logic gate stuff (#16943)

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

Content.Server/DeviceLinking/Systems/EdgeDetectorSystem.cs

@@ -0,0 +1,47 @@
+using Content.Server.DeviceLinking.Components;
+using Content.Server.DeviceNetwork;
+using Content.Server.MachineLinking.Events;
+using SignalReceivedEvent = Content.Server.DeviceLinking.Events.SignalReceivedEvent;
+
+namespace Content.Server.DeviceLinking.Systems;
+
+public sealed class EdgeDetectorSystem : EntitySystem
+{
+    [Dependency] private readonly DeviceLinkSystem _deviceLink = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<EdgeDetectorComponent, ComponentInit>(OnInit);
+        SubscribeLocalEvent<EdgeDetectorComponent, SignalReceivedEvent>(OnSignalReceived);
+    }
+
+    private void OnInit(EntityUid uid, EdgeDetectorComponent comp, ComponentInit args)
+    {
+        _deviceLink.EnsureSinkPorts(uid, comp.InputPort);
+        _deviceLink.EnsureSourcePorts(uid, comp.OutputHighPort, comp.OutputLowPort);
+    }
+
+    private void OnSignalReceived(EntityUid uid, EdgeDetectorComponent comp, ref SignalReceivedEvent args)
+    {
+        // only handle signals with edges
+        var state = SignalState.Momentary;
+        if (args.Data == null ||
+            !args.Data.TryGetValue(DeviceNetworkConstants.LogicState, out state) ||
+            state == SignalState.Momentary)
+            return;
+
+        if (args.Port != comp.InputPort)
+            return;
+
+        // make sure the level changed, multiple devices sending the same level are treated as one spamming
+        if (comp.State != state)
+        {
+            comp.State = state;
+
+            var port = state == SignalState.High ? comp.OutputHighPort : comp.OutputLowPort;
+            _deviceLink.InvokePort(uid, port);
+        }
+    }
+}