import * as _ from 'lodash' import { Bet } from './bet' import { deductFees, getProbability } from './calculate' import { Contract, outcome } from './contract' import { CREATOR_FEE, FEES } from './fees' export const getCancelPayouts = (contract: Contract, bets: Bet[]) => { const { pool } = contract const poolTotal = pool.YES + pool.NO console.log('resolved N/A, pool M$', poolTotal) const betSum = _.sumBy(bets, (b) => b.amount) return bets.map((bet) => ({ userId: bet.userId, payout: (bet.amount / betSum) * poolTotal, })) } export const getStandardPayouts = ( outcome: 'YES' | 'NO', contract: Contract, bets: Bet[] ) => { const [yesBets, noBets] = _.partition(bets, (bet) => bet.outcome === 'YES') const winningBets = outcome === 'YES' ? yesBets : noBets const pool = contract.pool.YES + contract.pool.NO const totalShares = _.sumBy(winningBets, (b) => b.shares) const winnerPayouts = winningBets.map((bet) => { const winnings = (bet.shares / totalShares) * pool return { userId: bet.userId, amount: bet.amount, profit: winnings - bet.amount, } }) const [profitable, unprofitable] = _.partition( winnerPayouts, (wp) => wp.profit >= 0 ) const totalProfits = _.sumBy(profitable, (wp) => wp.profit) const totalFees = FEES * totalProfits const deficit = _.sumBy(unprofitable, (wp) => -wp.profit) const adjTotalFees = deficit >= totalFees ? 0 : totalFees - deficit const creatorPayout = Math.min(adjTotalFees, CREATOR_FEE * totalProfits) const w = deficit > totalFees ? totalFees / deficit : 1 const adjUnprofitable = unprofitable.map((wp) => { const adjustment = w * -wp.profit return { ...wp, profit: wp.profit + adjustment, } }) console.log( 'resolved', outcome, 'pool', pool, 'profits', totalProfits, 'deficit', deficit, 'creator fee', creatorPayout ) return _.union(profitable, adjUnprofitable) .map(({ userId, amount, profit }) => ({ userId, payout: amount + (1 - FEES) * profit, })) .concat([{ userId: contract.creatorId, payout: creatorPayout }]) // add creator fee } export const getMktPayouts = ( contract: Contract, bets: Bet[], resolutionProbability?: number ) => { const p = resolutionProbability === undefined ? getProbability(contract.totalShares) : resolutionProbability const pool = contract.pool.YES + contract.pool.NO console.log('Resolved MKT at p=', p, 'pool: $M', pool) const [yesBets, noBets] = _.partition(bets, (bet) => bet.outcome === 'YES') const weightedShareTotal = p * _.sumBy(yesBets, (b) => b.shares) + (1 - p) * _.sumBy(noBets, (b) => b.shares) const yesPayouts = yesBets.map((bet) => ({ userId: bet.userId, payout: deductFees( bet.amount, ((p * bet.shares) / weightedShareTotal) * pool ), })) const noPayouts = noBets.map((bet) => ({ userId: bet.userId, payout: deductFees( bet.amount, (((1 - p) * bet.shares) / weightedShareTotal) * pool ), })) const creatorPayout = CREATOR_FEE * pool return [ ...yesPayouts, ...noPayouts, { userId: contract.creatorId, payout: creatorPayout }, ] } export const getPayouts = ( outcome: outcome, contract: Contract, bets: Bet[], resolutionProbability?: number ) => { switch (outcome) { case 'YES': case 'NO': return getStandardPayouts(outcome, contract, bets) case 'MKT': return getMktPayouts(contract, bets, resolutionProbability) case 'CANCEL': return getCancelPayouts(contract, bets) } }