Submit BBC Programme Now and Next to MQTT

bbc_now_next_mqtt.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'json'
require 'net/http'
require 'uri'
require 'mqtt'
require 'pp'

NOW_NEXT_RADIO_URL = 'http://www.bbc.co.uk/iplayer/ion/multinownext/service_type/radio/format/json'
NOW_NEXT_TV_URL = 'http://www.bbc.co.uk/iplayer/ion/multinownext/service_type/tv/format/json'

def get_json(url)
  uri = URI.parse(url)
  res = Net::HTTP.start(uri.host, uri.port) do |http|
    http.get(uri.request_uri)
  end
  if res.code == '200'
    JSON.parse(res.body)
  end
end

$cache = {}
def publish(topic, payload)
  if $cache[topic] != payload
    $mqtt.publish(topic, payload, retain=true)
    $cache[topic] = payload
  end
end

def publish_service(service, now_next, data)
  unless data.nil? or data.first.nil?
    data = data.first
    publish("bbc/#{now_next}/#{service}/pid", data['episode_id'])
    publish("bbc/#{now_next}/#{service}/title", data['complete_title'])
    publish("bbc/#{now_next}/#{service}/start", data['start_time_iso'])
    publish("bbc/#{now_next}/#{service}/end", data['end_time_iso'])
  end
end



$mqtt = MQTT::Client.connect(
  :remote_host => 'test.mosquitto.org',
  :client_id => 'ruby_bbc_now_next'
)

# FIXME: Start with the values on the broker
# and pre-populate the cache
#$mqtt.subscribe('bbc/now/#')
#$mqtt.subscribe('bbc/next/#')

def process_services(url)
  data = get_json(url)
  unless data.nil?
    data['blocklist'].each do |service|
      publish_service(service['id'], 'now', service['now'])
      publish_service(service['id'], 'next', service['next'])
    end
  end
end


loop do
  process_services(NOW_NEXT_TV_URL)
  process_services(NOW_NEXT_RADIO_URL)

  # Wait until the start of the next minute
  # FIXME: wait until the next programme ends
  sleep(60 - Time.now.sec)
end