Device Linking and better linking ui (#13645)

Co-authored-by: AJCM-git <60196617+AJCM-git@users.noreply.github.com>
Co-authored-by: Visne <39844191+Visne@users.noreply.github.com>
Co-authored-by: ElectroJr <leonsfriedrich@gmail.com>
Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>

Content.Server/DeviceLinking/Systems/DeviceLinkSystem.cs

@@ -0,0 +1,114 @@
+using Content.Server.DeviceLinking.Events;
+using Content.Server.DeviceNetwork;
+using Content.Server.DeviceNetwork.Components;
+using Content.Server.DeviceNetwork.Systems;
+using Content.Server.MachineLinking.Components;
+using Content.Shared.DeviceLinking;
+using Robust.Shared.Utility;
+
+namespace Content.Server.DeviceLinking.Systems;
+
+public sealed class DeviceLinkSystem : SharedDeviceLinkSystem
+{
+    [Dependency] private readonly DeviceNetworkSystem _deviceNetworkSystem = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+        SubscribeLocalEvent<SignalTransmitterComponent, MapInitEvent>(OnTransmitterStartup);
+        SubscribeLocalEvent<DeviceLinkSinkComponent, DeviceNetworkPacketEvent>(OnPacketReceived);
+    }
+
+    /// <summary>
+    /// Moves existing links from machine linking to device linking to ensure linked things still work even when the map wasn't updated yet
+    /// </summary>
+    private void OnTransmitterStartup(EntityUid sourceUid, SignalTransmitterComponent transmitterComponent, MapInitEvent args)
+    {
+        if (!TryComp<DeviceLinkSourceComponent?>(sourceUid, out var sourceComponent))
+            return;
+
+        Dictionary<EntityUid, List<(string, string)>> outputs = new();
+        foreach (var (transmitterPort, receiverPorts) in transmitterComponent.Outputs)
+        {
+
+            foreach (var receiverPort in receiverPorts)
+            {
+                outputs.GetOrNew(receiverPort.Uid).Add((transmitterPort, receiverPort.Port));
+            }
+        }
+
+        foreach (var (sinkUid, links) in outputs)
+        {
+            SaveLinks(null, sourceUid, sinkUid, links, sourceComponent);
+        }
+    }
+
+     #region Sending & Receiving
+    /// <summary>
+    /// Sends a network payload directed at the sink entity.
+    /// Just raises a <see cref="SignalReceivedEvent"/> without data if the source or the sink doesn't have a <see cref="DeviceNetworkComponent"/>
+    /// </summary>
+    /// <param name="uid">The source uid that invokes the port</param>
+    /// <param name="port">The port to invoke</param>
+    /// <param name="data">Optional data to send along</param>
+    /// <param name="sourceComponent"></param>
+    public void InvokePort(EntityUid uid, string port, NetworkPayload? data = null, DeviceLinkSourceComponent? sourceComponent = null)
+    {
+        if (!Resolve(uid, ref sourceComponent) || !sourceComponent.Outputs.TryGetValue(port, out var sinks))
+            return;
+
+        foreach (var sinkUid in sinks)
+        {
+            if (!sourceComponent.LinkedPorts.TryGetValue(sinkUid, out var links))
+                continue;
+
+            foreach (var (source, sink) in links)
+            {
+                if (source != port)
+                    continue;
+
+                //Just skip using device networking if the source or the sink doesn't support it
+                if (!HasComp<DeviceNetworkComponent>(uid) || !TryComp<DeviceNetworkComponent?>(sinkUid, out var sinkNetworkComponent))
+                {
+                    var eventArgs = new SignalReceivedEvent(sink, uid);
+
+                    RaiseLocalEvent(sinkUid, ref eventArgs);
+                    continue;
+                }
+
+                var payload = new NetworkPayload()
+                {
+                    [InvokedPort] = sink
+                };
+
+                if (data != null)
+                {
+                    //Prevent overriding the invoked port
+                    data.Remove(InvokedPort);
+                    foreach (var (key, value) in data)
+                    {
+                        payload.Add(key, value);
+                    }
+                }
+
+                _deviceNetworkSystem.QueuePacket(uid, sinkNetworkComponent.Address, payload, sinkNetworkComponent.ReceiveFrequency);
+            }
+        }
+    }
+
+    /// <summary>
+    /// Checks if the payload has a port defined and if the port is present on the sink.
+    /// Raises a <see cref="SignalReceivedEvent"/> containing the payload when the check passes
+    /// </summary>
+    private void OnPacketReceived(EntityUid uid, DeviceLinkSinkComponent component, DeviceNetworkPacketEvent args)
+    {
+        if (!args.Data.TryGetValue(InvokedPort, out string? port) || !(component.Ports?.Contains(port) ?? false))
+            return;
+
+        var eventArgs = new SignalReceivedEvent(port, args.Sender, args.Data);
+        RaiseLocalEvent(uid,  ref eventArgs);
+    }
+    #endregion
+
+
+}