<?php
/**
 * Class to dynamically create a zip file (archive) of file(s) and/or directory
 *
 * @author Rochak Chauhan  www.rochakchauhan.com
 * @package CreateZipFile
 * @see Distributed under "General Public License"
 * 
 * @version 1.0
 */

class CreateZipFile {

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

	/**
	 * Function to create the directory where the file(s) will be unzipped
	 *
	 * @param string $directoryName
	 * @access public
	 * @return void
	 */	
	public function addDirectory($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 );
		$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 string $directoryName
	 * @param string $data
	 * @return void
	 * @access public
	 */	
	public function addFile($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;
	}

	/**
	 * Function to return the zip file
	 *
	 * @return zipfile (archive)
	 * @access public
	 * @return void
	 */
	public 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";
	}

	/**
	 *
	 * Function to force the download of the archive as soon as it is created
	 *
	 * @param archiveName string - name of the created archive file
	 * @access public
	 * @return ZipFile via Header
	 */
	public function forceDownload($archiveName) {
		if(ini_get('zlib.output_compression')) {
			ini_set('zlib.output_compression', 'Off');
		}

		// Security checks
		if( $archiveName == "" ) {
			echo "<html><title>Public Photo Directory - Download </title><body><BR><B>ERROR:</B> The download file was NOT SPECIFIED.</body></html>";
			exit;
		}
		elseif ( ! file_exists( $archiveName ) ) {
			echo "<html><title>Public Photo Directory - Download </title><body><BR><B>ERROR:</B> File not found.</body></html>";
			exit;
		}

		header("Pragma: public");
		header("Expires: 0");
		header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
		header("Cache-Control: private",false);
		header("Content-Type: application/zip");
		header("Content-Disposition: attachment; filename=".basename($archiveName).";" );
		header("Content-Transfer-Encoding: binary");
		header("Content-Length: ".filesize($archiveName));
		readfile("$archiveName");
	}

	/**
	  * Function to parse a directory to return all its files and sub directories as array
	  *
	  * @param string $dir
	  * @access private
	  * @return array
	  */
	private function parseDirectory($rootPath, $seperator="/"){
		$fileArray=array();
		$handle = opendir($rootPath);
		while( ($file = @readdir($handle))!==false) {
			if($file !='.' && $file !='..'){
				if (is_dir($rootPath.$seperator.$file)){
					$array=$this->parseDirectory($rootPath.$seperator.$file);
					$fileArray=array_merge($array,$fileArray);
				}
				else {
					$fileArray[]=$rootPath.$seperator.$file;
				}
			}
		}		
		return $fileArray;
	}

	/**
	 * Function to Zip entire directory with all its files and subdirectories 
	 *
	 * @param string $dirName
	 * @access public
	 * @return void
	 */
	public function zipDirectory($dirName, $outputDir) {
		if (!is_dir($dirName)){
			trigger_error("CreateZipFile FATAL ERROR: Could not locate the specified directory $dirName", E_USER_ERROR);
		}
		$tmp=$this->parseDirectory($dirName);
		$count=count($tmp);
		$this->addDirectory($outputDir);
		for ($i=0;$i<$count;$i++){
			$fileToZip=trim($tmp[$i]);
			$newOutputDir=substr($fileToZip,0,(strrpos($fileToZip,'/')+1));
			$outputDir=$outputDir.$newOutputDir;
			$fileContents=file_get_contents($fileToZip);
			$this->addFile($fileContents,$fileToZip);
		}
	}
}
?>