export class LevelManager {
  private static _instance: LevelManager | undefined;

  static get instance(): LevelManager {
    if (!LevelManager._instance) {
      LevelManager._instance = new LevelManager();
    }
    return LevelManager._instance;
  }

  private readonly minIndex: number = 1;
  private currentIndex = 1;

  getCurrentIndex(): number {
    return this.currentIndex;
  }

  setCurrentIndex(index: number): void {
    const clamped = Math.max(this.minIndex, Math.floor(index || 0));
    this.currentIndex = clamped;
  }

  getNextIndex(): number {
    return this.currentIndex + 1;
  }
}