[GH-696] Allow clients to modify tickrate (#704)

* Add new ChangeTickrate protobuf message

* Add new handle_decoded_message matches functions to print unexpected messages in terminal

* Add new change_tickrate function and cast handler to modify the game tickrate when called

* Add new handle_decoded_message to catch change_tickrate message and call the corresponding function

apps/arena/lib/arena/game_socket_handler.ex

@@ -206,6 +206,9 @@ defmodule Arena.GameSocketHandler do
   defp handle_decoded_message(%{action_type: {:toggle_bots, _bots_params}}, state),
     do: GameUpdater.toggle_bots(state.game_pid)
 
+  defp handle_decoded_message(%{action_type: {:change_tickrate, tickrate_params}}, state),
+    do: GameUpdater.change_tickrate(state.game_pid, tickrate_params.tickrate)
+
   defp handle_decoded_message(_action_type, %{enable: false} = _state), do: nil
 
   defp handle_decoded_message(
@@ -244,5 +247,10 @@ defmodule Arena.GameSocketHandler do
     end
   end
 
-  defp handle_decoded_message(_, _), do: nil
+  # We don't do anything in these messages, we already handle these actions when we have to in previous functions.
+  defp handle_decoded_message(%{action_type: {action, _}}, _state) when action in [:move, :attack, :use_item], do: nil
+
+  defp handle_decoded_message(message, _) do
+    Logger.info("Unexpected message: #{inspect(message)}")
+  end
 end

apps/arena/lib/arena/game_updater.ex

@@ -47,6 +47,10 @@ defmodule Arena.GameUpdater do
     GenServer.cast(game_pid, :toggle_bots)
   end
 
+  def change_tickrate(game_pid, tickrate) do
+    GenServer.cast(game_pid, {:change_tickrate, tickrate})
+  end
+
   ##########################
   # END API
   ##########################
@@ -168,6 +172,10 @@ defmodule Arena.GameUpdater do
     {:noreply, state}
   end
 
+  def handle_cast({:change_tickrate, tickrate}, state) do
+    {:noreply, put_in(state, [:game_config, :game, :tick_rate_ms], tickrate)}
+  end
+
   ##########################
   # END API Callbacks
   ##########################

apps/arena/lib/arena/serialization/messages.pb.ex

@@ -641,6 +641,14 @@ defmodule Arena.Serialization.ToggleBots do
   use Protobuf, syntax: :proto3, protoc_gen_elixir_version: "0.12.0"
 end
 
+defmodule Arena.Serialization.ChangeTickrate do
+  @moduledoc false
+
+  use Protobuf, syntax: :proto3, protoc_gen_elixir_version: "0.12.0"
+
+  field(:tickrate, 1, type: :int64)
+end
+
 defmodule Arena.Serialization.GameAction do
   @moduledoc false
 
@@ -660,6 +668,13 @@ defmodule Arena.Serialization.GameAction do
 
   field(:toggle_zone, 6, type: Arena.Serialization.ToggleZone, json_name: "toggleZone", oneof: 0)
   field(:toggle_bots, 7, type: Arena.Serialization.ToggleBots, json_name: "toggleBots", oneof: 0)
+
+  field(:change_tickrate, 8,
+    type: Arena.Serialization.ChangeTickrate,
+    json_name: "changeTickrate",
+    oneof: 0
+  )
+
   field(:timestamp, 3, type: :int64)
 end
 

apps/arena_load_test/lib/arena_load_test/serialization/messages.pb.ex

@@ -688,6 +688,14 @@ defmodule ArenaLoadTest.Serialization.ToggleBots do
   use Protobuf, syntax: :proto3, protoc_gen_elixir_version: "0.12.0"
 end
 
+defmodule ArenaLoadTest.Serialization.ChangeTickrate do
+  @moduledoc false
+
+  use Protobuf, syntax: :proto3, protoc_gen_elixir_version: "0.12.0"
+
+  field(:tickrate, 1, type: :int64)
+end
+
 defmodule ArenaLoadTest.Serialization.GameAction do
   @moduledoc false
 
@@ -717,6 +725,12 @@ defmodule ArenaLoadTest.Serialization.GameAction do
     oneof: 0
   )
 
+  field(:change_tickrate, 8,
+    type: ArenaLoadTest.Serialization.ChangeTickrate,
+    json_name: "changeTickrate",
+    oneof: 0
+  )
+
   field(:timestamp, 3, type: :int64)
 end
 

apps/bot_manager/lib/protobuf/messages.pb.ex

@@ -641,6 +641,14 @@ defmodule BotManager.Protobuf.ToggleBots do
   use Protobuf, syntax: :proto3, protoc_gen_elixir_version: "0.12.0"
 end
 
+defmodule BotManager.Protobuf.ChangeTickrate do
+  @moduledoc false
+
+  use Protobuf, syntax: :proto3, protoc_gen_elixir_version: "0.12.0"
+
+  field(:tickrate, 1, type: :int64)
+end
+
 defmodule BotManager.Protobuf.GameAction do
   @moduledoc false
 
@@ -660,6 +668,13 @@ defmodule BotManager.Protobuf.GameAction do
 
   field(:toggle_zone, 6, type: BotManager.Protobuf.ToggleZone, json_name: "toggleZone", oneof: 0)
   field(:toggle_bots, 7, type: BotManager.Protobuf.ToggleBots, json_name: "toggleBots", oneof: 0)
+
+  field(:change_tickrate, 8,
+    type: BotManager.Protobuf.ChangeTickrate,
+    json_name: "changeTickrate",
+    oneof: 0
+  )
+
   field(:timestamp, 3, type: :int64)
 end