libraryDependencies += "de.lhns" %% "fs2-functork" % "0.2.2"
libraryDependencies += "de.lhns" %% "fs2-functork-doobie" % "0.2.2"

import cats.effect.Async
import cats.tagless._
import de.lhns.fs2.functork._
import de.lhns.fs2.functork.doobie.transactK
import doobie._
import doobie.implicits._
import fs2.Stream

trait Repo[F[_]] {
  def get(id: Long): F[Option[String]]

  def stream: Stream[F, (Long, String)]
}

object Repo {
  implicit val functorK: FunctorK[Repo] = Derive.functorK

  val impl: Repo[ConnectionIO] = new Repo[ConnectionIO] {
    override def get(id: Long): F[Option[String]] =
      sql"select value from table where id = $id"
        .query[String]
        .option

    override def stream: Stream[F, (Long, String)] =
      sql"select id, value from table"
        .query[(Long, String)]
        .stream
  }
}

object Main {
  def repo[F[_] : Async](xa: Transactor[F]): Repo[F] = {
    val transact = transactK(xa)
    Repo.impl.mapK(transact)
  }
}