#!/usr/bin/env ruby
#
# Plugin author: Gunnar Wolf <gwolf@gwolf.org>
#
# You are hereby granted authorization to copy, use, modify, distribute,
# and in general do anything you please with this plugin. It is too simple
# even to GPL-protect it.
#
# This plugin expects to receive via environment variables:
#
# icecast_host - Which host to monitor (default: 127.0.0.1)
# icecast_username - Username to connect with (default: admin)
# icecast_password - Password to connect with (default: hackme)
# icecast_realm - Realm to connect with (default: 'Icecast2 server')
#
require 'hpricot'
require 'open-uri'

def get_conf
  # Default values
  conf = { host: '127.0.0.1', port: 8000,
           username: 'admin', password: 'hackme' }
  conf.keys.each do |key|
    env_key = format('icecast_%s', key)
    conf[key] = ENV[env_key] if ENV.has_key?(env_key)
  end
  conf
end

def get_data(conf)
  begin
    data = Hpricot(open(format('http://%s:%s/admin/stats',
                               conf[:host], conf[:port]),
                        http_basic_authentication: [conf[:username],
                                                    conf[:password]]))
  rescue OpenURI::HTTPError
    puts 'Cannot connect: HTTP connection error'
    exit 1
  end
  data
end

def get_values(data)
  vals = {}
  %i[sources clients].each do |key|
    elem = data / key
    vals[key] = if elem.nil?
                  0
                else
                  elem.innerHTML
                end
  end
  vals
end

data = get_data(get_conf)
vals = get_values(data)

case ARGV[0]
when 'autoconf'
  puts 'yes'
when 'config'
  puts 'graph_title Total sources and clients for Icecast'
  puts 'graph_vlabel listeners'
  puts 'graph_category streaming'
  puts 'sources.label Total number of sources'
  puts 'clients.label Total number of clients'
else
  puts 'sources.value ' + vals[:sources]
  puts 'clients.value ' + vals[:clients]
end