something-erlang/lib/something_erlang_web/controllers/page_controller.ex

defmodule SomethingErlangWeb.PageController do
  use SomethingErlangWeb, :controller

  def home(conn, _params) do
    # The home page is often custom made,
    # so skip the default app layout.
    render(conn, :home)
  end

  def to_forum_path(conn, %{"forum_path" => path} = _params) do
    {redirect_good, thread, page} =
      case {
        Regex.run(~r{threadid=(\d+)}, path),
        Regex.run(~r{pagenumber=(\d+)}, path)
          } do
        {[_, thread], nil} -> {:ok, thread, 1}
        {[_, thread], [_, page]} -> {:ok, thread, page}
        _ -> {:error, nil, nil}
      end

    if redirect_good == :ok do
      redirect(conn, to: ~p"/thread/#{thread}?page=#{page}")
    else
      put_flash(conn, :error, "Could not resolve URL")
      render(conn, :home)
    end
  end

  def to_forum_path(conn, params) do
    params |> IO.inspect()
    render(conn, :home)
  end
end