feat: replace PlayerChat hook with Harmony patch on command dispatch

CommandHook/ChatCommandApiPatch.cs

@@ -0,0 +1,48 @@
+using System;
+using HarmonyLib;
+using Vintagestory.API.Common;
+using Vintagestory.API.Server;
+using Vintagestory.Common;
+
+namespace CommandHook;
+
+[HarmonyPatch(typeof(ChatCommandApi))]
+public static class ChatCommandApiPatch
+{
+    [HarmonyPatch(
+        "Execute",
+        new[] { typeof(string), typeof(TextCommandCallingArgs), typeof(Action<TextCommandResult>) }
+    )]
+    [HarmonyPrefix]
+    public static bool Prefix(
+        string commandName,
+        TextCommandCallingArgs args,
+        ref Action<TextCommandResult> onCommandComplete
+    )
+    {
+        var system = CommandHookModSystem.Instance;
+        if (system == null)
+            return true;
+
+        var sender = args.Caller.Player as IServerPlayer;
+        var data = new CommandData(sender, "/" + commandName);
+
+        if (system.FireBefore(commandName, ref data))
+        {
+            onCommandComplete?.Invoke(
+                new TextCommandResult { Status = EnumCommandStatus.Deferred }
+            );
+            return false;
+        }
+
+        var original = onCommandComplete;
+        onCommandComplete = result =>
+        {
+            original?.Invoke(result);
+            var afterData = data;
+            system.FireAfter(commandName, ref afterData, result);
+        };
+
+        return true;
+    }
+}

CommandHook/CommandHookModSystem.cs

@@ -1,35 +1,48 @@
 using System.Collections.Frozen;
+using HarmonyLib;
 using Vintagestory.API.Common;
-using Vintagestory.API.Datastructures;
 using Vintagestory.API.Server;
 
 namespace CommandHook;
 
 public class CommandHookModSystem : ModSystem
 {
+    internal static CommandHookModSystem? Instance;
+
     private FrozenDictionary<string, FrozenDictionary<string, CommandRegistration>> registrations =
         FrozenDictionary<string, FrozenDictionary<string, CommandRegistration>>.Empty;
 
+    private Harmony? harmony;
+
     public override bool ShouldLoad(EnumAppSide forSide) => forSide == EnumAppSide.Server;
 
     public override void StartServerSide(ICoreServerAPI api)
     {
+        Instance = this;
+        harmony = new Harmony(Mod.Info.ModID);
+        harmony.PatchAll();
         Mod.Logger.Notification("Loaded");
-        api.Event.PlayerChat += OnPlayerChat;
     }
 
-    private void OnPlayerChat(
-        IServerPlayer player,
-        int channelId,
-        ref string message,
-        ref string data,
-        BoolRef consumed
-    )
+    public override void Dispose()
     {
-        if (!message.StartsWith('/'))
-            return;
+        harmony?.UnpatchAll(Mod.Info.ModID);
+        Instance = null;
+    }
 
-        var cmdData = new CommandData(player, message);
-        // TODO dispatch
+    public bool FireBefore(string commandName, ref CommandData data)
+    {
+        if (registrations.TryGetValue(commandName, out var mods))
+            foreach (var (_, reg) in mods)
+                reg.Before?.Invoke(ref data);
+
+        return data.Cancel;
+    }
+
+    public void FireAfter(string commandName, ref CommandData data, TextCommandResult result)
+    {
+        if (registrations.TryGetValue(commandName, out var mods))
+            foreach (var (_, reg) in mods)
+                reg.After?.Invoke(ref data, result);
     }
 }