Extract omniauth methods into concern

app/controllers/users/omniauth_callbacks_controller.rb

@@ -3,19 +3,19 @@ module Users
   class OmniauthCallbacksController < Devise::OmniauthCallbacksController
     def vkontakte
       auth = request.env['omniauth.auth']
-      @user = User.from_omniauth(auth)
+      @user = OmniauthLogin.perform(auth).user
       if @user.persisted?
         sign_in_and_redirect @user, event: :authentication # this will throw if @user is not activated
         set_flash_message(:notice, :success, kind: 'VK') if is_navigational_format?
       else
-        session['devise.facebook_data'] = auth
+        session['devise.vkontake_data'] = auth
         redirect_to new_user_registration_url
       end
     end
 
     def google_oauth2
       auth = request.env['omniauth.auth']
-      @user = User.from_omniauth(auth)
+      @user = OmniauthLogin.perform(auth).user
       if @user.persisted?
         sign_in_and_redirect @user, event: :authentication # this will throw if @user is not activated
         set_flash_message(:notice, :success, kind: 'Google') if is_navigational_format?

app/models/user.rb

@@ -1,4 +1,4 @@
-# User is a preson, who lives in a hostel room
+# User is a preson, who lives in a room
 #
 # == Schema Information
 #
@@ -43,21 +43,7 @@ def room?
     room_id != nil
   end
 
-  # :reek:DuplicateMethodCall { allow_calls: ['auth.info', 'auth.provider', 'auth.uid'] }
-  def self.from_omniauth(auth)
-    if where(email: auth.info.email).exists?
-      user = find_by(email: auth.info.email)
-      user.update(provider: auth.provider, uid: auth.uid, photo_url: auth.info.image)
-      user.remember_me!
-      return user
-    end
-
-    create(email: auth.info.email, name: auth.info.name,
-           password: Devise.friendly_token[0, 20],
-           provider: auth.provider, uid: auth.uid,
-           photo_url: auth.info.image)
-  end
-
+  # method for omniauth
   def self.new_with_session(params, session)
     super.tap do |user|
       data = session['devise.vkontakte_data']

app/services/application_service.rb

@@ -1,8 +1,8 @@
 # to call: ApplicationService.(params)
 #
 class ApplicationService
-  def self.call(*args, **kwargs)
-    service = new(*args, **kwargs)
+  def self.perform(args)
+    service = new(args)
     service.perform
     service
   end

app/services/omniauth_login.rb

@@ -0,0 +1,34 @@
+# OmniauthLogin finds user by auth or creates new
+class OmniauthLogin < ApplicationService
+  attr_reader :user
+
+  # :reek:DuplicateMethodCall { allow_calls: ['auth.info'] }
+  def initialize(auth)
+    @params = {}
+    params[:email] = auth.info.email
+    params[:name] = auth.info.name
+    params[:photo_url] = auth.info.image
+    params[:provider] = auth.provider
+    params[:uid] = auth.uid
+  end
+
+  def perform
+    @user = find_user_by_email || create_new_user
+  end
+
+  private
+
+  attr_reader :params
+
+  def find_user_by_email
+    user = User.find_by(email: params[:email])
+    return unless user
+    user.update(params.select { |key, _| [:provider, :uid, :photo_url].include? key })
+    user.remember_me!
+    user
+  end
+
+  def create_new_user
+    User.create(params.merge(password: Devise.friendly_token[0, 20]))
+  end
+end