refactor method

show_poll.rb

def next_poll(current_site, current_user, poll_id = nil)
  poll = GobiertoParticipation::Poll.by_site(current_site).find(poll_id) if poll_id
  answerable_polls = GobiertoParticipation::Poll.by_site(current_site).answerable.order(ends_at: :asc)
  answerable_polls_by_user = answerable_polls.detect { |p| p.answerable_by?(current_user) } if current_user

  if current_user
    if poll && poll.answerable_by?(current_user)
      poll
    elsif answerable_polls_by_user
      answerable_polls_by_user
    end
  else
    if poll
      poll
    else
      answerable_polls.first
    end
  end
rescue ActiveRecord::RecordNotFound
  return ""
end