initial add

gobbos_delivery/scripts/states/StateMachine.cs

@@ -0,0 +1,54 @@
+using Godot;
+using System.Collections.Generic;
+
+public partial class StateMachine : State {
+    [Export]
+    public State InitialState { get; set; }
+
+    private State currentState;
+    private readonly Dictionary<string, State> stateList = [];
+
+    public override void _Ready() {
+        foreach (var child in GetChildren()) {
+            if (child is State state)
+            {
+                stateList.Add(child.Name.ToString().ToLower(), state);
+                state.Transitioned += OnChildTransition;
+            }
+        }
+
+        if (InitialState != null)
+        {
+            InitialState.Enter();
+            currentState = InitialState;
+        }
+    }
+
+    public void Process(float delta)
+    {
+        currentState?.Update(delta);
+    }
+
+    public override void PhysicsUpdate(double delta)
+    {
+        currentState?.PhysicsUpdate(delta);
+    }
+
+    public void OnChildTransition(Node sender, string newStateName)
+    {
+        if (sender != currentState)
+        {
+            return;
+        }
+
+        var newState = stateList[newStateName.ToLower()];
+        if (newState == null)
+        {
+            return;
+        }
+
+        currentState?.Exit();
+        newState.Enter();
+        currentState = newState;
+    }
+}