# encoding: utf-8 
require "mqtt"

module Agents
  class MqttAgent < Agent
    description <<-MD
    The MQTT agent allows both publication to an MQTT topic and subscription to an MQTT topic.

    Setup your own broker (http://jpmens.net/2013/09/01/installing-mosquitto-on-a-raspberry-pi/) or connect to a cloud service (www.cloudmqtt.com).

    MQTT is a generic transport protocol for machine to machine communication.

    You can do things like:

     * Publish to [RabbitMQ](http://www.rabbitmq.com/mqtt.html)
     * Run [OwnTracks, a location tracking tool](http://owntracks.org/) for iOS and Android
     * Subscribe to your home automation setup like [Ninjablocks](http://forums.ninjablocks.com/index.php?p=/discussion/661/today-i-learned-about-mqtt/p1) or [TheThingSystem](http://thethingsystem.com/dev/supported-things.html)

    Simply choose a topic (think email subject line) to publish/listen to, and configure your service.

    Hints:
    Many services run mqtts (mqtt over SSL) often with a custom certificate.

    You'll want to download their cert and install it locally, specifying the ```certificate_path``` configuration.


    Example configuration:

    <pre><code>{
      'uri' => 'mqtts://user:pass@locahost:8883'
      'ssl' => :TLSv1,
      'ca_file' => './ca.pem',
      'cert_file' => './client.crt',
      'key_file' => './client.key',
      'topic' => 'huginn'
    }
    </code></pre>

    Subscribe to CloCkWeRX's TheThingSystem instance (thethingsystem.com), where
    temperature and other events are being published.

    <pre><code>{
      'uri' => 'mqtt://kcqlmkgx:sVNoccqwvXxE@m10.cloudmqtt.com:13858'
      'topic' => 'the_thing_system/demo'
    }
    </code></pre>

    Subscribe to all topics
    <pre><code>{
      'uri' => 'mqtt://kcqlmkgx:sVNoccqwvXxE@m10.cloudmqtt.com:13858'
      'topic' => '/#'
    }
    </code></pre>

    Find out more detail on [subscription wildcards](http://www.eclipse.org/paho/files/mqttdoc/Cclient/wildcard.html)

    MD

    def validate_options
      # unless options['uid'].present? &&
      #   options['expected_update_period_in_days'].present?
      #   errors.add(:base, "expected_update_period_in_days and uid are required")
      # end
    end

    def working?
      !recent_error_logs?
    end

    def default_options
      {
        'uri' => 'mqtts://user:pass@locahost:8883',
        'ssl' => :TLSv1,
        'ca_file' => './ca.pem',
        'cert_file' => './client.crt',
        'key_file' => './client.key',
        'topic' => 'huginn'
      }
    end

    def mqtt_client
      client = MQTT::Client.new(options['uri'])

      if options['ssl']
        client.ssl = options['ssl'].to_sym
        client.ca_file = options['ca_file']
        client.cert_file = options['cert_file']
        client.key_file = options['key_file']
      end

      client
    end

    def receive(incoming_events)
      mqtt_client.connect do |c|
        incoming_events.each do |event|
          c.publish(options['topic'], payload)
        end
      end
    end


    def check
      mqtt_client.connect do |c|
        c.get(options['topic']) do |topic,message|
          create_event :payload => { 'topic' => topic, 'message' => message, 'time' => Time.now.to_i }
        end
      end
    end

  end
end