defmodule Mobilizon.Service.Streamer do @moduledoc """ # Streamer Handles streaming activities """ use GenServer require Logger def init(args) do {:ok, args} end def start_link do spawn(fn -> # 30 seconds Process.sleep(1000 * 30) GenServer.cast(__MODULE__, %{action: :ping}) end) GenServer.start_link(__MODULE__, %{}, name: __MODULE__) end def add_socket(topic, socket) do GenServer.cast(__MODULE__, %{action: :add, socket: socket, topic: topic}) end def remove_socket(topic, socket) do GenServer.cast(__MODULE__, %{action: :remove, socket: socket, topic: topic}) end def stream(topic, item) do GenServer.cast(__MODULE__, %{action: :stream, topic: topic, item: item}) end def handle_cast(%{action: :ping}, topics) do topics |> Map.values() |> List.flatten() |> Enum.each(fn socket -> Logger.debug("Sending keepalive ping") send(socket.transport_pid, {:text, ""}) end) spawn(fn -> # 30 seconds Process.sleep(1000 * 30) GenServer.cast(__MODULE__, %{action: :ping}) end) {:noreply, topics} end def handle_cast(%{action: :add, topic: topic, socket: socket}, sockets) do topic = internal_topic(topic, socket) sockets_for_topic = sockets[topic] || [] sockets_for_topic = Enum.uniq([socket | sockets_for_topic]) sockets = Map.put(sockets, topic, sockets_for_topic) Logger.debug(fn -> "Got new conn for #{topic}" end) {:noreply, sockets} end def handle_cast(%{action: :remove, topic: topic, socket: socket}, sockets) do topic = internal_topic(topic, socket) sockets_for_topic = sockets[topic] || [] sockets_for_topic = List.delete(sockets_for_topic, socket) sockets = Map.put(sockets, topic, sockets_for_topic) Logger.debug(fn -> "Removed conn for #{topic}" end) {:noreply, sockets} end def handle_cast(m, state) do Logger.info("Unknown: #{inspect(m)}, #{inspect(state)}") {:noreply, state} end defp internal_topic("user", socket) do "user:#{socket.assigns[:user].id}" end defp internal_topic(topic, _), do: topic end