<?php
class SF9_HTTPRequest
{
	var $_fp; // HTTP socket
	var $_url; // full URL
	var $_host; // HTTP host
	var $_protocol; // protocol (HTTP/HTTPS)
	var $_uri; // request URI
	var $_port; // port

	// constructor
	public function __construct($url)
	{
		$this->_url = $url;
		$this->_scan_url();
	}

	// scan url
	function _scan_url()
	{
		$req = $this->_url;

		$pos = strpos($req, '://');
		$this->_protocol = strtolower(substr($req, 0, $pos));

		$req = substr($req, $pos+3);
		$pos = strpos($req, '/');
		if ($pos === false)
		{
			$pos = strlen($req);
		}
		$host = substr($req, 0, $pos);

		if (strpos($host, ':') !== false)
		{
			list($this->_host, $this->_port) = explode(':', $host);
		}
		else
		{
			$this->_host = $host;
			$this->_port = ($this->_protocol == 'https') ? 443 : 80;
		}

		$this->_uri = substr($req, $pos);
		if ($this->_uri == '')
		{
			$this->_uri = '/';
		}
	}

	// download URL to string
	function DownloadToString()
	{
		$crlf = "\r\n";

		// generate request
		$req = 'GET '.$this->_uri.' HTTP/1.0'.$crlf.'Host: '.$this->_host.$crlf.$crlf;

		// fetch
		$this->_fp = fsockopen(($this->_protocol == 'https' ? 'ssl://' : '') . $this->_host, $this->_port);
		if ($this->_fp)
		{
			fwrite($this->_fp, $req);
			$response = '';
			while (is_resource($this->_fp) && $this->_fp && !feof($this->_fp))
			{
				$response .= fread($this->_fp, 1024);
			}
			fclose($this->_fp);

			// split header and body
			$pos = strpos($response, $crlf . $crlf);
			if($pos === false) return($response);
			$header = substr($response, 0, $pos);
			$body = substr($response, $pos + 2 * strlen($crlf));

			// parse headers
			$headers = array();
			$lines = explode($crlf, $header);
			foreach($lines as $line)
			if (($pos = strpos($line, ':')) !== false)
			{
				$headers[strtolower(trim(substr($line, 0, $pos)))] = trim(substr($line, $pos+1));
			}

			// redirection?
			if (isset($headers['location']))
			{
				$http = new SF9_HTTPRequest($headers['location']);
				return($http->DownloadToString($http));
			}
			else
			{
				return($body);
			}
		}
	}
}
?>