From 29014aa45f2393d9188f8839e836d81a79a39bc3 Mon Sep 17 00:00:00 2001
From: Kodi Craft <kodi@kdcf.me>
Date: Tue, 8 Oct 2024 15:34:57 +0200
Subject: [PATCH] Implement receiving chat messages

---
 apps/amethyst/lib/game.ex             | 11 +++++++++++
 apps/amethyst/lib/states/macros.ex    | 13 +++++++++++++
 apps/amethyst/lib/states/play.ex      |  8 +++++++-
 apps/example_game/lib/example/game.ex |  7 +++++++
 4 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/apps/amethyst/lib/game.ex b/apps/amethyst/lib/game.ex
index 08792ef..df683b8 100644
--- a/apps/amethyst/lib/game.ex
+++ b/apps/amethyst/lib/game.ex
@@ -88,6 +88,17 @@ defmodule Amethyst.Game do
     mod.accept_teleport(self(), id, refs)
   end
   @doc """
+  `chat/3` is called when a player sends a chat message. Note that it is not how slash commands should be handled.
+
+  - 'from' is the PID of the player's connection process (see `login/3`).
+  - 'message' is the chat message sent by the player.
+  - `state_refs` are your references (see `instantiate/1`)
+  """
+  @callback chat(from :: pid(), message :: binary(), state_refs :: map()) :: :ok
+  def chat(%{:mod => mod, :refs => refs}, message) do
+    mod.chat(self(), message, refs)
+  end
+  @doc """
   The terrain of a specific chunk column. This is automatically used to load chunks for a player.
 
   For now, this data must be formatted as a 3D list, indexed as [y][z][x].
diff --git a/apps/amethyst/lib/states/macros.ex b/apps/amethyst/lib/states/macros.ex
index c96abb9..fdeb172 100644
--- a/apps/amethyst/lib/states/macros.ex
+++ b/apps/amethyst/lib/states/macros.ex
@@ -14,6 +14,8 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+# TODO!!!: REDO THIS WHOLE THING AGAIN IT'S A MESS
+
 defmodule Amethyst.ConnectionState.Macros do
   @moduledoc """
   Useful macros for defining packets.
@@ -56,6 +58,13 @@ defmodule Amethyst.ConnectionState.Macros do
           else
             {[nil | acc], rest, :reversed}
           end
+        {:optional, {:raw, length}} ->
+          {[exists], rest} = Read.start(rest) |> Read.bool() |> Read.stop()
+          if exists do
+            Read.raw({acc, rest, :reversed}, length)
+          else
+            {[nil | acc], rest, :reversed}
+          end
         {:optional, t} ->
           {[exists], rest} = Read.start(rest) |> Read.bool() |> Read.stop()
           if exists do
@@ -63,6 +72,10 @@ defmodule Amethyst.ConnectionState.Macros do
           else
             {[nil | acc], rest, :reversed}
           end
+        {:fixed_bitset, length} ->
+          Read.fixed_bitset({acc, rest, :reversed}, length)
+        {:raw, length} ->
+          Read.raw({acc, rest, :reversed}, length)
         {:array, signature} ->
           {[count], rest} = Read.start(rest) |> Read.varint() |> Read.stop()
           if count == 0 do
diff --git a/apps/amethyst/lib/states/play.ex b/apps/amethyst/lib/states/play.ex
index 4d576eb..297cc65 100644
--- a/apps/amethyst/lib/states/play.ex
+++ b/apps/amethyst/lib/states/play.ex
@@ -161,7 +161,7 @@ defmodule Amethyst.ConnectionState.Play do
     message: :string,
     timestamp: :long,
     salt: :long,
-    signature: {:optional, :byte_array},
+    signature: {:optional, {:raw, 256}},
     message_count: :varint,
     acknowledged: {:fixed_bitset, 20}
   ]
@@ -241,6 +241,12 @@ defmodule Amethyst.ConnectionState.Play do
     end
   end
 
+  def handle(%{packet_type: :chat_message, message: msg, timestamp: _, salt: _, signature: _, message_count: _, acknowledged: _}, 767, state) do
+    # We will never support message signing
+    state |> Map.get(:game) |> Amethyst.Game.chat(msg)
+    :ok
+  end
+
   def handle(%{packet_type: :keep_alive, id: id}, 767, state) do
     ka = state |> Map.get(:keepalive)
     send(ka, {:respond, id})
diff --git a/apps/example_game/lib/example/game.ex b/apps/example_game/lib/example/game.ex
index e727907..b71f404 100644
--- a/apps/example_game/lib/example/game.ex
+++ b/apps/example_game/lib/example/game.ex
@@ -39,11 +39,18 @@ defmodule Example.Game do
     :ok
   end
 
+  @impl true
+  def chat(from, message, _state_refs) do
+    Logger.info("Player at #{inspect(from)} said: #{inspect(message)}")
+    :ok
+  end
+
   @impl true
   def joinable?(_refs) do
     true
   end
 
+
   @impl true
   def chunk(_from, {cx, cz}, _state_refs) do
     # Logger.info("Player at #{inspect(from)} wants to know chunk #{cx}, #{cz}")