Shopify Script for free product with coupon code - Free product is the least expensive

shopify-script-free-product-with-coupon.rb

if Input.cart
  FREEBIE_PRODUCT_PRICE = Money.zero
  FREEBIE_PRODUCT_ID = 0
  coupon_codes = Array["anniversary25", "coupon2", "coupon3"]
  if Input.cart.discount_code != nil
    if coupon_codes.include?(Input.cart.discount_code.code)
      if Input.cart.line_items.size > 1
        Input.cart.line_items.select do |line_item|
          if FREEBIE_PRODUCT_PRICE == Money.zero
            FREEBIE_PRODUCT_PRICE = line_item.variant.price
            FREEBIE_PRODUCT_ID = line_item.variant.id
          end
          if line_item.variant.price < FREEBIE_PRODUCT_PRICE
            freebie_in_cart = true
            cost_of_freebie = line_item.line_price
            FREEBIE_PRODUCT_ID = line_item.variant.id
            FREEBIE_PRODUCT_PRICE = line_item.variant.price
          end
        end
      end
    end
  end
  puts FREEBIE_PRODUCT_ID
  puts FREEBIE_PRODUCT_PRICE
   Input.cart.line_items.each do |item|
    if FREEBIE_PRODUCT_ID == item.variant.id
      if item.quantity > 1
        new_line_item = item.split(take: 1)
        new_line_item.change_line_price(Money.zero, message: "free gift")
        Input.cart.line_items << new_line_item
        next
      else
        item.change_line_price(Money.zero, message: "free gift")
      end
    end
  end
end
Output.cart = Input.cart