pay back excess liquidity

common/calculate-cpmm.ts

@@ -1,11 +1,10 @@
-import { sum, groupBy, mapValues, sumBy } from 'lodash'
+import { groupBy, mapValues, sumBy } from 'lodash'
 import { LimitBet } from './bet'
 
 import { CREATOR_FEE, Fees, LIQUIDITY_FEE, PLATFORM_FEE } from './fees'
 import { LiquidityProvision } from './liquidity-provision'
 import { computeFills } from './new-bet'
 import { binarySearch } from './util/algos'
-import { addObjects } from './util/object'
 
 export type CpmmState = {
   pool: { [outcome: string]: number }
@@ -267,48 +266,22 @@ export function addCpmmLiquidity(
   return { newPool, liquidity, newP }
 }
 
-const calculateLiquidityDelta = (p: number) => (l: LiquidityProvision) => {
-  const oldLiquidity = getCpmmLiquidity(l.pool, p)
+export function getCpmmLiquidityPoolWeights(liquidities: LiquidityProvision[]) {
+  const userAmounts = groupBy(liquidities, (w) => w.userId)
+  const totalAmount = sumBy(liquidities, (w) => w.amount)
 
-  const newPool = addObjects(l.pool, { YES: l.amount, NO: l.amount })
-  const newLiquidity = getCpmmLiquidity(newPool, p)
-
-  const liquidity = newLiquidity - oldLiquidity
-  return liquidity
-}
-
-export function getCpmmLiquidityPoolWeights(
-  state: CpmmState,
-  liquidities: LiquidityProvision[],
-  excludeAntes: boolean
-) {
-  const calcLiqudity = calculateLiquidityDelta(state.p)
-  const liquidityShares = liquidities.map(calcLiqudity)
-  const shareSum = sum(liquidityShares)
-
-  const weights = liquidityShares.map((shares, i) => ({
-    weight: shares / shareSum,
-    providerId: liquidities[i].userId,
-  }))
-
-  const includedWeights = excludeAntes
-    ? weights.filter((_, i) => !liquidities[i].isAnte)
-    : weights
-
-  const userWeights = groupBy(includedWeights, (w) => w.providerId)
-  const totalUserWeights = mapValues(userWeights, (userWeight) =>
-    sumBy(userWeight, (w) => w.weight)
+  return mapValues(
+    userAmounts,
+    (amounts) => sumBy(amounts, (w) => w.amount) / totalAmount
   )
-  return totalUserWeights
 }
 
 export function getUserLiquidityShares(
   userId: string,
   state: CpmmState,
-  liquidities: LiquidityProvision[],
-  excludeAntes: boolean
+  liquidities: LiquidityProvision[]
 ) {
-  const weights = getCpmmLiquidityPoolWeights(state, liquidities, excludeAntes)
+  const weights = getCpmmLiquidityPoolWeights(liquidities)
   const userWeight = weights[userId] ?? 0
 
   return mapValues(state.pool, (shares) => userWeight * shares)

common/payouts-fixed.ts

@@ -1,4 +1,3 @@
-
 import { Bet } from './bet'
 import { getProbability } from './calculate'
 import { getCpmmLiquidityPoolWeights } from './calculate-cpmm'
@@ -56,10 +55,10 @@ export const getLiquidityPoolPayouts = (
   outcome: string,
   liquidities: LiquidityProvision[]
 ) => {
-  const { pool } = contract
-  const finalPool = pool[outcome]
+  const { pool, subsidyPool } = contract
+  const finalPool = pool[outcome] + subsidyPool
 
-  const weights = getCpmmLiquidityPoolWeights(contract, liquidities, false)
+  const weights = getCpmmLiquidityPoolWeights(liquidities)
 
   return Object.entries(weights).map(([providerId, weight]) => ({
     userId: providerId,
@@ -95,10 +94,10 @@ export const getLiquidityPoolProbPayouts = (
   p: number,
   liquidities: LiquidityProvision[]
 ) => {
-  const { pool } = contract
-  const finalPool = p * pool.YES + (1 - p) * pool.NO
+  const { pool, subsidyPool } = contract
+  const finalPool = p * pool.YES + (1 - p) * pool.NO + subsidyPool
 
-  const weights = getCpmmLiquidityPoolWeights(contract, liquidities, false)
+  const weights = getCpmmLiquidityPoolWeights(liquidities)
 
   return Object.entries(weights).map(([providerId, weight]) => ({
     userId: providerId,

functions/src/resolve-market.ts

@@ -9,7 +9,15 @@ import {
   RESOLUTIONS,
 } from '../../common/contract'
 import { Bet } from '../../common/bet'
-import { getContractPath, getUser, getValues, isProd, log, payUser, revalidateStaticProps } from './utils'
+import {
+  getContractPath,
+  getUser,
+  getValues,
+  isProd,
+  log,
+  payUser,
+  revalidateStaticProps,
+} from './utils'
 import {
   getLoanPayouts,
   getPayouts,
@@ -145,6 +153,7 @@ export const resolvemarket = newEndpoint(opts, async (req, auth) => {
       resolutions,
       collectedFees,
     }),
+    subsidyPool: 0,
   }
 
   await contractDoc.update(updatedContract)

functions/src/withdraw-liquidity.ts

@@ -1,121 +0,0 @@
-import * as admin from 'firebase-admin'
-import { z } from 'zod'
-
-import { CPMMContract } from '../../common/contract'
-import { User } from '../../common/user'
-import { subtractObjects } from '../../common/util/object'
-import { LiquidityProvision } from '../../common/liquidity-provision'
-import { getUserLiquidityShares } from '../../common/calculate-cpmm'
-import { Bet } from '../../common/bet'
-import { getProbability } from '../../common/calculate'
-import { noFees } from '../../common/fees'
-
-import { APIError, newEndpoint, validate } from './api'
-import { redeemShares } from './redeem-shares'
-
-const bodySchema = z.object({
-  contractId: z.string(),
-})
-
-export const withdrawliquidity = newEndpoint({}, async (req, auth) => {
-  const { contractId } = validate(bodySchema, req.body)
-
-  return await firestore
-    .runTransaction(async (trans) => {
-      const lpDoc = firestore.doc(`users/${auth.uid}`)
-      const lpSnap = await trans.get(lpDoc)
-      if (!lpSnap.exists) throw new APIError(400, 'User not found.')
-      const lp = lpSnap.data() as User
-
-      const contractDoc = firestore.doc(`contracts/${contractId}`)
-      const contractSnap = await trans.get(contractDoc)
-      if (!contractSnap.exists) throw new APIError(400, 'Contract not found.')
-      const contract = contractSnap.data() as CPMMContract
-
-      const liquidityCollection = firestore.collection(
-        `contracts/${contractId}/liquidity`
-      )
-
-      const liquiditiesSnap = await trans.get(liquidityCollection)
-
-      const liquidities = liquiditiesSnap.docs.map(
-        (doc) => doc.data() as LiquidityProvision
-      )
-
-      const userShares = getUserLiquidityShares(
-        auth.uid,
-        contract,
-        liquidities,
-        true
-      )
-
-      // zero all added amounts for now
-      // can add support for partial withdrawals in the future
-      liquiditiesSnap.docs
-        .filter(
-          (_, i) => !liquidities[i].isAnte && liquidities[i].userId === auth.uid
-        )
-        .forEach((doc) => trans.update(doc.ref, { amount: 0 }))
-
-      const payout = Math.min(...Object.values(userShares))
-      if (payout <= 0) return {}
-
-      const newBalance = lp.balance + payout
-      const newTotalDeposits = lp.totalDeposits + payout
-      trans.update(lpDoc, {
-        balance: newBalance,
-        totalDeposits: newTotalDeposits,
-      } as Partial<User>)
-
-      const newPool = subtractObjects(contract.pool, userShares)
-
-      const minPoolShares = Math.min(...Object.values(newPool))
-      const adjustedTotal = contract.totalLiquidity - payout
-
-      // total liquidity is a bogus number; use minPoolShares to prevent from going negative
-      const newTotalLiquidity = Math.max(adjustedTotal, minPoolShares)
-
-      trans.update(contractDoc, {
-        pool: newPool,
-        totalLiquidity: newTotalLiquidity,
-      })
-
-      const prob = getProbability(contract)
-
-      // surplus shares become user's bets
-      const bets = Object.entries(userShares)
-        .map(([outcome, shares]) =>
-          shares - payout < 1 // don't create bet if less than 1 share
-            ? undefined
-            : ({
-                userId: auth.uid,
-                contractId: contract.id,
-                amount:
-                  (outcome === 'YES' ? prob : 1 - prob) * (shares - payout),
-                shares: shares - payout,
-                outcome,
-                probBefore: prob,
-                probAfter: prob,
-                createdTime: Date.now(),
-                isLiquidityProvision: true,
-                fees: noFees,
-              } as Omit<Bet, 'id'>)
-        )
-        .filter((x) => x !== undefined)
-
-      for (const bet of bets) {
-        const doc = firestore.collection(`contracts/${contract.id}/bets`).doc()
-        trans.create(doc, { id: doc.id, ...bet })
-      }
-
-      return userShares
-    })
-    .then(async (result) => {
-      // redeem surplus bet with pre-existing bets
-      await redeemShares(auth.uid, contractId)
-      console.log('userid', auth.uid, 'withdraws', result)
-      return result
-    })
-})
-
-const firestore = admin.firestore()

web/hooks/use-liquidity.ts

@@ -21,11 +21,6 @@ export const useLiquidity = (contractId: string) => {
 export const useUserLiquidity = (contract: CPMMContract, userId: string) => {
   const liquidities = useLiquidity(contract.id)
 
-  const userShares = getUserLiquidityShares(
-    userId,
-    contract,
-    liquidities ?? [],
-    true
-  )
+  const userShares = getUserLiquidityShares(userId, contract, liquidities ?? [])
   return userShares
 }