<?php
class createZip  {

	  var $compressedData = array();
	  var $centralDirectory = array(); // central directory
	  var $endOfCentralDirectory = "\x50\x4b\x05\x06\x00\x00\x00\x00"; //end of Central directory record
	  var $oldOffset = 0;

	/**
	 * Function to create the directory where the file(s) will be unzipped
	 *
	 * @param $directoryName string
	 *
	 */

	  function addDirectory($directoryName) {
		$directoryName = str_replace("\\", "/", $directoryName);

		$feedArrayRow = "\x50\x4b\x03\x04";
		$feedArrayRow .= "\x0a\x00";
		$feedArrayRow .= "\x00\x00";
		$feedArrayRow .= "\x00\x00";
		$feedArrayRow .= "\x00\x00\x00\x00";

		$feedArrayRow .= pack("V",0);
		$feedArrayRow .= pack("V",0);
		$feedArrayRow .= pack("V",0);
		$feedArrayRow .= pack("v", strlen($directoryName) );
		$feedArrayRow .= pack("v", 0 );
		$feedArrayRow .= $directoryName;

		$feedArrayRow .= pack("V",0);
		$feedArrayRow .= pack("V",0);
		$feedArrayRow .= pack("V",0);

		$this -> compressedData[] = $feedArrayRow;

		$newOffset = strlen(implode("", $this->compressedData));

		$addCentralRecord = "\x50\x4b\x01\x02";
		$addCentralRecord .="\x00\x00";
		$addCentralRecord .="\x0a\x00";
		$addCentralRecord .="\x00\x00";
		$addCentralRecord .="\x00\x00";
		$addCentralRecord .="\x00\x00\x00\x00";
		$addCentralRecord .= pack("V",0);
		$addCentralRecord .= pack("V",0);
		$addCentralRecord .= pack("V",0);
		$addCentralRecord .= pack("v", strlen($directoryName) );
		$addCentralRecord .= pack("v", 0 );
		$addCentralRecord .= pack("v", 0 );
		$addCentralRecord .= pack("v", 0 );
		$addCentralRecord .= pack("v", 0 );
		$ext = "\x00\x00\x10\x00";
		$ext = "\xff\xff\xff\xff";
		$addCentralRecord .= pack("V", 16 );

		$addCentralRecord .= pack("V", $this -> oldOffset );
		$this -> oldOffset = $newOffset;

		$addCentralRecord .= $directoryName;

		$this -> centralDirectory[] = $addCentralRecord;
	}

	/**
	 * Function to add file(s) to the specified directory in the archive
	 *
	 * @param $directoryName string
	 *
	 */

	  function addFile($data, $directoryName)   {

		$directoryName = str_replace("\\", "/", $directoryName);

		$feedArrayRow = "\x50\x4b\x03\x04";
		$feedArrayRow .= "\x14\x00";
		$feedArrayRow .= "\x00\x00";
		$feedArrayRow .= "\x08\x00";
		$feedArrayRow .= "\x00\x00\x00\x00";

		$uncompressedLength = strlen($data);
		$compression = crc32($data);
		$gzCompressedData = gzcompress($data);
		$gzCompressedData = substr( substr($gzCompressedData, 0, strlen($gzCompressedData) - 4), 2);
		$compressedLength = strlen($gzCompressedData);
		$feedArrayRow .= pack("V",$compression);
		$feedArrayRow .= pack("V",$compressedLength);
		$feedArrayRow .= pack("V",$uncompressedLength);
		$feedArrayRow .= pack("v", strlen($directoryName) );
		$feedArrayRow .= pack("v", 0 );
		$feedArrayRow .= $directoryName;

		$feedArrayRow .= $gzCompressedData;

		$feedArrayRow .= pack("V",$compression);
		$feedArrayRow .= pack("V",$compressedLength);
		$feedArrayRow .= pack("V",$uncompressedLength);

		$this -> compressedData[] = $feedArrayRow;

		$newOffset = strlen(implode("", $this->compressedData));

		$addCentralRecord = "\x50\x4b\x01\x02";
		$addCentralRecord .="\x00\x00";
		$addCentralRecord .="\x14\x00";
		$addCentralRecord .="\x00\x00";
		$addCentralRecord .="\x08\x00";
		$addCentralRecord .="\x00\x00\x00\x00";
		$addCentralRecord .= pack("V",$compression);
		$addCentralRecord .= pack("V",$compressedLength);
		$addCentralRecord .= pack("V",$uncompressedLength);
		$addCentralRecord .= pack("v", strlen($directoryName) );
		$addCentralRecord .= pack("v", 0 );
		$addCentralRecord .= pack("v", 0 );
		$addCentralRecord .= pack("v", 0 );
		$addCentralRecord .= pack("v", 0 );
		$addCentralRecord .= pack("V", 32 );

		$addCentralRecord .= pack("V", $this -> oldOffset );
		$this -> oldOffset = $newOffset;

		$addCentralRecord .= $directoryName;

		$this -> centralDirectory[] = $addCentralRecord;
	}

	/**
	 * Fucntion to return the zip file
	 *
	 * @return zipfile (archive)
	 */

	  function getZippedfile() {

		$data = implode("", $this -> compressedData);
		$controlDirectory = implode("", $this -> centralDirectory);

		return
			$data.
			$controlDirectory.
			$this -> endOfCentralDirectory.
			pack("v", sizeof($this -> centralDirectory)).
			pack("v", sizeof($this -> centralDirectory)).
			pack("V", strlen($controlDirectory)).
			pack("V", strlen($data)).
			"\x00\x00";
	}



}
?>