adding :ets to keep track of current value

lib/clip/currents.ex

@@ -0,0 +1,41 @@
+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