feat(oauth): add csas connection, allow oauth from react

7project/frontend/src/App.tsx

@@ -3,21 +3,54 @@ import './App.css';
 import LoginRegisterPage from './pages/LoginRegisterPage';
 import Dashboard from './pages/Dashboard';
 import { logout } from './api';
+import { BACKEND_URL } from './config';
 
 function App() {
   const [hasToken, setHasToken] = useState<boolean>(!!localStorage.getItem('token'));
+  const [processingCallback, setProcessingCallback] = useState<boolean>(false);
 
   useEffect(() => {
-    // Handle OAuth callback: /oauth-callback?access_token=...&token_type=...
-    if (window.location.pathname === '/oauth-callback') {
-      const params = new URLSearchParams(window.location.search);
-      const token = params.get('access_token');
-      if (token) {
-        localStorage.setItem('token', token);
-        setHasToken(true);
+    const path = window.location.pathname;
+
+    // Minimal handling for provider callbacks: /auth|/oauth/:provider/callback?code=...&state=...
+    const parts = path.split('/').filter(Boolean);
+    const isCallback = parts.length === 3 && (parts[0] === 'auth') && parts[2] === 'callback';
+
+    if (isCallback) {
+      // Guard against double invocation in React 18 StrictMode/dev
+      const w = window as any;
+      if (w.__oauthCallbackHandled) {
+        return;
       }
-      // Clean URL and redirect to home
-      window.history.replaceState({}, '', '/');
+      w.__oauthCallbackHandled = true;
+
+      setProcessingCallback(true);
+
+      const provider = parts[1];
+      const qs = window.location.search || '';
+      const base = BACKEND_URL.replace(/\/$/, '');
+      const url = `${base}/auth/${encodeURIComponent(provider)}/callback${qs}`;
+      (async () => {
+        try {
+          const token = localStorage.getItem('token');
+          const res = await fetch(url, {
+            method: 'GET',
+            credentials: 'include',
+            headers: token ? { Authorization: `Bearer ${token}` } : undefined,
+          });
+          let data: any = null;
+          try {
+            data = await res.json();
+          } catch {}
+          if (provider !== 'csas' && res.ok && data?.access_token) {
+            localStorage.setItem('token', data?.access_token);
+            setHasToken(true);
+          }
+        } catch {}
+        // Clean URL and go home regardless of result
+        setProcessingCallback(false);
+        window.history.replaceState({}, '', '/');
+      })();
     }
 
     const onStorage = (e: StorageEvent) => {
@@ -27,6 +60,24 @@ function App() {
     return () => window.removeEventListener('storage', onStorage);
   }, []);
 
+  if (processingCallback) {
+    return (
+      <div style={{ display: 'grid', placeItems: 'center', height: '100vh' }}>
+        <div className="card" style={{ width: 360, textAlign: 'center', padding: 24 }}>
+          <div style={{ display: 'flex', flexDirection: 'column', alignItems: 'center', gap: 12 }}>
+            <svg width="48" height="48" viewBox="0 0 50 50" aria-label="Loading">
+              <circle cx="25" cy="25" r="20" fill="none" stroke="#3b82f6" strokeWidth="5" strokeLinecap="round" strokeDasharray="31.4 31.4">
+                <animateTransform attributeName="transform" type="rotate" from="0 25 25" to="360 25 25" dur="0.9s" repeatCount="indefinite" />
+              </circle>
+            </svg>
+            <div>Finishing sign-in…</div>
+            <div className="muted">Please wait</div>
+          </div>
+        </div>
+      </div>
+    );
+  }
+
   if (!hasToken) {
     return <LoginRegisterPage onLoggedIn={() => setHasToken(true)} />;
   }