export default class XPManager extends Phaser.Events.EventEmitter {
  constructor(scene) {
    super();
    this.scene = scene;
    this.xp = 0;
    this.level = 1;
    this.nextLevelXP = this.calculateNextThreshold();
  }

  calculateNextThreshold() {
    return Math.round(100 * Math.pow(this.level, 1.5)); // simple exponential curve
  }

  addXP(amount) {
    this.xp += amount;
    if (this.xp >= this.nextLevelXP) {
      this.level++;
      this.nextLevelXP = this.calculateNextThreshold();
      this.emit('levelup', this.level);
    }
    this.scene.uiManager.updateXP(this.xp, this.nextLevelXP);
  }
}