Spend $30 on Max Factor and receive a free Max Factor Mascara.arb

FREEBIE_PRODUCT_ID = 4166628606026
CART_TOTAL_FOR_DISCOUNT_APPLIED = Money.new(cents: 3000)
TARGET_TAG = "brand_absolute"
DISCOUNT_MESSAGE = "Spend $30+ on Max Factor and get a free gift"

freebie_in_cart = false
cart_price_exceeds_discounted_freebie_amount = false
target_tag_found = false
cost_of_freebie = Money.zero
conditional_item_price = Money.zero
conditional_item_price_total = Money.zero

Input.cart.line_items.select do |line_item|
  product = line_item.variant.product
  product_tags = product.tags.map { |tag| tag.downcase.strip }
  if product_tags.include?(TARGET_TAG.downcase.strip)
      target_tag_found = true
      conditional_item_price = line_item.line_price
  else 
     target_tag_found = false   
     conditional_item_price = Money.zero
  end
  conditional_item_price_total =  conditional_item_price_total + conditional_item_price
  if product.id == FREEBIE_PRODUCT_ID
    freebie_in_cart = true
    cost_of_freebie = line_item.line_price
  end
end

if freebie_in_cart
  cart_subtotal_minus_freebie_cost = conditional_item_price_total - cost_of_freebie
  if cart_subtotal_minus_freebie_cost >= CART_TOTAL_FOR_DISCOUNT_APPLIED
    cart_price_exceeds_discounted_freebie_amount = true
  end
end

was_discount_applied = false
if cart_price_exceeds_discounted_freebie_amount
  Input.cart.line_items.each do |item|
    if item.variant.product.id == FREEBIE_PRODUCT_ID && was_discount_applied == false
      if item.quantity > 1
        new_line_item = item.split(take: 1)
        new_line_item.change_line_price(Money.zero, message: DISCOUNT_MESSAGE)
        Input.cart.line_items << new_line_item
        next
      else
        item.change_line_price(Money.zero, message: DISCOUNT_MESSAGE)
      end
    end
  end
end

Output.cart = Input.cart