add telegram agent

Gemfile

@@ -35,7 +35,7 @@ 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 'hypdf', '~> 1.0.10'          # PDFInfoAgent
 
 # Weibo Agents
 gem 'weibo_2', github: 'cantino/weibo_2', branch: 'master'
@@ -100,6 +100,7 @@ gem 'foreman', '~> 0.63.0'
 gem 'geokit', '~> 1.8.4'
 gem 'geokit-rails', '~> 2.0.1'
 gem 'httparty', '~> 0.13'
+gem 'httmultiparty', '~> 0.3.16'
 gem 'jquery-rails', '~> 3.1.3'
 gem 'json', '~> 1.8.1'
 gem 'jsonpath', '~> 0.5.6'

Gemfile.lock

@@ -267,19 +267,21 @@ GEM
     hipchat (1.2.0)
       httparty
     hpricot (0.8.6)
-    httmultiparty (0.3.10)
+    httmultiparty (0.3.16)
       httparty (>= 0.7.3)
+      mimemagic
       multipart-post
     http (0.6.4)
       http_parser.rb (~> 0.6.0)
     http-cookie (1.0.2)
       domain_name (~> 0.5)
     http_parser.rb (0.6.0)
-    httparty (0.13.1)
+    httparty (0.13.7)
       json (~> 1.8)
       multi_xml (>= 0.5.2)
-    hypdf (1.0.7)
-      httmultiparty (= 0.3.10)
+    hypdf (1.0.10)
+      httmultiparty (~> 0.3)
+      httparty (~> 0.13)
     i18n (0.7.0)
     jmespath (1.1.3)
     jquery-rails (3.1.3)
@@ -318,6 +320,7 @@ GEM
       thread_safe (~> 0.3, >= 0.3.1)
     method_source (0.8.2)
     mime-types (2.99.1)
+    mimemagic (0.3.1)
     mini_magick (4.2.3)
     mini_portile2 (2.0.0)
     minitest (5.8.4)
@@ -616,8 +619,9 @@ DEPENDENCIES
   guard-rspec (~> 4.6.4)
   haversine
   hipchat (~> 1.2.0)
+  httmultiparty (~> 0.3.16)
   httparty (~> 0.13)
-  hypdf (~> 1.0.7)
+  hypdf (~> 1.0.10)
   jquery-rails (~> 3.1.3)
   json (~> 1.8.1)
   jsonpath (~> 0.5.6)

app/models/agents/telegram_agent.rb

@@ -0,0 +1,96 @@
+require 'httmultiparty'
+require 'open-uri'
+require 'tempfile'
+
+module Agents
+  class TelegramAgent < Agent
+    cannot_be_scheduled!
+    cannot_create_events!
+    no_bulk_receive!
+
+    description <<-MD
+      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 a url whose contents will be sent to you.
+
+      **Setup**
+
+      1. Obtain an `auth_token` by [creating a new bot](https://telegram.me/botfather).
+      2. Send a private message to your bot by visiting https://telegram.me/YourHuginnBot
+      3. Obtain your private `chat_id` from the recently started conversation by visiting 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_ACTIONS = {
+      text:     :sendMessage,
+      photo:    :sendPhoto,
+      audio:    :sendAudio,
+      document: :sendDocument,
+      video:    :sendVideo
+    }.freeze
+
+    def telegram_bot_uri(method)
+      "https://api.telegram.org/bot#{interpolated['auth_token']}/#{method}"
+    end
+
+    def receive_event(event)
+      TELEGRAM_ACTIONS.each do |field, method|
+        payload = load_field event, field
+        next unless payload
+        send_telegram_message method, field => payload
+        unlink_file payload if payload.is_a? Tempfile
+      end
+    end
+
+    def send_telegram_message(method, params)
+      params[:chat_id] = interpolated['chat_id']
+      HTTMultiParty.post telegram_bot_uri(method), query: params
+    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
+
+    def unlink_file(file)
+      file.close
+      file.unlink
+    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([
+        { sendMessage: { text: 'Looks like its going to rain' } },
+        { sendMessage: { 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([{ sendPhoto: { 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([{ sendAudio: { 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([{ sendDocument: { 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([{ sendVideo: { 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