fix duplicate link previews on edit

packages/app/ui/components/BareChatInput/index.tsx

@@ -3,7 +3,6 @@ import { JSONContent, Story, pathToCite } from '@tloncorp/api/urbit';
 import {
   Attachment,
   JSONToInlines,
-  LinkAttachment,
   REF_REGEX,
   createDevLogger,
   diaryMixedToJSON,
@@ -66,6 +65,16 @@ const bareChatInputLogger = createDevLogger('bareChatInput', false);
 
 const DEFAULT_KEYBOARD_HEIGHT = 300;
 
+function normalizePreviewUrl(url: string) {
+  try {
+    const parsedUrl = new URL(url);
+    parsedUrl.hash = '';
+    return parsedUrl.toString();
+  } catch {
+    return url;
+  }
+}
+
 function useKeyboardHeight(maxInputHeightBasic: number) {
   const [maxInputHeight, setMaxInputHeight] = useState(maxInputHeightBasic);
 
@@ -558,34 +567,23 @@ function BareChatInput(
     const matches = textOutsideCodeBlocks.match(urlRegex) || [];
 
     // Normalize URLs (remove hash) and deduplicate
-    const currentUrls = [
-      ...new Set(
-        matches.map((url) => {
-          try {
-            const parsedUrl = new URL(url);
-            parsedUrl.hash = '';
-            return parsedUrl.toString();
-          } catch {
-            return url;
-          }
-        })
-      ),
-    ];
+    const currentUrls = [...new Set(matches.map(normalizePreviewUrl))];
 
     const prevUrls = prevUrlsRef.current;
-    const currentAttachments = attachmentsRef.current;
+    const linksByUrl = new Map(
+      attachmentsRef.current
+        .filter((a) => a.type === 'link')
+        .map((a) => [normalizePreviewUrl(a.url), a] as const)
+    );
 
-    // Find URLs that were removed from text
     const removedUrls = prevUrls.filter((url) => !currentUrls.includes(url));
-
-    // Find URLs that were added to text
-    const addedUrls = currentUrls.filter((url) => !prevUrls.includes(url));
+    const addedUrls = currentUrls.filter(
+      (url) => !prevUrls.includes(url) && !linksByUrl.has(url)
+    );
 
     // Remove attachments for URLs no longer in text
     removedUrls.forEach((url) => {
-      const attachment = currentAttachments.find(
-        (a): a is LinkAttachment => a.type === 'link' && a.url === url
-      );
+      const attachment = linksByUrl.get(url);
       if (attachment) {
         bareChatInputLogger.log('removing stale link attachment', { url });
         removeAttachment(attachment);