<?php
session_start();
require_once 'google_config.php';

// If we have an access token, the user is already connected.
if (isset($_SESSION['access_token'])) {
    header('Location: index.php');
    exit();
}

$auth_url = 'https://accounts.google.com/o/oauth2/v2/auth?' . http_build_query([
    'client_id' => GOOGLE_CLIENT_ID,
    'redirect_uri' => GOOGLE_REDIRECT_URI,
    'response_type' => 'code',
    'scope' => 'https://www.googleapis.com/auth/calendar.readonly',
    'access_type' => 'offline', // Required to get a refresh token
    'prompt' => 'consent' // Forces the consent screen to be shown every time
]);

header('Location: ' . $auth_url);
exit();
?>