class Adjustment

# File lib/wunder/adjustment.rb, line 4
def initialize(basket, promotional_rules)
  @basket = basket
  @promotional_rules = promotional_rules
  @product_promotional_rules = []
  @basket_promotional_rules = []
  @applied_promotional_rules = []
end

# File lib/wunder/adjustment.rb, line 12
def calculate_total
  adjusted_total = apply_item_discounts
  apply_basket_discounts(adjusted_total)
end

# File lib/wunder/adjustment.rb, line 17
def eligible_promotional_rules
  pr = (@basket_promotional_rules | @product_promotional_rules).map(&:label)
  pr.join(",")
end

# File lib/wunder/adjustment.rb, line 35
def apply_basket_discounts(items_total)
  @basket_promotional_rules =
    eligible_basket_promotional_discounts(items_total)

  unless @basket_promotional_rules.empty?
    @basket_promotional_rules.each do |promotional_rule|
      items_total = promotional_rule.calculate_total(items_total)
    end
  end

  items_total
end

# File lib/wunder/adjustment.rb, line 24
def apply_item_discounts
  adjusted_total = BigDecimal(0)

  basket.items.each do |basket_item|
    @product_promotional_rules = eligible_product_promo_discounts(basket_item)
    compute_item_discounted_price(basket_item)
    adjusted_total += basket_item.product.price * basket_item.quantity
  end
  adjusted_total
end

# File lib/wunder/adjustment.rb, line 48
def compute_item_discounted_price(basket_item)
  return if @product_promotional_rules.empty?
  @product_promotional_rules.each do |promotional_rule|
    price = promotional_rule.calculate_total(basket_item)
    basket_item.product.price = price unless price.nil?
  end
end

# File lib/wunder/adjustment.rb, line 62
def eligible_basket_promotional_discounts(total)
  promotional_rules.select do |promo_rule|
    promo_rule.on_item == false && promo_rule.rule.adjustable?(total)
  end
end

# File lib/wunder/adjustment.rb, line 56
def eligible_product_promo_discounts(basket_item)
  promotional_rules.select do |promo_rule|
    promo_rule.on_item == true && promo_rule.rule.eligible?(basket_item)
  end
end