La-Fabrik/.agent/skills/managers.md

Skill — Singleton Managers

Pattern

Every manager follows the exact same singleton structure:

export class SomeManager {
  private static _instance: SomeManager | null = null;

  static getInstance(): SomeManager {
    if (!SomeManager._instance) {
      SomeManager._instance = new SomeManager();
    }
    return SomeManager._instance;
  }

  private constructor() {
    // init logic
  }

  destroy(): void {
    // cleanup logic
    SomeManager._instance = null;
  }
}

Managers in this project

Manager	File	Role
AudioManager	src/managers/AudioManager.ts	Music and SFX playback.
InteractionManager	src/managers/InteractionManager.ts	Focus, nearby, trigger, grab, and hand-grab interaction state.
GameManager	target-state only	Future single source of truth for phase, zone, mission, input lock, dialogue.
CinematicManager	target-state only	Future GSAP timeline orchestrator.
ZoneManager	target-state only	Future zone entry/exit detection and LOD triggers.

GameManager is the orchestrator

export class GameManager {
  cinematic!: CinematicManager;
  audio!: AudioManager;
  zone!: ZoneManager;

  private constructor() {
    this.cinematic = CinematicManager.getInstance();
    this.audio = AudioManager.getInstance();
    this.zone = ZoneManager.getInstance();
  }
}

Components and hooks access other managers through GameManager only:

// Correct
GameManager.getInstance().cinematic.play("intro");

// Wrong — never import sub-managers directly in components
CinematicManager.getInstance().play("intro");

Subscribe pattern (GameManager only)

private listeners = new Set<() => void>()

subscribe(listener: () => void): () => void {
  this.listeners.add(listener)
  return () => this.listeners.delete(listener)
}

private emit(): void {
  this.listeners.forEach((cb) => cb())
}

Every set*() method calls this.emit() to notify subscribers.

React bridge hook

// hooks/useGameState.ts
export function useGameState() {
  const game = GameManager.getInstance();
  const [state, setState] = useState(game.getState());

  useEffect(() => {
    return game.subscribe(() => setState({ ...game.getState() }));
  }, [game]);

  return state;
}

Rules

• Max 4 managers total
• Only GameManager holds durable state with subscribe()
• Other managers are side-effect handlers — they do not store persistent state
• Always call destroy() on cleanup (App unmount)
• Never create manager instances with new — always use .getInstance()