Feature: Add online status to each user (#452)

* Feature: Add online status to each user
* Add OnlineStatusable, add availability status to thumbnail

app/models/concerns/availability_statusable.rb

@@ -0,0 +1,11 @@
+module AvailabilityStatusable
+  extend ActiveSupport::Concern
+
+  def online?
+    ::OnlineStatusTracker.subscription_count(pubsub_token) != 0
+  end
+
+  def availability_status
+    online? ? 'online' : 'offline'
+  end
+end

app/models/contact.rb

@@ -20,6 +20,7 @@
 class Contact < ApplicationRecord
   include Pubsubable
   include Avatarable
+  include AvailabilityStatusable
   validates :account_id, presence: true
 
   belongs_to :account

app/models/user.rb

@@ -48,6 +48,7 @@ class User < ApplicationRecord
   include Events::Types
   include Pubsubable
   include Avatarable
+  include AvailabilityStatusable
   include Rails.application.routes.url_helpers
 
   devise :database_authenticatable,