[lib] Fetch older messages when showInMessagePreview rejects messages…

… in local store

Summary:
This diff implements "Potential solution 3" described on Linear [here](https://linear.app/comm/issue/ENG-9556/hide-some-robotext-from-messagepreview#comment-62bdf153).

Depends on D13830

Test Plan:
Tested in combination with the rest of the stack:

1. Make sure membership operations (user joining / leaving) don't appear in `MessagePreview`
2. Make sure reactions to the viewer's messages still appear in `MessagePreview`
3. Make sure reactions to other user's messages don't appear in `MessagePreview`
4. Test fresh login to thread with only one message in the last 14 days, which is a reaction to a non-viewer message. Make sure the reaction initially appears in `MessagePreview`, but then is replaced after more messages are fetched by the client

Reviewers: tomek

Reviewed By: tomek

Differential Revision: https://phab.comm.dev/D13831

lib/hooks/message-hooks.js

@@ -4,11 +4,15 @@ import * as React from 'react';
 
 import { useGetLatestMessageEdit } from './latest-message-edit.js';
 import { messageInfoSelector } from '../selectors/chat-selectors.js';
-import { getOldestNonLocalMessageID } from '../shared/message-utils.js';
+import {
+  getOldestNonLocalMessageID,
+  useFetchMessages,
+} from '../shared/message-utils.js';
 import { messageSpecs } from '../shared/messages/message-specs.js';
 import type { MessageInfo } from '../types/message-types.js';
 import type { ThreadInfo } from '../types/minimally-encoded-thread-permissions-types.js';
 import { useSelector } from '../utils/redux-utils.js';
+import sleep from '../utils/sleep.js';
 
 function useOldestMessageServerID(threadID: string): ?string {
   return useSelector(state =>
@@ -102,6 +106,24 @@ function useMessageInfoForPreview(threadInfo: ThreadInfo): ?MessageInfo {
     })();
   }, [threadInfo, getMessageInfoForPreview]);
 
+  const shouldFetchOlderMessages =
+    !!messageInfoForPreview?.shouldFetchOlderMessages;
+
+  const [canFetchOlderMessages, setCanFetchOlderMessages] =
+    React.useState(true);
+  const fetchMessages = useFetchMessages(threadInfo);
+  React.useEffect(() => {
+    if (!canFetchOlderMessages || !shouldFetchOlderMessages) {
+      return;
+    }
+    setCanFetchOlderMessages(false);
+    void (async () => {
+      await fetchMessages();
+      await sleep(3000);
+      setCanFetchOlderMessages(true);
+    })();
+  }, [canFetchOlderMessages, shouldFetchOlderMessages, fetchMessages]);
+
   return messageInfoForPreview?.messageInfoForPreview;
 }