Rework Win2D editor layers

src/ReactorMaintenance.Simulation/LevelEditor.cs

@@ -2,6 +2,52 @@
 
 public static class LevelEditor
 {
+    public static LevelState MoveOccupant(LevelState level, GridPosition source, GridPosition destination)
+    {
+        if (!level.InBounds(source) || !level.IsFloor(destination) || source == destination)
+            return level;
+
+        var prop = level.GetProp(source);
+        if (prop.Type == EPropType.None)
+            return level.Robot.Position == source ? level with { Robot = level.Robot with { Position = destination } } : level;
+
+        if (level.GetProp(destination).Type != EPropType.None)
+            return level;
+
+        var next = level.SetProp(source, new()).SetProp(destination, prop);
+        if (prop.Type != EPropType.ReactorControl)
+            return next;
+
+        return next with {
+            Reactors = next.Reactors
+                           .Select(reactor => reactor.ControlPosition == source ? reactor with { ControlPosition = destination } : reactor)
+                           .ToArray()
+        };
+    }
+
+    public static LevelState CycleElectricityLeakAccess(LevelState level, GridPosition undergroundPosition)
+    {
+        if (!level.InBounds(undergroundPosition))
+            return level;
+
+        if (!level.GetUnderground(undergroundPosition, ECarrierType.Electricity).IsPresent)
+            return level;
+
+        var accessPositions = undergroundPosition.Neighbors().Where(level.IsFloor).ToArray();
+        if (accessPositions.Length == 0)
+            return level;
+
+        var existingLeak = level.Leaks.FirstOrDefault(leak => leak.Carrier == ECarrierType.Electricity && leak.UndergroundPosition == undergroundPosition);
+        var nextAccessPosition = accessPositions[0];
+        if (existingLeak is not null)
+        {
+            var index = Array.IndexOf(accessPositions, existingLeak.AccessPosition);
+            nextAccessPosition = accessPositions[(index + 1) % accessPositions.Length];
+        }
+
+        return SetLeak(level, undergroundPosition, nextAccessPosition, ECarrierType.Electricity);
+    }
+
     public static LevelState Apply(LevelState level, GridPosition position, EditorToolCommand command)
     {
         if (!level.InBounds(position))