fix(channels): preserve Feishu clarification thread continuity (#3285)

* fix(channels): preserve Feishu clarification thread continuity

* fix(channels): address Feishu clarification review feedback

---------

Co-authored-by: zzp1221 <zzp1221@users.noreply.github.com>
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

backend/app/channels/manager.py

@@ -15,7 +15,14 @@ import httpx
 from langgraph_sdk.errors import ConflictError
 
 from app.channels.commands import KNOWN_CHANNEL_COMMANDS
-from app.channels.message_bus import InboundMessage, InboundMessageType, MessageBus, OutboundMessage, ResolvedAttachment
+from app.channels.message_bus import (
+    PENDING_CLARIFICATION_METADATA_KEY,
+    InboundMessage,
+    InboundMessageType,
+    MessageBus,
+    OutboundMessage,
+    ResolvedAttachment,
+)
 from app.channels.store import ChannelStore
 from app.gateway.csrf_middleware import CSRF_COOKIE_NAME, CSRF_HEADER_NAME, generate_csrf_token
 from app.gateway.internal_auth import create_internal_auth_headers
@@ -202,6 +209,54 @@ def _extract_response_text(result: dict | list) -> str:
     return ""
 
 
+def _messages_from_result(result: dict | list) -> list[Any]:
+    if isinstance(result, list):
+        return result
+    if isinstance(result, dict):
+        messages = result.get("messages", [])
+        if isinstance(messages, list):
+            return messages
+    return []
+
+
+def _current_turn_messages(result: dict | list) -> list[dict[str, Any]]:
+    messages = _messages_from_result(result)
+    current_turn: list[dict[str, Any]] = []
+    for msg in reversed(messages):
+        if not isinstance(msg, dict):
+            continue
+        if msg.get("type") == "human":
+            break
+        current_turn.append(msg)
+    current_turn.reverse()
+    return current_turn
+
+
+def _has_current_turn_clarification(result: dict | list) -> bool:
+    """Return True only when the current turn's final result is clarification."""
+    for msg in reversed(_current_turn_messages(result)):
+        msg_type = msg.get("type")
+        if msg_type == "tool":
+            return msg.get("name") == "ask_clarification"
+        if msg_type == "ai":
+            content = msg.get("content")
+            if isinstance(content, str):
+                if content:
+                    return False
+            elif content:
+                return False
+            if msg.get("tool_calls"):
+                return False
+    return False
+
+
+def _response_metadata(base_metadata: dict[str, Any], *, pending_clarification: bool = False) -> dict[str, Any]:
+    metadata = _slim_metadata(base_metadata)
+    if pending_clarification:
+        metadata[PENDING_CLARIFICATION_METADATA_KEY] = True
+    return metadata
+
+
 def _extract_text_content(content: Any) -> str:
     """Extract text from a streaming payload content field."""
     if isinstance(content, str):
@@ -806,6 +861,7 @@ class ChannelManager:
                 raise
 
         response_text = _extract_response_text(result)
+        pending_clarification = _has_current_turn_clarification(result)
         artifacts = _extract_artifacts(result)
 
         logger.info(
@@ -831,7 +887,7 @@ class ChannelManager:
             artifacts=artifacts,
             attachments=attachments,
             thread_ts=msg.thread_ts,
-            metadata=_slim_metadata(msg.metadata),
+            metadata=_response_metadata(msg.metadata, pending_clarification=pending_clarification),
         )
         logger.info("[Manager] publishing outbound message to bus: channel=%s, chat_id=%s", msg.channel_name, msg.chat_id)
         await self.bus.publish_outbound(outbound)
@@ -893,7 +949,7 @@ class ChannelManager:
                         text=latest_text,
                         is_final=False,
                         thread_ts=msg.thread_ts,
-                        metadata=_slim_metadata(msg.metadata),
+                        metadata=_response_metadata(msg.metadata),
                     )
                 )
                 last_published_text = latest_text
@@ -907,6 +963,7 @@ class ChannelManager:
         finally:
             result = last_values if last_values is not None else {"messages": [{"type": "ai", "content": latest_text}]}
             response_text = _extract_response_text(result)
+            pending_clarification = _has_current_turn_clarification(result)
             artifacts = _extract_artifacts(result)
             response_text, attachments = _prepare_artifact_delivery(thread_id, response_text, artifacts)
 
@@ -938,7 +995,7 @@ class ChannelManager:
                     attachments=attachments,
                     is_final=True,
                     thread_ts=msg.thread_ts,
-                    metadata=_slim_metadata(msg.metadata),
+                    metadata=_response_metadata(msg.metadata, pending_clarification=pending_clarification),
                 )
             )