turnaround_time_resolver.rb

field :turnaround_time, Int, null: true
def turnaround_time(inbound_delivery, outbound_delivery)
  # If the outbound delivery hasn't departed, use the current time.
  departure_time = outbound_delivery.departure_time || Time.zone.now
  
  time_difference = departure_time - inbound_delivery.arrival_time
  
  # Round to convert a datetime difference into hours
  (time_difference / 1.hour).round
end