http4s-server.scala

//> using scala 3.3.0
//> using dep org.http4s::http4s-ember-server:0.23.23
//> using dep org.http4s::http4s-dsl:0.23.23

import cats.effect._
import com.comcast.ip4s._
import org.http4s.HttpRoutes
import org.http4s._
import org.http4s.dsl.io._
import org.http4s.ember.server._
import fs2.Stream
import scala.concurrent.duration._

case class Song(title: String, releasedYear: Int, artist: String)

object Main extends IOApp.Simple {
  val clockEverySeconds: Stream[IO, String] = Stream
    .awakeEvery[IO](1.second)
    .evalMap(_ => IO(java.time.OffsetDateTime.now().toString()))
    .intersperse("\n")

  val routes = HttpRoutes.of[IO] { case GET -> Root =>
    Ok(clockEverySeconds)
  }

  def run: IO[Unit] =
    EmberServerBuilder
      .default[IO]
      .withHost(ipv4"0.0.0.0")
      .withPort(port"8080")
      .withHttpApp(routes.orNotFound)
      .build
      .useForever
      .as(ExitCode.Success)
}