feat: regenerate in Chat, agent and Chatflow app (#7661)

api/core/prompt/utils/extract_thread_messages.py

@@ -0,0 +1,22 @@
+from constants import UUID_NIL
+
+
+def extract_thread_messages(messages: list[dict]) -> list[dict]:
+    thread_messages = []
+    next_message = None
+
+    for message in messages:
+        if not message.parent_message_id:
+            # If the message is regenerated and does not have a parent message, it is the start of a new thread
+            thread_messages.append(message)
+            break
+
+        if not next_message:
+            thread_messages.append(message)
+            next_message = message.parent_message_id
+        else:
+            if next_message in {message.id, UUID_NIL}:
+                thread_messages.append(message)
+                next_message = message.parent_message_id
+
+    return thread_messages