timeout':        args.TIMEOUT,
    }
    conn = lib.base.coe(lib.db_mysql.connect(mysql_connection))
    lib.base.coe(lib.db_mysql.check_select_privileges(conn))
    
    mystat = lib.db_mysql.lod2dict(get_status(conn))
    lib.db_mysql.close(conn)

    # init some vars
    msg = ''
    state = STATE_OK
    perfdata = ''

    # calculations
    mycalc = {}
    qps = round(float(mystat['Questions']) / float(mystat.get('Uptime', 1)), 1)
    mycalc['total_reads'] = int(mystat['Com_select'])
    mycalc['total_writes'] = int(mystat['Com_delete']) + int(mystat['Com_insert']) + int(mystat['Com_update']) + int(mystat['Com_replace'])
    if mycalc['total_reads'] == 0:
        mycalc['pct_reads']  = 0
        mycalc['pct_writes'] = 100
    else:
        mycalc['pct_reads'] = mycalc['total_reads'] / (mycalc['total_reads'] + mycalc['total_writes']) * 100
        mycalc['pct_writes'] = 100 - mycalc['pct_reads']

    # build the message
    msg += 'Up {} ({} q [{} qps], {} conn, TX: {}, RX: {}); Read/Write: {}%/{}%'.format(
        lib.human.seconds2human(int(mystat['Uptime'])),
        lib.human.number2human(int(mystat['Questions'])),
        lib.human.number2human(qps),
        lib.human.number2human(int(mystat['Connections'])),
        lib.human.number2human(int(mystat['Bytes_sent'])),
        lib.human.number2human(int(mystat['Bytes_received'])),
        round(mycalc['pct_reads'], 1),
        round(mycalc['pct_writes'], 1),
    )

    perfdata += lib.base.get_perfdata('mysql_bytes_received', mystat['Bytes_received'], 'B', None, None, 0, None)
    perfdata += lib.base.get_perfdata('mysql_bytes_sent', mystat['Bytes_sent'], 'B', None, None, 0, None)
    perfdata += lib.base.get_perfdata('mysql_com_delete', mystat['Com_delete'], 'c', None, None, 0, None)
    perfdata += lib.base.get_perfdata('mysql_com_insert', mystat['Com_insert'], 'c', None, None, 0, None)
    perfdata += lib.base.get_perfdata('mysql_com_replace', mystat['Com_replace'], 'c', None, None, 0, None)
    perfdata += lib.base.get_perfdata('mysql_com_select', mystat['Com_select'], 'c', None, None, 0, None)
    perfdata += lib.base.get_perfdata('mysql_com_update', mystat['Com_update'], 'c', None, None, 0, None)
    perfdata += lib.base.get_perfdata('mysql_connections', mystat['Connections'], 'c', None, None, 0, None)
    perfdata += lib.base.get_perfdata('mysql_questions', mystat['Questions'], 'c', None, None, 0, None)
    perfdata += lib.base.get_perfdata('mysql_uptime', mystat['Uptime'], 's', None, None, 0, None)

    perfdata += lib.base.get_perfdata('mysql_qps', qps, None, None, None, 0, None)
    perfdata += lib.base.get_perfdata('mysql_pct_reads', mycalc['pct_reads'], '%', None, None, 0, 100)
    perfdata += lib.base.get_perfdata('mysql_pct_writes', mycalc['pct_writes'], '%', None, None, 0, 100)

    # over and out
    lib.base.oao(msg, state, perfdata)


if __name__ == '__main__':
    try:
        main()
    except Exception:   # pylint: disable=W0703
        lib.base.cu()
