import type { Money } from '../../../../common/money.types';

import { DECIMAL_RADIX, decimalFromString, formatDecimal } from '../../../../common/decimal';

export const ZERO_KOPECKS = 0n;

const RUB_DECIMAL_PLACES = 2;

const MIN_KOPECKS = -9_223_372_036_854_775_808n;
const MAX_KOPECKS = 9_223_372_036_854_775_807n;

export function parseRubMoney(money: Money, positive = false): bigint {
  if (
    money?.currency !== 'RUB' ||
    typeof money.value !== 'string' ||
    money.value !== money.value.trim()
  ) {
    throw new TypeError('Expected RUB money with a decimal string');
  }
  const amount = decimalFromString(money.value);
  if (amount.scale > RUB_DECIMAL_PLACES) {
    throw new RangeError('RUB money supports at most two decimal places');
  }
  const kopecks = amount.value * DECIMAL_RADIX ** BigInt(RUB_DECIMAL_PLACES - amount.scale);
  if (kopecks < MIN_KOPECKS || kopecks > MAX_KOPECKS) {
    throw new RangeError('RUB money is outside the signed 64-bit range');
  }
  if (positive && kopecks <= ZERO_KOPECKS) {
    throw new RangeError('Operation amount must be positive');
  }
  return kopecks;
}

export function rubMoney(kopecks: bigint): Money {
  return {
    currency: 'RUB',
    value: formatDecimal({ value: kopecks, scale: RUB_DECIMAL_PLACES }),
  };
}