"Restore" S3 assets after updating Paperclip hash_data

main.rb

# Suppose we updated our hash_data for Paperclip
OLD_HASH = ":class/:attachment/:id/:style"
NEW_HASH = ":class/:attachment/:id/:style/:updated_at"
ACL = :public_read

def restore(r) 
  return unless r.file.exists? 
  
  new_key = r.file.path[1..-1]
  r.file.options[:hash_data] = OLD_HASH;
  old_key = r.file.path[1..-1]
    
  o = bucket.objects[old_key];
  if o.exists? 
    o.move_to(new_key, acl: ACL)
  else
    p "Doesn't exist: #{old_key}"
  end
  r.file.options[:hash_data] = NEW_HASH;
end