# frozen_string_literal: true

module PlanetExpress
  class LShipmentDiscountRule < Rule
    protected

    def applicable_to?(shipment)
      lp_provider_shipment?(shipment) &&
        third_l_shipment_in_month?(shipment) &&
        rule_not_applied_in_month_already?(shipment)
    end

    def discount_for(shipment)
      Discount.new(discount_amount(shipment), self)
    end

    private

    def lp_provider_shipment?(shipment)
      shipment.lp_provider?
    end

    def third_l_shipment_in_month?(shipment)
      provider = shipment.provider
      month = shipment.month

      count = shipment_repository.l_shipment_count_for_provider_and_month(provider,
                                                                          month)
      (count % 3) == 2
    end

    def rule_not_applied_in_month_already?(shipment)
      !shipment_repository.rule_applied_in_month?(shipment.month, self.class)
    end

    def discount_amount(shipment)
      desired_amount = price(shipment)
      discount_budget(shipment).maximum_possible_discount(desired_amount)
    end
  end
end