defmodule Script do
  def start(filepath) do
    with {:ok, content} <- File.read(filepath),
         ids_list <- String.split(content, "\n") do
      last_process_at = Time.utc_now()

      for id <- ids_list do
        last_process_at = Time.add(last_process_at, 10)
        call_this_func(id, last_process_at)
      end
    end
  end

  defp call_this_func(id, process_at) do
    IO.inspect(process_at)
  end
end

for id <- ids_list, reduce: last_process_at do
  last_process_at ->
        last_process_at = Time.add(last_process_at, 10)
        call_this_func(id, last_process_at)
                 last_process_at
end