manifold/functions/src/sell-bet.ts

75 lines
2.7 KiB
TypeScript

import * as admin from 'firebase-admin'
import { z } from 'zod'
import { APIError, newEndpoint, validate } from './api'
import { Contract } from '../../common/contract'
import { User } from '../../common/user'
import { Bet } from '../../common/bet'
import { getSellBetInfo } from '../../common/sell-bet'
import { addObjects, removeUndefinedProps } from '../../common/util/object'
const bodySchema = z.object({
contractId: z.string(),
betId: z.string(),
})
export const sellbet = newEndpoint({}, async (req, auth) => {
const { contractId, betId } = validate(bodySchema, req.body)
// run as transaction to prevent race conditions
return await firestore.runTransaction(async (transaction) => {
const contractDoc = firestore.doc(`contracts/${contractId}`)
const userDoc = firestore.doc(`users/${auth.uid}`)
const betDoc = firestore.doc(`contracts/${contractId}/bets/${betId}`)
const [contractSnap, userSnap, betSnap] = await transaction.getAll(
contractDoc,
userDoc,
betDoc
)
if (!contractSnap.exists) throw new APIError(400, 'Contract not found.')
if (!userSnap.exists) throw new APIError(400, 'User not found.')
if (!betSnap.exists) throw new APIError(400, 'Bet not found.')
const contract = contractSnap.data() as Contract
const user = userSnap.data() as User
const bet = betSnap.data() as Bet
const { closeTime, mechanism, collectedFees, volume } = contract
if (mechanism !== 'dpm-2')
throw new APIError(400, 'You can only sell bets on DPM-2 contracts.')
if (closeTime && Date.now() > closeTime)
throw new APIError(400, 'Trading is closed.')
if (auth.uid !== bet.userId)
throw new APIError(400, 'The specified bet does not belong to you.')
if (bet.isSold)
throw new APIError(400, 'The specified bet is already sold.')
const { newBet, newPool, newTotalShares, newTotalBets, fees } =
getSellBetInfo(bet, contract)
/* eslint-disable-next-line @typescript-eslint/no-non-null-assertion */
const saleAmount = newBet.sale!.amount
const newBalance = user.balance + saleAmount - (bet.loanAmount ?? 0)
const newBetDoc = firestore.collection(`contracts/${contractId}/bets`).doc()
transaction.update(userDoc, { balance: newBalance })
transaction.update(betDoc, { isSold: true })
transaction.create(newBetDoc, { id: betDoc.id, userId: user.id, ...newBet })
transaction.update(
contractDoc,
removeUndefinedProps({
pool: newPool,
totalShares: newTotalShares,
totalBets: newTotalBets,
collectedFees: addObjects(fees, collectedFees),
volume: volume + Math.abs(newBet.amount),
})
)
return {}
})
})
const firestore = admin.firestore()