Auth First Run (#1207)

Co-authored-by: Tommaso Sciortino <sciortino@gmail.com>
Co-authored-by: N. Taylor Mullen <ntaylormullen@google.com>

packages/cli/src/ui/hooks/useAuthCommand.ts

@@ -0,0 +1,57 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { useState, useCallback, useEffect } from 'react';
+import { LoadedSettings, SettingScope } from '../../config/settings.js';
+import { AuthType, Config, clearCachedCredentialFile } from '@gemini-cli/core';
+
+async function performAuthFlow(authMethod: AuthType, config: Config) {
+  await config.refreshAuth(authMethod);
+  console.log(`Authenticated via "${authMethod}".`);
+}
+
+export const useAuthCommand = (
+  settings: LoadedSettings,
+  setAuthError: (error: string | null) => void,
+  config: Config,
+) => {
+  const [isAuthDialogOpen, setIsAuthDialogOpen] = useState(
+    settings.merged.selectedAuthType === undefined,
+  );
+
+  useEffect(() => {
+    if (!isAuthDialogOpen) {
+      performAuthFlow(settings.merged.selectedAuthType as AuthType, config);
+    }
+  }, [isAuthDialogOpen, settings, config]);
+
+  const openAuthDialog = useCallback(() => {
+    setIsAuthDialogOpen(true);
+  }, []);
+
+  const handleAuthSelect = useCallback(
+    async (authMethod: string | undefined, scope: SettingScope) => {
+      if (authMethod) {
+        await clearCachedCredentialFile();
+        settings.setValue(scope, 'selectedAuthType', authMethod);
+      }
+      setIsAuthDialogOpen(false);
+      setAuthError(null);
+    },
+    [settings, setAuthError],
+  );
+
+  const handleAuthHighlight = useCallback((_authMethod: string | undefined) => {
+    // For now, we don't do anything on highlight.
+  }, []);
+
+  return {
+    isAuthDialogOpen,
+    openAuthDialog,
+    handleAuthSelect,
+    handleAuthHighlight,
+  };
+};