Updated EmptyController to have protections and error responses

• Updated:
- EmptyController to have protections and error responses

app/controllers/empty_controller.rb

@@ -2,6 +2,38 @@
 
 class EmptyController < ActionController::Base
 
+  include RateLimitHeaders
+
+  protect_from_forgery with: :null_session
+
+  rescue_from ActiveRecord::RecordInvalid, GabSocial::ValidationError do |e|
+    render json: { error: e.to_s }, status: 422
+  end
+
+  rescue_from ActiveRecord::RecordNotFound do
+    render json: { error: 'Record not found' }, status: 404
+  end
+
+  rescue_from HTTP::Error, GabSocial::UnexpectedResponseError do
+    render json: { error: 'Remote data could not be fetched' }, status: 503
+  end
+
+  rescue_from OpenSSL::SSL::SSLError do
+    render json: { error: 'Remote SSL certificate could not be verified' }, status: 503
+  end
+
+  rescue_from GabSocial::NotPermittedError do
+    render json: { error: 'This action is not allowed' }, status: 403
+  end
+
+  def doorkeeper_unauthorized_render_options(error: nil)
+    { json: { error: (error.try(:description) || 'Not authorized') } }
+  end
+
+  def doorkeeper_forbidden_render_options(*)
+    { json: { error: 'This action is outside the authorized scopes' } }
+  end
+
   protected
 
   def current_user