You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: challenges_controller.rb
    path of file: ./repos/ctf-scoreboard/app/controllers
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

class ChallengesController < ApplicationController
  include ChallengesHelper

  before_action :
    
  def find_and_log_flag
    flag = params[:challenge]&.[](:submitted_flag) # Safe navigation on a hash
    return if flag.nil?

    SubmittedFlag.create(user: current_user, challenge: @challenge, text: flag) unless current_user.admin?
    @flag_found = @challenge.find_flag(flag)
  end