Yes and no buttons on contract page (#868)

* Yes and no buttons on contract page

* Cheating by adding 0.05 to max shares but gives better quickbet UX

web/components/bet-button.tsx

@@ -32,6 +32,17 @@ export default function BetButton(props: {
   return (
     <>
       <Col className={clsx('items-center', className)}>
+        {user && (
+          <div className={'mb-1 w-24 text-center text-sm text-gray-500'}>
+            {hasYesShares
+              ? `(${Math.floor(yesShares)} ${
+                  isPseudoNumeric ? 'HIGHER' : 'YES'
+                })`
+              : hasNoShares
+              ? `(${Math.floor(noShares)} ${isPseudoNumeric ? 'LOWER' : 'NO'})`
+              : ''}
+          </div>
+        )}
         {user ? (
           <Button
             size="lg"
@@ -46,18 +57,6 @@ export default function BetButton(props: {
         ) : (
           <BetSignUpPrompt />
         )}
-
-        {user && (
-          <div className={'mt-1 w-24 text-center text-sm text-gray-500'}>
-            {hasYesShares
-              ? `(${Math.floor(yesShares)} ${
-                  isPseudoNumeric ? 'HIGHER' : 'YES'
-                })`
-              : hasNoShares
-              ? `(${Math.floor(noShares)} ${isPseudoNumeric ? 'LOWER' : 'NO'})`
-              : ''}
-          </div>
-        )}
       </Col>
 
       <Modal open={open} setOpen={setOpen} position="center">

web/components/contract/contract-card.tsx

@@ -25,7 +25,11 @@ import {
 } from 'common/calculate'
 import { AvatarDetails, MiscDetails, ShowTime } from './contract-details'
 import { getExpectedValue, getValueFromBucket } from 'common/calculate-dpm'
-import { getColor, ProbBar, QuickBet } from './quick-bet'
+import {
+  getColor,
+  ProbBar,
+  QuickBetArrows,
+} from 'web/components/contract/quick-bet-arrows'
 import { useContractWithPreload } from 'web/hooks/use-contract'
 import { useUser } from 'web/hooks/use-user'
 import { track } from '@amplitude/analytics-browser'
@@ -101,7 +105,7 @@ export function ContractCard(props: {
           ))}
       </Col>
       {showQuickBet ? (
-        <QuickBet contract={contract} user={user} className="z-10" />
+        <QuickBetArrows contract={contract} user={user} className="z-10" />
       ) : (
         <>
           {outcomeType === 'BINARY' && (

web/components/contract/contract-overview.tsx

@@ -27,21 +27,44 @@ import {
 } from 'common/contract'
 import { ContractDetails, ExtraMobileContractDetails } from './contract-details'
 import { NumericGraph } from './numeric-graph'
+import { QuickBetButtons } from 'web/components/contract/quick-bet-button'
 
 const OverviewQuestion = (props: { text: string }) => (
   <Linkify className="text-2xl text-indigo-700 md:text-3xl" text={props.text} />
 )
 
 const BetWidget = (props: { contract: CPMMContract }) => {
+  const { contract } = props
   const user = useUser()
   return (
-    <Col>
+    <Col className={'justify-center'}>
+      <Row className={'gap-4'}>
+        {contract.outcomeType === 'BINARY' &&
+          user &&
+          QuickBetButtons({
+            contract: contract as CPMMBinaryContract,
+            user: user,
+            side: 'NO',
+            className: 'self-end min-w-[60px]',
+          })}
         <BetButton contract={props.contract} />
+
+        {contract.outcomeType === 'BINARY' &&
+          user &&
+          QuickBetButtons({
+            contract: contract as CPMMBinaryContract,
+            user: user,
+            side: 'YES',
+            className: 'self-end min-w-[60px]',
+          })}
+      </Row>
+      <Row className={'items-center justify-center'}>
         {!user && (
           <div className="mt-1 text-center text-sm text-gray-500">
             (with play money!)
           </div>
         )}
+      </Row>
     </Col>
   )
 }
@@ -85,13 +108,13 @@ const BinaryOverview = (props: { contract: BinaryContract; bets: Bet[] }) => {
         </Row>
         <Row className="items-center justify-between gap-4 xl:hidden">
           <BinaryResolutionOrChance contract={contract} />
-          <ExtraMobileContractDetails contract={contract} />
           {tradingAllowed(contract) && (
             <BetWidget contract={contract as CPMMBinaryContract} />
           )}
         </Row>
       </Col>
       <ContractProbGraph contract={contract} bets={[...bets].reverse()} />
+      <ExtraMobileContractDetails contract={contract} />
     </Col>
   )
 }
@@ -140,11 +163,11 @@ const PseudoNumericOverview = (props: {
         </Row>
         <Row className="items-center justify-between gap-4 xl:hidden">
           <PseudoNumericResolutionOrExpectation contract={contract} />
-          <ExtraMobileContractDetails contract={contract} />
           {tradingAllowed(contract) && <BetWidget contract={contract} />}
         </Row>
       </Col>
       <ContractProbGraph contract={contract} bets={[...bets].reverse()} />
+      <ExtraMobileContractDetails contract={contract} />
     </Col>
   )
 }

web/components/contract/quick-bet-arrows.tsx

@@ -38,7 +38,7 @@ import { getBinaryProb } from 'common/contract-details'
 
 const BET_SIZE = 10
 
-export function QuickBet(props: {
+export function QuickBetArrows(props: {
   contract: BinaryContract | PseudoNumericContract
   user: User
   className?: string
@@ -243,7 +243,7 @@ export function ProbBar(props: { contract: Contract; previewProb?: number }) {
   )
 }
 
-function quickOutcome(contract: Contract, direction: 'UP' | 'DOWN') {
+export function quickOutcome(contract: Contract, direction: 'UP' | 'DOWN') {
   const { outcomeType } = contract
 
   if (outcomeType === 'BINARY' || outcomeType === 'PSEUDO_NUMERIC') {

web/components/contract/quick-bet-button.tsx

@@ -0,0 +1,128 @@
+import {
+  getOutcomeProbability,
+  getProbability,
+  getTopAnswer,
+} from 'common/calculate'
+import { getExpectedValue } from 'common/calculate-dpm'
+import { User } from 'common/user'
+import { Contract, CPMMBinaryContract, NumericContract } from 'common/contract'
+import { formatMoney } from 'common/util/format'
+import toast from 'react-hot-toast'
+import { useUserContractBets } from 'web/hooks/use-user-bets'
+import { placeBet } from 'web/lib/firebase/api'
+import { useSaveBinaryShares } from '../use-save-binary-shares'
+import { sellShares } from 'web/lib/firebase/api'
+import { calculateCpmmSale } from 'common/calculate-cpmm'
+import { track } from 'web/lib/service/analytics'
+import { useUnfilledBets } from 'web/hooks/use-bets'
+import { getBinaryProb } from 'common/contract-details'
+import { quickOutcome } from 'web/components/contract/quick-bet-arrows'
+import { Button } from 'web/components/button'
+
+const BET_SIZE = 10
+
+export function QuickBetButtons(props: {
+  contract: CPMMBinaryContract
+  user: User
+  side: 'YES' | 'NO'
+  className?: string
+}) {
+  const { contract, side, user } = props
+  let sharesSold: number | undefined
+  let sellOutcome: 'YES' | 'NO' | undefined
+  let saleAmount: number | undefined
+
+  const userBets = useUserContractBets(user.id, contract.id)
+  const unfilledBets = useUnfilledBets(contract.id) ?? []
+
+  const { yesShares, noShares } = useSaveBinaryShares(contract, userBets)
+  const oppositeShares = side === 'YES' ? noShares : yesShares
+  if (oppositeShares > 0.01) {
+    sellOutcome = side === 'YES' ? 'NO' : 'YES'
+
+    const prob = getProb(contract)
+    const maxSharesSold =
+      (BET_SIZE + 0.05) / (sellOutcome === 'YES' ? prob : 1 - prob)
+    sharesSold = Math.min(oppositeShares, maxSharesSold)
+
+    const { saleValue } = calculateCpmmSale(
+      contract,
+      sharesSold,
+      sellOutcome,
+      unfilledBets
+    )
+    saleAmount = saleValue
+  }
+
+  async function placeQuickBet() {
+    const betPromise = async () => {
+      if (sharesSold && sellOutcome) {
+        return await sellShares({
+          shares: sharesSold,
+          outcome: sellOutcome,
+          contractId: contract.id,
+        })
+      }
+
+      const outcome = quickOutcome(contract, side === 'YES' ? 'UP' : 'DOWN')
+      return await placeBet({
+        amount: BET_SIZE,
+        outcome,
+        contractId: contract.id,
+      })
+    }
+    const shortQ = contract.question.slice(0, 20)
+    const message =
+      sellOutcome && saleAmount
+        ? `${formatMoney(saleAmount)} sold of "${shortQ}"...`
+        : `${formatMoney(BET_SIZE)} on "${shortQ}"...`
+
+    toast.promise(betPromise(), {
+      loading: message,
+      success: message,
+      error: (err) => `${err.message}`,
+    })
+
+    track('quick bet button', {
+      slug: contract.slug,
+      outcome: side,
+      contractId: contract.id,
+    })
+  }
+
+  return (
+    <Button
+      size={'lg'}
+      onClick={() => placeQuickBet()}
+      color={side === 'YES' ? 'green' : 'red'}
+      className={props.className}
+    >
+      {side === 'YES' ? 'Yes' : 'No'}
+    </Button>
+  )
+}
+
+// Return a number from 0 to 1 for this contract
+// Resolved contracts are set to 1, for coloring purposes (even if NO)
+function getProb(contract: Contract) {
+  const { outcomeType, resolution, resolutionProbability } = contract
+  return resolutionProbability
+    ? resolutionProbability
+    : resolution
+    ? 1
+    : outcomeType === 'BINARY'
+    ? getBinaryProb(contract)
+    : outcomeType === 'PSEUDO_NUMERIC'
+    ? getProbability(contract)
+    : outcomeType === 'FREE_RESPONSE' || outcomeType === 'MULTIPLE_CHOICE'
+    ? getOutcomeProbability(contract, getTopAnswer(contract)?.id || '')
+    : outcomeType === 'NUMERIC'
+    ? getNumericScale(contract)
+    : 1 // Should not happen
+}
+
+function getNumericScale(contract: NumericContract) {
+  const { min, max } = contract
+  const ev = getExpectedValue(contract)
+  return (ev - min) / (max - min)
+}