<?php
ob_start();

/**
  * (C) Jaroslaw Miazga
  * http://the-portal.pl
*/

class RedirectionDetector
{
	 private $url;
	 private $redirectTo;
	 
	 /**
	  * Sets url of checking page
	  *
	  * @param $url string
	  * 
	 */
	  	 
	 
	 public function setUrl($url)
	 {
		 $this->url = $url;
	 }
	 
	 
	 /**
	  * Gets all headers
	  *
	  * @return $headers string
	  * 
	 */
	 
	 public function getHeaders()
	 {
		 $ch = curl_init($this->url);
		 curl_setopt($ch, CURLOPT_HEADER, 1);
		 curl_setopt($ch, CURLOPT_NOBODY, 1);
		 curl_exec($ch);
		 curl_close($ch);
		 
		 $headers = ob_get_clean();
		 
		 return $headers;

	 }
	 
	 /**
	  * Looking for redirection in meta tags
	  *
	  * @return bool true|false
	  * 
	 */
	 
	 
	 public function checkMetaTags()
	 {
		 $open = @file_get_contents($this->url);
		 if(eregi('<META HTTP-EQUIV="Refresh" CONTENT="(.*);URL=(.*)">', $open))
		 {
			 //if exists
			 return true;
		 }
		 else
		 {
			 //if not
			 return false;
		 }
	 }
	 
	 /**
	  * Gets page where is redirection
	  *
	  * @return string
	  * 
	 */
	 
	 
	 public function getRedirectedPage()
	 {
		 return $this->redirectTo;
	 }
	 
	 
	 /**
	  * Looking for hidden redirection such as header('Location: xxxxx');
	  *
	  * @return bool true|false
	  * 
	 */
	 
	 public function checkHidden()
	 {
		 preg_match_all('%Location: http://(.*)%', $this->getHeaders(), $match);
		 
		 
		 $found = $match[0][0];
		 $found = str_replace('Location: ', '', $found);
		 $this->redirectTo = $found;
		 $input = $this->url;
		 

		 
		 $host1 = parse_url($found);
		 $host2 = parse_url($input);
		 
		 $host_a = str_replace('www.', '', $host1['host']);
		 $host_b = $host2['host'];
		 
		 if($host_a == $host_b)
		 {
			 $this->redirectTo = null;
		 }
		 elseif(!empty($host_a))
		 {
			 $this->redirectTo = $found;
		 }
		 
		 if($host_a == $host_b)
		 {
			 return false;
		 }
		 elseif(!empty($host_a))
		 {
			 return true;
		 }

		

	 }
	 
	 /**
	  * Looking for all types of redirection
	  *
	  * @return bool true|false
	  * 
	 */
	 
	 public function checkAll()
	 {
		 if($this->checkHidden() || $this->checkMetaTags())
		 {
			 return true;
		 }
		 else
		 {
			 return false;
		 }
	 }
	 

	 
	 
	 
}
?>