Fixes Emergency Lights not charging (#2873)

* Fixes Emergency Lights not charging

* Removed extra imports

Content.Server/GameObjects/Components/Power/ApcNetComponents/PowerReceiverUsers/EmergencyLightComponent.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using Content.Shared.GameObjects.EntitySystems;
 using Robust.Server.GameObjects;
@@ -32,7 +32,7 @@ namespace Content.Server.GameObjects.Components.Power.ApcNetComponents.PowerRece
             }
         }
 
-        private EmergencyLightState _state = EmergencyLightState.Charging;
+        private EmergencyLightState _state = EmergencyLightState.Empty;
 
         [ViewVariables(VVAccess.ReadWrite)]
         private float _wattage;
@@ -139,11 +139,15 @@ namespace Content.Server.GameObjects.Components.Power.ApcNetComponents.PowerRece
         public override void Initialize()
         {
             base.Initialize();
+        }
 
-            Owner.EnsureComponentWarn(out PowerReceiverComponent receiver);
-
-            receiver.OnPowerStateChanged += UpdateState;
-            State = EmergencyLightState.Charging;
+        public override void OnAdd()
+        {
+            base.OnAdd();
+            if (Owner.TryGetComponent(out PowerReceiverComponent receiver))
+            {
+                receiver.OnPowerStateChanged += UpdateState;
+            }
         }
 
         public override void OnRemove()

Content.Server/GameObjects/EntitySystems/EmergencyLightSystem.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using Content.Server.GameObjects.Components.Power.ApcNetComponents.PowerReceiverUsers;
 using JetBrains.Annotations;
@@ -9,7 +9,7 @@ namespace Content.Server.GameObjects.EntitySystems
     [UsedImplicitly]
     internal sealed class EmergencyLightSystem : EntitySystem
     {
-        private readonly List<EmergencyLightComponent> _activeLights = new();
+        private readonly HashSet<EmergencyLightComponent> _activeLights = new();
 
         public override void Initialize()
         {
@@ -21,19 +21,13 @@ namespace Content.Server.GameObjects.EntitySystems
         {
             switch (message.State)
             {
+                case EmergencyLightComponent.EmergencyLightState.On:
                 case EmergencyLightComponent.EmergencyLightState.Charging:
-                    if (_activeLights.Contains(message.Component))
-                        _activeLights.Add(message.Component);
-
+                    _activeLights.Add(message.Component);
                     break;
                 case EmergencyLightComponent.EmergencyLightState.Full:
                 case EmergencyLightComponent.EmergencyLightState.Empty:
                     _activeLights.Remove(message.Component);
-                    break;
-                case EmergencyLightComponent.EmergencyLightState.On:
-                    if (!_activeLights.Contains(message.Component))
-                        _activeLights.Add(message.Component);
-
                     break;
                 default:
                     throw new ArgumentOutOfRangeException();
@@ -42,10 +36,9 @@ namespace Content.Server.GameObjects.EntitySystems
 
         public override void Update(float frameTime)
         {
-            for (var i = _activeLights.Count - 1; i >= 0; i--)
+            foreach (var activeLight in _activeLights)
             {
-                var comp = _activeLights[i];
-                comp.OnUpdate(frameTime);
+                activeLight.OnUpdate(frameTime);
             }
         }
     }

Resources/Prototypes/Entities/Constructible/Walls/emergency_light.yml

@@ -11,11 +11,11 @@
     offset: "0.5, 0"
     color: "#FF4020"
     mask: /Textures/Effects/LightMasks/emergency_mask.png
-  - type: EmergencyLight
   - type: PowerReceiver
   - type: Battery
     maxCharge: 30000
     startingCharge: 0
+  - type: EmergencyLight
   - type: Sprite
     sprite: Constructible/Lighting/emergency_light.rsi
     state: emergency_light_off