gistfile1.txt

var total:Double {
  var result = self.subtotal
  if let coupon = self.coupon, coupon.isactive{
    //percentage
    //fixed

    let sums = products.filter{$0.discounted}.compactMap({ ($0.price ?? 0.0) * Double($0.qty ?? 0) })
    let totalDiscounted = sums.reduce(0.0, +)
    if coupon.type == "fixed"{
      result -= (totalDiscounted - coupon.value)
    }else if coupon.type == "percentage"{
      result -= totalDiscounted*coupon.value
    }

 }
  return result
}


let discount:String?{
  var result:String = nil
  if let coupon = self.coupon , coupon.isactive{
    result = coupon.type == "fixed" ?  "\(coupon.value) $" : "\(coupon.value) %%"
  }
  return result
}