fix(chat): stabilize message identities

src/stores/chat/helper/message-mappers.ts

@@ -2,7 +2,12 @@ import type {
   ChatLockDetailData,
   ChatSendResponse,
 } from "@/data/schemas/chat";
-import type { UiMessage } from "@/stores/chat/ui-message";
+import {
+  createClientUiMessageIdentity,
+  createLegacyUiMessageIdentity,
+  createRemoteUiMessageIdentity,
+  type UiMessage,
+} from "@/stores/chat/ui-message";
 import { todayString } from "@/utils/date";
 
 /**
@@ -21,20 +26,33 @@ export function localMessagesToUi(
     lockDetail?: ChatLockDetailData;
   }[],
 ): UiMessage[] {
-  return records.map((m) => ({
-    ...(m.id ? { id: m.id } : {}),
-    content: getAiMessageDisplayContent({
-      content: m.content,
-      isFromAI: m.role === "assistant",
-      hasImage: Boolean(m.image?.url),
-    }),
-    isFromAI: m.role === "assistant",
-    date: messageDateFromCreatedAt(m.createdAt),
-    ...(m.audioUrl && m.lockDetail?.locked !== true
-      ? { audioUrl: m.audioUrl }
-      : {}),
-    ...deriveUiLockFields(m.lockDetail, m.image?.url),
-  }));
+  const occurrences = new Map<string, number>();
+  return records.map((m) => {
+    const isFromAI = m.role === "assistant";
+    const identityBase = m.id
+      ? `remote:${m.id}:${m.role}`
+      : `legacy:${createLegacyFingerprint(m)}`;
+    const occurrence = occurrences.get(identityBase) ?? 0;
+    occurrences.set(identityBase, occurrence + 1);
+    const identity = m.id
+      ? createRemoteUiMessageIdentity(m.id, isFromAI, occurrence)
+      : createLegacyUiMessageIdentity(identityBase, occurrence);
+
+    return {
+      ...identity,
+      content: getAiMessageDisplayContent({
+        content: m.content,
+        isFromAI,
+        hasImage: Boolean(m.image?.url),
+      }),
+      isFromAI,
+      date: messageDateFromCreatedAt(m.createdAt),
+      ...(m.audioUrl && m.lockDetail?.locked !== true
+        ? { audioUrl: m.audioUrl }
+        : {}),
+      ...deriveUiLockFields(m.lockDetail, m.image?.url),
+    };
+  });
 }
 
 /**
@@ -43,7 +61,9 @@ export function localMessagesToUi(
  */
 export function sendResponseToUiMessage(response: ChatSendResponse): UiMessage {
   return {
-    ...(response.messageId ? { id: response.messageId } : {}),
+    ...(response.messageId
+      ? createRemoteUiMessageIdentity(response.messageId, true)
+      : createClientUiMessageIdentity("reply")),
     content: getAiMessageDisplayContent({
       content: response.reply,
       isFromAI: true,
@@ -58,6 +78,28 @@ export function sendResponseToUiMessage(response: ChatSendResponse): UiMessage {
   };
 }
 
+function createLegacyFingerprint(record: {
+  type?: string;
+  content: string;
+  role: string;
+  createdAt: string;
+  audioUrl?: string | null;
+  image?: { type: string | null; url: string | null };
+  lockDetail?: ChatLockDetailData;
+}): string {
+  return JSON.stringify([
+    record.role,
+    record.type ?? "text",
+    record.content,
+    record.createdAt,
+    record.audioUrl ?? null,
+    record.image?.type ?? null,
+    record.image?.url ?? null,
+    record.lockDetail?.locked ?? null,
+    record.lockDetail?.reason ?? null,
+  ]);
+}
+
 function messageDateFromCreatedAt(createdAt: string): string {
   const parsed = new Date(createdAt);
   if (Number.isNaN(parsed.getTime())) return todayString();