pet dehydrated fish to make him nice to you (#14709)

* petting fish to make him nice to you

* fix fishe, refactor a bit

* fishe

* pro

* feedback, for now

* refactor

* pro

---------

Co-authored-by: deltanedas <@deltanedas:kde.org>

Content.Server/NPC/Systems/FactionExceptionSystem.cs

@@ -0,0 +1,33 @@
+using Content.Server.NPC.Components;
+
+namespace Content.Server.NPC.Systems;
+
+/// <summary>
+/// Prevents an NPC from attacking some entities from an enemy faction.
+/// </summary>
+public sealed class FactionExceptionSystem : EntitySystem
+{
+    /// <summary>
+    /// Returns whether the entity from an enemy faction won't be attacked
+    /// </summary>
+    public bool IsIgnored(FactionExceptionComponent comp, EntityUid target)
+    {
+        return comp.Ignored.Contains(target);
+    }
+
+    /// <summary>
+    /// Prevents an entity from an enemy faction from being attacked
+    /// </summary>
+    public void IgnoreEntity(FactionExceptionComponent comp, EntityUid target)
+    {
+        comp.Ignored.Add(target);
+    }
+
+    /// <summary>
+    /// Prevents a list of entities from an enemy faction from being attacked
+    /// </summary>
+    public void IgnoreEntities(FactionExceptionComponent comp, IEnumerable<EntityUid> ignored)
+    {
+        comp.Ignored.UnionWith(ignored);
+    }
+}