clacks/lib/clacks_web/controllers/objects_controller.ex

defmodule ClacksWeb.ObjectsController do
  use ClacksWeb, :controller
  alias Clacks.{Activity, Object}
  alias ClacksWeb.Router.Helpers, as: Routes
  alias ClacksWeb.Endpoint

  def get(conn, params) do
    case conn.assigns[:format] do
      "activity+json" ->
        get_object(conn, params)

      "html" ->
        redirect_to_status(conn, params)
    end
  end

  defp get_object(conn, _params) do
    object_id = current_url(conn)

    case Object.get_cached_by_ap_id(object_id) do
      nil ->
        conn
        |> resp(404, "Not Found")

      object ->
        conn
        |> put_resp_header("content-type", "application/activity+json")
        |> json(object.data)
    end
  end

  defp redirect_to_status(conn, _params) do
    object_id = current_url(conn)

    case Activity.get_by_object_ap_id(object_id, "Create") do
      nil ->
        conn
        |> resp(404, "Not Found")

      activity ->
        redirect(conn, to: Routes.frontend_path(Endpoint, :status, activity.id))
    end
  end
end