Refactor app instance to Keycloak SSO

app-instance/frontend/app/auth/callback/page.tsx

@@ -0,0 +1,68 @@
+'use client';
+
+import { useEffect, useState } from 'react';
+import { useRouter } from 'next/navigation';
+
+import {
+  clearLoginState,
+  exchangeKeycloakCallback,
+  loadLoginState,
+  parseAuthCallbackUrl,
+} from '@/lib/keycloak-oidc';
+import { getMe } from '@/lib/api';
+import { pickAppText } from '@/lib/i18n/core';
+import { useAppI18n } from '@/lib/i18n/provider';
+import { useChatStore } from '@/lib/store';
+
+export default function AuthCallbackPage() {
+  const { locale } = useAppI18n();
+  const router = useRouter();
+  const setUser = useChatStore((s) => s.setUser);
+  const [error, setError] = useState('');
+
+  useEffect(() => {
+    let cancelled = false;
+
+    const completeLogin = async () => {
+      const callback = parseAuthCallbackUrl();
+      if (callback.error) {
+        throw new Error(callback.errorDescription || callback.error);
+      }
+      if (!callback.code || !callback.state) {
+        throw new Error('Missing Keycloak callback code or state');
+      }
+      const loginState = loadLoginState();
+      if (!loginState || loginState.state !== callback.state) {
+        throw new Error('Invalid Keycloak login state');
+      }
+
+      const result = await exchangeKeycloakCallback({ code: callback.code, state: loginState });
+      clearLoginState();
+      const user = await getMe().catch(() => result.user);
+      if (cancelled) return;
+      setUser(user);
+      router.replace(loginState.nextPath || '/');
+    };
+
+    completeLogin().catch((exc) => {
+      clearLoginState();
+      if (!cancelled) {
+        setError(exc instanceof Error ? exc.message : String(exc));
+      }
+    });
+
+    return () => {
+      cancelled = true;
+    };
+  }, [router, setUser]);
+
+  return (
+    <div className="flex min-h-screen items-center justify-center px-4">
+      <div className="max-w-lg text-center text-sm text-muted-foreground">
+        {error
+          ? pickAppText(locale, `登录失败：${error}`, `Sign-in failed: ${error}`)
+          : pickAppText(locale, '正在完成登录...', 'Completing sign-in...')}
+      </div>
+    </div>
+  );
+}