Merge pull request #820 from nolt/feature-bots

(cherry picked from commit b10de0645a869485fbb5771a739abd06b5708c2d)

src/GameLogic/Bots/BotSelfDefensePlugIn.cs

@@ -0,0 +1,36 @@
+// <copyright file="BotSelfDefensePlugIn.cs" company="MUnique">
+// Licensed under the MIT License. See LICENSE file in the project root for full license information.
+// </copyright>
+
+namespace MUnique.OpenMU.GameLogic.Bots;
+
+using System.Runtime.InteropServices;
+using MUnique.OpenMU.GameLogic.Offline;
+using MUnique.OpenMU.GameLogic.PlugIns;
+using MUnique.OpenMU.PlugIns;
+
+/// <summary>
+/// Notes when a (human) player attacks a server-side bot, so the bot's combat AI can defend itself.
+/// Without this, a bot placidly keeps farming monsters while a player kills it - the most obviously
+/// bot-like behavior an observer can trigger. The actual counter-attack happens in the offline
+/// <see cref="CombatHandler"/>, which prioritizes a recent aggressor over its monster targets.
+/// </summary>
+[PlugIn]
+[Display(Name = "Bot self defense", Description = "Makes server-side bots fight back when a player attacks them.")]
+[Guid("7E2B9C41-5A8D-4F36-B190-3D6E84C7F215")]
+public class BotSelfDefensePlugIn : IAttackableGotHitPlugIn
+{
+    /// <inheritdoc />
+    public void AttackableGotHit(IAttackable attackable, IAttacker attacker, HitInfo hitInfo)
+    {
+        if (attackable is OfflinePlayer bot
+            && bot.Account?.IsBot == true
+            && bot.CurrentMiniGame is null // event fights (Chaos Castle) leave no grudge outside
+            && attacker is Player aggressor
+            && aggressor is not OfflinePlayer
+            && !ReferenceEquals(aggressor, attackable))
+        {
+            bot.RegisterAggressor(aggressor);
+        }
+    }
+}