update step

src/stateManager/GameStepManager.ts

@@ -0,0 +1,47 @@
+import type { GameStep } from "@/types/game";
+
+export class GameStepManager {
+  private static _instance: GameStepManager | null = null;
+
+  private _currentStep: GameStep = "intro";
+  private readonly _listeners = new Set<() => void>();
+
+  static getInstance(): GameStepManager {
+    if (!GameStepManager._instance) {
+      GameStepManager._instance = new GameStepManager();
+    }
+
+    return GameStepManager._instance;
+  }
+
+  private constructor() {}
+
+  getStep(): GameStep {
+    return this._currentStep;
+  }
+
+  transitionTo(step: GameStep): void {
+    if (this._currentStep === step) return;
+
+    this._currentStep = step;
+    this._emit();
+  }
+
+  subscribe(listener: () => void): () => void {
+    this._listeners.add(listener);
+
+    return () => {
+      this._listeners.delete(listener);
+    };
+  }
+
+  destroy(): void {
+    this._currentStep = "intro";
+    this._listeners.clear();
+    GameStepManager._instance = null;
+  }
+
+  private _emit(): void {
+    this._listeners.forEach((cb) => cb());
+  }
+}