discountPrice2(totalPrice) {
    let percentage = 0;
    if (totalPrice >= 1000 && totalPrice < 5000) {
      percentage = 3;
    } else if (totalPrice >= 5000 && totalPrice < 7000) {
      percentage = 5;
    } else if (totalPrice >= 7000 && totalPrice < 10000) {
      percentage = 7;
    } else if (totalPrice >= 10000 && totalPrice < 50000) {
      percentage = 10;
    } else if (totalPrice >= 50000) {
      percentage = 15;
    } else {
      percentage = 0;
    }
    return this.subtractPercentage(totalPrice, percentage);
  }

  discountPrice(totalPrice) {
    const ranges = [
      [1000, 5000, 3],
      [5000, 7000, 5],
      [7000, 10000, 7],
      [10000, 50000, 10],
      [50000, Number.MAX_SAFE_INTEGER, 15]
    ];

    for (let i = 0; i < ranges.length; i++) {
      if (totalPrice < 1000) {
        return this.subtractPercentage(totalPrice, 0);
      } else if (totalPrice >= ranges[i][0] && totalPrice <= ranges[i][1]) {
        return this.subtractPercentage(totalPrice, ranges[i][2]);
        break;
      }
    }
  }

  subtractPercentage(number, percentage) {
    number = parseFloat(number);
    return number - number / 100 * percentage;
  }