feat: add google concern

app/controllers/concerns/google.rb

@@ -0,0 +1,20 @@
+module GoogleConcern
+  extend ActiveSupport::Concern
+
+  def google_client
+    app_id = GlobalConfigService.load('GOOGLE_OAUTH_CLIENT_ID', nil)
+    app_secret = GlobalConfigService.load('GOOGLE_OAUTH_CLIENT_SECRET', nil)
+
+    ::OAuth2::Client.new(app_id, app_secret, {
+                           site: 'https://oauth2.googleapis.com',
+                           authorize_url: 'https://accounts.google.com/o/oauth2/auth',
+                           token_url: '/token'
+                         })
+  end
+
+  private
+
+  def base_url
+    ENV.fetch('FRONTEND_URL', 'http://localhost:3000')
+  end
+end

app/controllers/google/callbacks_controller.rb

@@ -1,4 +1,6 @@
 class Google::CallbacksController < OauthCallbackController
+  include GoogleConcern
+
   private
 
   def provider_name
@@ -10,13 +12,7 @@ class Google::CallbacksController < OauthCallbackController
   end
 
   def oauth_client
-    app_id = GlobalConfigService.load('GOOGLE_OAUTH_CLIENT_ID', nil)
-    app_secret = GlobalConfigService.load('GOOGLE_OAUTH_CLIENT_SECRET', nil)
-
-    ::OAuth2::Client.new(app_id, app_secret, {
-                           site: 'https://oauth2.googleapis.com',
-                           authorize_url: 'https://accounts.google.com/o/oauth2/auth',
-                           token_url: '/token'
-                         })
+    # from GoogleConcern
+    google_client
   end
 end