#!/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_sqlite  # pylint: disable=C0413
import lib.qts  # pylint: disable=C0413
import lib.txt  # pylint: disable=C0413
import lib.url  # pylint: disable=C0413
from lib.globals import (STATE_CRIT, STATE_OK,  # pylint: disable=C0413
                          STATE_UNKNOWN, STATE_WARN)

try:
    import xmltodict  # pylint: disable=C0413
except ImportError as e:
    print('Python module "xmltodict" is not installed.')
    sys.exit(STATE_UNKNOWN)


__author__ = 'Linuxfabrik GmbH, Zurich/Switzerland'
__version__ = '2025020401'

DESCRIPTION = """Returns the current system-wide CPU utilization as a percentage from QNAP
                 Appliances running QTS via API. Warns only if the overall CPU usage is above a
                 certain threshold within the last n checks (default: 5). The authentication is
                 done via a single API token (Token-based authentication), not via Session-based
                 authentication, which is stated as "legacy"."""

DEFAULT_COUNT = 5       # measurements; if check runs once per minute, this is a 5 minute interval
DEFAULT_CRIT = 90      # %
DEFAULT_INSECURE = False
DEFAULT_NO_PROXY = False
DEFAULT_TIMEOUT = 6
DEFAULT_USERNAME = 'admin'
DEFAULT_WARN = 80      # %


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(
        '--always-ok',
        help='Always returns OK.',
        dest='ALWAYS_OK',
        action='store_true',
        default=False,
    )

    parser.add_argument(
        '--count',
        help='Number of times the value must exceed specified thresholds before alerting. '
             'Default: %(default)s',
        dest='COUNT',
        type=int,
        default=DEFAULT_COUNT,
    )

    parser.add_argument(
        '-c', '--critical',
        help='Set the critical threshold CPU Usage Percentage. '
             'Default: %(default)s',
        dest='CRIT',
        type=int,
        default=DEFAULT_CRIT,
    )

    parser.add_argument(
        '--insecure',
        help='This option explicitly allows to perform "insecure" SSL connections. '
             'Default: %(default)s',
        dest='INSECURE',
        action='store_true',
        default=DEFAULT_INSECURE,
    )

    parser.add_argument(
        '--no-proxy',
        help='Do not use a proxy. '
             'Default: %(default)s',
        dest='NO_PROXY',
        action='store_true',
        default=DEFAULT_NO_PROXY,
    )

    parser.add_argument(
        '--password',
        help='QTS Password.',
        dest='PASSWORD',
        required=True,
    )

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

    parser.add_argument(
        '--url',
        help='QTS-based Appliance URL, for example https://192.168.1.1:8080.',
        dest='URL',
        required=True,
    )

    parser.add_argument(
        '--username',
        help='QTS User. '
             'Default: %(default)s',
        dest='USERNAME',
        default=DEFAULT_USERNAME,
    )

    parser.add_argument(
        '-w', '--warning',
        help='Set the warning threshold CPU Usage Percentage. '
             'Default: %(default)s',
        dest='WARN',
        type=int,
        default=DEFAULT_WARN,
    )

    return parser.parse_args()


def get_from_db(conn, threshold):
    result = lib.base.coe(lib.db_sqlite.select(
        conn,
        '''
        SELECT count(*) as cnt
        FROM perfdata
        WHERE cpu_usage > :cpu_usage
        ''',
        {'cpu_usage': threshold},
        fetchone=True
    ))
    return int(result['cnt'])


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

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

    auth_sid = lib.base.coe(lib.qts.get_auth_sid(args))

    # get system information
    url = '{}/cgi-bin/management/manaRequest.cgi?subfunc=sysinfo&hd=no&multicpu=1&sid={}'.format(
        args.URL,
        auth_sid,
    )
    result = lib.base.coe(
        lib.url.fetch(url, insecure=args.INSECURE, no_proxy=args.NO_PROXY, timeout=args.TIMEOUT)
    )
    data = xmltodict.parse(result)['QDocRoot']
    if data['authPassed'] == '0':
        lib.base.cu('Insufficient permissions.')

    stats = {}
    stats['cpu_usage'] = float(data['func']['ownContent']['root']['cpu_usage'].replace('%', ''))

    # create the db table
    definition = '''
        cpu_usage REAL NOT NULL
    '''
    conn = lib.base.coe(
        lib.db_sqlite.connect(filename='linuxfabrik-monitoring-plugins-qts-cpu-usage.db')
    )
    lib.base.coe(lib.db_sqlite.create_table(conn, definition))

    # save trend data to local sqlite database, limited to "count" rows max.
    lib.base.coe(lib.db_sqlite.insert(conn, stats))
    lib.base.coe(lib.db_sqlite.cut(conn, _max=args.COUNT))
    lib.base.coe(lib.db_sqlite.commit(conn))

    # now, calculate the WARN or CRIT.
    # overall state is not ok, if ...
    #   in a row in any column there is a value above the threshold
    #   and this is true for every row
    state = STATE_OK
    if get_from_db(conn, args.CRIT) == args.COUNT:
        state = STATE_CRIT
    elif get_from_db(conn, args.WARN) == args.COUNT:
        state = STATE_WARN
    lib.db_sqlite.close(conn)

    # build the message
    msg = '{}%'.format(stats['cpu_usage'])
    perfdata = lib.base.get_perfdata('cpu-usage', stats['cpu_usage'], '%', args.WARN, args.CRIT, 0, 100) # pylint: disable=C0301

    # over and out
    lib.base.oao(msg, state, perfdata, always_ok=args.ALWAYS_OK)


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