Compute recommendation scores from updateUserFeed

common/recommended-contracts.ts

@@ -142,36 +142,18 @@ export const getWordScores = (
   return normalizedWordScores
 }
 
-export function getContractScores(
-  contracts: Contract[],
+export function getContractScore(
+  contract: Contract,
   wordScores: { [word: string]: number }
 ) {
-  const scorePairs = contracts.map((contract) => {
   const wordFrequency = contractToWordFrequency(contract)
-
   const score = _.sumBy(Object.keys(wordFrequency), (word) => {
     const wordFreq = wordFrequency[word] ?? 0
     const weight = wordScores[word] ?? 0
     return wordFreq * weight
   })
 
-    return [contract, score] as [Contract, number]
-  })
-
-  /*
-  const questionPairs = _.sortBy(
-    scorePairs.map(
-      ([contract, score]) => [contract.question, score] as [string, number]
-    ),
-    ([, score]) => -score
-  )
-
-  console.log('score', questionPairs.slice(0, 100), questionPairs.slice(-100))
-  */
-
-  return _.fromPairs(
-    scorePairs.map(([contract, score]) => [contract.id, score])
-  )
+  return score
 }
 
 // Caluculate Term Frequency-Inverse Document Frequency (TF-IDF):

functions/src/scripts/update-feed.ts

@@ -8,7 +8,7 @@ import { getValues } from '../utils'
 import { User } from '../../../common/user'
 import { batchedWaitAll } from '../../../common/util/promise'
 import { Contract } from '../../../common/contract'
-import { updateUserRecommendations } from '../update-recommendations'
+import { updateWordScores } from '../update-recommendations'
 import {
   getFeedContracts,
   updateFeed as updateUserFeed,
@@ -29,7 +29,7 @@ async function updateFeed() {
   await batchedWaitAll(
     users.map((user) => async () => {
       console.log('Updating recs for', user.username)
-      await updateUserRecommendations(user, contracts)
+      await updateWordScores(user, contracts)
       console.log('Updating feed for', user.username)
       await updateUserFeed(user, feedContracts)
     })

functions/src/update-recommendations.ts

@@ -7,10 +7,7 @@ import { Contract } from '../../common/contract'
 import { Bet } from '../../common/bet'
 import { User } from '../../common/user'
 import { ClickEvent } from '../../common/tracking'
-import {
-  getContractScores,
-  getWordScores,
-} from '../../common/recommended-contracts'
+import { getWordScores } from '../../common/recommended-contracts'
 import { batchedWaitAll } from '../../common/util/promise'
 
 const firestore = admin.firestore()
@@ -25,14 +22,11 @@ export const updateRecommendations = functions.pubsub
     const users = await getValues<User>(firestore.collection('users'))
 
     await batchedWaitAll(
-      users.map((user) => () => updateUserRecommendations(user, contracts))
+      users.map((user) => () => updateWordScores(user, contracts))
     )
   })
 
-export const updateUserRecommendations = async (
-  user: User,
-  contracts: Contract[]
-) => {
+export const updateWordScores = async (user: User, contracts: Contract[]) => {
   const [bets, viewCounts, clicks] = await Promise.all([
     getValues<Bet>(
       firestore.collectionGroup('bets').where('userId', '==', user.id)
@@ -50,11 +44,9 @@ export const updateUserRecommendations = async (
   ])
 
   const wordScores = getWordScores(contracts, viewCounts ?? {}, clicks, bets)
-  const contractScores = getContractScores(contracts, wordScores)
 
   const cachedCollection = firestore.collection(
     `private-users/${user.id}/cache`
   )
   await cachedCollection.doc('wordScores').set(wordScores)
-  await cachedCollection.doc('contractScores').set(contractScores)
 }

functions/src/update-user-feed.ts

@@ -15,6 +15,7 @@ import { Bet } from '../../common/bet'
 import { Comment } from '../../common/comment'
 import { User } from '../../common/user'
 import { batchedWaitAll } from '../../common/util/promise'
+import { getContractScore } from '../../common/recommended-contracts'
 
 const firestore = admin.firestore()
 
@@ -59,27 +60,17 @@ export const updateFeed = async (user: User, contracts: Contract[]) => {
   const userCacheCollection = firestore.collection(
     `private-users/${user.id}/cache`
   )
-  const [recommendationScores, lastViewedTime] = await Promise.all([
-    getValue<{ [contractId: string]: number }>(
-      userCacheCollection.doc('contractScores')
-    ),
+  const [wordScores, lastViewedTime] = await Promise.all([
+    getValue<{ [word: string]: number }>(userCacheCollection.doc('wordScores')),
     getValue<{ [contractId: string]: number }>(
       userCacheCollection.doc('lastViewTime')
     ),
   ]).then((dicts) => dicts.map((dict) => dict ?? {}))
 
-  const averageRecScore =
-    1 +
-    _.sumBy(
-      contracts.filter((c) => recommendationScores[c.id] !== undefined),
-      (c) => recommendationScores[c.id]
-    ) /
-      (contracts.length + 1)
-
   const scoredContracts = contracts.map((contract) => {
     const score = scoreContract(
       contract,
-      recommendationScores[contract.id] ?? averageRecScore,
+      wordScores,
       lastViewedTime[contract.id]
     )
     return [contract, score] as [Contract, number]
@@ -105,12 +96,13 @@ export const updateFeed = async (user: User, contracts: Contract[]) => {
 
 function scoreContract(
   contract: Contract,
-  recommendationScore: number,
+  wordScores: { [word: string]: number },
   viewTime: number | undefined
 ) {
-  const lastViewedScore = getLastViewedScore(viewTime)
+  const recommendationScore = getContractScore(contract, wordScores)
   const activityScore = getActivityScore(contract, viewTime)
-  return recommendationScore * lastViewedScore * activityScore
+  const lastViewedScore = getLastViewedScore(viewTime)
+  return recommendationScore * activityScore * lastViewedScore
 }
 
 function getActivityScore(contract: Contract, viewTime: number | undefined) {