<?php

namespace application\extensions;

class Zip
{

    var $datasec = array();
    var $ctrl_dir = array();
    var $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00";
    var $old_offset = 0;

    function unix2DosTime($unixtime = 0)
    {
        $timearray = ($unixtime == 0) ? getdate() : getdate($unixtime);

        if ($timearray['year'] < 1980) {
            $timearray['year'] = 1980;
            $timearray['mon'] = 1;
            $timearray['mday'] = 1;
            $timearray['hours'] = 0;
            $timearray['minutes'] = 0;
            $timearray['seconds'] = 0;
        } // end if

        return (($timearray['year'] - 1980) << 25) | ($timearray['mon'] << 21) | ($timearray['mday'] << 16) |
        ($timearray['hours'] << 11) | ($timearray['minutes'] << 5) | ($timearray['seconds'] >> 1);
    }

// end of the 'unix2DosTime()' method

    function addFile($data, $name, $time = 0)
    {
        $name = str_replace('\\', '/', $name);

        $dtime = dechex($this->unix2DosTime($time));
        $hexdtime = '\x' . $dtime[6] . $dtime[7]
            . '\x' . $dtime[4] . $dtime[5]
            . '\x' . $dtime[2] . $dtime[3]
            . '\x' . $dtime[0] . $dtime[1];
        eval('$hexdtime = "' . $hexdtime . '";');

        $fr = "\x50\x4b\x03\x04";
        $fr .= "\x14\x00";   // ver needed to extract
        $fr .= "\x00\x00";   // gen purpose bit flag
        $fr .= "\x08\x00";   // compression method
        $fr .= $hexdtime;    // last mod time and date

        $unc_len = strlen($data);
        $crc = crc32($data);
        $zdata = gzcompress($data);
        $zdata = substr(substr($zdata, 0, strlen($zdata) - 4), 2); // fix crc bug
        $c_len = strlen($zdata);
        $fr .= pack('V', $crc);    // crc32
        $fr .= pack('V', $c_len);     // compressed filesize
        $fr .= pack('V', $unc_len);   // uncompressed filesize
        $fr .= pack('v', strlen($name)); // length of filename
        $fr .= pack('v', 0);    // extra field length
        $fr .= $name;

        $fr .= $zdata;


        $this->datasec[] = $fr;

        $cdrec = "\x50\x4b\x01\x02";
        $cdrec .= "\x00\x00";    // version made by
        $cdrec .= "\x14\x00";    // version needed to extract
        $cdrec .= "\x00\x00";    // gen purpose bit flag
        $cdrec .= "\x08\x00";    // compression method
        $cdrec .= $hexdtime;     // last mod time & date
        $cdrec .= pack('V', $crc);     // crc32
        $cdrec .= pack('V', $c_len);   // compressed filesize
        $cdrec .= pack('V', $unc_len);    // uncompressed filesize
        $cdrec .= pack('v', strlen($name)); // length of filename
        $cdrec .= pack('v', 0);    // extra field length
        $cdrec .= pack('v', 0);    // file comment length
        $cdrec .= pack('v', 0);    // disk number start
        $cdrec .= pack('v', 0);    // internal file attributes
        $cdrec .= pack('V', 32);   // external file attributes - 'archive' bit set

        $cdrec .= pack('V', $this->old_offset); // relative offset of local header
        $this->old_offset += strlen($fr);

        $cdrec .= $name;

        $this->ctrl_dir[] = $cdrec;
    }

// end of the 'addFile()' method

    function file()
    {
        $data = implode('', $this->datasec);
        $ctrldir = implode('', $this->ctrl_dir);

        return
            $data .
            $ctrldir .
            $this->eof_ctrl_dir .
            pack('v', sizeof($this->ctrl_dir)) . // total # of entries "on this disk"
            pack('v', sizeof($this->ctrl_dir)) . // total # of entries overall
            pack('V', strlen($ctrldir)) . // size of central dir
            pack('V', strlen($data)) . // offset to start of central dir
            "\x00\x00";        // .zip file comment length
    }

// end of the 'file()' method
}