Simplify nesting counter

src/NScenario/NestingCounter.cs

@@ -7,67 +7,41 @@ namespace NScenario
 {
     internal class NestingCounter
     {
-        private readonly ConcurrentDictionary<string, Stack<(bool, int)>> _levelNumber = new ConcurrentDictionary<string, Stack<(bool, int)>>();
-        public Level StartLevel(string levelKey)
+        class LevelCounter
         {
-            _ = _levelNumber.AddOrUpdate(levelKey, s =>
-            {
-                var stack = new Stack<(bool, int)>();
-                stack.Push((true, 0));
-                return stack;
-            }, (s, stack) =>
-            {
-                var (used, counter) = stack.Pop();
-                stack.Push((true, counter));
-                if (used)
-                {
-                    stack.Push((true, 0));
-                }
-
-                return stack;
-            });
-            var levelNumber = _levelNumber[levelKey].Count;
-            var currentLevelData = IncrementCurrentStepNumber(levelKey);
-            return new Level(() => EndLevel(levelKey, levelNumber), currentLevelData);
+            public int Counter { get; set; }
         }
 
-        private void EndLevel(string scenario, int height)
-        {
-            if (_levelNumber.TryGetValue(scenario, out var stepStack))
-            {
-                if (height < stepStack.Count)
-                {
-                    stepStack.Pop();
-                }
+        private readonly Stack<LevelCounter> _stack = new Stack<LevelCounter>();
 
-                var (_, counter) = stepStack.Pop();
-                stepStack.Push((false, counter));
-            }
+        public NestingCounter()
+        {
+            _stack.Push(new LevelCounter());
         }
 
-        private Stack<(bool, int)> IncrementCurrentStepNumber(string scenario)
+        public Level StartLevel()
         {
-            var stepStack = _levelNumber[scenario];
-            var (used, counter) = stepStack.Pop();
-            counter++;
-            stepStack.Push((used, counter));
-            return stepStack;
+            _stack.Peek().Counter++;
+            _stack.Push(new LevelCounter());
+            var data = _stack.ToArray().Skip(1).Reverse().Select(x => x.Counter).ToArray();
+            return new Level(() => _stack.Pop(), data);
         }
+
     }
 
-    public class Level:IDisposable
+    public class Level : IDisposable
     {
         public int Nesting { get; }
         private readonly Action _action;
 
-        public Level(Action action, Stack<(bool, int)> levelData)
+        public Level(Action action, int[] levelData)
         {
-            Nesting = levelData.Count -1;
-            LevelPath = levelData.ToArray().Reverse().Select(x => x.Item2);
+            Nesting = levelData.Length - 1;
+            LevelPath = levelData;
             _action = action;
         }
 
-        public IEnumerable<int> LevelPath { get; }
+        public IReadOnlyList<int> LevelPath { get; }
 
         public void Dispose() => _action.Invoke();
     }

src/NScenario/StepExecutors/LevelTrackingScenarioStepExecutor.cs

@@ -16,14 +16,14 @@ protected LevelTrackingScenarioStepExecutor(IScenarioStepExecutor scenarioStepEx
 
         public async Task Step(string scenarioName, string stepDescription, Func<Task> action, StepContext stepContext)
         {
-            using var level = _counter.StartLevel(stepContext.ScenarioName);
+            using var level = _counter.StartLevel();
             var decoratedDescription = DecorateDescription(stepDescription, level);
             await  _scenarioStepExecutorImplementation.Step(scenarioName, decoratedDescription, action, stepContext);
         }
 
         public async Task Step(string scenarioName, string stepDescription, Action action, StepContext stepContext)
         {
-            using var level = _counter.StartLevel(stepContext.ScenarioName);
+            using var level = _counter.StartLevel();
             var decoratedDescription = DecorateDescription(stepDescription, level);
             await  _scenarioStepExecutorImplementation.Step(scenarioName, decoratedDescription, action, stepContext);
         }