implement basic telegram agent

Gemfile

@@ -25,17 +25,18 @@ end
 
 # Optional libraries.  To conserve RAM, comment out any that you don't need,
 # then run `bundle` and commit the updated Gemfile and Gemfile.lock.
-gem 'twilio-ruby', '~> 3.11.5'    # TwilioAgent
-gem 'ruby-growl', '~> 4.1.0'      # GrowlAgent
-gem 'net-ftp-list', '~> 3.2.8'    # FtpsiteAgent
-gem 'wunderground', '~> 1.2.0'    # WeatherAgent
-gem 'forecast_io', '~> 2.0.0'     # WeatherAgent
-gem 'rturk', '~> 2.12.1'          # HumanTaskAgent
-gem 'hipchat', '~> 1.2.0'         # HipchatAgent
-gem 'xmpp4r',  '~> 0.5.6'         # JabberAgent
-gem 'mqtt'                        # MQTTAgent
-gem 'slack-notifier', '~> 1.0.0'  # SlackAgent
-gem 'hypdf', '~> 1.0.7'           # PDFInfoAgent
+gem 'twilio-ruby', '~> 3.11.5'       # TwilioAgent
+gem 'ruby-growl', '~> 4.1.0'         # GrowlAgent
+gem 'net-ftp-list', '~> 3.2.8'       # FtpsiteAgent
+gem 'wunderground', '~> 1.2.0'       # WeatherAgent
+gem 'forecast_io', '~> 2.0.0'        # WeatherAgent
+gem 'rturk', '~> 2.12.1'             # HumanTaskAgent
+gem 'hipchat', '~> 1.2.0'            # HipchatAgent
+gem 'xmpp4r',  '~> 0.5.6'            # JabberAgent
+gem 'mqtt'                           # MQTTAgent
+gem 'slack-notifier', '~> 1.0.0'     # SlackAgent
+gem 'hypdf', '~> 1.0.7'              # PDFInfoAgent
+gem 'telegram-bot-ruby', '~> 0.4.1'  # TelegramAgent
 
 # Weibo Agents
 gem 'weibo_2', github: 'cantino/weibo_2', branch: 'master'

Gemfile.lock

@@ -112,6 +112,10 @@ GEM
       multi_json (>= 1.0.0)
     aws-sdk-core (2.2.15)
       jmespath (~> 1.0)
+    axiom-types (0.1.1)
+      descendants_tracker (~> 0.0.4)
+      ice_nine (~> 0.11.0)
+      thread_safe (~> 0.3, >= 0.3.1)
     bcrypt (3.1.10)
     better_errors (1.1.0)
       coderay (>= 1.0.0)
@@ -146,6 +150,8 @@ GEM
     chronic (0.10.2)
     cliver (0.3.2)
     coderay (1.1.0)
+    coercible (1.0.0)
+      descendants_tracker (~> 0.0.1)
     coffee-rails (4.1.1)
       coffee-script (>= 2.2.0)
       railties (>= 4.0.0, < 5.1.x)
@@ -170,6 +176,8 @@ GEM
       activesupport (>= 3.0, < 5.0)
     delorean (2.1.0)
       chronic
+    descendants_tracker (0.0.4)
+      thread_safe (~> 0.3, >= 0.3.1)
     devise (3.5.4)
       bcrypt (~> 3.0)
       orm_adapter (~> 0.1)
@@ -225,6 +233,8 @@ GEM
       dotenv (>= 0.7)
       thor (>= 0.13.6)
     formatador (0.2.5)
+    gene_pool (1.4.1)
+      thread_safe
     geokit (1.8.5)
       multi_json (>= 1.3.2)
     geokit-rails (2.0.1)
@@ -281,6 +291,7 @@ GEM
     hypdf (1.0.7)
       httmultiparty (= 0.3.10)
     i18n (0.7.0)
+    ice_nine (0.11.2)
     jmespath (1.1.3)
     jquery-rails (3.1.3)
       railties (>= 3.0, < 5.0)
@@ -371,6 +382,11 @@ GEM
       multi_json (~> 1.3)
       omniauth-oauth (~> 1.0)
     orm_adapter (0.5.0)
+    persistent_http (1.0.6)
+      gene_pool (>= 1.3)
+    persistent_httparty (0.1.2)
+      httparty (~> 0.9)
+      persistent_http (< 2)
     pg (0.18.3)
     poltergeist (1.8.1)
       capybara (~> 2.1)
@@ -515,6 +531,10 @@ GEM
       net-ssh (>= 2.8.0)
     string-scrub (0.0.5)
     systemu (2.6.4)
+    telegram-bot-ruby (0.4.1)
+      httmultiparty
+      persistent_httparty
+      virtus
     term-ansicolor (1.3.0)
       tins (~> 1.0)
     therubyracer (0.12.2)
@@ -559,6 +579,11 @@ GEM
       macaddr (~> 1.0)
     uuidtools (2.1.5)
     vcr (2.9.2)
+    virtus (1.0.5)
+      axiom-types (~> 0.1)
+      coercible (~> 1.0)
+      descendants_tracker (~> 0.0, >= 0.0.3)
+      equalizer (~> 0.0, >= 0.0.9)
     warden (1.2.4)
       rack (>= 1.0)
     webmock (1.17.4)
@@ -664,6 +689,7 @@ DEPENDENCIES
   spring (~> 1.6.3)
   spring-commands-rspec (~> 1.0.4)
   string-scrub
+  telegram-bot-ruby (~> 0.4.1)
   therubyracer (~> 0.12.2)
   tumblr_client!
   twilio-ruby (~> 3.11.5)

app/models/agents/telegram_agent.rb

@@ -0,0 +1,92 @@
+require 'telegram/bot'
+require 'open-uri'
+require 'tempfile'
+
+module Agents
+  class TelegramAgent < Agent
+    cannot_be_scheduled!
+    cannot_create_events!
+    no_bulk_receive!
+
+    gem_dependency_check { defined?(Telegram) }
+
+    description <<-MD
+      #{'# Include `telegram-bot-ruby` in your Gemfile to use this Agent!' if dependencies_missing?}
+
+      The Telegram Agent receives and collects events and sends them via [Telegram](https://telegram.org/).
+
+      It is assumed that events have either a `text`, `photo`, `audio`, `document` or `video` key. You can use the EventFormattingAgent if your event does not provide these keys.
+
+      The value of `text` key is sent as a plain text message.
+      The value of `photo`, `audio`, `document` and `video` keys should be an url which contents are sent to you according to the type.
+
+      **Setup**
+
+      1. obtain an `auth_token` by [creating a new bot](https://telegram.me/botfather).
+      2. [send a private message to your bot](https://telegram.me/YourHuginnBot)
+      3. obtain your private `chat_id` [from the recently started conversation](https://api.telegram.org/bot<auth_token>/getUpdates)
+    MD
+
+    def default_options
+      {
+        auth_token: 'xxxxxxxxx:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
+        chat_id: 'xxxxxxxx'
+      }
+    end
+
+    def validate_options
+      errors.add(:base, 'auth_token is required') unless options['auth_token'].present?
+      errors.add(:base, 'chat_id is required') unless options['chat_id'].present?
+    end
+
+    def working?
+      received_event_without_error? && !recent_error_logs?
+    end
+
+    def receive(incoming_events)
+      incoming_events.each do |event|
+        receive_event event
+      end
+    end
+
+    private
+
+    TELEGRAM_FIELDS = {
+      text:     :send_message,
+      photo:    :send_photo,
+      audio:    :send_audio,
+      document: :send_document,
+      video:    :send_video
+    }.freeze
+
+    def receive_event(event)
+      TELEGRAM_FIELDS.each do |field, method|
+        payload = load_field event, field
+        next unless payload
+        send_telegram_message method, field => payload
+      end
+    end
+
+    def send_telegram_message(method, params)
+      params[:chat_id] = interpolated['chat_id']
+      Telegram::Bot::Client.run interpolated['auth_token'] do |bot|
+        bot.api.send method, params
+      end
+    end
+
+    def load_field(event, field)
+      payload = event.payload[field]
+      return false unless payload.present?
+      return payload if field == :text
+      load_file payload
+    end
+
+    def load_file(url)
+      file = Tempfile.new [File.basename(url), File.extname(url)]
+      file.binmode
+      file.write open(url).read
+      file.rewind
+      file
+    end
+  end
+end

spec/models/agents/telegram_agent_spec.rb

@@ -0,0 +1,102 @@
+require 'rails_helper'
+
+describe Agents::TelegramAgent do
+  before do
+    default_options = {
+      auth_token: 'xxxxxxxxx:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
+      chat_id: 'xxxxxxxx'
+    }
+    @checker = Agents::TelegramAgent.new name: 'Telegram Tester', options: default_options
+    @checker.user = users(:bob)
+    @checker.save!
+
+    @sent_messages = []
+    stub_methods
+  end
+
+  def stub_methods
+    stub.any_instance_of(Agents::TelegramAgent).send_telegram_message do |method, params|
+      @sent_messages << { method => params }
+    end
+
+    stub.any_instance_of(Agents::TelegramAgent).load_file do |_url|
+      :stubbed_file
+    end
+  end
+
+  def event_with_payload(payload)
+    event = Event.new
+    event.agent = agents(:bob_weather_agent)
+    event.payload = payload
+    event.save!
+    event
+  end
+
+  describe 'validation' do
+    before do
+      expect(@checker).to be_valid
+    end
+
+    it 'should validate presence of of auth_token' do
+      @checker.options[:auth_token] = ''
+      expect(@checker).not_to be_valid
+    end
+
+    it 'should validate presence of of chat_id' do
+      @checker.options[:chat_id] = ''
+      expect(@checker).not_to be_valid
+    end
+  end
+
+  describe '#receive' do
+    it 'processes multiple events properly' do
+      event_0 = event_with_payload text: 'Looks like its going to rain'
+      event_1 = event_with_payload text: 'Another text message'
+      @checker.receive [event_0, event_1]
+
+      expect(@sent_messages).to eq([
+        { send_message: { text: 'Looks like its going to rain' } },
+        { send_message: { text: 'Another text message' } }
+      ])
+    end
+
+    it 'accepts photo key and uses :send_photo to send the file' do
+      event = event_with_payload photo: 'https://example.com/image.png'
+      @checker.receive [event]
+
+      expect(@sent_messages).to eq([{ send_photo: { photo: :stubbed_file } }])
+    end
+
+    it 'accepts audio key and uses :send_audio to send the file' do
+      event = event_with_payload audio: 'https://example.com/sound.mp3'
+      @checker.receive [event]
+
+      expect(@sent_messages).to eq([{ send_audio: { audio: :stubbed_file } }])
+    end
+
+    it 'accepts document key and uses :send_document to send the file' do
+      event = event_with_payload document: 'https://example.com/document.pdf'
+      @checker.receive [event]
+
+      expect(@sent_messages).to eq([{ send_document: { document: :stubbed_file } }])
+    end
+
+    it 'accepts video key and uses :send_video to send the file' do
+      event = event_with_payload video: 'https://example.com/video.avi'
+      @checker.receive [event]
+
+      expect(@sent_messages).to eq([{ send_video: { video: :stubbed_file } }])
+    end
+  end
+
+  describe '#working?' do
+    it 'is not working without having received an event' do
+      expect(@checker).not_to be_working
+    end
+
+    it 'is working after receiving an event without error' do
+      @checker.last_receive_at = Time.now
+      expect(@checker).to be_working
+    end
+  end
+end