import 'dart:math';

class Utils {
  static double roundToDecimalPlaces(double value, int precision) {
    double mod = pow(10.0, precision).toDouble();
    return ((value * mod).round().toDouble() / mod);
  }

  static double addDoublesWithPrecision(double a, double b, int precision) {
    double mod = pow(10.0, precision).toDouble();
    double difference = (a * mod) + (b * mod);
    return difference.round() / mod;
  }

  static int getFractionDigitsLength(double value) {
    final fractionDigits = value.toString().split('.');
    return fractionDigits[1].length;
  }

  static String toStringMatchingTemplateFractionPrecision(
      double value, double template) {
    final precision = getFractionDigitsLength(template);
    return value.toStringAsFixed(precision);
  }

  static double convertMgPerDlToMmolPerL(int mgPerDl) {
    return Utils.roundToDecimalPlaces(mgPerDl * 0.0555, 2);
  }

  static int convertMmolPerLToMgPerDl(double mmolPerL) {
    return (mmolPerL * 18.018).round();
  }

  static double calculateCarbs(double carbsRatio, double portionSize) {
    return Utils.roundToDecimalPlaces(carbsRatio * portionSize / 100, 2);
  }

  static double calculateCarbsRatio(
      double carbsPerPortion, double portionSize) {
    return portionSize > 0
        ? Utils.roundToDecimalPlaces(carbsPerPortion * 100 / portionSize, 2)
        : 0;
  }

  static double calculatePortionSize(
      double carbsRatio, double carbsPerPortion) {
    return carbsRatio > 0
        ? Utils.roundToDecimalPlaces(carbsPerPortion * 100 / carbsRatio, 2)
        : 0;
  }
}