fix(chat): render cached history before network sync

src/stores/chat/__tests__/chat-machine.transitions.test.ts

@@ -9,15 +9,6 @@ import {
 import { chatMachine } from "@/stores/chat/chat-machine";
 import type { ChatEvent } from "@/stores/chat/chat-events";
 
-interface LoadHistoryOutput {
-  messages: UiMessage[];
-  hasMore: boolean;
-  newOffset: number;
-  localOverwritten: boolean;
-  localCount: number;
-  networkCount: number;
-}
-
 interface LoadMoreHistoryOutput {
   messages: UiMessage[];
   hasMore: boolean;
@@ -94,14 +85,7 @@ function createTestChatMachine(
 ) {
   return chatMachine.provide({
     actors: {
-      loadHistory: fromPromise<LoadHistoryOutput>(async () => ({
+      loadHistory: createLoadHistoryCallback(options.historyMessages ?? []),
-        messages: options.historyMessages ?? [],
-        hasMore: false,
-        newOffset: 0,
-        localOverwritten: true,
-        localCount: 0,
-        networkCount: 0,
-      })),
       loadMoreHistory: fromPromise<LoadMoreHistoryOutput, { offset: number }>(
         async () => ({
           messages: [],
@@ -150,6 +134,35 @@ function createTestChatMachine(
   });
 }
 
+function createLoadHistoryCallback(
+  messages: UiMessage[],
+  networkMessages: UiMessage[] = messages,
+) {
+  return fromCallback<ChatEvent>(({ sendBack }) => {
+    sendBack({
+      type: "ChatLocalHistoryLoaded",
+      output: {
+        messages,
+        hasMore: false,
+        newOffset: messages.length,
+        localCount: messages.length,
+      },
+    });
+    sendBack({
+      type: "ChatNetworkHistoryLoaded",
+      output: {
+        messages: networkMessages,
+        hasMore: false,
+        newOffset: networkMessages.length,
+        localOverwritten: true,
+        localCount: messages.length,
+        networkCount: networkMessages.length,
+      },
+    });
+    return () => undefined;
+  });
+}
+
 describe("chatMachine transitions", () => {
   it("keeps guest logout disabled while allowing upgrade to user login", async () => {
     const actor = createActor(createTestChatMachine()).start();
@@ -187,6 +200,76 @@ describe("chatMachine transitions", () => {
     actor.stop();
   });
 
+  it("renders local history before network history sync finishes", async () => {
+    let resolveNetwork!: () => void;
+    const networkReleased = new Promise<void>((resolve) => {
+      resolveNetwork = resolve;
+    });
+    const localMessage: UiMessage = {
+      id: "local-msg",
+      content: "cached local message",
+      isFromAI: true,
+      date: "2026-07-02",
+    };
+    const networkMessage: UiMessage = {
+      id: "network-msg",
+      content: "fresh network message",
+      isFromAI: true,
+      date: "2026-07-02",
+    };
+    const machine = chatMachine.provide({
+      actors: {
+        loadHistory: fromCallback<ChatEvent>(({ sendBack }) => {
+          sendBack({
+            type: "ChatLocalHistoryLoaded",
+            output: {
+              messages: [localMessage],
+              hasMore: false,
+              newOffset: 1,
+              localCount: 1,
+            },
+          });
+          void networkReleased.then(() => {
+            sendBack({
+              type: "ChatNetworkHistoryLoaded",
+              output: {
+                messages: [networkMessage],
+                hasMore: false,
+                newOffset: 1,
+                localOverwritten: true,
+                localCount: 1,
+                networkCount: 1,
+              },
+            });
+          });
+          return () => undefined;
+        }),
+      },
+    });
+    const actor = createActor(machine).start();
+
+    actor.send({ type: "ChatUserLogin", token: "token" });
+    await waitFor(actor, (snapshot) =>
+      snapshot.matches({ userSession: "ready" }),
+    );
+
+    expect(actor.getSnapshot().context.messages).toMatchObject([
+      { id: "local-msg", content: "cached local message" },
+    ]);
+
+    resolveNetwork();
+    await waitFor(
+      actor,
+      (snapshot) => snapshot.context.messages[0]?.id === "network-msg",
+    );
+
+    expect(actor.getSnapshot().context.messages).toMatchObject([
+      { id: "network-msg", content: "fresh network message" },
+    ]);
+
+    actor.stop();
+  });
+
   it("ignores guest login while an authenticated user session is active", async () => {
     const actor = createActor(createTestChatMachine()).start();
 
@@ -254,14 +337,7 @@ describe("chatMachine transitions", () => {
   it("tracks replying state by queued batch instead of user message count", async () => {
     const machine = chatMachine.provide({
       actors: {
-        loadHistory: fromPromise<LoadHistoryOutput>(async () => ({
+        loadHistory: createLoadHistoryCallback([]),
-          messages: [],
-          hasMore: false,
-          newOffset: 0,
-          localOverwritten: true,
-          localCount: 0,
-          networkCount: 0,
-        })),
         loadMoreHistory: fromPromise<LoadMoreHistoryOutput, { offset: number }>(
           async () => ({
             messages: [],

src/stores/chat/chat-events.ts

@@ -22,6 +22,15 @@ export type ChatEvent =
   | { type: "ChatGuestLogin" }
   | { type: "ChatUserLogin"; token: string }
   | { type: "ChatLogout" }
+  | {
+      type: "ChatLocalHistoryLoaded";
+      output: import("./chat-history-sync").LocalHistorySnapshotOutput;
+    }
+  | {
+      type: "ChatNetworkHistoryLoaded";
+      output: import("./chat-history-sync").NetworkHistorySyncOutput;
+    }
+  | { type: "ChatHistoryLoadFailed"; error: unknown }
   // 业务事件
   | { type: "ChatSendMessage"; content: string }
   | { type: "ChatSendImage"; imageBase64: string }

src/stores/chat/chat-history-flow.ts

@@ -1,28 +1,51 @@
-import { fromPromise } from "xstate";
+import { fromCallback, fromPromise } from "xstate";
 
 import { getChatRepository } from "@/data/repositories/chat_repository";
 import { Logger, Result } from "@/utils";
 
-import { readAndSyncHistory } from "./chat-history-sync";
+import {
+  readLocalHistorySnapshot,
+  syncNetworkHistory,
+} from "./chat-history-sync";
 import {
   PAGE_SIZE,
   localMessagesToUi,
 } from "./chat-machine.helpers";
+import type { ChatEvent } from "./chat-events";
 
 const log = new Logger("StoresChatChatHistoryFlow");
 
 type UiMessage = import("@/data/dto/chat").UiMessage;
 
 export const chatHistoryActors = {
-  loadHistory: fromPromise<{
+  loadHistory: fromCallback<ChatEvent>(({ sendBack }) => {
-    messages: UiMessage[];
+    let cancelled = false;
-    hasMore: boolean;
+
-    newOffset: number;
+    void (async () => {
-    localOverwritten: boolean;
+      const localSnapshot = await readLocalHistorySnapshot();
-    localCount: number;
+      if (cancelled) return;
-    networkCount: number;
+      sendBack({
-  }>(async () => {
+        type: "ChatLocalHistoryLoaded",
-    return readAndSyncHistory();
+        output: localSnapshot,
+      });
+
+      const networkSnapshot = await syncNetworkHistory(
+        localSnapshot.localCount,
+      );
+      if (cancelled || !networkSnapshot) return;
+      sendBack({
+        type: "ChatNetworkHistoryLoaded",
+        output: networkSnapshot,
+      });
+    })().catch((error: unknown) => {
+      if (cancelled) return;
+      log.error("[chat-machine] loadHistoryActor failed", { error });
+      sendBack({ type: "ChatHistoryLoadFailed", error });
+    });
+
+    return () => {
+      cancelled = true;
+    };
   }),
 
   loadMoreHistory: fromPromise<

src/stores/chat/chat-history-sync.ts

@@ -17,7 +17,17 @@ export type ReadAndSyncHistoryOutput = {
   networkCount: number;
 };
 
-function createGreetingMessage(): UiMessage {
+export type LocalHistorySnapshotOutput = {
+  /** Local cached messages. Empty local history includes a UI greeting. */
+  messages: UiMessage[];
+  hasMore: boolean;
+  newOffset: number;
+  localCount: number;
+};
+
+export type NetworkHistorySyncOutput = ReadAndSyncHistoryOutput;
+
+export function createGreetingMessage(): UiMessage {
   return {
     content:
       "You're here! Facebook is so restrictive, " +
@@ -28,13 +38,7 @@ function createGreetingMessage(): UiMessage {
   };
 }
 
-/**
+export async function readLocalHistorySnapshot(): Promise<LocalHistorySnapshotOutput> {
- * History sync flow:
- * 1. Read local history for fallback.
- * 2. Read network history as the authoritative source.
- * 3. Overwrite local history with network data.
- */
-export async function readAndSyncHistory(): Promise<ReadAndSyncHistoryOutput> {
   const chatRepo = getChatRepository();
   const greetingMessage = createGreetingMessage();
 
@@ -47,27 +51,32 @@ export async function readAndSyncHistory(): Promise<ReadAndSyncHistoryOutput> {
     count: localMessages.length,
   });
 
+  const snapshotMessages =
+    localMessages.length === 0 ? [greetingMessage] : localMessages;
+  if (snapshotMessages[0] === greetingMessage) {
+    log.debug("[chat-machine] loadHistory EMPTY -> prepend greeting (local)");
+  }
+
+  return {
+    messages: snapshotMessages,
+    hasMore: localMessages.length >= PAGE_SIZE,
+    newOffset: snapshotMessages.length,
+    localCount: localMessages.length,
+  };
+}
+
+export async function syncNetworkHistory(
+  localCount: number,
+): Promise<NetworkHistorySyncOutput | null> {
+  const chatRepo = getChatRepository();
+  const greetingMessage = createGreetingMessage();
+
   const networkResult = await chatRepo.getHistory(PAGE_SIZE, 0);
   if (Result.isErr(networkResult)) {
     log.error("[chat-machine] loadHistory NETWORK FAILED", {
       error: networkResult.error,
     });
-
+    return null;
-    const fallbackMessages =
-      localMessages.length === 0 ? [greetingMessage] : localMessages;
-    if (fallbackMessages[0] === greetingMessage) {
-      log.debug(
-        "[chat-machine] loadHistory EMPTY -> prepend greeting (network-failed path)",
-      );
-    }
-    return {
-      messages: fallbackMessages,
-      hasMore: false,
-      newOffset: fallbackMessages.length,
-      localOverwritten: false,
-      localCount: localMessages.length,
-      networkCount: 0,
-    };
   }
 
   const networkUi = localMessagesToUi(networkResult.data.messages);
@@ -95,7 +104,28 @@ export async function readAndSyncHistory(): Promise<ReadAndSyncHistoryOutput> {
     hasMore: finalMessages.length >= PAGE_SIZE,
     newOffset: finalMessages.length,
     localOverwritten,
-    localCount: localMessages.length,
+    localCount,
     networkCount: networkUi.length,
   };
 }
+
+/**
+ * History sync flow:
+ * 1. Read local history for fallback.
+ * 2. Read network history as the authoritative source.
+ * 3. Overwrite local history with network data.
+ */
+export async function readAndSyncHistory(): Promise<ReadAndSyncHistoryOutput> {
+  const localSnapshot = await readLocalHistorySnapshot();
+  const networkSnapshot = await syncNetworkHistory(localSnapshot.localCount);
+  if (networkSnapshot) return networkSnapshot;
+
+  return {
+    messages: localSnapshot.messages,
+    hasMore: localSnapshot.hasMore,
+    newOffset: localSnapshot.newOffset,
+    localOverwritten: false,
+    localCount: localSnapshot.localCount,
+    networkCount: 0,
+  };
+}

src/stores/chat/chat-machine.helpers.ts

@@ -26,3 +26,23 @@ export function applyHistoryLoadedOutput(
     historyLoaded: true,
   };
 }
+
+export function applyNetworkHistoryLoadedOutput(
+  context: ChatState,
+  output: {
+    messages: UiMessage[];
+    hasMore: boolean;
+    newOffset: number;
+  },
+): Pick<
+  ChatState,
+  "messages" | "hasMore" | "historyOffset" | "historyLoaded"
+> {
+  const optimisticTail = context.messages.slice(context.historyOffset);
+  return {
+    messages: [...output.messages, ...optimisticTail],
+    hasMore: output.hasMore,
+    historyOffset: output.newOffset,
+    historyLoaded: true,
+  };
+}

src/stores/chat/chat-machine.ts

@@ -34,6 +34,7 @@ import type { ChatEvent } from "./chat-events";
 import {
   applyHttpSendOutput,
   applyHistoryLoadedOutput,
+  applyNetworkHistoryLoadedOutput,
   countLockedHistoryMessages,
   shouldAutoUnlockHistory,
   shouldPromptUnlockHistory,
@@ -78,6 +79,46 @@ export const chatMachine = setup({
     clearChatSession: assign(() => ({
       ...initialState,
     })),
+
+    applyLocalHistoryLoaded: assign(({ event }) => {
+      if (event.type !== "ChatLocalHistoryLoaded") return {};
+      return applyHistoryLoadedOutput(event.output);
+    }),
+
+    applyNetworkHistoryLoaded: assign(({ context, event }) => {
+      if (event.type !== "ChatNetworkHistoryLoaded") return {};
+      return applyNetworkHistoryLoadedOutput(context, event.output);
+    }),
+
+    applyNetworkHistoryLoadedAndClearPayment: assign(({ context, event }) => {
+      if (event.type !== "ChatNetworkHistoryLoaded") return {};
+      return {
+        ...applyNetworkHistoryLoadedOutput(context, event.output),
+        isLoadingMore: false,
+        paymentUnlockPending: false,
+      };
+    }),
+
+    showUnlockHistoryPromptFromNetwork: assign(({ context, event }) => {
+      if (event.type !== "ChatNetworkHistoryLoaded") return {};
+      const nextHistory = applyNetworkHistoryLoadedOutput(
+        context,
+        event.output,
+      );
+      return {
+        ...nextHistory,
+        isLoadingMore: false,
+        paymentUnlockPending: false,
+        unlockHistoryPromptVisible: true,
+        lockedHistoryCount: countLockedHistoryMessages(nextHistory.messages),
+        unlockHistoryError: null,
+      };
+    }),
+
+    markHistoryLoadFailed: assign({
+      isLoadingMore: false,
+      historyLoaded: true,
+    }),
   },
 }).createMachine({
   id: "chat",
@@ -98,15 +139,27 @@ export const chatMachine = setup({
     },
 
     guestSession: {
-      invoke: {
+      invoke: [
+        {
           id: "messageQueue",
           src: "httpMessageQueue",
         },
+        {
+          id: "loadHistory",
+          src: "loadHistory",
+        },
+      ],
       on: {
         ChatUserLogin: {
           target: "#chat.userSession",
           actions: "startUserSession",
         },
+        ChatNetworkHistoryLoaded: {
+          actions: "applyNetworkHistoryLoaded",
+        },
+        ChatHistoryLoadFailed: {
+          actions: "markHistoryLoadFailed",
+        },
         ChatQueuedSendStarted: {
           actions: "markQueuedSendStarted",
         },
@@ -120,25 +173,18 @@ export const chatMachine = setup({
       initial: "initializing",
       states: {
         initializing: {
-          always: [
+          on: {
-            {
+            ChatLocalHistoryLoaded: {
               target: "ready",
-              guard: ({ context }) => context.historyLoaded,
+              actions: "applyLocalHistoryLoaded",
             },
-          ],
+            ChatNetworkHistoryLoaded: {
-          invoke: {
+              target: "ready",
-            id: "loadHistory",
+              actions: "applyNetworkHistoryLoaded",
-            src: "loadHistory",
-            onDone: {
-              actions: assign(({ event }) =>
-                applyHistoryLoadedOutput(event.output),
-              ),
             },
-            onError: {
+            ChatHistoryLoadFailed: {
-              // 失败也标 loaded，不卡 init（让 UI 还是能进 ready，屏幕可能空）
+              target: "ready",
-              actions: assign({
+              actions: "markHistoryLoadFailed",
-                historyLoaded: true,
-              }),
             },
           },
         },
@@ -178,15 +224,50 @@ export const chatMachine = setup({
     },
 
     userSession: {
-      invoke: {
+      invoke: [
+        {
           id: "messageQueue",
           src: "httpMessageQueue",
         },
+        {
+          id: "loadHistory",
+          src: "loadHistory",
+        },
+      ],
       on: {
         ChatLogout: {
           target: "#chat.idle",
           actions: "clearChatSession",
         },
+        ChatNetworkHistoryLoaded: [
+          {
+            guard: ({ context, event }) =>
+              event.type === "ChatNetworkHistoryLoaded" &&
+              context.paymentUnlockPending &&
+              shouldAutoUnlockHistory(event.output.messages),
+            target: ".unlockingHistory",
+            actions: [
+              "applyNetworkHistoryLoadedAndClearPayment",
+              "markUnlockHistoryStarted",
+            ],
+          },
+          {
+            guard: ({ context, event }) =>
+              event.type === "ChatNetworkHistoryLoaded" &&
+              context.paymentUnlockPending &&
+              shouldPromptUnlockHistory(event.output.messages),
+            target: ".ready",
+            actions: "showUnlockHistoryPromptFromNetwork",
+          },
+          {
+            guard: ({ context }) =>
+              !context.isUnlockingHistory && !context.isUnlockingMessage,
+            actions: "applyNetworkHistoryLoaded",
+          },
+        ],
+        ChatHistoryLoadFailed: {
+          actions: "markHistoryLoadFailed",
+        },
         ChatQueuedSendStarted: {
           actions: "markQueuedSendStarted",
         },
@@ -232,53 +313,39 @@ export const chatMachine = setup({
       initial: "initializing",
       states: {
         initializing: {
-          invoke: {
+          on: {
-            src: "loadHistory",
+            ChatLocalHistoryLoaded: {
-            onDone: [
+              target: "ready",
+              actions: "applyLocalHistoryLoaded",
+            },
+            ChatNetworkHistoryLoaded: [
               {
                 guard: ({ context, event }) =>
+                  event.type === "ChatNetworkHistoryLoaded" &&
                   context.paymentUnlockPending &&
                   shouldAutoUnlockHistory(event.output.messages),
                 target: "unlockingHistory",
                 actions: [
-                  assign(({ event }) => ({
+                  "applyNetworkHistoryLoadedAndClearPayment",
-                    ...applyHistoryLoadedOutput(event.output),
-                    isLoadingMore: false,
-                  })),
                   "markUnlockHistoryStarted",
                 ],
               },
               {
                 guard: ({ context, event }) =>
+                  event.type === "ChatNetworkHistoryLoaded" &&
                   context.paymentUnlockPending &&
                   shouldPromptUnlockHistory(event.output.messages),
                 target: "ready",
-                actions: assign(({ event }) => ({
+                actions: "showUnlockHistoryPromptFromNetwork",
-                  ...applyHistoryLoadedOutput(event.output),
-                  isLoadingMore: false,
-                  paymentUnlockPending: false,
-                  unlockHistoryPromptVisible: true,
-                  lockedHistoryCount: countLockedHistoryMessages(
-                    event.output.messages,
-                  ),
-                  unlockHistoryError: null,
-                })),
               },
               {
                 target: "ready",
-                actions: assign(({ event }) => ({
+                actions: "applyNetworkHistoryLoadedAndClearPayment",
-                  ...applyHistoryLoadedOutput(event.output),
-                  isLoadingMore: false,
-                  paymentUnlockPending: false,
-                })),
               },
             ],
-            onError: {
+            ChatHistoryLoadFailed: {
               target: "ready",
-              actions: assign({
+              actions: "markHistoryLoadFailed",
-                isLoadingMore: false,
-                historyLoaded: true,
-              }),
             },
           },
         },

src/stores/chat/chat-state.ts

@@ -27,8 +27,8 @@ export interface ChatState {
   isLoadingMore: boolean;
   hasMore: boolean;
   historyOffset: number;
-  /** history 加载完成标志（initial load —— local → network → save 跑完）
+  /** history 首屏可展示标志（本地快照加载完成即可进入 ready）
-   * - guestSession.initializing / user sessions initializing 走 always barrier
+   * - 网络历史加载完成后会再次刷新消息列表
    * - 不被 `loadMoreHistoryActor` 设置（翻页是另一码事）
    */
   historyLoaded: boolean;