polkadot-js/common

// Copyright 2017-2024 @polkadot/util authors & contributors
// SPDX-License-Identifier: Apache-2.0

import type { BN } from '../bn/bn.js';
import type { ToBn } from '../types.js';

import { bnToBn } from '../bn/toBn.js';
import { formatDecimal } from './formatDecimal.js';
import { getSeparator } from './getSeparator.js';

interface Options {
  /**
   * @description The locale to use
   */
  locale?: string;
}

/**
 * @name formatNumber
 * @description Formats a number into string format with thousand separators
 */
export function formatNumber <ExtToBn extends ToBn> (
  value?: ExtToBn | BN | bigint | number | null,
  { locale = 'en' }: Options = {}
): string {
  const { thousand } = getSeparator(locale);

  return formatDecimal(bnToBn(value).toString(), thousand);
}