order apply_coupn

def apply_coupons
    applied_coupons = []
    active_coupons = family.family_coupons.active.order(:created_at).map(&:coupon).flatten
    total = self.subtotal
    while !total.zero? && !active_coupons.empty?
      active_coupons.filter { |c| c.coupon_type == "permanent_percent" }.each do |coupon|
        total = total * coupon.amount / 100.0.to_i
        applied_coupons.push(coupon)
        active_coupons -= [coupon]
      end
      active_coupons.filter { |c| c.coupon_type == "percent" }.each do |coupon|
        total = total * coupon.amount / 100.0.to_i
        applied_coupons.push(coupon)
        active_coupons -= [coupon]
      end
      active_coupons.filter { |c| c.coupon_type == "amount_in_cents" }.each do |coupon|
        if total >= 1
          total -= coupon.amount
          applied_coupons.push(coupon)
          active_coupons -= [coupon]
        end
      end
    end
    return total
  end