<?php
#################################################################
#  Copyright notice
#
#  (c) 2013 Jérôme Schneider <mail@jeromeschneider.fr>
#  All rights reserved
#
#  http://flake.codr.fr
#
#  This script is part of the Flake project. The Flake
#  project is free software; you can redistribute it
#  and/or modify it under the terms of the GNU General Public
#  License as published by the Free Software Foundation; either
#  version 2 of the License, or (at your option) any later version.
#
#  The GNU General Public License can be found at
#  http://www.gnu.org/copyleft/gpl.html.
#
#  This script is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  This copyright notice MUST APPEAR in all copies of the script!
#################################################################

namespace Flake\Util;

class Tools extends \Flake\Core\FLObject {
	
	private function __construct() {	# private constructor to force static class
	}
	
	public static function getCurrentUrl() {
		if(MONGOOSE_SERVER) {
			$sUrl = $GLOBALS["_SERVER"]["REQUEST_URI"];
			if(array_key_exists("QUERY_STRING", $GLOBALS["_SERVER"]) && trim($GLOBALS["_SERVER"]["QUERY_STRING"]) !== "") {
				$sUrl .= "?" . $GLOBALS["_SERVER"]["QUERY_STRING"];
			}
		} else {
			$sUrl = $GLOBALS["_SERVER"]["REQUEST_URI"];	# Would be REDIRECT_URL for ServerRewrite
		}
		
		return $sUrl;
	}
	
	public static function getCurrentProtocol() {
		if(isset($GLOBALS['_SERVER']['HTTP_X_FORWARDED_PROTO']) && !empty($GLOBALS['_SERVER']['HTTP_X_FORWARDED_PROTO'])) {
			return $GLOBALS['_SERVER']['HTTP_X_FORWARDED_PROTO'];
		}
		
		if((!empty($GLOBALS["_SERVER"]["HTTPS"]) && $GLOBALS["_SERVER"]['HTTPS'] !== 'off') || intval($_SERVER['SERVER_PORT']) === 443) {
			return "https";
		}
		
		return "http";
	}
	
	public static function deCamelCase($sString, $sGlue=" ") {
		$sSep = md5(rand());
		$sRes = preg_replace('/(?!^)[[:upper:]][[:lower:]]/', '$0', preg_replace('/(?!^)[[:upper:]]+/', $sSep . '$0', $sString));
		if($sGlue !== "" && preg_match('/^[[:upper:]].*/', $sRes)) {
			$sRes = $sSep . $sRes;
		}
		
		return str_replace($sSep, $sGlue, $sRes);
	}
	
	public static function serverToRelativeWebPath($sAbsPath) {
		return "/" . str_replace(PROJECT_PATH_WWWROOT, "", $sAbsPath);
	}

	public static function view_array($array_in) {
		if (is_array($array_in))	{
			$result='<table border="1" cellpadding="1" cellspacing="0" bgcolor="white">';
			if (!count($array_in))	{$result.= '<tr><td><font face="Verdana,Arial" size="1"><b>'.htmlspecialchars("EMPTY!").'</b></font></td></tr>';}
			while (list($key,$val)=each($array_in))	{
				$result.= '<tr><td valign="top"><font face="Verdana,Arial" size="1">'.htmlspecialchars((string)$key).'</font></td><td>';
				if (is_array($array_in[$key]))	{
					$result.= \Flake\Util\Tools::view_array($array_in[$key]);
				} else {
					if(is_object($val)) {
						if(method_exists($val, "__toString")) {
							$sWhat = nl2br(htmlspecialchars((string)$val));
						} else {
							$sWhat = nl2br(htmlspecialchars(get_class($val)));
						}
					} elseif(is_bool($val)) {
						$sWhat = ($val === TRUE ? "boolean:TRUE" : "boolean:FALSE");
					} else {
						$sWhat = nl2br(htmlspecialchars((string)$val));
					}
					
					$result .= '<font face="Verdana,Arial" size="1" color="red">' . $sWhat . '<br /></font>';
				}
				
				$result.= '</td></tr>';
			}
			$result.= '</table>';
		} else	{
			$result  = '<table border="1" cellpadding="1" cellspacing="0" bgcolor="white">
				<tr>
					<td><font face="Verdana,Arial" size="1" color="red">'.nl2br(htmlspecialchars((string)$array_in)).'<br /></font></td>
				</tr>
			</table>';	// Output it as a string.
		}
		return $result;
	}

	public static function debug($var="",$brOrHeader=0)	{
		if($brOrHeader === 0) {
			try {
				$trail = debug_backtrace();
				$trail = array_reverse($trail);
				array_pop($trail);	// la ligne d'appel à debug
				array_pop($trail);	// la ligne d'appel à debug
				$aLastNode = array_pop($trail);	// l'appel qui nous intéresse

				if(array_key_exists("class", $aLastNode)) {
					$sClass = @strval($aLastNode["class"]);
				} else {
					$sClass = "";
				}
				
				if(array_key_exists("type", $aLastNode)) {
					$sType = @strval($aLastNode["type"]);
				} else {
					$sType = "";
				}
				
				$brOrHeader = $sClass.$sType.@strval($aLastNode['function']);
			} catch(\Exception $e) {
				$brOrHeader = "Undetermined context";
			}
		}

		if ($brOrHeader)	{
			echo '<table border="0" cellpadding="0" cellspacing="0" bgcolor="white" style="border:0px; margin-top:3px; margin-bottom:3px;"><tr><td style="background-color:#bbbbbb; font-family: verdana,arial; font-weight: bold; font-size: 10px;">'.htmlspecialchars((string)$brOrHeader).'</td></tr><tr><td>';
		}

		if (is_array($var))	{
			echo \Flake\Util\Tools::view_array($var);
		} elseif (is_object($var))	{
			echo '<b>|Object:<pre>';
			print_r($var);
			echo '</pre>|</b>';
		} elseif ((string)$var!='')	{
			echo '<b>|'.htmlspecialchars((string)$var).'|</b>';
		} else {
			echo '<b>| debug |</b>';
		}

		if ($brOrHeader) {
			echo '</td></tr></table>';
		}
	}

	public static function debug_trail()	{
		$trail = debug_backtrace();
		$trail = array_reverse($trail);
		array_pop($trail);

		$path = array();
		foreach($trail as $dat)	{
			$path[] = $dat['class'].$dat['type'].$dat['function'];
		}

		return implode(' // ',$path);
	}

	public static function POST($sVar = FALSE) {
		if($sVar !== FALSE) {
			$aData = \Flake\Util\Tools::POST();
			if(array_key_exists($sVar, $aData)) {
				return $aData[$sVar];
			}
			
			return "";
		}
		
		return is_array($GLOBALS["_POST"]) ? $GLOBALS["_POST"] : array();
	}

	public static function GET($sVar = FALSE) {
		if($sVar !== FALSE) {
			$aData = \Flake\Util\Tools::GET();
			if(array_key_exists($sVar, $aData)) {
				return $aData[$sVar];
			}
			
			return "";
		}
		
		return is_array($GLOBALS["_GET"]) ? $GLOBALS["_GET"] : array();
	}

	public static function GP($sVar = FALSE) {
		if($sVar !== FALSE) {
			$aData = \Flake\Util\Tools::GP();
			if(array_key_exists($sVar, $aData)) {
				return $aData[$sVar];
			}
			
			return "";
		}
		
		return array_merge(
			\Flake\Util\Tools::GET(),
			\Flake\Util\Tools::POST()
		);
	}
	
	public static function safelock($sString) {
		return substr(md5(PROJECT_SAFEHASH_SALT . ":" . $sString), 0, 5);
	}
	
	public static function redirect($sUrl) {
		header("Location: " . $sUrl);
		exit(0);
	}
	
	public static function redirectUsingMeta($sUrl) {
		$sDoc = "<html><head><meta http-equiv='refresh' content='0; url=" . $sUrl . "'></meta></head><body></body></html>";
		echo $sDoc;
		exit(0);
	}
	
	public static function refreshPage() {
		header("Location: " . \Flake\Util\Tools::getCurrentUrl());
		exit(0);
	}
	
	public static function validEmail($sEmail) {
		return (filter_var($sEmail, FILTER_VALIDATE_EMAIL) !== FALSE);
	}
	
	public static function filterFormInput($sInput) {
		return strip_tags($sInput);
	}
	
	public static function getHumanDate($iStamp) {
		return ucwords(strftime("%A, %d %B %Y", $iStamp));
	}
	
	public static function getHumanTime($iStamp) {
		return strftime("%Hh%M", $iStamp);
	}
	
	public static function trimExplode($string, $delim=",", $removeEmptyValues = false, $limit = 0) {
		$explodedValues = explode($delim, $string);

		$result = array_map('trim', $explodedValues);

		if ($removeEmptyValues) {
			$temp = array();
			foreach($result as $value) {
				if ($value !== '') {
					$temp[] = $value;
				}
			}
			$result = $temp;
		}

		if ($limit != 0) {
			if ($limit < 0) {
				$result = array_slice($result, 0, $limit);
			} elseif (count($result) > $limit) {
				$lastElements = array_slice($result, $limit - 1);
				$result = array_slice($result, 0, $limit - 1);
				$result[] = implode($delim, $lastElements);
			}
		}

		return $result;
	}
		
	/**
	 * Taken from TYPO3
	 * Returns true if the first part of $str matches the string $partStr
	 *
	 * @param	string		Full string to check
	 * @param	string		Reference string which must be found as the "first part" of the full string
	 * @return	boolean		True if $partStr was found to be equal to the first part of $str
	 */
	public static function isFirstPartOfStr($str,$partStr)	{
		// Returns true, if the first part of a $str equals $partStr and $partStr is not ''
		$psLen = strlen($partStr);
		if ($psLen)	{
			return substr($str,0,$psLen)==(string)$partStr;
		} else return false;
	}
	
	/**
	 * Binary-reads a file
	 *
	 * @param	string		$sPath: absolute server path to file
	 * @return	string		file contents
	 */
	public static function file_readBin($sPath) {
		$sData = "";
		$rFile = fopen($sPath, "rb");
		while(!feof($rFile)) {
			$sData .= fread($rFile, 1024);
		}
		fclose($rFile);

		return $sData;
	}
	
	/**
	 * Binary-writes a file
	 *
	 * @param	string		$sPath: absolute server path to file
	 * @param	string		$sData: file contents
	 * @param	boolean		$bUTF8: add UTF8-BOM or not ?
	 * @return	void
	 */
	public static function file_writeBin($sPath, $sData) {
		$rFile=fopen($sPath, "wb");
		fputs($rFile, $sData);
		fclose($rFile);
	}
	
	public static function sendHtmlMail($sToAddress, $sSubject, $sBody, $sFromName, $sFromAddress, $sReplyToName, $sReplyToAddress) {
		
		$sMessage = <<<TEST
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
	<head>
		<title>Email</title>
	</head>
	<body>
	{$sBody}
	</body>
</html>
TEST;

		$sHeaders  = "From: " . $sFromName . "<" . $sFromAddress . ">" . "\r\n";
		$sHeaders .= "Reply-To: " . $sReplyToName . "<" . $sReplyToAddress . ">" . "\r\n";
		$sHeaders .= "Bcc: " . $sReplyToName . "<" . $sReplyToAddress . ">" . "\r\n";
		$sHeaders .= "Content-Type: text/html" . "\r\n";
		
		mail($sToAddress, $sSubject, $sMessage, $sHeaders);
	}
	
	public static function shortMD5($sValue) {
		return strtolower(substr(md5($sValue), 0, 5));
	}
	
	public static function overrideFirstWithSecond($sFirst, $sSecond) {
		if(trim($sSecond) !== "") {
			return $sSecond;
		}
		
		return "" . $sFirst;
	}
		
	public static function parseTemplateCode($sCode, $aMarkers) {
		
		$loader = new \Twig_Loader_String();
		$twig = new \Twig_Environment($loader);
		
		return $twig->render($sCode, $aMarkers);
	}
	
	
	public static function is_a($object, $class) {
	    if(is_object($object)) return $object instanceof $class;
	    if(is_string($object)){
			if(is_object($class)) $class=get_class($class);
			
			if(class_exists($class, TRUE)) {	# TRUE to autoload class
				return @is_subclass_of($object, $class) || $object==$class;
			}
			
			if(interface_exists($class)) {
				$reflect = new \ReflectionClass($object);
				return $reflect->implementsInterface($class);
			}
			
		}
		return false;
	}
	
	public static function HTTPStatus($iCode, $sMessage) {
		header("HTTP/1.1 404 Not Found");
		header("Status: 404 Not Found");
		die("<h1>HTTP Status " . $iCode . " : " . $sMessage . "</h1>");
	}
	
	public static function number2Rank($a) {
		$a = intval($a);
		
		if ($a === 1) {
			return "premier";
		} elseif($a === 2) {
			return "second";
		}
		
		$sNumber = self::number2Human($a);
		
		$sLastLetter = substr($sNumber, -1, 1);
		if($sLastLetter === "e") {
			$sNumber = substr($sNumber, 0, -1);
		} elseif($sLastLetter === "q") {
			$sNumber = $sNumber . "u";
		} elseif($sLastLetter === "f") {
			$sNumber = substr($sNumber, 0, -1) . "v";
		}
		
		return $sNumber . "ième";
	}
	
	public static function number2Human($a) {
		$temp = explode('.',$a);
		if (isset($temp[1]) && $temp[1]!='') {
			return self::number2Human($temp[0]).' virgule '.self::number2Human($temp[1]) ;
		}
		
		if ($a<0) return 'moins '.self::number2Human(-$a);
		
		if ($a<17) {
			switch ($a) {
				case 0: return 'zero';
				case 1: return 'un';
				case 2: return 'deux';
				case 3: return 'trois';
				case 4: return 'quatre';
				case 5: return 'cinq';
				case 6: return 'six';
				case 7: return 'sept';
				case 8: return 'huit';
				case 9: return 'neuf';
				case 10: return 'dix';
				case 11: return 'onze';
				case 12: return 'douze';
				case 13: return 'treize';
				case 14: return 'quatorze';
				case 15: return 'quinze';
				case 16: return 'seize';
			}
		} else if ($a<20) {
			return 'dix-' . self::number2Human($a-10);
		} else if ($a<100) {
			if ($a%10==0) {
				switch($a) {
					case 20: return 'vingt';
					case 30: return 'trente';
					case 40: return 'quarante';
					case 50: return 'cinquante';
					case 60: return 'soixante';
					case 70: return 'soixante-dix';
					case 80: return 'quatre-vingt';
					case 90: return 'quatre-vingt-dix';
				}
			} elseif(substr($a, -1) == 1) {
				if( ((int)($a/10)*10)<70 ) {
					return self::number2Human((int)($a/10)*10).'-et-un';
				} elseif ($a==71) {
					return 'soixante-et-onze';
				} elseif ($a==81) {
					return 'quatre-vingt-un';
				} elseif ($a==91) {
					return 'quatre-vingt-onze';
				}
			} elseif ($a<70) {
				return self::number2Human($a-$a%10).'-'.self::number2Human($a%10);
			} elseif ($a<80) {
				return self::number2Human(60).'-'.self::number2Human($a%20);
			} else {
				return self::number2Human(80).'-'.self::number2Human($a%20);
			}
		} else if ($a==100) {
			return 'cent';
		} else if ($a<200) {
			return self::number2Human(100).' '.self::number2Human($a%100);
		} else if ($a<1000) {
			return self::number2Human((int)($a/100)).' '.self::number2Human(100).' '.self::number2Human($a%100);
		} else if ($a==1000) {
			return 'mille';
		} else if ($a<2000) {
			return self::number2Human(1000).' '.self::number2Human($a%1000).' ';
		} else if ($a<1000000) {
			return self::number2Human((int)($a/1000)).' '.self::number2Human(1000).' '.self::number2Human($a%1000);
		}
	}
	
	public static function stringToUrlToken($sString) {
		
		# Taken from TYPO3 extension realurl
				
		$space = "-";
		$sString = strtr($sString, ' -+_\'', $space . $space . $space . $space . $space); // convert spaces
		
		if(function_exists("iconv")) {
			$sString = iconv('UTF-8', 'ASCII', $sString);
		}
		
		$sString = strtolower($sString);
		
		$sString = preg_replace('/[^a-zA-Z0-9\\' . $space . ']/', '', $sString);
		$sString = preg_replace('/\\' . $space . '{2,}/', $space, $sString); // Convert multiple 'spaces' to a single one
		$sString = trim($sString, $space);
		
		return $sString;
	}
	
	public static function isCliPhp() {
		return strtolower(php_sapi_name()) === "cli";
	}
	
	public static function getIP() {

		$alt_ip = $_SERVER['REMOTE_ADDR'];

		if(isset($_SERVER['HTTP_CLIENT_IP'])) {
			$alt_ip = $_SERVER['HTTP_CLIENT_IP'];
		} else if(isset($_SERVER['HTTP_X_FORWARDED_FOR']) AND preg_match_all('#\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}#s', $_SERVER['HTTP_X_FORWARDED_FOR'], $matches)) {
			
			// make sure we dont pick up an internal IP defined by RFC1918
			foreach($matches[0] AS $ip) {
				if (!preg_match('#^(10|172\.16|192\.168)\.#', $ip)) {
					$alt_ip = $ip;
					break;
				}
			}
		} else if (isset($_SERVER['HTTP_FROM'])) {
			$alt_ip = $_SERVER['HTTP_FROM'];
		}
		
		return $alt_ip;
	}
	
	public static function getUserAgent() {
		return $_SERVER['HTTP_USER_AGENT'];
	}
	
	###########
	public static function appendSlash($sString) {
		return self::appendString($sString, "/");
	}
	
	public static function prependSlash($sString) {
		return self::prependString($sString, "/");
	}
	
	public static function stripBeginSlash($sString) {
		return self::stripBeginString($sString, "/");
	}
	
	public static function stripEndSlash($sString) {
		return self::stripEndString($sString, "/");
	}
	
	public static function trimSlashes($sString) {
		return self::stripBeginSlash(self::stripEndSlash($sString));
	}
	
	###########
	public static function appendString($sString, $sAppend) {
		if(substr($sString, -1 * strlen($sAppend)) !== $sAppend) {
			$sString .= $sAppend;
		}
		
		return $sString;
	}
	
	public static function prependString($sString, $sAppend) {
		if(substr($sString, 0, 1 * strlen($sAppend)) !== $sAppend) {
			$sString = $sAppend . $sString;
		}
		
		return $sString;
	}
	
	public static function stripBeginString($sString, $sAppend) {
		if(substr($sString, 0, 1 * strlen($sAppend)) === $sAppend) {
			$sString = substr($sString, strlen($sAppend));
		}
		
		return $sString;
	}
	
	public static function stripEndString($sString, $sAppend) {
		if(substr($sString, -1 * strlen($sAppend)) === $sAppend) {
			$sString = substr($sString, 0, -1 * strlen($sAppend));
		}
		
		return $sString;
	}
	
	public static function trimStrings($sString, $sAppend) {
		return self::stripBeginString(self::stripEndString($sString, $sAppend), $sAppend);
	}
	
	public static function stringEndsWith($sHaystack, $sNeedle) {
		return substr($sHaystack, strlen($sNeedle) * -1) === $sNeedle;
	}
	
	###########
	
	public static function router() {
		return "\Flake\Util\Router\QuestionMarkRewrite";
	}
	
	public static function arrayIsAssoc($aArray) {
		if(!is_array($aArray)) {
			throw new \Exception("\Flake\Util\Tools::arrayIsAssoc(): parameter has to be an array.");
		}
		
		# Taken from http://stackoverflow.com/questions/173400/php-arrays-a-good-way-to-check-if-an-array-is-associative-or-sequential#answer-4254008
		# count() will return 0 if numeric, and > 0 if assoc, even partially
		return (bool)count(array_filter(array_keys($aArray), 'is_string'));
	}
	
	public static function arrayIsSeq($aArray) {
		return !self::arrayIsAssoc($aArray);
	}
	
	public static function echoAndCutClient($sMessage='') {
		ignore_user_abort(TRUE);
#		set_time_limit(0); 

		header("Connection: close");
		header("Content-Length: ".strlen($sMessage)); 
		echo $sMessage; 
		echo str_repeat("\r\n", 10); // just to be sure 
		flush(); 
	}
	
	public static function milliseconds() {
		return intval((microtime(TRUE) * 1000));
	}
	
	public static function stopWatch($sWhat) {
#		return;
		$iStop = \Flake\Util\Tools::milliseconds();
		
		$trail = debug_backtrace();
		$aLastNode = $trail[0];	// l'appel qui nous intéresse
		$sFile = basename($aLastNode["file"]);
		$iLine = intval($aLastNode["line"]);
		
		if(!array_key_exists("FLAKE_STOPWATCHES", $GLOBALS)) {
			$GLOBALS["FLAKE_STOPWATCHES"] = array();
		}
		
		if(!array_key_exists($sWhat, $GLOBALS["FLAKE_STOPWATCHES"])) {
			$GLOBALS["FLAKE_STOPWATCHES"][$sWhat] = $iStop;
		} else {
			$iTime = $iStop - $GLOBALS["FLAKE_STOPWATCHES"][$sWhat];
			echo "<h3 style='color: silver'><span style='display: inline-block; width: 400px;'>@" . $sFile . "+" . $iLine . ":</span>" . $sWhat . ":" . $iTime . " ms</h1>";
			flush();
		}
	}
	
	# Taken from http://www.php.net/manual/en/function.gzdecode.php#82930
	public static function gzdecode($data, &$filename='', &$error='', $maxlength=null) {
	    $len = strlen($data);
	    if ($len < 18 || strcmp(substr($data,0,2),"\x1f\x8b")) {
	        $error = "Not in GZIP format.";
	        return null;  // Not GZIP format (See RFC 1952)
	    }
	    $method = ord(substr($data,2,1));  // Compression method
	    $flags  = ord(substr($data,3,1));  // Flags
	    if ($flags & 31 != $flags) {
	        $error = "Reserved bits not allowed.";
	        return null;
	    }
	    // NOTE: $mtime may be negative (PHP integer limitations)
	    $mtime = unpack("V", substr($data,4,4));
	    $mtime = $mtime[1];
	    $xfl   = substr($data,8,1);
	    $os    = substr($data,8,1);
	    $headerlen = 10;
	    $extralen  = 0;
	    $extra     = "";
	    if ($flags & 4) {
	        // 2-byte length prefixed EXTRA data in header
	        if ($len - $headerlen - 2 < 8) {
	            return false;  // invalid
	        }
	        $extralen = unpack("v",substr($data,8,2));
	        $extralen = $extralen[1];
	        if ($len - $headerlen - 2 - $extralen < 8) {
	            return false;  // invalid
	        }
	        $extra = substr($data,10,$extralen);
	        $headerlen += 2 + $extralen;
	    }
	    $filenamelen = 0;
	    $filename = "";
	    if ($flags & 8) {
	        // C-style string
	        if ($len - $headerlen - 1 < 8) {
	            return false; // invalid
	        }
	        $filenamelen = strpos(substr($data,$headerlen),chr(0));
	        if ($filenamelen === false || $len - $headerlen - $filenamelen - 1 < 8) {
	            return false; // invalid
	        }
	        $filename = substr($data,$headerlen,$filenamelen);
	        $headerlen += $filenamelen + 1;
	    }
	    $commentlen = 0;
	    $comment = "";
	    if ($flags & 16) {
	        // C-style string COMMENT data in header
	        if ($len - $headerlen - 1 < 8) {
	            return false;    // invalid
	        }
	        $commentlen = strpos(substr($data,$headerlen),chr(0));
	        if ($commentlen === false || $len - $headerlen - $commentlen - 1 < 8) {
	            return false;    // Invalid header format
	        }
	        $comment = substr($data,$headerlen,$commentlen);
	        $headerlen += $commentlen + 1;
	    }
	    $headercrc = "";
	    if ($flags & 2) {
	        // 2-bytes (lowest order) of CRC32 on header present
	        if ($len - $headerlen - 2 < 8) {
	            return false;    // invalid
	        }
	        $calccrc = crc32(substr($data,0,$headerlen)) & 0xffff;
	        $headercrc = unpack("v", substr($data,$headerlen,2));
	        $headercrc = $headercrc[1];
	        if ($headercrc != $calccrc) {
	            $error = "Header checksum failed.";
	            return false;    // Bad header CRC
	        }
	        $headerlen += 2;
	    }
	    // GZIP FOOTER
	    $datacrc = unpack("V",substr($data,-8,4));
	    $datacrc = sprintf('%u',$datacrc[1] & 0xFFFFFFFF);
	    $isize = unpack("V",substr($data,-4));
	    $isize = $isize[1];
	    // decompression:
	    $bodylen = $len-$headerlen-8;
	    if ($bodylen < 1) {
	        // IMPLEMENTATION BUG!
	        return null;
	    }
	    $body = substr($data,$headerlen,$bodylen);
	    $data = "";
	    if ($bodylen > 0) {
	        switch ($method) {
	        case 8:
	            // Currently the only supported compression method:
	            $data = gzinflate($body,$maxlength);
	            break;
	        default:
	            $error = "Unknown compression method.";
	            return false;
	        }
	    }  // zero-byte body content is allowed
	    // Verifiy CRC32
	    $crc   = sprintf("%u",crc32($data));
	    $crcOK = $crc == $datacrc;
	    $lenOK = $isize == strlen($data);
	    if (!$lenOK || !$crcOK) {
	        $error = ( $lenOK ? '' : 'Length check FAILED. ') . ( $crcOK ? '' : 'Checksum FAILED.');
	        return false;
	    }
	    return $data;
	}
}
