Move more stuff from other places into Omnibot.Core

* Present rooms are tracked by Omnibot.Core now, instead of
  Omnibot.State
* Channel synchronization is done through Omnibot.Core instead of
  Omnibot.Irc
* Add Omnibot.Module.on_init/1 callback, which returns a "state" value
  for the module to keep track of. By default, the state is nil.

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

lib/core.ex

@@ -2,42 +2,71 @@ defmodule Omnibot.Core do
   use Omnibot.Module
   alias Omnibot.State
 
+  @impl true
   def on_join(irc, channel, nick) do
     cfg = State.cfg()
     if nick == cfg.nick do
-      State.add_channel(channel)
+      add_channel(channel)
       # Sync if we join a channel we shouldn't be in
       if !Enum.member?(State.all_channels(), channel),
-        do: Irc.sync_channels(irc)
+        do: sync_channels(irc)
     end
   end
 
+  @impl true
   def on_part(irc, channel, nick) do
     cfg = State.cfg()
     if nick == cfg.nick do
-      State.remove_channel(channel)
+      remove_channel(channel)
       # Sync if we join a channel we forcibly part a channel we shouldn't leave
       if Enum.member?(State.all_channels(), channel),
-        do: Irc.sync_channels(irc)
+        do: sync_channels(irc)
     end
   end
 
+  @impl true
   def on_kick(irc, channel, _nick, target) do
     cfg = State.cfg()
     if target == cfg.nick do
-      State.remove_channel(channel)
+      remove_channel(channel)
       # Generally, being kicked is not intentionally leaving a channel, so always sync here
-      Irc.sync_channels(irc)
+      sync_channels(irc)
     end
   end
 
   @impl true
   def on_msg(irc, msg) do
     case String.upcase(msg.command) do
-      "001" -> Irc.sync_channels(irc)
+      "001" -> sync_channels(irc)
       "PING" -> Irc.send_msg(irc, "PONG", msg.params)
       _ -> route_msg(irc, msg)
     end
   end
+
+  @impl true
+  def on_init(_cfg) do
+    MapSet.new()
+  end
+
+  defp sync_channels(irc) do
+    desired = MapSet.new(State.all_channels())
+    present = state()
+
+    to_join = MapSet.difference(desired, present)
+      |> MapSet.to_list()
+    to_part = MapSet.difference(present, desired)
+      |> MapSet.to_list()
+
+    Enum.each(to_join, fn channel -> Irc.join(irc, channel) end)
+    Enum.each(to_part, fn channel -> Irc.part(irc, channel) end)
+  end
+
+  defp add_channel(channel) do
+    update_state(fn state -> MapSet.put(state, channel) end)
+  end
+  
+  defp remove_channel(channel) do
+    update_state(fn state -> MapSet.delete(state, channel) end)
+  end
 end
 

lib/irc.ex

@@ -28,8 +28,6 @@ defmodule Omnibot.Irc do
 
   def part(irc, channel), do: send_msg(irc, "PART", channel)
 
-  def sync_channels(irc), do: GenServer.cast(irc, :sync_channels)
-
   defp route_msg(irc, msg) do
     channel = Msg.channel(msg)
     State.channel_modules(channel)
@@ -72,22 +70,6 @@ defmodule Omnibot.Irc do
     {:noreply, socket}
   end
 
-  @impl true
-  def handle_cast(:sync_channels, socket) do
-    cfg = State.cfg()
-    desired = MapSet.new(Config.all_channels(cfg))
-    present = MapSet.new(State.channels())
-    to_join = MapSet.difference(desired, present)
-      |> MapSet.to_list()
-    to_part = MapSet.difference(present, desired)
-      |> MapSet.to_list()
-
-    Enum.each(to_join, fn channel -> join(self(), channel) end)
-    Enum.each(to_part, fn channel -> part(self(), channel) end)
-
-    {:noreply, socket}
-  end
-  
   @impl true
   def handle_info({:tcp, _socket, line}, socket) do
     Logger.debug(String.trim(line))

lib/module.ex

@@ -15,7 +15,10 @@ defmodule Omnibot.Module do
         def on_part(_irc, _channel, _nick), do: nil
 
         @impl true
-        def on_kick(_irc, _channel, _nick), do: nil
+        def on_kick(_irc, _channel, _nick, _target), do: nil
+
+        @impl true
+        def on_init(_cfg), do: nil
       end
     end
   end
@@ -30,11 +33,24 @@ defmodule Omnibot.Module do
       @behaviour Module
 
       def start_link(opts) do
-        Agent.start_link(fn -> opts[:cfg] end, opts ++ [name: __MODULE__])
+        cfg = opts[:cfg]
+        Agent.start_link(fn -> {cfg, on_init(cfg)} end, opts ++ [name: __MODULE__])
       end
 
       def cfg do
-        Agent.get(__MODULE__, & &1)
+        Agent.get(__MODULE__, fn {cfg, _} -> cfg end)
+      end
+
+      def state do
+        Agent.get(__MODULE__, fn {_, state} -> state end)
+      end
+
+      def update_state(update, timeout \\ 5000) do
+        Agent.update(
+          __MODULE__,
+          fn {cfg, state} -> {cfg, apply(update, [state])} end,
+          timeout
+        )
       end
 
       @impl Module
@@ -66,8 +82,8 @@ defmodule Omnibot.Module do
             on_part(irc, channel, nick)
 
           "KICK" ->
-            [channel | _] = msg.params
+            [channel, target | _] = msg.params
-            on_kick(irc, channel, nick)
+            on_kick(irc, channel, nick, target)
 
           _ ->
             nil
@@ -91,7 +107,8 @@ defmodule Omnibot.Module do
             ) :: any
   @callback on_join(irc :: pid(), channel :: String.t(), nick :: String.t()) :: any
   @callback on_part(irc :: pid(), channel :: String.t(), nick :: String.t()) :: any
-  @callback on_kick(irc :: pid(), channel :: String.t(), nick :: String.t()) :: any
+  @callback on_kick(irc :: pid(), channel :: String.t(), nick :: String.t(), target :: String.t()) :: any
+  @callback on_init(cfg :: any) :: any
 
   defmacro command(cmd, opts) do
     quote generated: true do

lib/state.ex

@@ -36,30 +36,6 @@ defmodule Omnibot.State do
   @doc "Gets all loaded modules from the given state."
   def loaded_modules(state), do: GenServer.call(state, :loaded_modules)
 
-  @doc "Gets all channels that the bot is present in from the default State process."
-  def channels(), do: channels(__MODULE__)
-
-  @doc "Gets all channels that the bot is present in from the given State process."
-  def channels(state) do
-    GenServer.call(state, :channels)
-  end
-  
-  @doc "Adds a channel to the list of joined channels of the default State process, if it is not already present."
-  def add_channel(channel), do: add_channel(__MODULE__, channel)
-
-  @doc "Adds a channel to the list of joined channels of the given State process, if it is not already present."
-  def add_channel(state, channel) do
-    GenServer.cast(state, {:add_channel, channel})
-  end
-
-  @doc "Removes a channel from the list of joined channels of the default State process, if it exists."
-  def remove_channel(channel), do: remove_channel(__MODULE__, channel)
-
-  @doc "Removes a channel from the list of joined channels of the given State process, if it exists."
-  def remove_channel(state, channel) do
-    GenServer.cast(state, {:remove_channel, channel})
-  end
-
   def all_channels(), do: all_channels(__MODULE__)
 
   def all_channels(state) do
@@ -100,11 +76,6 @@ defmodule Omnibot.State do
     {:reply, state.cfg, state}
   end
 
-  @impl true
-  def handle_call(:channels, _from, state) do
-    {:reply, state.channels, state}
-  end
-
   @impl true
   def handle_call(:loaded_modules, _from, state) do
     {:reply, state.module_map, state}
@@ -115,14 +86,4 @@ defmodule Omnibot.State do
     state = %{state | module_map: Map.put(state.module_map, module, cfg)}
     {:noreply, state}
   end
-
-  @impl true
-  def handle_cast({:add_channel, channel}, state) do
-    {:noreply, %{state | channels: state.channels |> MapSet.put(channel)}}
-  end
-
-  @impl true
-  def handle_cast({:remove_channel, channel}, state) do
-    {:noreply, %{state | channels: state.channels |> MapSet.delete(channel)}}
-  end
 end