Re-organize all projects (#4166)

Content.Server/Fluids/PuddleSystem.cs

@@ -0,0 +1,48 @@
+using Content.Server.Fluids.Components;
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Map;
+
+namespace Content.Server.Fluids
+{
+    [UsedImplicitly]
+    internal sealed class PuddleSystem : EntitySystem
+    {
+        [Dependency] private readonly IMapManager _mapManager = default!;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            _mapManager.TileChanged += HandleTileChanged;
+        }
+
+        public override void Shutdown()
+        {
+            base.Shutdown();
+            _mapManager.TileChanged -= HandleTileChanged;
+        }
+
+        //TODO: Replace all this with an Unanchored event that deletes the puddle
+        private void HandleTileChanged(object? sender, TileChangedEventArgs eventArgs)
+        {
+            // If this gets hammered you could probably queue up all the tile changes every tick but I doubt that would ever happen.
+            foreach (var puddle in ComponentManager.EntityQuery<PuddleComponent>(true))
+            {
+                // If the tile becomes space then delete it (potentially change by design)
+                var puddleTransform = puddle.Owner.Transform;
+                if(!puddleTransform.Anchored)
+                    continue;
+
+                var grid = _mapManager.GetGrid(puddleTransform.GridID);
+                if (eventArgs.NewTile.GridIndex == puddle.Owner.Transform.GridID &&
+                    grid.TileIndicesFor(puddleTransform.Coordinates) == eventArgs.NewTile.GridIndices &&
+                    eventArgs.NewTile.Tile.IsEmpty)
+                {
+                    puddle.Owner.QueueDelete();
+                    break; // Currently it's one puddle per tile, if that changes remove this
+                }
+            }
+        }
+    }
+}