<?php

namespace Kanboard\Core\Security;

use Kanboard\Core\Base;

/**
 * Token Handler
 *
 * @package  security
 * @author   Frederic Guillot
 */
class Token extends Base
{
    /**
     * Generate a random token with different methods: openssl or /dev/urandom or fallback to uniqid()
     *
     * @static
     * @access public
     * @return string  Random token
     */
    public static function getToken()
    {
        return bin2hex(random_bytes(30));
    }

    /**
     * Generate and store a CSRF token in the current session
     *
     * @access public
     * @return string  Random token
     */
    public function getCSRFToken()
    {
        if (! session_exists('csrf')) {
            session_set('csrf', []);
        }

        $nonce = self::getToken();
        session_merge('csrf', [$nonce => true]);

        return $nonce;
    }

    /**
     * Check if the token exists for the current session (a token can be used only one time)
     *
     * @access public
     * @param  string   $token   CSRF token
     * @return bool
     */
    public function validateCSRFToken($token)
    {
        $tokens = session_get('csrf');
        if (isset($tokens[$token])) {
            unset($tokens[$token]);
            session_set('csrf', $tokens);
            return true;
        }

        return false;
    }
}