type view = Config of Config.config | Timer of Config.config

let () =
  let html = Document.querySelectorUnsafe "html" in
  let main = Document.querySelectorUnsafe "main" in
  let rec showView v =
    Animation.replaceChild html main (fun _ ->
        match v with
        | Config config ->
            ConfigView.render config (fun config -> showView (Timer config))
        | Timer config ->
            TimerView.render config (fun config -> showView (Config config)))
  in
  showView (Config Config.init)