Merge pull request #820 from nolt/feature-bots

(cherry picked from commit b10de0645a869485fbb5771a739abd06b5708c2d)

src/GameLogic/Bots/BotRevengePlugIn.cs

@@ -0,0 +1,40 @@
+// <copyright file="BotRevengePlugIn.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 kills a server-side bot, so the bot can march back to the place of
+/// its death after respawning and take revenge on the killer. A bot which shrugs off being killed
+/// and calmly heads for the next hunting ground is an obvious bot giveaway - a real player comes
+/// back angry. The return march happens in the <see cref="BotNavigator"/>; the counter-attack in
+/// the offline <see cref="CombatHandler"/>, whose re-armed aggressor memory keeps the killer
+/// prioritized - struck only once the game's own rules make it legal (see <see cref="BotPvpRules"/>).
+/// </summary>
+[PlugIn]
+[Display(Name = "Bot revenge", Description = "Makes server-side bots return to their death site and take revenge on the player who killed them.")]
+[Guid("29B871B0-FBCF-44D4-A677-8A9832AAC193")]
+public class BotRevengePlugIn : IAttackableGotKilledPlugIn
+{
+    /// <inheritdoc />
+    public ValueTask AttackableGotKilledAsync(IAttackable killed, IAttacker? killer)
+    {
+        if (killed is OfflinePlayer bot
+            && bot.Account?.IsBot == true
+            && bot.CurrentMiniGame is null // a death in an event (Chaos Castle) is part of the game, not a wrong to avenge
+            && killer is Player killerPlayer
+            && killerPlayer is not OfflinePlayer
+            && !ReferenceEquals(killerPlayer, killed))
+        {
+            bot.RegisterDeathByPlayer(killerPlayer);
+        }
+
+        return ValueTask.CompletedTask;
+    }
+}