Handle new user: use default feed of top markets this week

common/recommended-contracts.ts

@@ -5,6 +5,8 @@ import { ClickEvent } from './tracking'
 import { filterDefined } from './util/array'
 import { addObjects } from './util/object'
 
+export const MAX_FEED_CONTRACTS = 75
+
 export const getRecommendedContracts = (
   contractsById: { [contractId: string]: Contract },
   yourBetOnContractIds: string[]
@@ -146,6 +148,8 @@ export function getContractScore(
   contract: Contract,
   wordScores: { [word: string]: number }
 ) {
+  if (Object.keys(wordScores).length === 0) return 1
+
   const wordFrequency = contractToWordFrequency(contract)
   const score = _.sumBy(Object.keys(wordFrequency), (word) => {
     const wordFreq = wordFrequency[word] ?? 0

functions/src/update-user-feed.ts

@@ -14,13 +14,14 @@ import {
 import { Bet } from '../../common/bet'
 import { Comment } from '../../common/comment'
 import { User } from '../../common/user'
-import { getContractScore } from '../../common/recommended-contracts'
+import {
+  getContractScore,
+  MAX_FEED_CONTRACTS,
+} from '../../common/recommended-contracts'
 import { callCloudFunction } from './call-cloud-function'
 
 const firestore = admin.firestore()
 
-const MAX_FEED_CONTRACTS = 75
-
 export const updateFeed = functions.pubsub
   .schedule('every 60 minutes')
   .onRun(async () => {

web/hooks/use-algo-feed.ts

@@ -8,6 +8,10 @@ import { trackLatency } from '../lib/firebase/tracking'
 import { User } from '../../common/user'
 import { getUserFeed } from '../lib/firebase/users'
 import { useUpdatedContracts } from './use-contracts'
+import {
+  getRecentBetsAndComments,
+  getTopWeeklyContracts,
+} from '../lib/firebase/contracts'
 
 type feed = {
   contract: Contract
@@ -23,7 +27,9 @@ export const useAlgoFeed = (user: User | null | undefined) => {
   useEffect(() => {
     if (user) {
       getUserFeed(user.id).then((feed) => {
-        setFeed(feed)
+        if (feed.length === 0) {
+          getDefaultFeed().then((feed) => setFeed(feed))
+        } else setFeed(feed)
 
         trackLatency('feed', getTime())
         console.log('feed load time', getTime())
@@ -44,3 +50,11 @@ const useUpdateFeed = (feed: feed | undefined) => {
       }))
     : undefined
 }
+
+const getDefaultFeed = async () => {
+  const contracts = await getTopWeeklyContracts()
+  const feed = await Promise.all(
+    contracts.map((c) => getRecentBetsAndComments(c))
+  )
+  return feed
+}

web/hooks/use-contracts.ts

@@ -94,6 +94,8 @@ export const useUpdatedContracts = (contracts: Contract[] | undefined) => {
       })
     })
 
+    triggerUpdate((n) => n + 1)
+
     return () => {
       disposes.forEach((dispose) => dispose())
     }

web/lib/firebase/contracts.ts

@@ -23,6 +23,9 @@ import { createRNG, shuffle } from '../../../common/util/random'
 import { getCpmmProbability } from '../../../common/calculate-cpmm'
 import { formatMoney, formatPercent } from '../../../common/util/format'
 import { DAY_MS } from '../../../common/util/time'
+import { MAX_FEED_CONTRACTS } from '../../../common/recommended-contracts'
+import { Bet } from '../../../common/bet'
+import { Comment } from '../../../common/comment'
 export type { Contract }
 
 export function contractPath(contract: Contract) {
@@ -231,6 +234,16 @@ export async function getHotContracts() {
   )
 }
 
+const topWeeklyQuery = query(
+  contractCollection,
+  where('isResolved', '==', false),
+  orderBy('volume7Days', 'desc'),
+  limit(MAX_FEED_CONTRACTS)
+)
+export async function getTopWeeklyContracts() {
+  return await getValues<Contract>(topWeeklyQuery)
+}
+
 const closingSoonQuery = query(
   contractCollection,
   where('isResolved', '==', false),
@@ -276,3 +289,33 @@ export async function getDailyContracts(
 
   return contractsByDay
 }
+
+export async function getRecentBetsAndComments(contract: Contract) {
+  const contractDoc = doc(db, 'contracts', contract.id)
+
+  const [recentBets, recentComments] = await Promise.all([
+    getValues<Bet>(
+      query(
+        collection(contractDoc, 'bets'),
+        where('createdTime', '>', Date.now() - DAY_MS),
+        orderBy('createdTime', 'desc'),
+        limit(1)
+      )
+    ),
+
+    getValues<Comment>(
+      query(
+        collection(contractDoc, 'comments'),
+        where('createdTime', '>', Date.now() - 3 * DAY_MS),
+        orderBy('createdTime', 'desc'),
+        limit(3)
+      )
+    ),
+  ])
+
+  return {
+    contract,
+    recentBets,
+    recentComments,
+  }
+}