Fill in more of placebet

common/new-bet.ts

@@ -37,17 +37,19 @@ export type BetInfo = {
 const computeFill = (
   betAmount: number,
   outcome: 'YES' | 'NO',
-  limitProb: number,
+  limitProb: number | undefined,
   cpmmState: CpmmState,
   matchedBet: LimitBet
 ) => {
   const prob = getCpmmProbability(cpmmState.pool, cpmmState.p)
 
   if (
-    outcome === 'YES'
+    limitProb !== undefined &&
+    (outcome === 'YES'
       ? Math.min(prob, matchedBet.limitProb) > limitProb
-      : Math.max(prob, matchedBet.limitProb) < limitProb
+      : Math.max(prob, matchedBet.limitProb) < limitProb)
   ) {
+    // No fill.
     return undefined
   }
 
@@ -59,20 +61,19 @@ const computeFill = (
     // Fill from pool.
     const limit =
       outcome === 'YES'
-        ? Math.min(matchedBet.limitProb, limitProb)
+        ? Math.min(matchedBet.limitProb, limitProb ?? Infinity)
-        : Math.max(matchedBet.limitProb, limitProb)
+        : Math.max(matchedBet.limitProb, limitProb ?? -Infinity)
-    const amount = calculateCpmmAmount(cpmmState, limit, 'YES')
+    const amount = calculateCpmmAmount(cpmmState, limit, outcome)
 
     const { shares, newPool, newP, fees } = calculateCpmmPurchase(
       cpmmState,
       amount,
-      'YES'
+      outcome
     )
     const newState = { pool: newPool, p: newP }
 
     return {
       maker: {
-        betId: 'bet',
         matchedBetId: null,
         shares,
         amount,
@@ -80,7 +81,6 @@ const computeFill = (
         fees,
       },
       taker: {
-        betId: 'bet',
         matchedBetId: null,
         shares,
         amount,
@@ -88,17 +88,16 @@ const computeFill = (
     }
   }
 
-  // Fill from bet.
+  // Fill from matchedBet.
   const amount = Math.min(betAmount, matchedBet.amount)
   const shares = matchedBet.shares * (amount / matchedBet.amount)
   const maker = {
-    betId: matchedBet.id,
+    bet: matchedBet,
-    matchedBetId: 'bet',
+    matchedBetId: 'taker',
     amount,
     shares,
   }
   const taker = {
-    betId: 'bet',
     matchedBetId: matchedBet.id,
     amount,
     shares,
@@ -106,20 +105,33 @@ const computeFill = (
   return { maker, taker }
 }
 
-export const getBinaryCpmmLimitBetInfo = (
+export const getBinaryCpmmBetInfo = (
   outcome: 'YES' | 'NO',
   betAmount: number,
   contract: CPMMBinaryContract,
-  limitProb: number,
+  limitProb: number | undefined,
   unfilledBets: LimitBet[] // Sorted by limitProb, createdTime
 ) => {
-  const fills: LimitBet['fills'] = []
+  const takers: {
+    matchedBetId: string | null
+    amount: number
+    shares: number
+  }[] = []
+  const makers: { bet: LimitBet; amount: number; shares: number }[] = []
 
   let cpmmState = { pool: contract.pool, p: contract.p }
   let totalFees = noFees
 
-  for (const bet of unfilledBets) {
+  let i = 0
-    const fill = computeFill(betAmount, outcome, limitProb, cpmmState, bet)
+  while (i < unfilledBets.length) {
+    const matchedBet = unfilledBets[i]
+    const fill = computeFill(
+      betAmount,
+      outcome,
+      limitProb,
+      cpmmState,
+      matchedBet
+    )
     if (!fill) break
 
     const { maker, taker } = fill
@@ -130,12 +142,43 @@ export const getBinaryCpmmLimitBetInfo = (
       cpmmState = maker.state
       totalFees = addObjects(totalFees, maker.fees)
     } else {
-      fills.push(maker)
+      makers.push(maker)
+      i++
     }
-    fills.push(taker)
+    takers.push(taker)
   }
 
-  return { fills, cpmmState, totalFees }
+  const probBefore = getCpmmProbability(contract.pool, contract.p)
+  const probAfter = getCpmmProbability(cpmmState.pool, cpmmState.p)
+
+  const takerAmount = sumBy(takers, 'amount')
+  const takerShares = sumBy(takers, 'shares')
+  const isFilled = Math.abs(betAmount - takerAmount) < 0.000000001
+
+  const newBet = {
+    amount: betAmount,
+    isFilled,
+    fills: takers,
+    contractId: contract.id,
+    shares: takerShares,
+    outcome,
+    probBefore,
+    probAfter,
+    loanAmount: 0,
+    createdTime: Date.now(),
+    fees: totalFees,
+  }
+
+  const { liquidityFee } = totalFees
+  const newTotalLiquidity = (contract.totalLiquidity ?? 0) + liquidityFee
+
+  return {
+    newBet,
+    newPool: cpmmState.pool,
+    newP: cpmmState.p,
+    newTotalLiquidity,
+    makers,
+  }
 }
 
 export const getNewBinaryCpmmBetInfo = (

functions/src/place-bet.ts

@@ -6,8 +6,7 @@ import { Contract, CPMM_MIN_POOL_QTY } from '../../common/contract'
 import { User } from '../../common/user'
 import {
   BetInfo,
-  getBinaryCpmmLimitBetInfo,
+  getBinaryCpmmBetInfo,
-  getNewBinaryCpmmBetInfo,
   getNewBinaryDpmBetInfo,
   getNewMultiBetInfo,
   getNumericBetsInfo,
@@ -17,6 +16,7 @@ import { redeemShares } from './redeem-shares'
 import { log } from './utils'
 import { LimitBet } from 'common/bet'
 import { Query } from 'firebase-admin/firestore'
+import { sumBy } from 'lodash'
 
 const bodySchema = z.object({
   contractId: z.string(),
@@ -70,18 +70,28 @@ export const placebet = newEndpoint(['POST'], async (req, auth) => {
       newTotalBets,
       newTotalLiquidity,
       newP,
-    } = await (async (): Promise<BetInfo> => {
+      makers,
+    } = await (async (): Promise<
+      BetInfo & {
+        makers?: {
+          bet: LimitBet
+          amount: number
+          shares: number
+        }[]
+      }
+    > => {
       if (outcomeType == 'BINARY' && mechanism == 'dpm-2') {
         const { outcome } = validate(binarySchema, req.body)
         return getNewBinaryDpmBetInfo(outcome, amount, contract, loanAmount)
       } else if (outcomeType == 'BINARY' && mechanism == 'cpmm-1') {
         const { outcome, limitProb } = validate(binarySchema, req.body)
+        const boundedLimitProb = limitProb ?? (outcome === 'YES' ? 1 : 0)
         const unfilledBetsQuery = contractDoc
           .collection('bets')
           .where('outcome', '==', outcome === 'YES' ? 'NO' : 'YES')
           .where('isFilled', '==', false)
           .where('isCancelled', '==', false)
-          .where('limitProb', outcome === 'YES' ? '<=' : '>=', limitProb)
+          .where('limitProb', outcome === 'YES' ? '<=' : '>=', boundedLimitProb)
           .orderBy('createdTime', 'desc')
           .orderBy(
             'limitProb',
@@ -91,16 +101,13 @@ export const placebet = newEndpoint(['POST'], async (req, auth) => {
         const unfilledBetsSnap = await trans.get(unfilledBetsQuery)
         const unfilledBets = unfilledBetsSnap.docs.map((doc) => doc.data())
 
-        if (limitProb !== undefined) {
+        return getBinaryCpmmBetInfo(
-           getBinaryCpmmLimitBetInfo(
+          outcome,
-            outcome,
+          amount,
-            amount,
+          contract,
-            contract,
+          limitProb,
-            limitProb,
+          unfilledBets
-            unfilledBets,
+        )
-          )
-        }
-        return getNewBinaryCpmmBetInfo(outcome, amount, contract, loanAmount)
       } else if (outcomeType == 'FREE_RESPONSE' && mechanism == 'dpm-2') {
         const { outcome } = validate(freeResponseSchema, req.body)
         const answerDoc = contractDoc.collection('answers').doc(outcome)
@@ -129,6 +136,25 @@ export const placebet = newEndpoint(['POST'], async (req, auth) => {
     const betDoc = contractDoc.collection('bets').doc()
     trans.create(betDoc, { id: betDoc.id, userId: user.id, ...newBet })
     log('Created new bet document.')
+
+    if (makers) {
+      for (const maker of makers) {
+        const { bet, amount, shares } = maker
+        const newFill = { amount, shares, matchedBetId: betDoc.id }
+        const fills = [...bet.fills, newFill]
+        const totalShares = sumBy(fills, 'shares')
+        const isFilled =
+          Math.abs(sumBy(fills, 'amount') - bet.amount) < 0.0000001
+
+        log('Updated a matched limit bet.')
+        trans.update(contractDoc.collection('bets').doc(bet.id), {
+          fills,
+          isFilled,
+          shares: totalShares,
+        })
+      }
+    }
+
     trans.update(userDoc, { balance: newBalance })
     log('Updated user balance.')
     trans.update(