stealth clothing (#19397)

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

Content.Shared/Clothing/EntitySystems/StealthClothingSystem.cs

@@ -0,0 +1,137 @@
+using Content.Shared.Actions;
+using Content.Shared.Clothing.Components;
+using Content.Shared.Inventory.Events;
+using Content.Shared.Stealth;
+using Content.Shared.Stealth.Components;
+using Robust.Shared.GameStates;
+
+namespace Content.Shared.Clothing.EntitySystems;
+
+/// <summary>
+/// Handles the toggle action and disables stealth when clothing is unequipped.
+/// </summary>
+public sealed class StealthClothingSystem : EntitySystem
+{
+    [Dependency] private readonly SharedStealthSystem _stealth = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<StealthClothingComponent, GetItemActionsEvent>(OnGetItemActions);
+        SubscribeLocalEvent<StealthClothingComponent, ToggleStealthEvent>(OnToggleStealth);
+        SubscribeLocalEvent<StealthClothingComponent, AfterAutoHandleStateEvent>(OnHandleState);
+        SubscribeLocalEvent<StealthClothingComponent, GotUnequippedEvent>(OnUnequipped);
+    }
+
+    /// <summary>
+    /// Sets the clothing's stealth effect for the user.
+    /// </summary>
+    /// <returns>True if it was changed, false otherwise</returns>
+    public bool SetEnabled(EntityUid uid, EntityUid user, bool enabled, StealthClothingComponent? comp = null)
+    {
+        if (!Resolve(uid, ref comp) || comp.Enabled == enabled)
+            return false;
+
+        // TODO remove this when clothing unequip on delete is less sus
+        // prevent debug assert when ending round and its disabled
+        if (MetaData(user).EntityLifeStage >= EntityLifeStage.Terminating)
+            return false;
+
+        comp.Enabled = enabled;
+        Dirty(uid, comp);
+
+        var stealth = EnsureComp<StealthComponent>(user);
+        // slightly visible, but doesn't change when moving so it's ok
+        var visibility = enabled ? stealth.MinVisibility + comp.Visibility : stealth.MaxVisibility;
+        _stealth.SetVisibility(user, visibility, stealth);
+        _stealth.SetEnabled(user, enabled, stealth);
+        return true;
+    }
+
+    /// <summary>
+    /// Raise <see cref="AddStealthActionEvent"/> then add the toggle action if it was not cancelled.
+    /// </summary>
+    private void OnGetItemActions(EntityUid uid, StealthClothingComponent comp, GetItemActionsEvent args)
+    {
+        var ev = new AddStealthActionEvent(args.User);
+        RaiseLocalEvent(uid, ev);
+        if (ev.Cancelled)
+            return;
+
+        args.Actions.Add(comp.ToggleAction);
+    }
+
+    /// <summary>
+    /// Raises <see cref="AttemptStealthEvent"/> if enabling.
+    /// </summary>
+    private void OnToggleStealth(EntityUid uid, StealthClothingComponent comp, ToggleStealthEvent args)
+    {
+        args.Handled = true;
+        var user = args.Performer;
+        if (comp.Enabled)
+        {
+            SetEnabled(uid, user, false, comp);
+            return;
+        }
+
+        var ev = new AttemptStealthEvent(user);
+        RaiseLocalEvent(uid, ev);
+        if (ev.Cancelled)
+            return;
+
+        SetEnabled(uid, user, true, comp);
+    }
+
+    /// <summary>
+    /// Calls <see cref="SetEnabled"/> when server sends new state.
+    /// </summary>
+    private void OnHandleState(EntityUid uid, StealthClothingComponent comp, ref AfterAutoHandleStateEvent args)
+    {
+        // SetEnabled checks if it is the same, so change it to before state was received from the server
+        var enabled = comp.Enabled;
+        comp.Enabled = !enabled;
+        var user = Transform(uid).ParentUid;
+        SetEnabled(uid, user, enabled, comp);
+    }
+
+    /// <summary>
+    /// Force unstealths the user, doesnt remove StealthComponent since other things might use it
+    /// </summary>
+    private void OnUnequipped(EntityUid uid, StealthClothingComponent comp, GotUnequippedEvent args)
+    {
+        SetEnabled(uid, args.Equipee, false, comp);
+    }
+}
+
+/// <summary>
+/// Raised on the stealth clothing when attempting to add an action.
+/// </summary>
+public class AddStealthActionEvent : CancellableEntityEventArgs
+{
+    /// <summary>
+    /// User that equipped the stealth clothing.
+    /// </summary>
+    public EntityUid User;
+
+    public AddStealthActionEvent(EntityUid user)
+    {
+        User = user;
+    }
+}
+
+/// <summary>
+/// Raised on the stealth clothing when the user is attemping to enable it.
+/// </summary>
+public class AttemptStealthEvent : CancellableEntityEventArgs
+{
+    /// <summary>
+    /// User that is attempting to enable the stealth clothing.
+    /// </summary>
+    public EntityUid User;
+
+    public AttemptStealthEvent(EntityUid user)
+    {
+        User = user;
+    }
+}