Re-organize all projects (#4166)

Content.Server/Light/EntitySystems/EmergencyLightSystem.cs

@@ -0,0 +1,45 @@
+using System;
+using System.Collections.Generic;
+using Content.Server.Light.Components;
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects;
+
+namespace Content.Server.Light.EntitySystems
+{
+    [UsedImplicitly]
+    internal sealed class EmergencyLightSystem : EntitySystem
+    {
+        private readonly HashSet<EmergencyLightComponent> _activeLights = new();
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            SubscribeLocalEvent<EmergencyLightMessage>(HandleEmergencyLightMessage);
+        }
+
+        private void HandleEmergencyLightMessage(EmergencyLightMessage message)
+        {
+            switch (message.State)
+            {
+                case EmergencyLightComponent.EmergencyLightState.On:
+                case EmergencyLightComponent.EmergencyLightState.Charging:
+                    _activeLights.Add(message.Component);
+                    break;
+                case EmergencyLightComponent.EmergencyLightState.Full:
+                case EmergencyLightComponent.EmergencyLightState.Empty:
+                    _activeLights.Remove(message.Component);
+                    break;
+                default:
+                    throw new ArgumentOutOfRangeException();
+            }
+        }
+
+        public override void Update(float frameTime)
+        {
+            foreach (var activeLight in _activeLights)
+            {
+                activeLight.OnUpdate(frameTime);
+            }
+        }
+    }
+}