<?php
/**
 * @package     Joomla.Platform
 * @subpackage  FileSystem
 *
 * @copyright   Copyright (C) 2005 - 2011 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE
 */

defined('JPATH_PLATFORM') or die;

/**
 * Tar format adapter for the JArchive class
 *
 * This class is inspired from and draws heavily in code and concept from the Compress package of
 * The Horde Project <http://www.horde.org>
 *
 * @contributor  Michael Slusarz <slusarz@horde.org>
 * @contributor  Michael Cochrane <mike@graftonhall.co.nz>
 *
 * @package     Joomla.Platform
 * @subpackage  FileSystem
 * @since       11.1
 */
class JArchiveTar extends JObject
{
    /**
     * Tar file types.
     * @var array
     */
    var $_types = array (
        0x0 => 'Unix file',
        0x30 => 'File',
        0x31 => 'Link',
        0x32 => 'Symbolic link',
        0x33 => 'Character special file',
        0x34 => 'Block special file',
        0x35 => 'Directory',
        0x36 => 'FIFO special file',
        0x37 => 'Contiguous file'
    );

    /**
     * Tar file flags.
     * @var array
     */
    var $_flags = array (
        'FTEXT' => 0x01,
        'FHCRC' => 0x02,
        'FEXTRA' => 0x04,
        'FNAME' => 0x08,
        'FCOMMENT' => 0x10
    );

    /**
     * Tar file data buffer
     * @var string
     */
    var $_data = null;

    /**
     * Tar file metadata array
     * @var array
     */
    var $_metadata = null;

    /**
    * Extract a ZIP compressed file to a given path
    *
    * @param    string  $archive        Path to ZIP archive to extract
    * @param    string  $destination    Path to extract archive into
    * @param    array   $options        Extraction options [unused]
    *
    * @return   boolean True if successful
    * @since    11.1
    */
    public function extract($archive, $destination, $options = array ())
    {
        // Initialise variables.
        $this->_data = null;
        $this->_metadata = null;

        $stream = JFactory::getStream();
        if (!$stream->open($archive, 'rb')) {
            $this->set('error.message', JText::_('JLIB_FILESYSTEM_TAR_UNABLE_TO_READ'));

            return JError::raiseWarning(100, $this->get('error.message'));
        }

        $position = 0;
        $return_array = array ();
        $i = 0;
        // Tar has items in 512 byte packets
        $chunksize = 512; 
        while ($entry = $stream->read($chunksize))
        {

            $info = @ unpack("a100filename/a8mode/a8uid/a8gid/a12size/a12mtime/a8checksum/Ctypeflag/a100link/a6magic/a2version/a32uname/a32gname/a8devmajor/a8devminor", $entry);

            if (!$info) {
                $this->set('error.message', JText::_('JLIB_FILESYSTEM_TAR_UNABLE_TO_DECOMPRESS'));

                return JError::raiseWarning(100, $this->get('error.message'));
            }

            $size = octdec($info['size']);
            $bsize = ceil($size / $chunksize) * $chunksize;
            $contents = '';

            if ($size) {

                $contents = substr($stream->read($bsize), 0, octdec($info['size']));
            }

            if ($info['filename']) {
                $file = array (
                    'attr' => null,
                    'data' => null,
                    'date' => octdec($info['mtime']),
                    'name' => trim($info['filename']),
                    'size' => octdec($info['size']),
                    'type' => isset ($this->_types[$info['typeflag']]) ? $this->_types[$info['typeflag']] : null);

                if (($info['typeflag'] == 0) || ($info['typeflag'] == 0x30) || ($info['typeflag'] == 0x35)) {
                    /* File or folder. */
                    $file['data'] = $contents;

                    $mode = hexdec(substr($info['mode'], 4, 3));
                    $file['attr'] = (($info['typeflag'] == 0x35) ? 'd' : '-') .
                    (($mode & 0x400) ? 'r' : '-') .
                    (($mode & 0x200) ? 'w' : '-') .
                    (($mode & 0x100) ? 'x' : '-') .
                    (($mode & 0x040) ? 'r' : '-') .
                    (($mode & 0x020) ? 'w' : '-') .
                    (($mode & 0x010) ? 'x' : '-') .
                    (($mode & 0x004) ? 'r' : '-') .
                    (($mode & 0x002) ? 'w' : '-') .
                    (($mode & 0x001) ? 'x' : '-');
                }
                else {
                    /* Some other type. */
                }

                $type = strtolower($file['type']);

                if ($type == 'file' || $type == 'unix file') {
                    $path = JPath::clean($destination.DS.$file['name']);

                    // Make sure the destination folder exists
                    if (!JFolder::create(dirname($path))) {
                        $this->set('error.message', JText::_('JLIB_FILESYSTEM_TAR_UNABLE_TO_CREATE_DESTINATION'));

                        return JError::raiseWarning(100, $this->get('error.message'));
                    }

                    if (JFile::write($path, $contents, true) === false) {
                        $this->set('error.message', JText::_('JLIB_FILESYSTEM_TAR_UNABLE_TO_WRITE_ENTRY'));

                        return JError::raiseWarning(100, $this->get('error.message'));
                    }
                    // Reclaim some memory
                    $contents = ''; 
                }
            }
        }

        $stream->close();

        return true;
    }
}