Shopify Script - $X off if cart is over $Y

min_discount_order_amount = Money.new(cents:100) * 30 #minimum amount needed to have in cart to get discount
total = Input.cart.subtotal_price_was
discount = if total > min_discount_order_amount
              500 #discount amount you are offering in cents
            else
              0
            end
message = "Here's $5 off" #discount message shown to customer

Input.cart.line_items.each do |line_item|
  product = line_item.variant.product
  next if product.gift_card?
  line_item.change_line_price(line_item.line_price - Money.new(cents: discount), message: message) unless discount == 0
end

Output.cart = Input.cart