manifold/functions/src/resolve-market.ts
2021-12-14 12:54:26 -06:00

108 lines
3.3 KiB
TypeScript

import * as functions from 'firebase-functions'
import * as admin from 'firebase-admin'
import * as _ from 'lodash'
import { Contract } from './types/contract'
import { User } from './types/user'
import { Bet } from './types/bet'
export const PLATFORM_FEE = 0.01 // 1%
export const CREATOR_FEE = 0.01 // 1%
export const resolveMarket = functions
.runWith({ minInstances: 1 })
.https
.onCall(async (data: {
outcome: string
contractId: string
}, context) => {
const userId = context?.auth?.uid
if (!userId) return { status: 'error', message: 'Not authorized' }
const { outcome, contractId } = data
if (!['YES', 'NO', 'CANCEL'].includes(outcome))
return { status: 'error', message: 'Invalid outcome' }
const contractDoc = firestore.doc(`contracts/${contractId}`)
const contractSnap = await contractDoc.get()
if (!contractSnap.exists)
return { status: 'error', message: 'Invalid contract' }
const contract = contractSnap.data() as Contract
if (contract.creatorId !== userId)
return { status: 'error', message: 'User not creator of contract' }
if (contract.resolution)
return { status: 'error', message: 'Contract already resolved' }
await contractDoc.update({
isResolved: true,
resolution: outcome,
resolutionTime: Date.now()
})
console.log('contract ', contractId, 'resolved to:', outcome)
const betsSnap = await firestore.collection(`contracts/${contractId}/bets`).get()
const bets = betsSnap.docs.map(doc => doc.data() as Bet)
const payouts = outcome === 'CANCEL'
? bets.map(bet => ({
userId: bet.userId,
payout: bet.amount
}))
: getPayouts(outcome, contract, bets)
console.log('payouts:', payouts)
const groups = _.groupBy(payouts, payout => payout.userId)
const userPayouts = _.mapValues(groups, group => _.sumBy(group, g => g.payout))
const payoutPromises = Object
.entries(userPayouts)
.map(payUser)
return await Promise.all(payoutPromises)
.catch(e => ({ status: 'error', message: e }))
.then(() => ({ status: 'success' }))
})
const firestore = admin.firestore()
const getPayouts = (outcome: string, contract: Contract, bets: Bet[]) => {
const [yesBets, noBets] = _.partition(bets, bet => bet.outcome === 'YES')
const [pot, winningBets] = outcome === 'YES'
? [contract.pot.NO - contract.seedAmounts.NO, yesBets]
: [contract.pot.YES - contract.seedAmounts.YES, noBets]
const finalPot = (1 - PLATFORM_FEE - CREATOR_FEE) * pot
const creatorPayout = CREATOR_FEE * pot
console.log('final pot:', finalPot, 'creator fee:', creatorPayout)
const sumWeights = _.sumBy(winningBets, bet => bet.dpmWeight)
const winnerPayouts = winningBets.map(bet => ({
userId: bet.userId,
payout: bet.amount + (bet.dpmWeight / sumWeights * finalPot)
}))
return winnerPayouts
.concat([{ userId: contract.creatorId, payout: creatorPayout }]) // add creator fee
}
const payUser = ([userId, payout]: [string, number]) => {
return firestore.runTransaction(async transaction => {
const userDoc = firestore.doc(`users/${userId}`)
const userSnap = await transaction.get(userDoc)
if (!userSnap.exists) return
const user = userSnap.data() as User
const newUserBalance = user.balance + payout
transaction.update(userDoc, { balance: newUserBalance })
})
}