autodoor_occupancy_disabler

#!/usr/bin/ruby

# AutoDoor Occupancy Disabler
#  Notifies the AutoDoor system when the lab is unoccupied.
# Input: Exchange 'statistics.occupancy'
# Output: AutoDoor system via ssh

require 'rubygems'
require 'amqp'
require 'net/http'
require 'json'
require 'inifile'

cfg = IniFile.load(File.expand_path("~/.labamqprc"))
amqp_host = cfg['broker']['BrokerHost']
aod_cfg = cfg['autodoor_occupancy_disabler']
amqp_user = aod_cfg['BrokerUsername']
amqp_pass = aod_cfg['BrokerPassword']

AMQP.logging = true
AMQP.start(:host => amqp_host, :user => amqp_user, :pass => amqp_pass) do
  amq = AMQP::Channel.new
  door_exchange = amq.fanout('statistics.occupancy', :durable => false, :auto_delete => false);
  door_queue = amq.queue('statistics.occupancy.autodoor', :durable => false, :auto_delete => true);
  door_queue.bind(door_exchange);
  door_queue.subscribe do |header, msg|
    json = JSON.load(msg)
    next if !(json['change'] and json['area'] == 'Lab' and !json['occupied'])
    # if we get here the entire lab is unoccupied, shut off the autodoor
    system("ssh root@autodoor rm -f /var/run/autodoor_on");
    puts "Lab unoccupied, disabling AutoDoor."
  end
end