Files
CommandHook/CommandHook/ChatCommandApiPatch.cs
T

102 lines
4.4 KiB
C#

using System;
using HarmonyLib;
using Vintagestory.API.Common;
using Vintagestory.API.Server;
using Vintagestory.Common;
namespace CommandHook;
/// <summary>
/// Harmony prefix patch on <c>ChatCommandApi.Execute</c>. This is the only place
/// CommandHook hooks into the game, everything else in the mod feeds into this.
/// </summary>
[HarmonyPatch(typeof(ChatCommandApi))]
public static class ChatCommandApiPatch
{
/// <summary>
/// Runs before the game's own command execution. Fires Before listeners for
/// <paramref name="commandName"/> and, if none of them cancel, lets the
/// original <c>Execute</c> run and wraps <paramref name="onCommandComplete"/>
/// so After listeners fire once a result exists.
/// </summary>
/// <remarks>
/// Runs for both invocation paths, server console and a connected player
/// typing in chat, since both go through <c>Execute</c> the same way
/// internally.
/// <para>
/// If a Before listener sets <see cref="CommandData.Cancel"/>, this returns
/// false to stop the original <c>Execute</c> from running at all, and
/// invokes <paramref name="onCommandComplete"/> directly with a
/// <see cref="EnumCommandStatus.Deferred"/> result so the caller doesn't see
/// a generic failure. After listeners are not fired in this case.
/// </para>
/// <para>
/// If nothing cancels, this returns true and lets the original <c>Execute</c>
/// run, but first replaces <paramref name="onCommandComplete"/> with a wrapper
/// that calls the original callback, then fires After. The original callback
/// always runs first, so nothing about the vanilla command flow changes from
/// the caller's point of view.
/// </para>
/// </remarks>
/// <param name="commandName">The command name being executed, without the leading slash.</param>
/// <param name="args">The calling args supplied by the game, used here to resolve the sender.</param>
/// <param name="onCommandComplete">
/// The completion callback supplied by the game. Replaced with a wrapper that
/// fires After listeners after invoking the original.
/// </param>
/// <returns>
/// False to skip the original <c>Execute</c> (a Before listener cancelled it),
/// true to let it run normally.
/// </returns>
[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;
// Instance is null before StartServerSide runs or after Dispose. Harmony
// patches stay applied for the process lifetime, so this null check is
// what actually guards against firing into a torn-down mod.
if (system == null)
return true;
var sender = args.Caller.Player as IServerPlayer;
// Console invocations have no IServerPlayer, the cast just yields null,
// which is exactly what CommandData(sender, ...) expects to mean "console".
var data = new CommandData(sender, commandName, "/" + commandName);
if (system.FireBefore(commandName, ref data))
{
// Cancelled by a Before listener. Report Deferred rather than just
// swallowing it silently, so the original caller (console or player)
// sees something other than the command quietly doing nothing.
onCommandComplete?.Invoke(
new TextCommandResult { Status = EnumCommandStatus.Deferred }
);
return false;
}
// Not cancelled. Capture the game's own callback before replacing it,
// since we still need to call it, this patch only adds behavior around
// the vanilla flow, it never removes the vanilla completion handling.
var original = onCommandComplete;
onCommandComplete = result =>
{
original?.Invoke(result);
// data is captured by the closure, copy it so FireAfter gets its
// own ref target instead of sharing one with whatever else might
// still be holding the original local.
var afterData = data;
system.FireAfter(commandName, ref afterData, result);
};
return true;
}
}