Clear and reregister devices for atmos alarms (#11391)

* deregister sensors upon device list update and re-register after clearing devices

* fire alarms, too

* adds the last set of known devices to the device list update event

* update UI upon clearing everything out

* addresses reviews

Content.Server/Atmos/Monitor/Systems/AirAlarmSystem.cs

@@ -168,6 +168,24 @@ public sealed class AirAlarmSystem : EntitySystem
 
     private void OnDeviceListUpdate(EntityUid uid, AirAlarmComponent component, DeviceListUpdateEvent args)
     {
+        var query = GetEntityQuery<DeviceNetworkComponent>();
+        foreach (var device in args.OldDevices)
+        {
+            if (!query.TryGetComponent(device, out var deviceNet))
+            {
+                continue;
+            }
+
+            _atmosDevNetSystem.Deregister(uid, deviceNet.Address);
+        }
+
+        component.ScrubberData.Clear();
+        component.SensorData.Clear();
+        component.VentData.Clear();
+        component.KnownDevices.Clear();
+
+        UpdateUI(uid, component);
+
         SyncRegisterAllDevices(uid);
     }
 
@@ -294,8 +312,8 @@ public sealed class AirAlarmSystem : EntitySystem
         }
 
         var addr = string.Empty;
-        if (EntityManager.TryGetComponent(uid, out DeviceNetworkComponent? netConn)) addr = netConn.Address;
-
+        if (EntityManager.TryGetComponent(uid, out DeviceNetworkComponent? netConn))
+            addr = netConn.Address;
 
         if (args.AlarmType == AtmosAlarmType.Danger)
         {

Content.Server/Atmos/Monitor/Systems/AtmosDeviceNetwork.cs

@@ -15,6 +15,11 @@ public sealed class AtmosDeviceNetworkSystem : EntitySystem
     /// </summary>
     public const string RegisterDevice = "atmos_register_device";
 
+    /// <summary>
+    ///     Deregister a device's address on this device.
+    /// </summary>
+    public const string DeregisterDevice = "atmos_deregister_device";
+
     /// <summary>
     ///     Synchronize the data this device has with the sender.
     /// </summary>
@@ -32,6 +37,16 @@ public sealed class AtmosDeviceNetworkSystem : EntitySystem
         _deviceNet.QueuePacket(uid, address, registerPayload);
     }
 
+    public void Deregister(EntityUid uid, string? address)
+    {
+        var deregisterPayload = new NetworkPayload
+        {
+            [DeviceNetworkConstants.Command] = DeregisterDevice
+        };
+
+        _deviceNet.QueuePacket(uid, address, deregisterPayload);
+    }
+
     public void Sync(EntityUid uid, string? address)
     {
         var syncPayload = new NetworkPayload

Content.Server/Atmos/Monitor/Systems/AtmosMonitoringSystem.cs

@@ -98,6 +98,9 @@ public sealed class AtmosMonitorSystem : EntitySystem
             case AtmosDeviceNetworkSystem.RegisterDevice:
                 component.RegisteredDevices.Add(args.SenderAddress);
                 break;
+            case AtmosDeviceNetworkSystem.DeregisterDevice:
+                component.RegisteredDevices.Remove(args.SenderAddress);
+                break;
             case AtmosAlarmableSystem.ResetAll:
                 Reset(uid);
                 // Don't clear alarm states here.

Content.Server/Atmos/Monitor/Systems/FireAlarmSystem.cs

@@ -1,5 +1,6 @@
 using Content.Server.AlertLevel;
 using Content.Server.Atmos.Monitor.Components;
+using Content.Server.DeviceNetwork.Components;
 using Content.Server.DeviceNetwork.Systems;
 using Content.Server.Power.Components;
 using Content.Server.Power.EntitySystems;
@@ -32,6 +33,17 @@ public sealed class FireAlarmSystem : EntitySystem
 
     private void OnDeviceListSync(EntityUid uid, FireAlarmComponent component, DeviceListUpdateEvent args)
     {
+        var query = GetEntityQuery<DeviceNetworkComponent>();
+        foreach (var device in args.OldDevices)
+        {
+            if (!query.TryGetComponent(device, out var deviceNet))
+            {
+                continue;
+            }
+
+            _atmosDevNet.Deregister(uid, deviceNet.Address);
+        }
+
         _atmosDevNet.Register(uid, null);
         _atmosDevNet.Sync(uid, null);
     }

Content.Shared/DeviceNetwork/Systems/SharedDeviceListSystem.cs

@@ -24,6 +24,7 @@ public abstract class SharedDeviceListSystem : EntitySystem
         if (!Resolve(uid, ref deviceList))
             return DeviceListUpdateResult.NoComponent;
 
+        var oldDevices = deviceList.Devices.ToList();
         var newDevices = merge ? new HashSet<EntityUid>(deviceList.Devices) : new();
         var devicesList = devices.ToList();
 
@@ -35,7 +36,7 @@ public abstract class SharedDeviceListSystem : EntitySystem
 
         deviceList.Devices = newDevices;
 
-        RaiseLocalEvent(uid, new DeviceListUpdateEvent(devicesList));
+        RaiseLocalEvent(uid, new DeviceListUpdateEvent(oldDevices, devicesList));
 
         Dirty(deviceList);
 
@@ -71,11 +72,13 @@ public abstract class SharedDeviceListSystem : EntitySystem
 
 public sealed class DeviceListUpdateEvent : EntityEventArgs
 {
-    public DeviceListUpdateEvent(List<EntityUid> devices)
+    public DeviceListUpdateEvent(List<EntityUid> oldDevices, List<EntityUid> devices)
     {
+        OldDevices = oldDevices;
         Devices = devices;
     }
 
+    public List<EntityUid> OldDevices { get; }
     public List<EntityUid> Devices { get; }
 }