Add get_message_types() to plugin API

This allows plugins to specify the types of messages they handle. This
will be used specifically for the nickserv plugin, but could be useful
for other things too.

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

omnibot/bot.py

@@ -61,7 +61,7 @@ class Bot:
         self.connection.register("JOIN", self.on_join)
         self.connection.register("PART", self.on_part)
         self.connection.register("KICK", self.on_kick)
-        self.connection.register("PRIVMSG", self.on_message)
+        self.connection.register("*", self.on_message)
         # Connect
         log.info("Connecting to %s", self.server_config.server)
         await self.connection.connect()
@@ -135,7 +135,13 @@ class Bot:
             # Don't raise on_message events for ourselves.
             return
         line = message.parameters[1]
-        plugins = self.channel_plugins(channel)
+        # Filter plugins by get_message_types() and channel
+        plugins = [
+            plugin
+            for plugin in self.channel_plugins(channel)
+            if message.command in plugin.get_message_types()
+        ]
+        if plugins:
             await asyncio.gather(
                 *[plugin.on_message(conn, channel, who, line) for plugin in plugins]
             )

omnibot/plugin.py

@@ -19,6 +19,16 @@ class Plugin:
         self.__plugin_config = plugin_config
         self.__bot = bot
 
+    def get_message_types(self) -> Sequence[str]:
+        """
+        Gets the message types that this plugin listens for.
+
+        This is usually going to be just PRIVMSG by itself, i.e. `["PRIVMSG"]`.
+        However, if you want to handle different messages (such as PART, JOIN,
+        KICK, etc) then you can change that here.
+        """
+        return ["PRIVMSG"]
+
     @property
     def channels(self) -> Sequence[str]:
         if "channels" in self.plugin_config: