[D1X] Use user action and viewing history to inform suggested follows (#4727)

* Use user action and viewing history to inform suggested follows

* Remove dynamic spreads

* Track more info about seen posts

* Add ranking

---------

Co-authored-by: Dan Abramov <dan.abramov@gmail.com>

src/state/queries/post-feed.ts

@@ -17,11 +17,13 @@ import {
 
 import {HomeFeedAPI} from '#/lib/api/feed/home'
 import {aggregateUserInterests} from '#/lib/api/feed/utils'
+import {DISCOVER_FEED_URI} from '#/lib/constants'
 import {moderatePost_wrapped as moderatePost} from '#/lib/moderatePost_wrapped'
 import {logger} from '#/logger'
 import {STALE} from '#/state/queries'
 import {DEFAULT_LOGGED_OUT_PREFERENCES} from '#/state/queries/preferences/const'
 import {useAgent} from '#/state/session'
+import * as userActionHistory from '#/state/userActionHistory'
 import {AuthorFeedAPI} from 'lib/api/feed/author'
 import {CustomFeedAPI} from 'lib/api/feed/custom'
 import {FollowingFeedAPI} from 'lib/api/feed/following'
@@ -131,6 +133,7 @@ export function usePostFeedQuery(
     result: InfiniteData<FeedPage>
   } | null>(null)
   const lastPageCountRef = useRef(0)
+  const isDiscover = feedDesc.includes(DISCOVER_FEED_URI)
 
   // Make sure this doesn't invalidate unless really needed.
   const selectArgs = React.useMemo(
@@ -139,8 +142,15 @@ export function usePostFeedQuery(
       disableTuner: params?.disableTuner,
       moderationOpts,
       ignoreFilterFor: opts?.ignoreFilterFor,
+      isDiscover,
     }),
-    [feedTuners, params?.disableTuner, moderationOpts, opts?.ignoreFilterFor],
+    [
+      feedTuners,
+      params?.disableTuner,
+      moderationOpts,
+      opts?.ignoreFilterFor,
+      isDiscover,
+    ],
   )
 
   const query = useInfiniteQuery<
@@ -219,8 +229,13 @@ export function usePostFeedQuery(
       (data: InfiniteData<FeedPageUnselected, RQPageParam>) => {
         // If the selection depends on some data, that data should
         // be included in the selectArgs object and read here.
-        const {feedTuners, disableTuner, moderationOpts, ignoreFilterFor} =
-          selectArgs
+        const {
+          feedTuners,
+          disableTuner,
+          moderationOpts,
+          ignoreFilterFor,
+          isDiscover,
+        } = selectArgs
 
         const tuner = disableTuner
           ? new NoopFeedTuner()
@@ -293,6 +308,21 @@ export function usePostFeedQuery(
                     }
                   }
 
+                  if (isDiscover) {
+                    userActionHistory.seen(
+                      slice.items.map(item => ({
+                        feedContext: item.feedContext,
+                        likeCount: item.post.likeCount ?? 0,
+                        repostCount: item.post.repostCount ?? 0,
+                        replyCount: item.post.replyCount ?? 0,
+                        isFollowedBy: Boolean(
+                          item.post.author.viewer?.followedBy,
+                        ),
+                        uri: item.post.uri,
+                      })),
+                    )
+                  }
+
                   return {
                     _reactKey: slice._reactKey,
                     _isFeedPostSlice: true,

src/state/queries/post.ts

@@ -8,6 +8,7 @@ import {logEvent, LogEvents, toClout} from '#/lib/statsig/statsig'
 import {updatePostShadow} from '#/state/cache/post-shadow'
 import {Shadow} from '#/state/cache/types'
 import {useAgent, useSession} from '#/state/session'
+import * as userActionHistory from '#/state/userActionHistory'
 import {useIsThreadMuted, useSetThreadMute} from '../cache/thread-mutes'
 import {findProfileQueryData} from './profile'
 
@@ -92,6 +93,7 @@ export function usePostLikeMutationQueue(
           uri: postUri,
           cid: postCid,
         })
+        userActionHistory.like([postUri])
         return likeUri
       } else {
         if (prevLikeUri) {
@@ -99,6 +101,7 @@ export function usePostLikeMutationQueue(
             postUri: postUri,
             likeUri: prevLikeUri,
           })
+          userActionHistory.unlike([postUri])
         }
         return undefined
       }

src/state/queries/profile.ts

@@ -23,6 +23,7 @@ import {logEvent, LogEvents, toClout} from '#/lib/statsig/statsig'
 import {Shadow} from '#/state/cache/types'
 import {STALE} from '#/state/queries'
 import {resetProfilePostsQueries} from '#/state/queries/post-feed'
+import * as userActionHistory from '#/state/userActionHistory'
 import {updateProfileShadow} from '../cache/profile-shadow'
 import {useAgent, useSession} from '../session'
 import {
@@ -233,6 +234,7 @@ export function useProfileFollowMutationQueue(
         const {uri} = await followMutation.mutateAsync({
           did,
         })
+        userActionHistory.follow([did])
         return uri
       } else {
         if (prevFollowingUri) {
@@ -240,6 +242,7 @@ export function useProfileFollowMutationQueue(
             did,
             followUri: prevFollowingUri,
           })
+          userActionHistory.unfollow([did])
         }
         return undefined
       }

src/state/userActionHistory.ts

@@ -0,0 +1,71 @@
+import React from 'react'
+
+const LIKE_WINDOW = 100
+const FOLLOW_WINDOW = 100
+const SEEN_WINDOW = 100
+
+export type SeenPost = {
+  uri: string
+  likeCount: number
+  repostCount: number
+  replyCount: number
+  isFollowedBy: boolean
+  feedContext: string | undefined
+}
+
+export type UserActionHistory = {
+  /**
+   * The last 100 post URIs the user has liked
+   */
+  likes: string[]
+  /**
+   * The last 100 DIDs the user has followed
+   */
+  follows: string[]
+  /**
+   * The last 100 post URIs the user has seen from the Discover feed only
+   */
+  seen: SeenPost[]
+}
+
+const userActionHistory: UserActionHistory = {
+  likes: [],
+  follows: [],
+  seen: [],
+}
+
+export function getActionHistory() {
+  return userActionHistory
+}
+
+export function useActionHistorySnapshot() {
+  return React.useState(() => getActionHistory())[0]
+}
+
+export function like(postUris: string[]) {
+  userActionHistory.likes = userActionHistory.likes
+    .concat(postUris)
+    .slice(-LIKE_WINDOW)
+}
+export function unlike(postUris: string[]) {
+  userActionHistory.likes = userActionHistory.likes.filter(
+    uri => !postUris.includes(uri),
+  )
+}
+
+export function follow(dids: string[]) {
+  userActionHistory.follows = userActionHistory.follows
+    .concat(dids)
+    .slice(-FOLLOW_WINDOW)
+}
+export function unfollow(dids: string[]) {
+  userActionHistory.follows = userActionHistory.follows.filter(
+    uri => !dids.includes(uri),
+  )
+}
+
+export function seen(posts: SeenPost[]) {
+  userActionHistory.seen = userActionHistory.seen
+    .concat(posts)
+    .slice(-SEEN_WINDOW)
+}