a design challenge

billing_flow.rb

class Order
  has_one :receipt

  def paid(receipt)
    self.receipt = receipt
  end
end

class Receipt
  belongs_to :order
end


class BillingService
  def charge
    charge_details = Stripe::Charge.create(stripe_details)
    Processor.new(charge_details).process
  end   

  private

  def for_stripe
    # formats @order details for stripe params
  end  
end

class Processor
  def process
    Receipt.new(for_receipt)
  end

  private

  def for_receipt
    # formats @charge_details into a Receipt object
  end
end

order = Order.new(plan: 1, quantity: 5)
receipt = BillingService.new(order).charge

order.paid(receipt)