1 files changed, 42 insertions, 0 deletions
diff --git a/lib/lsg_irc/buffer_plugin.ex b/lib/lsg_irc/buffer_plugin.ex
new file mode 100644
index 0000000..8d3cacd
--- /dev/null
+++ b/lib/lsg_irc/buffer_plugin.ex
@@ -0,0 +1,42 @@
+defmodule LSG.IRC.BufferPlugin do
+  @table __MODULE__.ETS
+  def irc_doc, do: nil
+
+  def table(), do: @table
+
+  def select_buffer(network, channel, limit \\ 50) do
+    import Ex2ms
+    spec = fun do {{n, c, _}, m} when n == ^network and (c == ^channel or is_nil(c)) -> m end
+    :ets.select(@table, spec, limit)
+  end
+
+  def start_link() do
+    GenServer.start_link(__MODULE__, [], name: __MODULE__)
+  end
+
+  def init(_) do
+    for e <- ~w(messages triggers events outputs) do
+      {:ok, _} = Registry.register(IRC.PubSub, e, plugin: __MODULE__)
+    end
+    {:ok, :ets.new(@table, [:named_table, :ordered_set, :protected])}
+  end
+
+  def handle_info({:irc, :trigger, _, message}, ets), do: handle_message(message, ets)
+  def handle_info({:irc, :text, message}, ets), do: handle_message(message, ets)
+  def handle_info({:irc, :event, event}, ets), do: handle_message(event, ets)
+
+  defp handle_message(message = %{network: network}, ets) do
+    key = {network, Map.get(message, :channel), ts(message.at)}
+    :ets.insert(ets, {key, message})
+    {:noreply, ets}
+  end
+
+  defp ts(naive = %NaiveDateTime{}) do
+    ts = naive
+    |> DateTime.from_naive!("Etc/UTC")
+    |> DateTime.to_unix()
+
+    -ts
+  end
+
+end