Update chat.js

public/js/chat.js

@@ -40,12 +40,14 @@ on('ws:connected', () => {
 
 /**
  * Extract a flat array from the tree-based message structure.
- * The server stores messages in a tree with versions; each version has a tail.
- * This extracts the current branch's messages as a flat array.
+ * Only follows the currently selected version branch at each level.
+ * Each message's version has a tail; only the selected version's tail is included.
  */
 function extractFlatHistoryFromTree(rootMessage) {
   if (!rootMessage) return [];
   
+  const history = [];
+  
   const ensureValidContent = (msg) => {
     if (msg.content === undefined || msg.content === null) {
       msg.content = '';
@@ -53,31 +55,35 @@ function extractFlatHistoryFromTree(rootMessage) {
     return msg;
   };
   
-  const history = [ensureValidContent(rootMessage)];
-  const currentVerIdx = rootMessage.currentVersionIdx ?? 0;
-  
-  if (!Array.isArray(rootMessage.versions)) {
-    return history;
-  }
-  
-  if (currentVerIdx >= rootMessage.versions.length) {
-    return history;
-  }
-  
-  const currentTail = rootMessage.versions[currentVerIdx]?.tail;
+  // Recursively extract only the currently selected version's branch
+  const extractBranch = (message) => {
+    history.push(ensureValidContent(message));
+    
+    // Get the currently selected version index for this message
+    const currentVersionIdx = message.currentVersionIdx ?? 0;
+    const versions = message.versions || [];
+    
+    // Validate version index is in bounds
+    if (currentVersionIdx >= versions.length) {
+      return;
+    }
+    
+    const currentVersion = versions[currentVersionIdx];
+    if (!currentVersion) return;
+    
+    // Only process the selected version's tail if it exists and has items
+    const tail = currentVersion.tail;
+    if (!Array.isArray(tail) || tail.length === 0) {
+      return;
+    }
+    
+    // Recursively extract each message in the current version's tail
+    for (const tailMessage of tail) {
+      extractBranch(tailMessage);
+    }
+  };
   
-  if (currentTail && Array.isArray(currentTail)) {
-    const walkTail = (tail) => {
-      for (const msg of tail) {
-        history.push(ensureValidContent(msg));
-        const ver = msg.versions?.[msg.currentVersionIdx ?? 0];
-        if (ver?.tail && Array.isArray(ver.tail)) {
-          walkTail(ver.tail);
-        }
-      }
-    };
-    walkTail(currentTail);
-  }
+  extractBranch(rootMessage);
   return history;
 }