<?php
session_start();
require_once '../config/db.php';
require_once '../includes/functions.php';

// Include Composer autoloader
require_once '../vendor/autoload.php';

if (!isset($_SESSION['loggedin']) || $_SESSION['loggedin'] !== true) {
    header("location: ../index.php");
    exit;
}

$client_id = get_setting($pdo_sys, 'google_client_id');
$client_secret = get_setting($pdo_sys, 'google_client_secret');

if (empty($client_id) || empty($client_secret)) {
    $_SESSION['settings_error'] = "กรุณาตั้งค่า Client ID และ Client Secret ก่อนทำการเชื่อมต่อ";
    header("location: ../settings.php");
    exit;
}

$client = new Google\Client();
$client->setClientId($client_id);
$client->setClientSecret($client_secret);

// Construct redirect URI dynamically
$protocol = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on') ? "https" : "http";
$host = $_SERVER['HTTP_HOST'];
$base_dir = dirname(dirname($_SERVER['PHP_SELF']));
$redirect_uri = $protocol . "://" . $host . $base_dir . "/auth/google_callback.php";
$redirect_uri = str_replace('//auth', '/auth', $redirect_uri);

$client->setRedirectUri($redirect_uri);
$client->addScope(Google\Service\Calendar::CALENDAR_EVENTS);
$client->setAccessType('offline');
$client->setPrompt('consent');

$auth_url = $client->createAuthUrl();
header('Location: ' . filter_var($auth_url, FILTER_SANITIZE_URL));
exit;
?>