import BigNumber from "bignumber.js";
import { RoundingMode } from "../typing";

enum RoundingModeMap {
  "up" = BigNumber.ROUND_UP,
  "down" = BigNumber.ROUND_DOWN,
  "truncate" = BigNumber.ROUND_DOWN,
  "halfUp" = BigNumber.ROUND_HALF_UP,
  "default" = BigNumber.ROUND_HALF_UP,
  "halfDown" = BigNumber.ROUND_HALF_DOWN,
  "halfEven" = BigNumber.ROUND_HALF_EVEN,
  "banker" = BigNumber.ROUND_HALF_EVEN,
  "ceiling" = BigNumber.ROUND_CEIL,
  "ceil" = BigNumber.ROUND_CEIL,
  "floor" = BigNumber.ROUND_FLOOR,
}

/**
 * @param {RoundingMode} roundMode BigNumber's rounding mode shortcut.
 *
 * @return {BigNumber.RoundingMode} The related BigNumber rounding mode.
 */
export function expandRoundMode(
  roundMode: RoundingMode,
): BigNumber.RoundingMode {
  return (RoundingModeMap[roundMode] ??
    RoundingModeMap.default) as BigNumber.RoundingMode;
}