reply button in feeds opens thread (#9143)

* the reply button should open the replies to a post, not present a text input for you to enter your Big Thought into. i think a lot of people don’t even realize that the point has already been written

* Feature gate, fix event

---------

Co-authored-by: Eric Bailey <git@esb.lol>

src/view/com/posts/PostFeedItem.tsx

@@ -11,6 +11,7 @@ import {
 } from '@atproto/api'
 import {msg, Trans} from '@lingui/macro'
 import {useLingui} from '@lingui/react'
+import {useNavigation} from '@react-navigation/native'
 import {useQueryClient} from '@tanstack/react-query'
 
 import {useActorStatus} from '#/lib/actor-status'
@@ -19,6 +20,8 @@ import {MAX_POST_LINES} from '#/lib/constants'
 import {useOpenComposer} from '#/lib/hooks/useOpenComposer'
 import {usePalette} from '#/lib/hooks/usePalette'
 import {makeProfileLink} from '#/lib/routes/links'
+import {type NavigationProp} from '#/lib/routes/types'
+import {useGate} from '#/lib/statsig/statsig'
 import {sanitizeDisplayName} from '#/lib/strings/display-names'
 import {sanitizeHandle} from '#/lib/strings/handles'
 import {countLines} from '#/lib/strings/helpers'
@@ -167,35 +170,50 @@ let FeedItemInner = ({
 }): React.ReactNode => {
   const queryClient = useQueryClient()
   const {openComposer} = useOpenComposer()
+  const navigation = useNavigation<NavigationProp>()
   const pal = usePalette('default')
+  const gate = useGate()
   const {_} = useLingui()
 
   const [hover, setHover] = useState(false)
 
-  const href = useMemo(() => {
+  const [href, rkey] = useMemo(() => {
     const urip = new AtUri(post.uri)
-    return makeProfileLink(post.author, 'post', urip.rkey)
+    return [makeProfileLink(post.author, 'post', urip.rkey), urip.rkey]
   }, [post.uri, post.author])
   const {sendInteraction, feedSourceInfo} = useFeedFeedbackContext()
 
   const onPressReply = () => {
-    sendInteraction({
-      item: post.uri,
-      event: 'app.bsky.feed.defs#interactionReply',
-      feedContext,
-      reqId,
-    })
-    openComposer({
-      replyTo: {
-        uri: post.uri,
-        cid: post.cid,
-        text: record.text || '',
-        author: post.author,
-        embed: post.embed,
-        moderation,
-        langs: record.langs,
-      },
-    })
+    if (gate('feed_reply_button_open_thread')) {
+      sendInteraction({
+        item: post.uri,
+        event: 'app.bsky.feed.defs#clickthroughItem',
+        feedContext,
+        reqId,
+      })
+      navigation.navigate('PostThread', {
+        name: post.author.did,
+        rkey,
+      })
+    } else {
+      sendInteraction({
+        item: post.uri,
+        event: 'app.bsky.feed.defs#interactionReply',
+        feedContext,
+        reqId,
+      })
+      openComposer({
+        replyTo: {
+          uri: post.uri,
+          cid: post.cid,
+          text: record.text || '',
+          author: post.author,
+          embed: post.embed,
+          moderation,
+          langs: record.langs,
+        },
+      })
+    }
   }
 
   const onOpenAuthor = () => {