Liquidity withdrawal (#457)

* withdrawLiquidity cloud function

* update rules

* exclude antes from getCpmmLiquidityPoolWeights

* update correct lp shares

* liquidity panel

* don't create bet if less than 1 surplus share

* withdrawLiquidity return type

* static analysis fix

* hook dependency

* prettier

* renaming

* typo

* getCpmmLiquidityPoolWeights: always exclude antes

* delete unused function

* casting

common/calculate-cpmm.ts

@@ -1,4 +1,4 @@
-import { sum, groupBy, mapValues, sumBy } from 'lodash'
+import { sum, groupBy, mapValues, sumBy, partition } from 'lodash'
 
 import { CPMMContract } from './contract'
 import { CREATOR_FEE, Fees, LIQUIDITY_FEE, noFees, PLATFORM_FEE } from './fees'
@@ -260,13 +260,7 @@ export function addCpmmLiquidity(
   return { newPool, liquidity, newP }
 }
 
-export function getCpmmLiquidityPoolWeights(
-  contract: CPMMContract,
-  liquidities: LiquidityProvision[]
-) {
-  const { p } = contract
-
-  const liquidityShares = liquidities.map((l) => {
+const calculateLiquidityDelta = (p: number) => (l: LiquidityProvision) => {
   const oldLiquidity = getCpmmLiquidity(l.pool, p)
 
   const newPool = addObjects(l.pool, { YES: l.amount, NO: l.amount })
@@ -274,13 +268,22 @@ export function getCpmmLiquidityPoolWeights(
 
   const liquidity = newLiquidity - oldLiquidity
   return liquidity
-  })
+}
 
-  const shareSum = sum(liquidityShares)
+export function getCpmmLiquidityPoolWeights(
+  contract: CPMMContract,
+  liquidities: LiquidityProvision[]
+) {
+  const [antes, nonAntes] = partition(liquidities, (l) => !!l.isAnte)
+
+  const calcLiqudity = calculateLiquidityDelta(contract.p)
+  const liquidityShares = nonAntes.map(calcLiqudity)
+
+  const shareSum = sum(liquidityShares) + sum(antes.map(calcLiqudity))
 
   const weights = liquidityShares.map((s, i) => ({
     weight: s / shareSum,
-    providerId: liquidities[i].userId,
+    providerId: nonAntes[i].userId,
   }))
 
   const userWeights = groupBy(weights, (w) => w.providerId)
@@ -290,22 +293,13 @@ export function getCpmmLiquidityPoolWeights(
   return totalUserWeights
 }
 
-// export function removeCpmmLiquidity(
-//   contract: CPMMContract,
-//   liquidity: number
-// ) {
-//   const { YES, NO } = contract.pool
-//   const poolLiquidity = getCpmmLiquidity({ YES, NO })
-//   const p = getCpmmProbability({ YES, NO }, contract.p)
+export function getUserLiquidityShares(
+  userId: string,
+  contract: CPMMContract,
+  liquidities: LiquidityProvision[]
+) {
+  const weights = getCpmmLiquidityPoolWeights(contract, liquidities)
+  const userWeight = weights[userId] ?? 0
 
-//   const f = liquidity / poolLiquidity
-//   const [payoutYes, payoutNo] = [f * YES, f * NO]
-
-//   const betAmount = Math.abs(payoutYes - payoutNo)
-//   const betOutcome = p >= 0.5 ? 'NO' : 'YES' // opposite side as adding liquidity
-//   const payout = Math.min(payoutYes, payoutNo)
-
-//   const newPool = { YES: YES - payoutYes, NO: NO - payoutNo }
-
-//   return { newPool, payout, betAmount, betOutcome }
-// }
+  return mapValues(contract.pool, (shares) => userWeight * shares)
+}

common/util/object.ts

@@ -23,3 +23,18 @@ export const addObjects = <T extends { [key: string]: number }>(
 
   return newObj as T
 }
+
+export const subtractObjects = <T extends { [key: string]: number }>(
+  obj1: T,
+  obj2: T
+) => {
+  const keys = union(Object.keys(obj1), Object.keys(obj2))
+  const newObj = {} as any
+
+  for (const key of keys) {
+    newObj[key] = (obj1[key] ?? 0) - (obj2[key] ?? 0)
+  }
+
+  return newObj as T
+}
+

firestore.rules

@@ -65,6 +65,10 @@ service cloud.firestore {
       allow read;
     }
 
+    match /{somePath=**}/liquidity/{liquidityId} {
+      allow read;
+    }
+
     function commentMatchesUser(userId, comment) {
       // it's a bad look if someone can impersonate other ids/names/avatars so check everything
       let user = get(/databases/$(database)/documents/users/$(userId));

functions/src/index.ts

@@ -35,3 +35,4 @@ export * from './place-bet'
 export * from './sell-bet'
 export * from './sell-shares'
 export * from './create-contract'
+export * from './withdraw-liquidity'

functions/src/withdraw-liquidity.ts

@@ -0,0 +1,111 @@
+import * as functions from 'firebase-functions'
+import * as admin from 'firebase-admin'
+
+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 } from './api'
+
+export const withdrawLiquidity = functions
+  .runWith({ minInstances: 1 })
+  .https.onCall(
+    async (
+      data: {
+        contractId: string
+      },
+      context
+    ) => {
+      const userId = context?.auth?.uid
+      if (!userId) return { status: 'error', message: 'Not authorized' }
+
+      const { contractId } = data
+      if (!contractId)
+        return { status: 'error', message: 'Missing contract id' }
+
+      const result = await firestore.runTransaction(async (trans) => {
+        const lpDoc = firestore.doc(`users/${userId}`)
+        const lpSnap = await trans.get(lpDoc)
+        if (!lpSnap.exists) throw new APIError(400, 'User not found.')
+        const lp = lpSnap.data() as User
+
+        const contractDoc = firestore.doc(`contracts/${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/${contractId}/liquidity`
+        )
+
+        const liquiditiesSnap = await trans.get(liquidityCollection)
+
+        const liquidities = liquiditiesSnap.docs.map(
+          (doc) => doc.data() as LiquidityProvision
+        )
+
+        const userShares = getUserLiquidityShares(userId, contract, liquidities)
+
+        // zero all added amounts for now
+        // can add support for partial withdrawals in the future
+        liquiditiesSnap.docs
+          .filter(
+            (_, i) => !liquidities[i].isAnte && liquidities[i].userId === userId
+          )
+          .forEach((doc) => trans.update(doc.ref, { amount: 0 }))
+
+        const payout = Math.min(...Object.values(userShares))
+        if (payout <= 0) return {}
+
+        const newBalance = lp.balance + payout
+        trans.update(lpDoc, { balance: newBalance })
+
+        const newPool = subtractObjects(contract.pool, userShares)
+        const newTotalLiquidity = contract.totalLiquidity - payout
+        trans.update(contractDoc, {
+          pool: newPool,
+          totalLiquidity: newTotalLiquidity,
+        })
+
+        const prob = getProbability(contract)
+
+        // surplus shares become user's bets
+        const bets = Object.entries(userShares)
+          .map(([outcome, shares]) =>
+            shares - payout < 1 // don't create bet if less than 1 share
+              ? undefined
+              : ({
+                  userId: userId,
+                  contractId: contract.id,
+                  amount: shares - payout,
+                  shares: shares - payout,
+                  outcome,
+                  probBefore: prob,
+                  probAfter: prob,
+                  createdTime: Date.now(),
+                  fees: noFees,
+                } as Omit<Bet, 'id'>)
+          )
+          .filter((x) => x !== undefined)
+
+        for (const bet of bets) {
+          const doc = firestore
+            .collection(`contracts/${contract.id}/bets`)
+            .doc()
+          trans.create(doc, { id: doc.id, ...bet })
+        }
+
+        return userShares
+      })
+
+      console.log('userid', userId, 'withdraws', result)
+      return { status: 'success', userShares: result }
+    }
+  )
+
+const firestore = admin.firestore()

web/components/add-liquidity-panel.tsx

@@ -1,87 +0,0 @@
-import clsx from 'clsx'
-import { useState } from 'react'
-
-import { Contract } from 'common/contract'
-import { formatMoney } from 'common/util/format'
-import { useUser } from 'web/hooks/use-user'
-import { addLiquidity } from 'web/lib/firebase/fn-call'
-import { AmountInput } from './amount-input'
-import { Row } from './layout/row'
-
-export function AddLiquidityPanel(props: { contract: Contract }) {
-  const { contract } = props
-  const { id: contractId } = contract
-
-  const user = useUser()
-
-  const [amount, setAmount] = useState<number | undefined>(undefined)
-  const [error, setError] = useState<string | undefined>(undefined)
-  const [isSuccess, setIsSuccess] = useState(false)
-  const [isLoading, setIsLoading] = useState(false)
-
-  const onAmountChange = (amount: number | undefined) => {
-    setIsSuccess(false)
-    setAmount(amount)
-
-    // Check for errors.
-    if (amount !== undefined) {
-      if (user && user.balance < amount) {
-        setError('Insufficient balance')
-      } else if (amount < 1) {
-        setError('Minimum amount: ' + formatMoney(1))
-      } else {
-        setError(undefined)
-      }
-    }
-  }
-
-  const submit = () => {
-    if (!amount) return
-
-    setIsLoading(true)
-    setIsSuccess(false)
-
-    addLiquidity({ amount, contractId })
-      .then((r) => {
-        if (r.status === 'success') {
-          setIsSuccess(true)
-          setError(undefined)
-          setIsLoading(false)
-        } else {
-          setError('Server error')
-        }
-      })
-      .catch((e) => setError('Server error'))
-  }
-
-  return (
-    <>
-      <div className="text-gray-500">
-        Subsidize this market by adding liquidity for traders.
-      </div>
-
-      <Row>
-        <AmountInput
-          amount={amount}
-          onChange={onAmountChange}
-          label="M$"
-          error={error}
-          disabled={isLoading}
-        />
-        <button
-          className={clsx('btn btn-primary ml-2', isLoading && 'btn-disabled')}
-          onClick={submit}
-          disabled={isLoading}
-        >
-          Add
-        </button>
-      </Row>
-
-      {isSuccess && amount && (
-        <div>Success! Added {formatMoney(amount)} in liquidity.</div>
-      )}
-
-      {isLoading && <div>Processing...</div>}
-    </>
-  )
-}

web/components/contract/contract-info-dialog.tsx

@@ -12,7 +12,7 @@ import {
   contractPool,
   getBinaryProbPercent,
 } from 'web/lib/firebase/contracts'
-import { AddLiquidityPanel } from '../add-liquidity-panel'
+import { LiquidityPanel } from '../liquidity-panel'
 import { CopyLinkButton } from '../copy-link-button'
 import { Col } from '../layout/col'
 import { Modal } from '../layout/modal'
@@ -113,13 +113,8 @@ export function ContractInfoDialog(props: { contract: Contract; bets: Bet[] }) {
           <TagsInput contract={contract} />
           <div />
 
-          {contract.mechanism === 'cpmm-1' &&
-            !contract.resolution &&
-            (!closeTime || closeTime > Date.now()) && (
-              <>
-                <div className="">Add liquidity</div>
-                <AddLiquidityPanel contract={contract} />
-              </>
+          {contract.mechanism === 'cpmm-1' && !contract.resolution && (
+            <LiquidityPanel contract={contract} />
           )}
         </Col>
       </Modal>

web/components/liquidity-panel.tsx

@@ -0,0 +1,199 @@
+import clsx from 'clsx'
+import { useEffect, useState } from 'react'
+
+import { CPMMContract } from 'common/contract'
+import { formatMoney } from 'common/util/format'
+import { useUser } from 'web/hooks/use-user'
+import { addLiquidity, withdrawLiquidity } from 'web/lib/firebase/fn-call'
+import { AmountInput } from './amount-input'
+import { Row } from './layout/row'
+import { useUserLiquidity } from 'web/hooks/use-liquidity'
+import { Tabs } from './layout/tabs'
+import { NoLabel, YesLabel } from './outcome-label'
+import { Col } from './layout/col'
+
+export function LiquidityPanel(props: { contract: CPMMContract }) {
+  const { contract } = props
+
+  const user = useUser()
+  const lpShares = useUserLiquidity(contract, user?.id ?? '')
+
+  const [showWithdrawal, setShowWithdrawal] = useState(false)
+
+  useEffect(() => {
+    if (!showWithdrawal && lpShares && lpShares.YES && lpShares.NO)
+      setShowWithdrawal(true)
+  }, [showWithdrawal, lpShares])
+
+  return (
+    <Tabs
+      tabs={[
+        {
+          title: 'Add liquidity',
+          content: <AddLiquidityPanel contract={contract} />,
+        },
+        ...(showWithdrawal
+          ? [
+              {
+                title: 'Withdraw liquidity',
+                content: (
+                  <WithdrawLiquidityPanel
+                    contract={contract}
+                    lpShares={lpShares as { YES: number; NO: number }}
+                  />
+                ),
+              },
+            ]
+          : []),
+      ]}
+    />
+  )
+}
+
+function AddLiquidityPanel(props: { contract: CPMMContract }) {
+  const { contract } = props
+  const { id: contractId } = contract
+
+  const user = useUser()
+
+  const [amount, setAmount] = useState<number | undefined>(undefined)
+  const [error, setError] = useState<string | undefined>(undefined)
+  const [isSuccess, setIsSuccess] = useState(false)
+  const [isLoading, setIsLoading] = useState(false)
+
+  const onAmountChange = (amount: number | undefined) => {
+    setIsSuccess(false)
+    setAmount(amount)
+
+    // Check for errors.
+    if (amount !== undefined) {
+      if (user && user.balance < amount) {
+        setError('Insufficient balance')
+      } else if (amount < 1) {
+        setError('Minimum amount: ' + formatMoney(1))
+      } else {
+        setError(undefined)
+      }
+    }
+  }
+
+  const submit = () => {
+    if (!amount) return
+
+    setIsLoading(true)
+    setIsSuccess(false)
+
+    addLiquidity({ amount, contractId })
+      .then((r) => {
+        if (r.status === 'success') {
+          setIsSuccess(true)
+          setError(undefined)
+          setIsLoading(false)
+        } else {
+          setError('Server error')
+        }
+      })
+      .catch((e) => setError('Server error'))
+  }
+
+  return (
+    <>
+      <div className="mb-2 text-gray-500">
+        Subsidize this market by adding liquidity for traders.
+      </div>
+
+      <Row>
+        <AmountInput
+          amount={amount}
+          onChange={onAmountChange}
+          label="M$"
+          error={error}
+          disabled={isLoading}
+        />
+        <button
+          className={clsx('btn btn-primary ml-2', isLoading && 'btn-disabled')}
+          onClick={submit}
+          disabled={isLoading}
+        >
+          Add
+        </button>
+      </Row>
+
+      {isSuccess && amount && (
+        <div>Success! Added {formatMoney(amount)} in liquidity.</div>
+      )}
+
+      {isLoading && <div>Processing...</div>}
+    </>
+  )
+}
+
+function WithdrawLiquidityPanel(props: {
+  contract: CPMMContract
+  lpShares: { YES: number; NO: number }
+}) {
+  const { contract, lpShares } = props
+  const { YES: yesShares, NO: noShares } = lpShares
+
+  const [error, setError] = useState<string | undefined>(undefined)
+  const [isSuccess, setIsSuccess] = useState(false)
+  const [isLoading, setIsLoading] = useState(false)
+
+  const submit = () => {
+    setIsLoading(true)
+    setIsSuccess(false)
+
+    withdrawLiquidity({ contractId: contract.id })
+      .then((r) => {
+        setIsSuccess(true)
+        setError(undefined)
+        setIsLoading(false)
+      })
+      .catch((e) => setError('Server error'))
+  }
+
+  if (isSuccess)
+    return (
+      <div className="text-gray-500">
+        Success! Your liquidity was withdrawn.
+      </div>
+    )
+
+  if (!yesShares && !noShares)
+    return (
+      <div className="text-gray-500">
+        You do not have any liquidity positions to withdraw.
+      </div>
+    )
+
+  return (
+    <Col>
+      <div className="mb-4 text-gray-500">
+        Your liquidity position is currently:
+      </div>
+
+      <span>
+        {yesShares.toFixed(2)} <YesLabel /> shares
+      </span>
+
+      <span>
+        {noShares.toFixed(2)} <NoLabel /> shares
+      </span>
+
+      <Row className="mt-4 mb-2">
+        <button
+          className={clsx(
+            'btn btn-outline btn-sm ml-2',
+            isLoading && 'btn-disabled'
+          )}
+          onClick={submit}
+          disabled={isLoading}
+        >
+          Withdraw
+        </button>
+      </Row>
+
+      {isLoading && <div>Processing...</div>}
+    </Col>
+  )
+}

web/hooks/use-liquidity.ts

@@ -0,0 +1,26 @@
+import { useEffect, useState } from 'react'
+
+import { CPMMContract } from 'common/contract'
+import { LiquidityProvision } from 'common/liquidity-provision'
+import { getUserLiquidityShares } from 'common/calculate-cpmm'
+
+import { listenForLiquidity } from 'web/lib/firebase/liquidity'
+
+export const useLiquidity = (contractId: string) => {
+  const [liquidities, setLiquidities] = useState<
+    LiquidityProvision[] | undefined
+  >(undefined)
+
+  useEffect(() => {
+    return listenForLiquidity(contractId, setLiquidities)
+  }, [contractId])
+
+  return liquidities
+}
+
+export const useUserLiquidity = (contract: CPMMContract, userId: string) => {
+  const liquidities = useLiquidity(contract.id)
+
+  const userShares = getUserLiquidityShares(userId, contract, liquidities ?? [])
+  return userShares
+}

web/lib/firebase/fn-call.ts

@@ -10,6 +10,11 @@ import { safeLocalStorage } from '../util/local'
 export const cloudFunction = <RequestData, ResponseData>(name: string) =>
   httpsCallable<RequestData, ResponseData>(functions, name)
 
+export const withdrawLiquidity = cloudFunction<
+  { contractId: string },
+  { status: 'error' | 'success'; userShares: { [outcome: string]: number } }
+>('withdrawLiquidity')
+
 export const createFold = cloudFunction<
   { name: string; about: string; tags: string[] },
   { status: 'error' | 'success'; message?: string; fold?: Fold }

web/lib/firebase/liquidity.ts

@@ -0,0 +1,17 @@
+import { collection, query } from 'firebase/firestore'
+
+import { db } from './init'
+import { listenForValues } from './utils'
+import { LiquidityProvision } from 'common/liquidity-provision'
+
+export function listenForLiquidity(
+  contractId: string,
+  setLiquidity: (lps: LiquidityProvision[]) => void
+) {
+  const lpQuery = query(collection(db, 'contracts', contractId, 'liquidity'))
+
+  return listenForValues<LiquidityProvision>(lpQuery, (lps) => {
+    lps.sort((lp1, lp2) => lp1.createdTime - lp2.createdTime)
+    setLiquidity(lps)
+  })
+}