vega-frontend-monorepo/libs/deal-ticket/src/hooks/use-order-closeout.ts

import { BigNumber } from 'bignumber.js';
import type { OrderSubmissionBody } from '@vegaprotocol/wallet';
import { useVegaWallet } from '@vegaprotocol/wallet';
import {
  addDecimal,
  formatNumber,
  removePaginationWrapper,
} from '@vegaprotocol/react-helpers';
import { useMarketPositions } from './use-market-positions';
import { useMarketDataMarkPrice } from './use-market-data-mark-price';
import { usePartyMarketDataQuery } from './__generated__/PartyMarketData';
import { Schema } from '@vegaprotocol/types';
import type { PartyBalanceQuery } from './__generated__/PartyBalance';
import { useSettlementAccount } from './use-settlement-account';
import type { MarketDealTicket } from '@vegaprotocol/market-list';

interface Props {
  order: OrderSubmissionBody['orderSubmission'];
  market: MarketDealTicket;
  partyData?: PartyBalanceQuery;
}

export const useOrderCloseOut = ({
  order,
  market,
  partyData,
}: Props): string | null => {
  const { pubKey } = useVegaWallet();
  const accounts = removePaginationWrapper(
    partyData?.party?.accountsConnection?.edges
  );
  const account = useSettlementAccount(
    market.tradableInstrument.instrument.product.settlementAsset.id,
    accounts
  );
  const { data } = usePartyMarketDataQuery({
    pollInterval: 5000,
    variables: { partyId: pubKey || '' },
    skip: !pubKey,
  });

  const markPriceData = useMarketDataMarkPrice(market.id);
  const marketPositions = useMarketPositions({
    marketId: market.id,
    partyId: pubKey || '',
  });

  const marginMaintenanceLevel = new BigNumber(
    addDecimal(
      data?.party?.marginsConnection?.edges?.find(
        (nodes) => nodes.node.market.id === market.id
      )?.node.maintenanceLevel || 0,
      market.decimalPlaces
    )
  );

  const dataAccounts = removePaginationWrapper(
    data?.party?.accountsConnection?.edges
  );
  const positionAccount = dataAccounts.find(
    (account) => account.market?.id === market.id
  );
  const positionAccountBalance = new BigNumber(
    addDecimal(
      positionAccount?.balance || 0,
      positionAccount?.asset?.decimals || 0
    )
  );
  const generalAccountBalance = new BigNumber(
    addDecimal(account?.balance || 0, account?.asset.decimals || 0)
  );
  const volume = new BigNumber(
    addDecimal(
      marketPositions?.openVolume.toString() || '0',
      market.positionDecimalPlaces
    )
  )[order.side === Schema.Side.SIDE_BUY ? 'plus' : 'minus'](order.size);
  const markPrice = new BigNumber(
    addDecimal(
      markPriceData?.market?.data?.markPrice || 0,
      markPriceData?.market?.decimalPlaces || 0
    )
  );
  // regarding formula (marginMaintenanceLevel - positionAccountBalance - generalAccountBalance) / volume + markPrice
  const marginDifference = marginMaintenanceLevel
    .minus(positionAccountBalance)
    .minus(generalAccountBalance);
  const closeOut = marginDifference.div(volume).plus(markPrice);
  if (closeOut.isPositive()) {
    return formatNumber(closeOut, market.decimalPlaces);
  }
  return null;
};