fuuidnewtype.scala

package io.chrisdavenport

import cats._
import cats.implicits._
import cats.effect.{IO, Sync}
import java.util.UUID

abstract class FUUIDModule {
  type FUUID

  def fromUUID(f: UUID): FUUID

  def toUUID(f: FUUID): UUID

  def fromString(s: String): Option[FUUID]

  def randomFUUID[F[_]: Sync]: F[FUUID]
}

private[chrisdavenport] object FUUIDImpl extends FUUIDModule {
  override type FUUID = UUID

  override def fromUUID(f: UUID): UUID = f

  override def toUUID(f: UUID): UUID = f

  override def fromString(s: String): Option[UUID] =
    try {
      Some(UUID.fromString(s))
    } catch {
      case e: Throwable if !e.isInstanceOf[VirtualMachineError] => None
    }

  override def randomFUUID[F[_]: Sync]: F[UUID] = Sync[F].delay(fromUUID(UUID.randomUUID))
}

object fuuid {

  val FUUID: FUUIDModule = FUUIDImpl

  type FUUID = FUUID.FUUID

  implicit val instancesFUUID: Hash[FUUID] with Order[FUUID] with Show[FUUID] =
    new Hash[FUUID] with Order[FUUID] with Show[FUUID] {
      override def show(t: FUUID): String = FUUID.toUUID(t).toString

      override def eqv(x: FUUID, y: FUUID): Boolean =
        FUUID.toUUID(x).equals(FUUID.toUUID(y))

      override def hash(x: FUUID): Int = FUUID.toUUID(x).hashCode()

      override def compare(x: FUUID, y: FUUID): Int =
        FUUID.toUUID(x).compareTo(FUUID.toUUID(y))
    }
}