Refactor Flammable to be ECS. (#4671)

- Refactor IHotItem into IsHotEvent.
- Refactor IFireAct into TileFireEvent.

Content.Server/Light/Components/MatchstickComponent.cs

@@ -12,9 +12,8 @@ using Robust.Shared.ViewVariables;
 namespace Content.Server.Light.Components
 {
     [RegisterComponent]
-    [ComponentReference(typeof(IHotItem))]
     [Friend(typeof(MatchstickSystem))]
-    public class MatchstickComponent : Component, IHotItem
+    public class MatchstickComponent : Component
     {
         public override string Name => "Matchstick";
 
@@ -41,10 +40,5 @@ namespace Content.Server.Light.Components
         /// </summary>
         [ComponentDependency]
         public readonly PointLightComponent? PointLightComponent = default!;
-
-        bool IHotItem.IsCurrentlyHot()
-        {
-            return CurrentState == SharedBurningStates.Lit;
-        }
     }
 }

Content.Server/Light/EntitySystems/MatchstickSystem.cs

@@ -24,6 +24,7 @@ namespace Content.Server.Light.EntitySystems
         {
             base.Initialize();
             SubscribeLocalEvent<MatchstickComponent, InteractUsingEvent>(OnInteractUsing);
+            SubscribeLocalEvent<MatchstickComponent, IsHotEvent>(OnIsHotEvent);
         }
 
         public override void Update(float frameTime)
@@ -40,14 +41,22 @@ namespace Content.Server.Light.EntitySystems
 
         private void OnInteractUsing(EntityUid uid, MatchstickComponent component, InteractUsingEvent args)
         {
-            if (!args.Handled
-                && args.Used.TryGetComponent<IHotItem>(out var hotItem)
-                && hotItem.IsCurrentlyHot()
-                && component.CurrentState == SharedBurningStates.Unlit)
-            {
-                Ignite(component, args.User);
-                args.Handled = true;
-            }
+            if (args.Handled || component.CurrentState != SharedBurningStates.Unlit)
+                return;
+
+            var isHotEvent = new IsHotEvent();
+            RaiseLocalEvent(args.Used.Uid, isHotEvent, false);
+
+            if (!isHotEvent.IsHot)
+                return;
+
+            Ignite(component, args.User);
+            args.Handled = true;
+        }
+
+        private void OnIsHotEvent(EntityUid uid, MatchstickComponent component, IsHotEvent args)
+        {
+            args.IsHot = component.CurrentState == SharedBurningStates.Lit;
         }
 
         public void Ignite(MatchstickComponent component, IEntity user)