m.scala

object Main extends IOApp {

  val coordReg = """(\d+) (\d+)""".r

  override def run(args: List[String]): IO[ExitCode] = {
    implicit val ec: ExecutionContextExecutor = ExecutionContext.global
    program[IO].compile.drain.as(ExitCode.Success)
  }

  def program[F[_]: Monad : ContextShift](implicit ec: ExecutionContext, sync: Sync[F]): Stream[F, Unit] = {
    val control = RectangleControl[F](10, 10, 10)
    val lineIn = io.stdin[F](1024, ec).filter(_ != '\r').split(_ == '\n'.toByte)
    val boards = lineIn.scan(control.empty)((board, in) => board.flatMap { b =>
      val line = in.map(_.toChar).toList.mkString
      if(line.matches(coordReg.regex)) {
        val coordReg(x, y) = line
        control.unearth(Vec2[F](x.toInt, y.toInt))(b)
      } else {
        Stream.eval(sync.delay(println("Invalid input!"))).map(_ => b)
      }
    }).flatten
    boards.flatMap(control.show).evalMap(s => sync.delay(println(s)))
  }

}