From feefae16c6fb0d2c7caaf3194f5683f05f3db1ec Mon Sep 17 00:00:00 2001
From: Hunter B <hmbown@gmail.com>
Date: Sat, 30 May 2026 23:55:00 -0700
Subject: [PATCH] fix(feishu): preserve per-chat model state

---
 integrations/feishu-bridge/src/index.mjs     | 30 +++++++++++++-------
 integrations/feishu-bridge/src/lib.mjs       | 12 ++++++++
 integrations/feishu-bridge/test/lib.test.mjs | 26 +++++++++++++++++
 3 files changed, 58 insertions(+), 10 deletions(-)

diff --git a/integrations/feishu-bridge/src/index.mjs b/integrations/feishu-bridge/src/index.mjs
index 0a485b5c..69b1b968 100644
--- a/integrations/feishu-bridge/src/index.mjs
+++ b/integrations/feishu-bridge/src/index.mjs
@@ -16,6 +16,7 @@ import {
   parseList,
   parseApprovalDecisionArgs,
   parseTextContent,
+  preservedChatStateFields,
   splitMessage,
   stripGroupPrefix
 } from "./lib.mjs";
@@ -266,6 +267,7 @@ async function ensureThread(chatId, { forceNew = false } = {}) {
   });
 
   const state = {
+    ...preservedChatStateFields(existing),
     threadId: thread.id,
     lastSeq: 0,
     activeTurnId: null,
@@ -505,7 +507,9 @@ async function resumeThread(chatId, args) {
     return;
   }
   const detail = await runtimeJson(`/v1/threads/${encodeURIComponent(threadId)}`);
+  const existing = await threadStore.getChat(chatId);
   await threadStore.setChat(chatId, {
+    ...preservedChatStateFields(existing),
     threadId,
     lastSeq: Number(detail.latest_seq || 0),
     activeTurnId: null,
@@ -601,22 +605,28 @@ async function sendText(chatId, text) {
     throw new Error("Lark SDK client does not expose im message create API");
   }
 
+  let canReply = Boolean(replyMessage);
   for (const chunk of splitMessage(text, config.maxReplyChars)) {
     const body = {
       msg_type: "text",
       content: JSON.stringify({ text: chunk })
     };
-    if (replyMessage) {
-      await replyMessage({
-        path: { message_id: replyToMessageId },
-        data: body
-      });
-    } else {
-      await createMessage({
-        params: { receive_id_type: "chat_id" },
-        data: { ...body, receive_id: chatId }
-      });
+    if (canReply) {
+      try {
+        await replyMessage({
+          path: { message_id: replyToMessageId },
+          data: body
+        });
+        continue;
+      } catch (error) {
+        canReply = false;
+        console.warn("Feishu reply API failed; falling back to message create", error);
+      }
     }
+    await createMessage({
+      params: { receive_id_type: "chat_id" },
+      data: { ...body, receive_id: chatId }
+    });
   }
 }
 
diff --git a/integrations/feishu-bridge/src/lib.mjs b/integrations/feishu-bridge/src/lib.mjs
index 2408fe81..217b6beb 100644
--- a/integrations/feishu-bridge/src/lib.mjs
+++ b/integrations/feishu-bridge/src/lib.mjs
@@ -166,6 +166,17 @@ export function commandAction(command) {
   }
 }
 
+export function preservedChatStateFields(state = {}) {
+  const preserved = {};
+  if (Object.prototype.hasOwnProperty.call(state || {}, "model")) {
+    preserved.model = state.model || null;
+  }
+  if (state?.replyToMessageId) {
+    preserved.replyToMessageId = state.replyToMessageId;
+  }
+  return preserved;
+}
+
 export function splitMessage(text, maxChars = 3500) {
   const value = String(text || "");
   const chars = Array.from(value);
@@ -346,6 +357,7 @@ export function helpText() {
     "/threads - recent runtime threads",
     "/new - create a new thread for this chat",
     "/resume <thread_id> - bind this chat to an existing thread",
+    "/model <name|default> - set or reset this chat's model",
     "/interrupt - interrupt the active turn",
     "/compact - compact the current thread",
     "/allow <approval_id> [remember] - approve a pending tool call",
diff --git a/integrations/feishu-bridge/test/lib.test.mjs b/integrations/feishu-bridge/test/lib.test.mjs
index ca242035..40e264d2 100644
--- a/integrations/feishu-bridge/test/lib.test.mjs
+++ b/integrations/feishu-bridge/test/lib.test.mjs
@@ -12,8 +12,10 @@ import {
   parseCommand,
   parseList,
   parseTextContent,
+  preservedChatStateFields,
   splitMessage,
   stripGroupPrefix,
+  helpText,
   validateBridgeConfig
 } from "../src/lib.mjs";
 
@@ -89,12 +91,36 @@ test("commandAction maps bridge commands and falls back to prompts", () => {
     kind: "resume",
     threadId: "thread-1"
   });
+  assert.deepEqual(commandAction(parseCommand("/model deepseek-v4-pro")), {
+    kind: "set_model",
+    modelName: "deepseek-v4-pro"
+  });
   assert.deepEqual(commandAction(parseCommand("/unknown value")), {
     kind: "prompt",
     prompt: "/unknown value"
   });
 });
 
+test("helpText documents per-chat model switching", () => {
+  assert.match(helpText(), /\/model <name\|default>/);
+});
+
+test("preservedChatStateFields carries model across state replacement", () => {
+  assert.deepEqual(
+    preservedChatStateFields({
+      threadId: "old-thread",
+      model: "deepseek-v4-flash",
+      replyToMessageId: "om_123",
+      activeTurnId: "turn-1"
+    }),
+    {
+      model: "deepseek-v4-flash",
+      replyToMessageId: "om_123"
+    }
+  );
+  assert.deepEqual(preservedChatStateFields({ model: null }), { model: null });
+});
+
 test("parseApprovalDecisionArgs extracts remember flag", () => {
   assert.deepEqual(parseApprovalDecisionArgs("ap_123 remember"), {
     approvalId: "ap_123",