<?php
/**
 * Piwik - Open source web analytics
 *
 * @link http://piwik.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 *
 * @category Piwik_Plugins
 * @package Piwik_SEO
 */

/**
 * The functions below are derived/adapted from GetRank.org's
 * Free PageRank Script v2.0, released under GPL.
 *
 * @copyright Copyright (C) 2007 - 2010 GetRank.Org  All rights reserved.
 * @link http://www.getrank.org/free-pagerank-script/
 * @license GPL
 * @package Piwik_SEO
 */
class Piwik_SEO_RankChecker
{
	private $url;

	public function __construct($url)
	{
		$this->url = self::extractDomainFromUrl($url);
	}

	/**
	 * Extract domain from URL as the web services generally
	 * expect only a domain name (i.e., no protocol, port, path, query, etc).
	 *
	 * @param string $url
	 * @return string
	 */
	static public function extractDomainFromUrl($url)
	{
		return preg_replace(
			array(
				'~^https?\://~si',	// strip protocol
				'~[/:#?;%&].*~',	// strip port, path, query, anchor, etc
				'~\.$~',			// trailing period
			),
			'', $url);
	}

	/**
	 * Web service proxy that retrieves the content at the specified URL
	 *
	 * @param string $url
	 * @return string
	 */
	private function getPage($url)
	{
		try {
			return str_replace('&nbsp;', ' ', Piwik_Http::sendHttpRequest($url, $timeout = 10, @$_SERVER['HTTP_USER_AGENT']));
		} catch(Exception $e) {
			return '';
		}
	}

    /**
     * Returns the google page rank for the current url
     *
     * @return int
     */
    public function getPageRank()
	{
		$chwrite = $this->CheckHash($this->HashURL($this->url));

		$url="http://toolbarqueries.google.com/tbr?client=navclient-auto&ch=".$chwrite."&features=Rank&q=info:".$this->url."&num=100&filter=0";
		$data = $this->getPage($url);
		preg_match('#Rank_[0-9]:[0-9]:([0-9]+){1,}#si', $data, $p);
		$value = isset($p[1]) ? $p[1] : 0;

		return $value;
	}

    /**
     * Returns the alexa traffic rank for the current url
     *
     * @return int
     */
    public function getAlexaRank()
	{
        $xml = @simplexml_load_string($this->getPage('http://data.alexa.com/data?cli=10&url=' . urlencode($this->url)));
		return $xml ? $xml->SD->POPULARITY['TEXT'] : '';
	}

    /**
     * Returns the number of Dmoz.org entries for the current url
     *
     * @return int
     */
	public function getDmoz()
	{
        $url = 'http://www.dmoz.org/search?q=' . urlencode($this->url);
		$data = $this->getPage($url);
        preg_match('#Open Directory Sites[^\(]+\([0-9]-[0-9]+ of ([0-9]+)\)#', $data, $p);
        if (!empty($p[1])) {
            return (int) $p[1];
        }
        return 0;
	}

    /**
     * Returns the number of pages google holds in it's index for the current url
     *
     * @return int
     */
    public function getIndexedPagesGoogle()
	{
        $url = 'http://www.google.com/search?hl=en&q=site%3A' . urlencode($this->url);
		$data = $this->getPage($url);
        if (preg_match('#about ([0-9\,]+) results#i', $data, $p)) {
            return (int) str_replace(',', '', $p[1]);
		}
        return 0;
	}

    /**
     * Returns the number of pages bing holds in it's index for the current url
     *
     * @return int
     */
    public function getIndexedPagesBing()
	{
        $url = 'http://www.bing.com/search?mkt=en-US&q=site%3A' . urlencode($this->url);
		$data = $this->getPage($url);
        if (preg_match('#([0-9\,]+) results#i', $data, $p)) {
            return (int) str_replace(',', '', $p[1]);
		}
        return 0;
	}

    /**
     * Returns the domain age for the current url
     *
     * @return int
     */
    public function getAge()
    {
        $ageArchiveOrg = $this->_getAgeArchiveOrg();
        $ageWhoIs = $this->_getAgeWhoIs();
        $ageWhoisCom = $this->_getAgeWhoisCom();

        $ages = array();

        if($ageArchiveOrg > 0) {
            $ages[] = $ageArchiveOrg;
        }

        if($ageWhoIs > 0) {
            $ages[] = $ageWhoIs;
        }

        if($ageWhoisCom > 0) {
            $ages[] = $ageWhoisCom;
        }

        if(count($ages) > 1) {
            $maxAge = min($ages);
        } else {
            $maxAge = array_shift($ages);
        }

        if ($maxAge) {
            return Piwik::getPrettyTimeFromSeconds(time() - $maxAge);
        }
        return false;
    }

    /**
     * Returns the domain age archive.org lists for the current url
     *
     * @return int
     */
    protected function _getAgeArchiveOrg()
    {
        $url  = str_replace('www.', '', $this->url);
        $data = @$this->getPage('http://wayback.archive.org/web/*/' . urlencode($url));
        preg_match('#<a href=\"([^>]*)' . preg_quote($url) . '/\">([^<]*)<\/a>#', $data, $p);
        if (!empty($p[2])) {
            $value = strtotime($p[2]);
            if ($value === false) {
                return 0;
            }
            return $value;
        }
        return 0;
    }

    /**
     * Returns the domain age who.is lists for the current url
     *
     * @return int
     */
    protected function _getAgeWhoIs()
    {
        $url  = preg_replace('/^www\./', '', $this->url);
        $url  = 'http://www.who.is/whois/' . urlencode($url);
        $data = $this->getPage($url);
        preg_match('#(?:Creation Date|Created On|Registered on)\.*:\s*([ \ta-z0-9\/\-:\.]+)#si', $data, $p);
        if (!empty($p[1])) {
            $value = strtotime(trim($p[1]));
            if ($value === false) {
                return 0;
            }
            return $value;
        }
        return 0;
    }

    /**
     * Returns the domain age whois.com lists for the current url
     *
     * @return int
     */
    protected function _getAgeWhoisCom()
    {
        $url  = preg_replace('/^www\./', '', $this->url);
        $url  = 'http://www.whois.com/whois/' . urlencode($url);
        $data = $this->getPage($url);
        preg_match('#(?:Creation Date|Created On):\s*([ \ta-z0-9\/\-:\.]+)#si', $data, $p);
        if (!empty($p[1])) {
            $value = strtotime(trim($p[1]));
            if ($value === false) {
                return 0;
            }
            return $value;
        }
        return 0;
    }

	/**
	 * Convert numeric string to int
	 *
	 * @see getPageRank()
	 *
	 * @param string $Str
	 * @param int $Check
	 * @param int $Magic
	 * @return int
	 */
	private function StrToNum($Str, $Check, $Magic)
	{
		$Int32Unit = 4294967296; // 2^32

		$length = strlen($Str);
		for($i = 0; $i < $length; $i++)
		{
			$Check *= $Magic;
			// If the float is beyond the boundaries of integer (usually +/- 2.15e+9 = 2^31),
			// the result of converting to integer is undefined
			// refer to http://www.php.net/manual/en/language.types.integer.php
			if($Check >= $Int32Unit)
			{
				$Check = ($Check - $Int32Unit * (int) ($Check / $Int32Unit));
				//if the check less than -2^31
				$Check = ($Check < -2147483648) ? ($Check + $Int32Unit) : $Check;
			}
			$Check += ord($Str{$i});
		}
		return $Check;
	}

	/**
	 * Generate a hash for a url
	 *
	 * @see getPageRank()
	 *
	 * @param string $String
	 * @return int
	 */
	private function HashURL($String)
	{
		$Check1 = $this->StrToNum($String, 0x1505, 0x21);
		$Check2 = $this->StrToNum($String, 0, 0x1003F);

		$Check1 >>= 2;
		$Check1 = (($Check1 >> 4) & 0x3FFFFC0 ) | ($Check1 & 0x3F);
		$Check1 = (($Check1 >> 4) & 0x3FFC00 ) | ($Check1 & 0x3FF);
		$Check1 = (($Check1 >> 4) & 0x3C000 ) | ($Check1 & 0x3FFF);

		$T1 = (((($Check1 & 0x3C0) << 4) | ($Check1 & 0x3C)) <<2 ) | ($Check2 & 0xF0F );
		$T2 = (((($Check1 & 0xFFFFC000) << 4) | ($Check1 & 0x3C00)) << 0xA) | ($Check2 & 0xF0F0000 );

		return ($T1 | $T2);
	}

	/**
	 * Generate a checksum for the hash string
	 *
	 * @see getPageRank()
	 *
	 * @param int $Hashnum
	 * @return string
	 */
	private function CheckHash($Hashnum)
	{
		$CheckByte = 0;
		$Flag = 0;

		$HashStr = sprintf('%u', $Hashnum) ;
		$length = strlen($HashStr);

		for($i = $length - 1; $i >= 0; $i --)
		{
			$Re = $HashStr{$i};
			if(1 === ($Flag % 2)) {
				$Re += $Re;
				$Re = (int)($Re / 10) + ($Re % 10);
			}
			$CheckByte += $Re;
			$Flag ++;
		}

		$CheckByte %= 10;
		if(0 !== $CheckByte)
		{
			$CheckByte = 10 - $CheckByte;
			if(1 === ($Flag % 2) )
			{
				if(1 === ($CheckByte % 2))
				{
					$CheckByte += 9;
				}
				$CheckByte >>= 1;
			}
		}

		return '7'.$CheckByte.$HashStr;
	}
}
