defmodule Clip.Currents do
  use GenServer
  require Logger

  @purge_interval :timer.minutes(60)

  def start_link(_) do
    GenServer.start_link(__MODULE__, %{}, name: ClipCurrents)
  end

  def init(opts) do
    :ets.new(:users_clips, [:set, :named_table, :public])
    state = %{
      interval: opts[:purge_interval] || @purge_interval,
      timer: nil
    }
    {:ok, schedule_purge(state)}
  end

  def set(email_addr, value) do
    :ets.insert(:users_clips, {email_addr, value})
    :ok
  end

  def get(email_addr) do
    cur_val = case :ets.lookup(:users_clips, email_addr) do
      [{^email_addr, value}] -> value
      [] -> ""
    end
    {:ok, cur_val}
  end

  def handle_info(:purge, state) do
    Logger.info("should purge old entries but doesn't, yet")
    {:noreply, schedule_purge(state)}
  end

  defp schedule_purge(state) do
    %{state | timer: Process.send_after(self(), :purge, state.interval)}
  end
end