availability_provider.rb

class Variant::AvailabilityProvider

  attr_accessor :variant, :context

  def initialize(variant, context = nil)
    @variant = variant
    @context = context
  end

  def is_available?
    return false if variant.out_of_stock? || !variant.enabled?
    return true if variant.is_kit? || variant.is_gift? || variant.is_bundle?

    if variant.product.track_variant_availability?
      variant.count_available.try(:">", 0)
    else
      variant.count_on_hand.try(:">", 0)
    end
  end
end