优化会话标题生成逻辑

src/routes/chat.ts

@@ -278,18 +278,27 @@ export const buildChatRouter = (
           const assistantText = collectTextContent(assistantMessage?.parts ?? []);
           const existingSessionTitle = sessionBridge.getSessionTitle(binding.sessionId);
           let sessionTitle = existingSessionTitle;
+          const { userMessageCount, assistantMessageCount } =
+            await getConversationTurnStats(runtime, binding.sessionId);
           const shouldGenerateTitle =
-            !existingSessionTitle &&
-            (await isFirstRoundConversation(runtime, binding.sessionId));
+            userMessageCount <= 3 &&
+            assistantMessageCount >= 1;
           if (shouldGenerateTitle) {
             sessionTitle = await generateSessionTitle(runtime, {
               sessionId: binding.sessionId,
               latestUserMessage: parsed.data.message,
+              fallbackTitle: existingSessionTitle,
             });
-            sessionBridge.setSessionTitle(binding.sessionId, sessionTitle);
+            if (sessionTitle !== existingSessionTitle) {
+              sessionBridge.setSessionTitle(binding.sessionId, sessionTitle);
+            }
           }
           if (!streamClosed && !res.writableEnded && !res.destroyed) {
-            if (shouldGenerateTitle && sessionTitle) {
+            if (
+              shouldGenerateTitle &&
+              sessionTitle &&
+              sessionTitle !== existingSessionTitle
+            ) {
               res.write(
                 toSse("session_title", {
                   session_id: clientSessionId,
@@ -1044,16 +1053,25 @@ const buildTitleConversationContext = async (
     .slice(0, 2400);
 };
 
-const isFirstRoundConversation = async (
+const getConversationTurnStats = async (
   runtime: OpencodeRuntimeAdapter,
   sessionId: string,
 ) => {
   const messages = await runtime.messages(sessionId, 12);
-  const chatMessageCount = messages.filter(
-    (message) =>
-      message.info.role === "user" || message.info.role === "assistant",
-  ).length;
-  return chatMessageCount === 2;
+  return messages.reduce(
+    (stats, message) => {
+      if (message.info.role === "user") {
+        stats.userMessageCount += 1;
+      } else if (message.info.role === "assistant") {
+        stats.assistantMessageCount += 1;
+      }
+      return stats;
+    },
+    {
+      userMessageCount: 0,
+      assistantMessageCount: 0,
+    },
+  );
 };
 
 const normalizeGeneratedTitle = (rawTitle: string, fallback: string) => {