<?php

/**
 * Sitemap
 * Using DOM Document search throught page and extract href attributes
 *
 */
class Sitemap {

    public $baseUrl;

    private $basePath = '/';

    private $sitemapName = 'sitemap.xml';

    private $disallowedUrls =  array('#', 'google', 'facebook', 'twitter', 'status', 'login', 'register', 'wishlist', 'account', 'linkedin', 'checkout');


    public function __construct()
    {
        $this->html = new DOMDocument();
    }
    /**
     * @return string
     */
    public function getBasePath()
    {
        return $this->basePath;
    }

    /**
     * @param string $basePath
     */
    public function setBasePath($basePath)
    {
        $this->basePath = $basePath;
    }

    /**
     * @return string
     */
    public function getSitemapName()
    {
        return $this->sitemapName;
    }

    /**
     * @param string $sitemapName
     */
    public function setSitemapName($sitemapName)
    {
        $this->sitemapName = $sitemapName;
    }
    /**
     * Use this method if want to set custom baseurl other then is setted in SitemapSettings
     *
     * @param string $url
     */
    public function setBaseUrl($url)
    {
        $this->baseUrl = $url;
    }

    /**
     * Generate sitemap and write directly to file
     * Using base url as start point for creating sitemap
     */
    public function generateSitemap()
    {
        $sitemap = $this->_sitemap($this->baseUrl);

        foreach ($sitemap as $addurl )
        {
            if($this->exludedList($addurl) == TRUE){
                 $sitemaps[] = $this->_sitemap($addurl);
            }
        }

        $sitemapXML = $this->createXml($sitemaps, $url);  // Undefined URL

        return $this->writeToFile($sitemapXML);
    }


    private function _sitemap($url)
    {
        $this->debugError();
        $this->html->loadHTML( file_get_contents($url));

        foreach ( $this->html->getElementsByTagname( 'a' ) as $link ) {
            $urlsite = $link->getAttribute( 'href' );

            if( ($this->exludedList($urlsite) == TRUE) && (!empty($urlsite)) ){
                if( !$this->getUrlProtocol($urlsite) )
                {
                    $href[] = $this->baseUrl.trim($urlsite, '/');
                } else {
                    if($this->checkExist($urlsite))
                        $href[] = $urlsite;
                }
            }
        }

        return $href;
    }


    /**
     * Check if collected url is relative or absolute url
     *
     * @param string $urlsite
     */
    private function getUrlProtocol($urlsite)
    {
        $protocol = parse_url($urlsite,PHP_URL_SCHEME);

        if(empty($protocol)){
            return false;
        }

        return true;
    }


    private function createXml($map, $url){

        $sitemapXML = '<?xml version="1.0" encoding="UTF-8"?>
                        <urlset xmlns="http://www.google.com/schemas/sitemap/0.9">';

        foreach ($this->unique($map) as $value) {

            $sitemapXML .= '<url>
                        <loc>'. $value .'</loc>
                        <lastmod>'. date('Y-m-d') .'T'. date('H:i:s').'+01:00</lastmod>
                        <changefreq>daily</changefreq>
                        <priority>0.5</priority>
                      </url>';
        }

        $sitemapXML .= '</urlset>';

        return $sitemapXML;
    }

    /**
     * This method exlude urls from sitemap if contain value from array
     *
     * @param string $urlForCheck
     */
    public function exludedList($urlForCheck)
    {

        $i = 0;
        foreach ($this->disallowedUrls as $value) {

            if(strpos($urlForCheck, $value) !== FALSE){
                $i++;
            }
        }

        if($i > 0){
            return false;
        } else {
            return true;
        }
    }

    public function unique($input)
    {
        $input = call_user_func_array('array_merge', $input);
        $input = array_unique($input);
        $input = array_values($input);

        return $input;
    }

    private function checkExist($urlsite)
    {
        $ch = curl_init();

        $cOption = array(
            CURLOPT_URL => $urlsite,
            CURLOPT_HEADER => true,
            CURLOPT_NOBODY => true,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => 10
        );

        curl_setopt_array($ch, $cOption);

        curl_exec($ch);
        $info = curl_getinfo($ch,CURLINFO_HTTP_CODE);

        if( $info == 0 ){
            return FALSE;
        } else {
            return TRUE;
        }
    }

    public function writeToFile($sitemap)
    {
        $file = $this->getSitemapName();
        $open = fopen($file, 'w');

        if(fwrite($open, $sitemap) !== FALSE){
            $check = 'Mapa sajta je uspešno generisana<br> Link do mape <a href="'. $this->baseUrl .'sitemap.xml" target="_blank">mapa</a>.';
        } else {
            $check = 'Došlo je do greške prilikom generisanja mape';
        }
        fclose($open);

        return $check;
    }

    public function debugError()
    {
        return libxml_use_internal_errors(true);
    }
}

?>