let youthAgeModificators = function (abilityScores) {
  abilityScores["Strength"] -= 2;
  abilityScores["Intelligence"] -= 2;
  abilityScores["Wisdom"] -= 2;
  return abilityScores;
};

let adultAgeModificators = function (abilityScores) {
  /* No adjustments for Adult */
  return abilityScores;
};

let middleAgeModificators = function (abilityScores) {
  abilityScores["Strength"] -= 2;
  abilityScores["Dexterity"] -= 2;
  abilityScores["Constitution"] -= 2;
  return abilityScores;
};

let oldAgeModificators = function (abilityScores) {
  abilityScores["Strength"] -= 4;
  abilityScores["Dexterity"] -= 4;
  abilityScores["Constitution"] -= 4;
  abilityScores["Charisma"] -= 2;
  return abilityScores;
};

let ancientAgeModificators = function (abilityScores) {
  abilityScores["Strength"] -= 6;
  abilityScores["Dexterity"] -= 6;
  abilityScores["Constitution"] -= 6;
  abilityScores["Charisma"] -= 4;
  return abilityScores;
};

// Low Fantasy: реалистичный мир, где доля взрослых выше, а возрастные категории распределены ближе к реальности.
let ages = {
  Youth: {
    chance: 15.0,
    explanation: "equivalent to human 13 – 17",
    abilities_modificator: youthAgeModificators,
  },
  Adult: {
    chance: 50.0,
    explanation: "equivalent to human 18 – 35",
    abilities_modificator: adultAgeModificators,
  },
  MiddleAged: {
    chance: 20.0,
    explanation: "equivalent to human 36 – 55",
    abilities_modificator: middleAgeModificators,
  },
  Old: {
    chance: 10.0,
    explanation: "equivalent to human 56 – 75",
    abilities_modificator: oldAgeModificators,
  },
  Ancient: {
    chance: 5.0,
    explanation: "equivalent to human 76 – 95",
    abilities_modificator: ancientAgeModificators,
  },
};

function getAgeAndModifyAbilities(abilityScores) {
  // Клонируем словарь abilityScores, чтобы не изменять оригинал
  let clonedAbilityScores = Object.assign({}, abilityScores);

  // Получаем сумму шансов для нормализации
  let totalChance = Object.values(ages).reduce(
    (sum, { chance }) => sum + chance,
    0
  );

  // Генерируем случайное значение от 0 до 100
  let randomValue = Math.random() * 100;

  let cumulativeChance = 0;
  let selectedAgeGroup = null;

  for (let [
    ageGroup,
    { chance, explanation, abilities_modificator },
  ] of Object.entries(ages)) {
    // Нормализуем шанс текущей возрастной категории
    let normalizedChance = (chance / totalChance) * 100;
    cumulativeChance += normalizedChance;

    if (randomValue <= cumulativeChance) {
      selectedAgeGroup = {
        ageCategory: ageGroup,
        ageExplanation: explanation,
        abilities_modificator,
      };
      break;
    }
  }

  if (!selectedAgeGroup) {
    throw new Error("Age group selection failed.");
  }

  // Применяем модификаторы к клонированным способностям
  let { ageCategory, ageExplanation, abilities_modificator } = selectedAgeGroup;
  let agedAbilityScores = abilities_modificator(clonedAbilityScores);

  return [ageCategory, ageExplanation, agedAbilityScores];
}

dv.ages = {
  getAgeAndModifyAbilities,
};