# @module FlexCommerce::PaypalExpress
module FlexCommerce
  module PaypalExpress
    # @class ShippingMethodsForCart
    # 
    # This deals with free shipping promotions and updates the shipping methods accordingly
    class ShippingMethodsForCart

      include Enumerable

      def initialize(cart:, shipping_methods:)
        self.cart = cart
        self.shipping_methods = shipping_methods
        self.shipping_promotions = cart.available_shipping_promotions
      end

      def call
        free_shipping_method_ids = [ ]
        shipping_promotions.reverse.each do |promotion|
          # See if promotion is having a shipping method, 
          # and also see if that cart total is eligible for promotion
          if promotion.shipping_methods && can_apply_promotion_to_cart?(promotion: promotion)
            free_shipping_method_ids << promotion.shipping_methods.map(&:id)
          end
        end

        free_shipping_method_ids.flatten!
        updated_shipping_methods = []
        shipping_methods.each do |shipping_method|
          shipping_method_free = free_shipping_method_ids.include?(shipping_method.id)
          updated_shipping_methods << CartShippingMethod.new(shipping_method, shipping_method_free)
        end
        updated_shipping_methods
      end

      private

      attr_accessor :cart, :shipping_methods, :shipping_promotions

      def can_apply_promotion_to_cart?(promotion:)
        (cart.sub_total - cart.total_discount) >= promotion.minimum_cart_total&.to_i
      end

    end
  end
end