ninja 2 electric boogaloo (#15534)

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

Content.Shared/Ninja/Systems/EmagProviderSystem.cs

@@ -0,0 +1,72 @@
+using Content.Shared.Administration.Logs;
+using Content.Shared.Emag.Systems;
+using Content.Shared.Database;
+using Content.Shared.Interaction;
+using Content.Shared.Ninja.Components;
+using Content.Shared.Tag;
+using Content.Shared.Whitelist;
+
+namespace Content.Shared.Ninja.Systems;
+
+/// <summary>
+/// Handles emagging whitelisted objects when clicked.
+/// </summary>
+public sealed class EmagProviderSystem : EntitySystem
+{
+    [Dependency] private readonly EmagSystem _emag = default!;
+    [Dependency] private readonly ISharedAdminLogManager _adminLogger = default!;
+    [Dependency] private readonly SharedNinjaGlovesSystem _gloves = default!;
+    [Dependency] private readonly TagSystem _tags = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<EmagProviderComponent, BeforeInteractHandEvent>(OnBeforeInteractHand);
+    }
+
+    /// <summary>
+    /// Emag clicked entities that are on the whitelist.
+    /// </summary>
+    private void OnBeforeInteractHand(EntityUid uid, EmagProviderComponent comp, BeforeInteractHandEvent args)
+    {
+        // TODO: change this into a generic check event thing
+        if (args.Handled || !_gloves.AbilityCheck(uid, args, out var target))
+            return;
+
+        // only allowed to emag entities on the whitelist
+        if (comp.Whitelist != null && !comp.Whitelist.IsValid(target, EntityManager))
+            return;
+
+        // only allowed to emag non-immune entities
+        if (_tags.HasTag(target, comp.EmagImmuneTag))
+            return;
+
+        var handled = _emag.DoEmagEffect(uid, target);
+        if (!handled)
+            return;
+
+        _adminLogger.Add(LogType.Emag, LogImpact.High, $"{ToPrettyString(uid):player} emagged {ToPrettyString(target):target}");
+        var ev = new EmaggedSomethingEvent(target);
+        RaiseLocalEvent(uid, ref ev);
+        args.Handled = true;
+    }
+
+    /// <summary>
+    /// Set the whitelist for emagging something outside of yaml.
+    /// </summary>
+    public void SetWhitelist(EntityUid uid, EntityWhitelist? whitelist, EmagProviderComponent? comp = null)
+    {
+        if (!Resolve(uid, ref comp))
+            return;
+
+        comp.Whitelist = whitelist;
+        Dirty(uid, comp);
+    }
+}
+
+/// <summary>
+/// Raised on the player when emagging something.
+/// </summary>
+[ByRefEvent]
+public record struct EmaggedSomethingEvent(EntityUid Target);