feat(chat): 支持流式回复与用户节点导航

review_agent/services.py

@@ -1,9 +1,11 @@
 from __future__ import annotations
 
+import json
+
 from django.db.models import Q, QuerySet
 from django.utils import timezone
 
-from .llm import LLMConfigurationError, LLMRequestError, generate_reply
+from .llm import LLMConfigurationError, LLMRequestError, generate_reply, stream_reply
 from .models import Conversation, Message
 
 
@@ -81,6 +83,47 @@ def send_message(conversation: Conversation, content: str) -> tuple[Message, Mes
     return user_message, assistant_message
 
 
+def stream_message(conversation: Conversation, content: str):
+    """Yields SSE events while collecting a streamed assistant reply."""
+
+    user_message = append_user_message(conversation, content)
+    assistant_parts: list[str] = []
+
+    yield sse_event(
+        "meta",
+        {
+            "conversation_id": conversation.pk,
+            "title": conversation.title or build_conversation_title(content),
+            "user_message_id": user_message.pk,
+            "user_message": user_message.content,
+        },
+    )
+
+    try:
+        for chunk in stream_reply(conversation, content):
+            assistant_parts.append(chunk)
+            yield sse_event("chunk", {"delta": chunk})
+    except (LLMConfigurationError, LLMRequestError) as exc:
+        fallback = f"模型调用失败：{exc}"
+        assistant_parts = [fallback]
+        yield sse_event("error", {"message": fallback})
+
+    assistant_message = append_assistant_message(conversation, "".join(assistant_parts).strip())
+
+    if conversation.title.startswith("新对话"):
+        conversation.title = build_conversation_title(content)
+        conversation.save(update_fields=["title", "updated_at"])
+
+    yield sse_event(
+        "done",
+        {
+            "assistant_message_id": assistant_message.pk,
+            "conversation_id": conversation.pk,
+            "title": conversation.title,
+        },
+    )
+
+
 def build_conversation_title(content: str) -> str:
     """Creates a concise title from the first user message."""
 
@@ -88,3 +131,9 @@ def build_conversation_title(content: str) -> str:
     if not normalized:
         return "新对话"
     return normalized[:24]
+
+
+def sse_event(event_name: str, payload: dict[str, object]) -> str:
+    """Formats one server-sent event frame."""
+
+    return f"event: {event_name}\ndata: {json.dumps(payload, ensure_ascii=False)}\n\n"