def check_registration_status
    if params[:signed_request].present?
      signed_request = params[:signed_request]
      @oauth = Koala::Facebook::OAuth.new(212830502085409, "x")
      sig = @oauth.parse_signed_request(signed_request)
      @user = User.first(conditions: { facebook_id: sig['user_id'] })
      if @user.present?
        redirect_to root_url
      else
        begin
          @graph = Koala::Facebook::GraphAPI.new(sig['oauth_token'])
          @fbuser = @graph.get_object("me")
          @user = User.create(facebook_token: sig['oauth_token']) do |user|
            user.email = @fbuser["email"]
            user.facebook_id = @fbuser["id"]
            user.name = @fbuser["name"]
          end

          @user.save!
          redirect_to root_url
        rescue
          redirect_to '/registro'
        end
      end
    end
  end