Show custom feed of contracts from folds your follow or have bet on.

common/util/array.ts

@@ -0,0 +1,3 @@
+export function filterDefined<T>(array: (T | null | undefined)[]) {
+  return array.filter((item) => item) as T[]
+}

firestore.rules

@@ -52,5 +52,9 @@ service cloud.firestore {
       allow read;
       allow write: if request.auth.uid == userId;
     }
+
+    match /{somePath=**}/followers/{userId} {
+      allow read;
+    }
   }
 }

web/components/bets-list.tsx

@@ -32,12 +32,12 @@ import { OutcomeLabel, YesLabel, NoLabel, MarketLabel } from './outcome-label'
 
 export function BetsList(props: { user: User }) {
   const { user } = props
-  const bets = useUserBets(user?.id ?? '')
+  const bets = useUserBets(user.id)
 
   const [contracts, setContracts] = useState<Contract[]>([])
 
   useEffect(() => {
-    const loadedBets = bets === 'loading' ? [] : bets
+    const loadedBets = bets ? bets : []
     const contractIds = _.uniq(loadedBets.map((bet) => bet.contractId))
 
     let disposed = false
@@ -52,7 +52,7 @@ export function BetsList(props: { user: User }) {
     }
   }, [bets])
 
-  if (bets === 'loading') {
+  if (!bets) {
     return <></>
   }
 

web/hooks/use-user-bets.ts

@@ -1,11 +1,11 @@
 import { useEffect, useState } from 'react'
 import { Bet, listenForUserBets } from '../lib/firebase/bets'
 
-export const useUserBets = (userId: string) => {
-  const [bets, setBets] = useState<Bet[] | 'loading'>('loading')
+export const useUserBets = (userId: string | undefined) => {
+  const [bets, setBets] = useState<Bet[] | undefined>(undefined)
 
   useEffect(() => {
-    return listenForUserBets(userId, setBets)
+    if (userId) return listenForUserBets(userId, setBets)
   }, [userId])
 
   return bets

web/lib/firebase/folds.ts

@@ -1,7 +1,9 @@
 import {
   collection,
+  collectionGroup,
   deleteDoc,
   doc,
+  getDocs,
   query,
   setDoc,
   updateDoc,
@@ -12,7 +14,7 @@ import { Fold } from '../../../common/fold'
 import { Contract, contractCollection } from './contracts'
 import { db } from './init'
 import { User } from './users'
-import { getValues, listenForValue, listenForValues } from './utils'
+import { getValue, getValues, listenForValue, listenForValues } from './utils'
 
 const foldCollection = collection(db, 'folds')
 
@@ -39,6 +41,10 @@ export function listenForFolds(setFolds: (folds: Fold[]) => void) {
   return listenForValues(foldCollection, setFolds)
 }
 
+export function getFold(foldId: string) {
+  return getValue<Fold>(doc(foldCollection, foldId))
+}
+
 export async function getFoldBySlug(slug: string) {
   const q = query(foldCollection, where('slug', '==', slug))
   const folds = await getValues<Fold>(q)
@@ -147,3 +153,13 @@ export async function getFoldsByTags(tags: string[]) {
 
   return _.sortBy(folds, (fold) => -1 * fold.followCount)
 }
+
+export async function getFollowedFolds(userId: string) {
+  const snapshot = await getDocs(
+    query(collectionGroup(db, 'followers'), where('userId', '==', userId))
+  )
+  const foldIds = snapshot.docs.map(
+    (doc) => doc.ref.parent.parent?.id as string
+  )
+  return foldIds
+}

web/pages/activity.tsx

@@ -100,7 +100,7 @@ export function ActivityFeed(props: {
             <div key={contract.id} className="py-6 px-2 sm:px-4">
               <ContractFeed
                 contract={contract}
-                bets={contractBets[i] ?? []}
+                bets={contractBets[i]}
                 comments={contractComments[i]}
                 feedType="activity"
               />

web/pages/home.tsx

@@ -1,70 +1,123 @@
-import React from 'react'
+import React, { useEffect, useState } from 'react'
 import Router from 'next/router'
 import _ from 'lodash'
 
 import { Contract, listAllContracts } from '../lib/firebase/contracts'
 import { Page } from '../components/page'
 import { ActivityFeed, findActiveContracts } from './activity'
-import {
-  getRecentComments,
-  Comment,
-  listAllComments,
-} from '../lib/firebase/comments'
-import { Bet, getRecentBets, listAllBets } from '../lib/firebase/bets'
+import { Comment, listAllComments } from '../lib/firebase/comments'
+import { Bet, listAllBets } from '../lib/firebase/bets'
 import FeedCreate from '../components/feed-create'
 import { Spacer } from '../components/layout/spacer'
 import { Col } from '../components/layout/col'
 import { useUser } from '../hooks/use-user'
 import { useContracts } from '../hooks/use-contracts'
+import { getFollowedFolds, listAllFolds } from '../lib/firebase/folds'
+import { Fold } from '../../common/fold'
+import { filterDefined } from '../../common/util/array'
+import { useUserBets } from '../hooks/use-user-bets'
 
 export async function getStaticProps() {
-  const [contracts, recentComments, recentBets] = await Promise.all([
+  const [contracts, folds] = await Promise.all([
     listAllContracts().catch((_) => []),
-    getRecentComments().catch(() => []),
-    getRecentBets().catch(() => []),
+    listAllFolds().catch(() => []),
   ])
 
-  const activeContracts = findActiveContracts(
-    contracts,
-    recentComments,
-    recentBets
-  )
-  const activeContractBets = await Promise.all(
-    activeContracts.map((contract) => listAllBets(contract.id).catch((_) => []))
-  )
-  const activeContractComments = await Promise.all(
-    activeContracts.map((contract) =>
-      listAllComments(contract.id).catch((_) => [])
-    )
-  )
-
   return {
     props: {
-      activeContracts,
-      activeContractBets,
-      activeContractComments,
+      contracts,
+      folds,
     },
 
     revalidate: 60, // regenerate after a minute
   }
 }
 
-const Home = (props: {
-  activeContracts: Contract[]
-  activeContractBets: Bet[][]
-  activeContractComments: Comment[][]
-}) => {
-  const { activeContracts, activeContractBets, activeContractComments } = props
+const Home = (props: { contracts: Contract[]; folds: Fold[] }) => {
+  const { folds } = props
 
   const user = useUser()
 
-  const contracts = useContracts() ?? activeContracts
-  const contractsMap = _.fromPairs(
-    contracts.map((contract) => [contract.id, contract])
+  const contracts = useContracts() ?? props.contracts
+
+  const [followedFoldIds, setFollowedFoldIds] = useState<string[] | undefined>(
+    undefined
   )
-  const updatedContracts = activeContracts.map(
-    (contract) => contractsMap[contract.id]
+
+  useEffect(() => {
+    if (user) {
+      getFollowedFolds(user.id).then((foldIds) => setFollowedFoldIds(foldIds))
+    }
+  }, [user])
+
+  const followedFolds = filterDefined(
+    (followedFoldIds ?? []).map((id) => folds.find((fold) => fold.id === id))
   )
+  const tagSet = new Set(
+    _.flatten(followedFolds.map((fold) => fold.lowercaseTags))
+  )
+
+  const yourBets = useUserBets(user?.id)
+  const yourBetContracts = new Set(
+    (yourBets ?? []).map((bet) => bet.contractId)
+  )
+
+  const feedContracts =
+    followedFoldIds && yourBets
+      ? contracts.filter(
+          (contract) =>
+            contract.lowercaseTags.some((tag) => tagSet.has(tag)) ||
+            yourBetContracts.has(contract.id)
+        )
+      : undefined
+
+  const feedContractsKey = feedContracts?.map(({ id }) => id).join(',')
+
+  const [feedBets, setFeedBets] = useState<Bet[][] | undefined>()
+  const [feedComments, setFeedComments] = useState<Comment[][] | undefined>()
+
+  useEffect(() => {
+    if (feedContracts) {
+      Promise.all(
+        feedContracts.map((contract) => listAllBets(contract.id))
+      ).then(setFeedBets)
+      Promise.all(
+        feedContracts.map((contract) => listAllComments(contract.id))
+      ).then(setFeedComments)
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [feedContractsKey])
+
+  const oneDayMS = 24 * 60 * 60 * 1000
+  const recentBets =
+    feedBets &&
+    feedBets.flat().filter((bet) => bet.createdTime > Date.now() - oneDayMS)
+
+  const activeContracts =
+    feedContracts &&
+    feedComments &&
+    recentBets &&
+    findActiveContracts(feedContracts, feedComments.flat(), recentBets, 365)
+
+  const contractBets = activeContracts
+    ? activeContracts.map(
+        (contract) => feedBets[feedContracts.indexOf(contract)]
+      )
+    : []
+  const contractComments = activeContracts
+    ? activeContracts.map(
+        (contract) => feedComments[feedContracts.indexOf(contract)]
+      )
+    : []
+
+  console.log({
+    followedFoldIds,
+    followedFolds,
+    yourBetContracts,
+    feedContracts,
+    feedBets,
+    feedComments,
+  })
 
   if (user === null) {
     Router.replace('/')
@@ -74,14 +127,16 @@ const Home = (props: {
   return (
     <Page assertUser="signed-in">
       <Col className="items-center">
-        <Col className="max-w-3xl">
+        <Col className="max-w-3xl w-full">
           <FeedCreate user={user ?? undefined} />
           <Spacer h={4} />
-          <ActivityFeed
-            contracts={updatedContracts}
-            contractBets={activeContractBets}
-            contractComments={activeContractComments}
-          />
+          {activeContracts ? (
+            <ActivityFeed
+              contracts={activeContracts}
+              contractBets={contractBets}
+              contractComments={contractComments}
+            />
+          ) : null}
         </Col>
       </Col>
     </Page>