<?php
/**
 * Redirect to Google OAuth — admin login entry point
 */
require_once __DIR__ . '/../../../includes/auth.php';

if (AdminAuth::isLoggedIn()) {
    header('Location: /admin/');
    exit;
}

if (!defined('GOOGLE_CLIENT_ID') || !GOOGLE_CLIENT_ID) {
    die('Google OAuth is not configured. Set GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET in config.');
}

$state = bin2hex(random_bytes(16));
$_SESSION['google_oauth_state'] = $state;

$params = http_build_query([
    'client_id'     => GOOGLE_CLIENT_ID,
    'redirect_uri'  => GOOGLE_REDIRECT_URI,
    'response_type' => 'code',
    'scope'         => 'openid email profile',
    'state'         => $state,
    'access_type'   => 'online',
    'prompt'        => 'select_account',
]);

header('Location: https://accounts.google.com/o/oauth2/v2/auth?' . $params);
exit;