Different handling for diferent kinds of images

gistfile1.scala

trait ImageResource {
  def publicUrl: String
}

case class URLImage(source: URL) extends ImageResource {
  def publicUrl = source.url
}

case class CDNImage(bucketName: String, key: String, cdnBaseUrl: String) extends ImageResource {
  lazy val cdnUrl = URL(cdnBaseUrl) :+ key
  def publicUrl = cdnUrl.url
}