<?php

namespace BRSystems\Core\Library\cGoogle2FA;

use PHPGangsta_GoogleAuthenticator;

/**
 * Google Two Factor Authentication class
 *
 * @category LIB cGoogle2FA
 * @author Mareks Keišs <mareks.keiss@brsystems.lv>
 * @since Version 1.0
 */
class cGoogle2FA
{
    private $oGA;
    /**
     * Class constructor
     */
    public function __construct()
    {
        $this->oGA = new PHPGangsta_GoogleAuthenticator();
    }

    /**
     * Function to get new google authenticator secret
     *
     * @author Mareks Keišs <mareks.keiss@brsystems.lv>
     * @category LIB cGoogle2FA
     * @return string - encrypted string
     */
    public function getNewGoogleAuthSecret()
    {
        return $this->oGA->createSecret();
    }

    /**
     * Function to get next google authenticator access code
     *
     * @author Mareks Keišs <mareks.keiss@brsystems.lv>
     * @category LIB cGoogle2FA
     * @param string $sSecret - secret linked for user account
     * @return string - encrypted string
     */
    public function getGoogleAuthCode($sSecret)
    {
        return $this->oGA->getCode($sSecret);
    }

    /**
     * Function to get new google authenticator secret QR code
     *
     * @author Mareks Keišs <mareks.keiss@brsystems.lv>
     * @category LIB cGoogle2FA
     * @param string $sSecret - secret to be linked for user account
     * @param string $sUserTitle - user account string
     * @param string $sIssuer - issuer title
     * @return string - encrypted string
     */
    public function getNewGoogleAuthSecretQRCodeLink($sSecret, $sUserTitle = '', $sIssuer = '')
    {
        // Replace all invalid symbols
        $sIssuer = preg_replace('/[:;\'\\"\/*-+=#$^&(){}\[\],`~§±]/i', '', $sIssuer);
        $sUserTitle = preg_replace('/[:;\'\\"\/*-+=#$^&(){}\[\],`~§±]/i', '', $sUserTitle);
        $sUserTitle = preg_replace('/ /', '_', $sUserTitle);

        return $this->oGA->getQRCodeGoogleUrl($sUserTitle, $sSecret, $sIssuer);
    }

    /**
     * Function to get new google authenticator secret QR code
     *
     * @author Mareks Keišs <mareks.keiss@brsystems.lv>
     * @category LIB cGoogle2FA
     * @param string $sSecret - linked secret to user account
     * @param string $sCode - input code to check
     * @param int $iTolerance - code tolerance 1 - 30s, 2 - 1min, 8 - 4min
     * @return string - encrypted string
     */
    public function verifyCode($sSecret, $sCode, $iTolerance = 1)
    {
        return $this->oGA->verifyCode($sSecret, $sCode, $iTolerance);    // 2 = 2*30sec clock tolerance
    }
}