module SolidusMe
  class ShippingEstimator

    def initialize
      store = Spree::Store.first
      @preferences = Preferences.new(store).preferences
      @me_client = MeApi::Client.new(@preferences[:access_token])
    end

    def shipping_rates(package, _frontend_only = true)
      melhor_envio_rates = get_rates_from_melhor_envio(package)
      shipping_rates = melhor_envio_rates.map do |melhor_envio_rate|
        build_shipping_rate(melhor_envio_rate, package)
      end

      unless shipping_rates.empty?
        default_shipping_rate = Spree::Config.shipping_rate_selector_class.new(shipping_rates).find_default
        default_shipping_rate.selected = true
      end

      shipping_rates
    end

    private

    def get_rates_from_melhor_envio(package)
      begin
        weight = package.contents.map {|content| content.weight }.sum
        price = package.contents.map {|content| content.price }.sum
        zipcode = package.order.ship_address.zipcode
        services = @preferences[:services] || ["SEDEX", "PAC", "Mini Envios", ".Package", ".Com"]

        rates = @me_client.rates(
          from: @preferences[:postal_code_from],
          to: zipcode,
          weight_kg: (weight/1000),
          contents_value_brl: price
        )
        rates.select { |rate| rate.price > 0 && services.include?(rate.service_name) }
      rescue
        [
          OpenStruct.new({
            price: 15.00,
            service_name: "",
            carrier_name: "Frete padrão",
            delivery_range: { min: 5, max: 5 }
          })
        ]
      end
    end

    def build_shipping_rate(melhor_envio_rate, package)
      shipping_method = Spree::ShippingMethod.find_or_create_by(
        carrier: melhor_envio_rate.carrier_name,
        service_level: melhor_envio_rate.service_name,
      ) do |shipping_method|
        shipping_method.name = "#{melhor_envio_rate.carrier_name} #{melhor_envio_rate.service_name}"
        shipping_method.calculator = Spree::Calculator::Shipping::FlatRate.create
        shipping_method.shipping_categories = Spree::ShippingCategory.all
        shipping_method.available_to_users = true
      end
      
      Spree::ShippingRate.new(
        shipping_method: shipping_method,
        cost: melhor_envio_rate.price,
        min_delivery_time: melhor_envio_rate.delivery_range["min"],
        max_delivery_time: melhor_envio_rate.delivery_range["max"]
      )
    end
  end
end