class Trainer {
  #monsters = [];
  #inventory = [];

  /**
   * @type {('trainer' | 'monster')}
   */
  type = 'trainer';

  /**
   * @type {Monster[]}
   */
  monsters = [];

  /**
   * @type {InventoryItem[]}
   */
  inventory = [];

  /**
   * @type {Monster}
   */
  activeMonster = [];

  constructor (monsters, inventory = []) {
    this.#monsters = monsters;
    this.#inventory = inventory;
  }

  async initialize () {
    for (const monsterData of this.#monsters) {
      const monster = await fetchMonster(monsterData.slug);

      monster.level = monsterData.level || monster.level;

      this.monsters.push(monster);
    }

    this.activeMonster = this.monsters[0];

    for (const itemData of this.#inventory) {
      const item = new InventoryItem(await fetchItem(itemData.slug));

      item.amount = itemData.amount || 1;

      this.inventory.push(item);
    }
  }
}