WIP: Move to using modules for implementing core behavior

Since modules can now intercept all messages in the channels they're
listening for, it'd be cool to have modules handling things like making
sure the Omnibot.State stays updated as appropriate, and that pings are
ponged, etc.

This will probably deprecate the router, since it's been reduced to a
single function call, but we'll see about that.

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

lib/irc/msg.ex

@@ -65,6 +65,17 @@ defmodule Omnibot.Irc.Msg do
       params: params,
     }
   end
+
+  @doc "Gets the channel that the given message is targeting, if any."
+  def channel(msg) do
+    case String.upcase(msg.command) do
+      "PRIVMSG" -> Enum.at(msg.params, 0)
+      "JOIN" -> Enum.at(msg.params, 0)
+      "PART" -> Enum.at(msg.params, 0)
+      "KICK" -> Enum.at(msg.params, 0)
+      _ -> nil
+    end
+  end
 end
 
 defimpl String.Chars, for: Irc.Msg.Prefix do