<?php

class FBUtil {

	static function file_post_contents($url, $basic_auth=false, $remove_headers=true) {
		$url = parse_url($url);

		if (!isset($url['port'])) {
		  if ($url['scheme'] == 'http') { $url['port']=80; }
		  elseif ($url['scheme'] == 'https') { $url['port']=443; }
		}
		$url['query']=isset($url['query'])?$url['query']:'';

		$url['protocol']=$url['scheme'].'://';
		$eol="\r\n";

		if($basic_auth) {
			$headers =  "POST ".$url['protocol'].$url['host'].$url['path']." HTTP/1.0".$eol.
						"Host: ".$url['host'].$eol.
						"Referer: ".$url['protocol'].$url['host'].$url['path'].$eol.
						"Content-Type: application/x-www-form-urlencoded".$eol.
						"Content-Length: ".strlen($url['query']).$eol.
						$basic_auth.$eol.
						$eol.$url['query'];
		} else {
			$headers =  "POST ".$url['protocol'].$url['host'].$url['path']." HTTP/1.0".$eol.
						"Host: ".$url['host'].$eol.
						"Referer: ".$url['protocol'].$url['host'].$url['path'].$eol.
						"Content-Type: application/x-www-form-urlencoded".$eol.
						"Content-Length: ".strlen($url['query']).$eol.
						$eol.
						$url['query'];
		}

		$fp = fsockopen($url['host'], $url['port'], $errno, $errstr, 30);
		if($fp) {
		  fputs($fp, $headers);
		  $result = '';
		  while(!feof($fp)){  
			  $result .= fgets($fp, 128);
		  }

		  fclose($fp);
		  if ($remove_headers == true) {
			//removes headers
			// don't know regex super-well, but this should work just fine
			$header_end = strpos($result, "\r\n\r\n");
			$header_end += 4;

			$result = substr($result, $header_end);
		  }

		  return $result;
		}
	}

	static function generate_sig($params_array, $secret) {
		$str = '';

		ksort($params_array);
		// Note: make sure that the signature parameter is not already included in
		//       $params_array.
		foreach ($params_array as $k=>$v) {
		  $str .= "$k=$v";
		}
		$str .= $secret;

		return md5($str);
	}

	static function get_http_header_value($header, $name) {
		$start_pos = stripos($header, $name);
		$start_pos += strlen($name) + 2;
		$value = substr($header, $start_pos);

		$end_pos = strpos($value, "\r\n");
		$value = substr($header, $start_pos, $end_pos);

		return $value;
	}

	static function do_fb_method($fb_secret, $params) {
		$facebook_api_host = 'api.facebook.com:80';

		$sig = FBUtil::generate_sig($params, $fb_secret);
		
		$params['sig'] = $sig;

		$eol="\r\n";
		$boundary = md5(time());

		// build content string
		$data = '--'.$boundary.$eol;
		foreach($params as $name => $value) {
			$data .= "Content-Disposition: form-data; name=\"$name\"".$eol.$eol.$value.$eol.'--'.$boundary.$eol;
		}

		$content_length = strlen($data);
		// send request to facebook
		$headers =  "POST /restserver.php HTTP/1.0".$eol.
					"Host: ".$url['host'].$eol.
					"Referer: ".$url['protocol'].$url['host'].$url['path'].$eol.
					"Content-Type: multipart/form-data; boundary=".$boundary.$eol.
					"Content-Length: $content_length".$eol.
					"MIME-version: 1.0".$eol.
					$eol.$data.$eol.'--';

		$fp = fsockopen($facebook_api_host, 80, $errno, $errstr, 30);
		if($fp) {
		  fputs($fp, $headers);
		  $result = '';
		  while(!feof($fp)){  
			  $result .= fgets($fp, 128);
		  }

		  fclose($fp);
		  if ($remove_headers == true) {
			//removes headers
			// don't know regex super-well, but this should work just fine
			$header_end = strpos($result, "\r\n\r\n");
			$header_end += 4;

			$result = substr($result, $header_end);
		  }

		  return $result;
		}
	}
}
?>