feat(chat): unlock paid messages before payment

src/app/chat/chat-screen.tsx

@@ -7,11 +7,18 @@ import { useRouter } from "next/navigation";
 import { useAuthState } from "@/stores/auth/auth-context";
 import { useChatDispatch, useChatState } from "@/stores/chat/chat-context";
 import { useUserState } from "@/stores/user/user-context";
+import { ROUTE_BUILDERS, ROUTES } from "@/router/routes";
 import {
   openChatInExternalBrowser,
   recordExternalBrowserPromptShown,
   resolveExternalBrowserPromptEligibility,
 } from "@/lib/chat/chat_external_browser";
+import {
+  consumePendingChatUnlock,
+  peekPendingChatUnlock,
+  savePendingChatUnlock,
+  type PendingChatUnlockKind,
+} from "@/lib/navigation/chat_unlock_session";
 
 import { MobileShell } from "@/app/_components/core";
 
@@ -45,6 +52,9 @@ export function ChatScreen() {
 
   // isGuest 派生（chat-screen 是唯一知道这个值的地方 —— chat 机器无 isGuest 字段）
   const isGuest = deriveIsGuest(authState.loginStatus);
+  const isAuthenticatedUser =
+    authState.loginStatus !== "notLoggedIn" &&
+    authState.loginStatus !== "guest";
 
   // 消息数量限制由后端统一返回 lockDetail，前端不再处理本地额度。
   const showMessageLimitBanner =
@@ -102,17 +112,79 @@ export function ChatScreen() {
     authState.loginStatus,
   ]);
 
+  useEffect(() => {
+    if (!state.historyLoaded || !isAuthenticatedUser) return;
+
+    const pending = peekPendingChatUnlock();
+    if (!pending || pending.returnUrl !== ROUTES.chat) return;
+
+    const consumed = consumePendingChatUnlock();
+    if (!consumed) return;
+
+    chatDispatch({
+      type: "ChatUnlockMessageRequested",
+      messageId: consumed.messageId,
+      kind: consumed.kind,
+    });
+  }, [
+    chatDispatch,
+    isAuthenticatedUser,
+    state.historyLoaded,
+  ]);
+
+  useEffect(() => {
+    const request = state.unlockPaywallRequest;
+    if (!request) return;
+
+    savePendingChatUnlock({
+      messageId: request.messageId,
+      kind: request.kind,
+      returnUrl: ROUTES.chat,
+      stage: "payment",
+    });
+    chatDispatch({ type: "ChatUnlockPaywallNavigationConsumed" });
+    router.push(
+      ROUTE_BUILDERS.subscription(
+        getInsufficientCreditsSubscriptionType(userState.isVip),
+        { returnTo: "chat" },
+      ),
+    );
+  }, [
+    chatDispatch,
+    router,
+    state.unlockPaywallRequest,
+    userState.isVip,
+  ]);
+
   async function handleOpenExternalBrowser(): Promise<void> {
     setShowExternalBrowserDialog(false);
     await openChatInExternalBrowser();
   }
 
-  function openChatPaywallSubscription(): void {
-    router.push(getChatPaywallNavigationUrl(authState.loginStatus));
+  function requestMessageUnlock(
+    messageId: string,
+    kind: PendingChatUnlockKind,
+  ): void {
+    if (!isAuthenticatedUser) {
+      savePendingChatUnlock({
+        messageId,
+        kind,
+        returnUrl: ROUTES.chat,
+        stage: "auth",
+      });
+      router.push(ROUTE_BUILDERS.authWithRedirect(ROUTES.chat));
+      return;
+    }
+
+    chatDispatch({
+      type: "ChatUnlockMessageRequested",
+      messageId,
+      kind,
+    });
   }
 
-  function handleUnlockPrivateMessage(): void {
-    openChatPaywallSubscription();
+  function handleUnlockPrivateMessage(messageId: string): void {
+    requestMessageUnlock(messageId, "private");
   }
 
   function handleMessageLimitUnlock(): void {
@@ -129,8 +201,8 @@ export function ChatScreen() {
     );
   }
 
-  function handleUnlockVoiceMessage(): void {
-    openChatPaywallSubscription();
+  function handleUnlockVoiceMessage(messageId: string): void {
+    requestMessageUnlock(messageId, "voice");
   }
 
   return (
@@ -154,6 +226,8 @@ export function ChatScreen() {
             messages={state.messages}
             isReplyingAI={state.isReplyingAI}
             isGuest={isGuest}
+            isUnlockingMessage={state.isUnlockingMessage}
+            unlockingMessageId={state.unlockingMessageId}
             onUnlockPrivateMessage={handleUnlockPrivateMessage}
             onUnlockVoiceMessage={handleUnlockVoiceMessage}
           />