#!/usr/bin/env python3
"""

=head1 NAME

bbb - monitor Bigbluebutton server (users, rooms, videostreams ...)

=head1 APPLICABLE SYSTEMS

Bigbluebutton server

=head1 CONFIGURATION

No configuration is needed. This script will fetch the secret from the local
bbb instance

https://docs.bigbluebutton.org/dev/api.html

=head1 AUTHOR

Copyright 2021 Henning Rieger <age@systemausfall.org>

With many thanks to the original Author Bernd Wurst (bwurst.org)

=head1 LICENSE
GNU General Public License v3.0 or later

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

=cut
"""

import sys
import subprocess
import re
import hashlib
import urllib.request
from urllib.error import URLError, HTTPError
import os
from xml.etree import ElementTree

bbbconf_path = "/usr/bin/bbb-conf"


def config():
    """ autoconfig values """
    print("graph_title BigBlueButton")
    print("graph_vlabel Numbers")
    print("graph_category other")
    print("meetings.label Rooms")
    print("users.label User")
    print("videostreams.label Videostreams")
    print("listeners.label Listeners")
    print("speakers.label Speakers")
    print("moderators.label Moderators")


def bbb_stats():
    URL = None
    secret = None

    # find out url and secret from local bbb instance
    if os.path.exists(bbbconf_path):
        # Ubuntu 16.04 with Python 3.5 is recommended for bbb 2.2.x
        if sys.version_info.major == 3 and sys.version_info.minor < 7:
            tmp = subprocess.run([bbbconf_path, '--secret'],
                                 stdout=subprocess.PIPE, universal_newlines=True)
        else:
            tmp = subprocess.run([bbbconf_path, '--secret'], capture_output=True, text=True)
        output = tmp.stdout

        for line in output.splitlines():
            m = re.search('URL: (?P<URL>.*/bigbluebutton/)', line)
            if m:
                URL = m.group('URL')
                continue
            m = re.search('Secret: (?P<secret>.*)$', line)
            if m:
                secret = m.group('secret')

    if not URL or not secret:
        print('error getting URL and/or secret. Is "bbb-conf --secret" returning it?')
        sys.exit(1)

    # prepare api request
    APIURL = URL + 'api/'
    apimethod = 'getMeetings'
    querystring = ''

    h = hashlib.sha1((apimethod + querystring + secret).encode('utf-8'))
    checksum = h.hexdigest()

    if len(querystring) > 0:
        querystring = querystring + '&'

    requesturl = APIURL + apimethod + '?' + querystring + 'checksum=' + checksum

    # make api request
    response = urllib.request.urlopen(requesturl)
    responsedata = response.read()
    try:
        tree = ElementTree.fromstring(responsedata)
    except HTTPError as e:
        print('There was an error with the recieved data from bbb api.')
        print('Error code: ', e.code)
        sys.exit(1)
    except URLError as e:
        print('There was an error with the recieved data from bbb api.')
        print('Reason: ', e.reason)
        sys.exit(1)
    else:
        if tree.find('returncode').text != 'SUCCESS':
            print('There was an error within the API data')
            sys.exit(1)

    meetings = tree.find('meetings')

    # get numbers from api response
    num_meetings = 0
    num_users = 0
    num_video = 0
    num_listeners = 0
    num_speakers = 0
    num_moderators = 0

    for m in meetings.iter('meeting'):
        meetname = m.find('meetingName').text
        participants = m.find('participantCount').text
        video = m.find('videoCount').text
        listeners = m.find('listenerCount').text
        speakers = m.find('voiceParticipantCount').text
        moderators = m.find('moderatorCount').text

        meta = m.find('metadata')
        if meta.find('bbb-context') is not None:
            meetname = meta.find('bbb-context').text + ' / ' + meetname

        num_meetings += 1
        num_users += int(participants)
        num_video += int(video)
        num_listeners += int(listeners)
        num_speakers += int(speakers)
        num_moderators += int(moderators)

    # finally print everything
    print('meetings.value %2i' % (num_meetings))
    print('users.value %2i' % (num_users))
    print('videostreams.value %2i' % (num_video))
    print('listeners.value %2i' % (num_listeners))
    print('speakers.value %2i' % (num_speakers))
    print('moderators.value %2i' % (num_moderators))


if __name__ == '__main__':
    if len(sys.argv) > 1 and sys.argv[1] == 'autoconf':
        if os.path.exists(bbbconf_path):
            print("yes")
        else:
            print("no (%s not found)" % bbbconf_path)
    elif len(sys.argv) > 1 and sys.argv[1] == 'config':
        config()
    else:
        bbb_stats()