public autoAttack(enemy: Commander): void {
    interface IAtackerBestTargetTupple { attacker: Creature; bestTarget: Creature; }
    const attackerBestTargetTupple: IAtackerBestTargetTupple = [...this._army]
      .map((attackerCreature: Creature) =>
        ({ attacker: attackerCreature, bestTarget: attackerCreature.findBestTarget(enemy._army) }))
      .sort((tupleA: IAtackerBestTargetTupple, tupleB: IAtackerBestTargetTupple) =>
        (tupleA.bestTarget.healthPoints - tupleA.attacker.calculateActualDamage(tupleA.bestTarget))
        - (tupleB.bestTarget.healthPoints - tupleB.attacker.calculateActualDamage(tupleB.bestTarget)))
      .sort((tupleA: IAtackerBestTargetTupple, tupleB: IAtackerBestTargetTupple) =>
        tupleB.bestTarget.damage - tupleA.bestTarget.damage)
      .find((bestTuple: IAtackerBestTargetTupple) => bestTuple);

      this.applyAttack(attackerBestTargetTupple.attacker,
        attackerBestTargetTupple.bestTarget,
        enemy._army);
      if (attackerBestTargetTupple.bestTarget.healthPoints === 0) {
        enemy._army = enemy._army
          .filter(creature => creature !== attackerBestTargetTupple.bestTarget);
      }
  }

  public applyAttack(attacker: Creature, target: Creature, enemyArmy: Creature[]): void {
    attacker.attack(target);
  }
}