Html2Pdf.php

<?php
/**
 * Created by PhpStorm.
 * User: crose
 * Date: 4/17/17
 * Time: 10:17 PM
 *
 * Check: CODING.md > 'Print' and 'Download'
 *
 */

namespace qfq;

require_once(__DIR__ . '/../store/Config.php');
require_once(__DIR__ . '/../store/Session.php');
require_once(__DIR__ . '/../store/Sip.php');
require_once(__DIR__ . '/../Constants.php');
require_once(__DIR__ . '/../helper/KeyValueStringParser.php');
require_once(__DIR__ . '/../helper/SessionCookie.php');
require_once(__DIR__ . '/../helper/Logger.php');


/**
 * Class Html2Pdf
 * @package qfq
 */
class Html2Pdf {

    /**
     * @var array
     */
    private $config = array();

    /**
     * @var \qfq\Session
     */
    private $session = null;

    /**
     * @var \qfq\SessionCookie
     */
    private $sessionCookie = null;

    /**
     * @var \qfq\Sip
     */
    private $sip = null;

    /**
     * @var string
     */
    private $logFile = '';

    /**
     * Read QFQ config. Only SYSTEM_BASE_URL_PRINT and SYSTEM_WKHTMLTOPDF will be used.
     * Check and get all clean _GET Parameter. Build a URL based on SYSTEM_BASE_URL_PRINT and the delivered URL params.
     *
     * @param array $config
     * @param       $phpUnit
     *
     * @throws UserFormException
     * @throws \exception
     */
    public function __construct(array $config = array(), $phpUnit = false) {

        if (count($config) == 0) {
            $config = Config::readConfig('');
        }

        $this->config = $config;

        if (!isset($config[SYSTEM_BASE_URL]) || $config[SYSTEM_BASE_URL] == '') {
            throw new \exception('Please configure ' . SYSTEM_BASE_URL, ERROR_HTML2PDF_MISSING_CONFIG);
        }

        if (!isset($config[SYSTEM_CMD_WKHTMLTOPDF]) || $config[SYSTEM_CMD_WKHTMLTOPDF] == '') {
            throw new \exception('Please configure ' . SYSTEM_CMD_WKHTMLTOPDF, ERROR_HTML2PDF_MISSING_CONFIG);
        }

        $this->session = Session::getInstance($phpUnit);
        $this->sessionCookie = new SessionCookie($config);
        $this->sip = new Sip($phpUnit);

        $this->logFile = $config[SYSTEM_SQL_LOG];
    }

    /**
     * Return an array with GET params who are clean - they do not violate $pattern.
     *
     * @param array $get
     * @return array
     */
    private function readCleanGetParam(array $get) {

        $param = array();
        $pattern = '^[\-_\.,;:\/a-zA-Z0-9]*$';

        foreach ($get as $key => $value) {
            if (preg_match("/$pattern/", $value) === 1) {
                $param[$key] = $value;
            }
        }

        return $param;
    }

    /**
     * Set HTML Header to initiate PDF download.
     *
     * @param $filename
     */
    private function setHeader($filename) {

        header("Content-Disposition: inline; filename=\"$filename\"");
        header("Content-Type: application/pdf");
        header("Content-Transfer-Encoding: binary");
    }


    /**
     * Converts a Webpage (URL) to a PDF file.
     * The URL might be a local Typo3 page (without hostname, starting with the parameter) or a full URL.
     *
     * @param string $token TOKEN_URL | TOKEN_URL_PARAM | TOKEN_PAGE | TOKEN_UID
     * @param string $url id=exportPage&r=123, www.nzz.ch/issue?id=456
     *
     * @return string rendered file - please delete later
     * @throws CodeException
     * @throws UserFormException
     * @throws \exception
     */
    public function page2pdf($token, $url) {
        $rcArgs = array();
        $urlParamString = '';
        $host = '';

        switch ($token) {
            case TOKEN_UID:
            case TOKEN_URL:
                $arr = explode('?', $url, 2);
                $host = $arr[0];
                $urlParamString = $arr[1] ?? '';
                break;
            case TOKEN_URL_PARAM:
            case TOKEN_PAGE:
                $host = $this->config[SYSTEM_BASE_URL];
                $urlParamString = $url;
                break;
            default:
                break;
        }

        $rcSipEncode = false;
        $urlParam = OnString::splitParam($urlParamString, $rcArgs, $rcSipEncode);

        $rcArgs = OnArray::arrayEscapeshellarg($rcArgs);
        $options = KeyValueStringParser::unparse($rcArgs, ' ', ' ');

        $urlParamString = KeyValueStringParser::unparse($urlParam, '=', '&');
        if ($rcSipEncode) {
            $urlParamString = $this->sip->queryStringToSip($urlParamString, RETURN_URL);
        }

        $url = Support::mergeUrlComponents('', $host, $urlParamString);

        if (substr($url, 0, 4) != 'http' && $token != TOKEN_UID) {
            $url = 'http://' . $url;
        }

        $urlPrint = escapeshellarg($url);
        $wkhtmlToPdf = $this->config[SYSTEM_CMD_WKHTMLTOPDF];

        $filename = HelperFile::tempnam();
        $filenameEscape = escapeshellarg($filename);

        $cookieOptions = '--cookie-jar ' . escapeshellarg($this->sessionCookie->getFile());
        $customHeader = '--custom-header User-Agent ' . escapeshellarg($_SERVER['HTTP_USER_AGENT']) . ' --custom-header-propagation'; // By default 'Typo3' expects the same User-Agent for the FE-Session

        // Very important: The current lock on session SESSION_NAME has to be freed, cause wkhtmltopdf will use the same
        // session in a few moments and this script remains active during that time and that would cause a deadlock else.
        $this->session->close();
        $cmd = "$wkhtmlToPdf $customHeader $cookieOptions $options $urlPrint $filenameEscape";

        if ($this->logFile != '') {
            Logger::logMessage("Html2Pdf: $cmd", $this->logFile);
        }

        $rc = 0;
        $line = system($cmd, $rc);

        if ($rc != 0) {
            throw new \exception("Error [RC=$rc] $line: $cmd - in case of trouble: check carefully that *all* CSS, JS, " .
                "images are accessible. 'wkhtml' does not report problems but fails.", ERROR_HTML2PDF_WKHTML_FAILED);
        }

        return $filename;
    }

    /**
     * @throws \exception
     */
    public function outputHtml2Pdf() {

        $get = $this->readCleanGetParam($_GET);
        $urlParam = KeyValueStringParser::unparse($get, '=', '&');
        $pageId = Support::setIfNotSet($get, HTML2PDF_PAGEID, 0);

        $filename = $this->page2pdf(TOKEN_URL_PARAM, $urlParam);

        $this->setHeader('print.' . $pageId . '.pdf');
        @readfile($filename);
        @unlink($filename);

        exit; // Do an extremely hard exit here to make sure there are no more additional bytes sent (makes the delivered PDF unusable).

    }

}