Add Omnibot.Module

Modules can easily be defined with `use Omnibot.Module`.
Omnibot.Contrib.Fortune has been updated to use this.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

lib/contrib/fortune.ex

@@ -1,7 +1,5 @@
 defmodule Omnibot.Contrib.Fortune do
-  use GenServer
-  alias Omnibot.Irc
-  require Logger
+  use Omnibot.Module
 
   @fortunes [
     "Reply hazy, try again",
@@ -21,10 +19,6 @@ defmodule Omnibot.Contrib.Fortune do
 
   ## Client API
 
-  def start_link(opts) do
-    GenServer.start_link(__MODULE__, opts[:cfg], opts)
-  end
-
   def privmsg(module, channel, nick, line) do
     GenServer.cast(module, {:privmsg, {channel, nick, line}})
   end
@@ -32,26 +26,11 @@ defmodule Omnibot.Contrib.Fortune do
   ## Server callbacks
 
   @impl true
-  def init(cfg) do
-    #Logger.debug("Starting fortune module")
-    #IO.inspect(self())
-    {:ok, cfg}
-  end
-
-  @impl true
-  def handle_call(:unload, _from, cfg) do
-    Logger.info("Unloading")
-    {:reply, :ok, cfg}
-  end
-
-  @impl true
-  def handle_cast({:privmsg, {channel, nick, line}}, cfg) do
-    if IO.inspect(line) == "!fortune" do
+  def on_channel_msg(channel, nick, line) do
+    if line == "!fortune" do
       fortune = Enum.random(@fortunes)
       reply = "#{nick}: #{fortune}"
-      Irc.send_to(Irc, channel, reply)
-    end
-
-    {:noreply, cfg}
+      Irc.send_to(channel, reply)
+    end
   end
 end

lib/irc.ex

@@ -22,12 +22,16 @@ defmodule Omnibot.Irc do
 
   def send_msg(irc, command, param), do: send_msg(irc, command, [param])
 
+  def send_to(channel, text), do: send_to(__MODULE__, channel, text)
   def send_to(irc, channel, text), do: send_msg(irc, "PRIVMSG", [channel, text])
 
+  def join(channel), do: join(__MODULE__, channel)
   def join(irc, channel), do: send_msg(irc, "JOIN", channel)
 
+  def part(channel), do: part(__MODULE__, channel)
   def part(irc, channel), do: send_msg(irc, "PART", channel)
 
+  def sync_channels(), do: sync_channels(__MODULE__)
   def sync_channels(irc), do: GenServer.cast(irc, :sync_channels)
 
   ## Server callbacks

lib/module.ex

@@ -0,0 +1,72 @@
+defmodule Omnibot.Module do
+  defmacro __using__([]) do
+    quote do
+      use GenServer
+      alias Omnibot.{Irc, Module}
+      require Logger
+
+      @behaviour Module
+
+      ## Client API
+
+      def start_link(opts) do
+        GenServer.start_link(__MODULE__, opts[:cfg], opts ++ [name: __MODULE__])
+      end
+
+      def msg(msg), do: GenServer.cast(__MODULE__, msg)
+      def msg(module, msg), do: GenServer.cast(module, {:msg, msg})
+
+      ## Server callbacks
+
+      @impl GenServer
+      def init(cfg), do: {:ok, cfg}
+
+      @impl Module
+      def on_msg(msg) do
+        route_msg(msg)
+      end
+
+      def route_msg(msg) do
+        nick = msg.prefix.nick
+        case String.upcase(msg.command) do
+          "PRIVMSG" -> [channel | text] = msg.params
+            on_channel_msg(channel, nick, Enum.join(text, " "))
+          "JOIN" -> [channel | _] = msg.params
+            on_join(channel, nick)
+          "PART" -> [channel | _] = msg.params
+            on_part(channel, nick)
+          "KICK" -> [channel | _] = msg.params
+            on_kick(channel, nick)
+          _ -> nil
+        end
+      end
+
+      @impl Module
+      def on_channel_msg(_channel, _nick, _line), do: nil
+
+      @impl Module
+      def on_join(_channel, _nick), do: nil
+
+      @impl Module
+      def on_part(_channel, _nick), do: nil
+
+      @impl Module
+      def on_kick(_channel, _nick), do: nil
+
+      @impl GenServer
+      def handle_cast({:msg, msg}, cfg) do
+        on_msg(msg)
+        {:noreply, cfg}
+      end
+
+      defoverridable Module
+      defoverridable GenServer
+    end
+  end
+
+  @callback on_msg(msg :: %Omnibot.Irc.Msg{}) :: any
+  @callback on_channel_msg(channel :: String.t, nick :: String.t, line :: String.t) :: any
+  @callback on_join(channel :: String.t, nick :: String.t) :: any
+  @callback on_part(channel :: String.t, nick :: String.t) :: any
+  @callback on_kick(channel :: String.t, nick :: String.t) :: any
+end

lib/router.ex

@@ -3,6 +3,19 @@ defmodule Omnibot.Router do
   alias Omnibot.{Config, Irc, Irc.Msg, State}
   
   def route(irc, msg) do
+    # TODO - consider removing this check and specific handling into the `use Omnibot.Module` block
+    # PROS:
+    # - Don't have to determine message command twice (first here, second in Omnibot.Module)
+    # - Allows for much more powerful modules. JOIN, PART, KICK, etc handlers would be modules themselves
+    #   - This is an extremely big win IMO
+    #
+    # CONS:
+    # - All routed functionality needs to be in a module
+    #   - This may get a little old
+    # - A failed command could cause important messages to be missed (?)
+    #   - Do messages in a named PID's mailbox persist after that PID goes away? My guess is "no"
+    #   - To get around this, there could be a mailbox for "special" commands, probably using ETS
+    # 
     case String.upcase(msg.command) do
       "PRIVMSG" -> handle(irc, :privmsg, msg)
       "JOIN" -> handle(irc, :join, msg)
@@ -15,15 +28,12 @@ defmodule Omnibot.Router do
   end
 
   def handle(_irc, :privmsg, msg) do
-    # TODO : get channel, pass along to modules
-    [channel | params] = msg.params
-    line = Enum.join(params, " ")
-    nick = msg.prefix.nick
+    [channel | _params] = msg.params
 
     # Find modules that want this message
     State.cfg()
       |> Config.channel_modules(channel)
-      |> Enum.each(fn {module, _} -> module.privmsg(module, channel, nick, line) end)
+      |> Enum.each(fn {module, _} -> module.msg(module, msg) end)
   end
 
   def handle(_irc, :join, %Msg {prefix: %Msg.Prefix{nick: nick}, params: [channel | _]}) do