Fingerprint Reader System (#35600)

* init

* public api

* stuff

* weh

Content.Shared/FingerprintReader/FingerprintReaderSystem.cs

@@ -0,0 +1,100 @@
+using System.Diagnostics.CodeAnalysis;
+using Content.Shared.Forensics.Components;
+using Content.Shared.Inventory;
+using Content.Shared.Popups;
+using JetBrains.Annotations;
+
+namespace Content.Shared.FingerprintReader;
+
+// TODO: This has a lot of overlap with the AccessReaderSystem, maybe merge them in the future?
+public sealed class FingerprintReaderSystem : EntitySystem
+{
+    [Dependency] private readonly InventorySystem _inventory = default!;
+    [Dependency] private readonly SharedPopupSystem _popup = default!;
+
+    /// <summary>
+    /// Checks if the given user has fingerprint access to the target entity.
+    /// </summary>
+    /// <param name="target">The target entity.</param>
+    /// <param name="user">User trying to gain access.</param>
+    /// <returns>True if access was granted, otherwise false.</returns>
+    [PublicAPI]
+    public bool IsAllowed(Entity<FingerprintReaderComponent?> target, EntityUid user)
+    {
+        if (!Resolve(target, ref target.Comp, false))
+            return true;
+
+        if (target.Comp.AllowedFingerprints.Count == 0)
+            return true;
+
+        // Check for gloves first
+        if (!target.Comp.IgnoreGloves && TryGetBlockingGloves(user, out var gloves))
+        {
+            if (target.Comp.FailGlovesPopup != null)
+                _popup.PopupEntity(Loc.GetString(target.Comp.FailGlovesPopup, ("blocker", gloves)), target, user);
+            return false;
+        }
+
+        // Check fingerprint match
+        if (!TryComp<FingerprintComponent>(user, out var fingerprint) || fingerprint.Fingerprint == null ||
+            !target.Comp.AllowedFingerprints.Contains(fingerprint.Fingerprint))
+        {
+            if (target.Comp.FailPopup != null)
+                _popup.PopupEntity(Loc.GetString(target.Comp.FailPopup), target, user);
+
+            return false;
+        }
+
+        return true;
+    }
+
+    /// <summary>
+    /// Gets the blocking gloves of a user. Gloves count as blocking if they hide fingerprints.
+    /// </summary>
+    /// <param name="user">Entity wearing the gloves.</param>
+    /// <param name="blocker">The returned gloves, if they exist.</param>
+    /// <returns>True if blocking gloves were found, otherwise False.</returns>
+    [PublicAPI]
+    public bool TryGetBlockingGloves(EntityUid user, [NotNullWhen(true)] out EntityUid? blocker)
+    {
+        blocker = null;
+
+        if (_inventory.TryGetSlotEntity(user, "gloves", out var gloves) && HasComp<FingerprintMaskComponent>(gloves))
+        {
+            blocker = gloves;
+            return true;
+        }
+
+        return false;
+    }
+
+    /// <summary>
+    /// Sets the allowed fingerprints for a fingerprint reader
+    /// </summary>
+    [PublicAPI]
+    public void SetAllowedFingerprints(Entity<FingerprintReaderComponent> target, HashSet<string> fingerprints)
+    {
+        target.Comp.AllowedFingerprints = fingerprints;
+        Dirty(target);
+    }
+
+    /// <summary>
+    /// Adds an allowed fingerprint to a fingerprint reader
+    /// </summary>
+    [PublicAPI]
+    public void AddAllowedFingerprint(Entity<FingerprintReaderComponent> target, string fingerprint)
+    {
+        target.Comp.AllowedFingerprints.Add(fingerprint);
+        Dirty(target);
+    }
+
+    /// <summary>
+    /// Removes an allowed fingerprint from a fingerprint reader
+    /// </summary>
+    [PublicAPI]
+    public void RemoveAllowedFingerprint(Entity<FingerprintReaderComponent> target, string fingerprint)
+    {
+        target.Comp.AllowedFingerprints.Remove(fingerprint);
+        Dirty(target);
+    }
+}