import scala.util.Try

/**
 * Type-safe UUID wrapper that encodes the type it relates to.  This class explicitly hides its
 * UUID value to prevent converting it between types.
 */
class UUID[A] private(private val uuid: UUID.Raw) {
  override def toString = uuid.toString
}

object UUID {
  type Raw = java.util.UUID
  def fromRaw[A](uuid: Raw): UUID[A] = new UUID(uuid)
  def gen[A](): UUID[A] = fromRaw(java.util.UUID.randomUUID())
  def genRaw(): java.util.UUID = java.util.UUID.randomUUID()
  def fromString[A](s: String): Either[String, UUID[A]] = fromStringRaw(s).right.map(fromRaw)
  def fromStringRaw(s: String): Either[String, java.util.UUID] = {
    Try { java.util.UUID.fromString(s) }.toOption.toRight(s"Invalid UUID string: $s")
  }
  def unsafeFromString[A](s: String): UUID[A] = fromRaw(unsafeFromStringRaw(s))
  def unsafeFromStringRaw(s: String): Raw = fromStringRaw(s).fold({ e => throw new RuntimeException(e) }, identity)
}