AugurProject/augur-ui

import { SCALAR } from "modules/markets/constants/market-types";
import { createBigNumber } from "utils/create-big-number";
import { MALFORMED_OUTCOME } from "utils/constants";

export default function calculatePayoutNumeratorsValue(
  market,
  payout,
  isInvalid
) {
  const { maxPrice, minPrice, numTicks, marketType } = market;
  const isScalar = marketType === SCALAR;

  if (!payout) return null;
  if (payout.length === 0) return null;
  if (isInvalid) return null;

  if (isScalar) {
    const longPayout = createBigNumber(payout[1], 10);
    const priceRange = createBigNumber(maxPrice, 10).minus(
      createBigNumber(minPrice, 10)
    );
    // calculation: ((longPayout * priceRange) / numTicks) + minPrice
    return longPayout
      .times(priceRange)
      .dividedBy(createBigNumber(numTicks, 10))
      .plus(createBigNumber(minPrice, 10))
      .toString();
  }
  // test if stake payout is malformed
  if (payout.reduce((p, ticks) => (ticks > 0 ? p + 1 : p), 0) > 1) {
    return MALFORMED_OUTCOME;
  }

  return payout.findIndex(item => item > 0).toString();
}