<?php
/**
 * TTarFileExtractor class file
 *
 * @author Vincent Blavet <vincent@phpconcept.net>
 * @copyright Copyright &copy; 1997-2003 The PHP Group
 * @version $Id: TTarFileExtractor.php 3188 2012-07-12 12:13:23Z ctrlaltca $
 * @package System.IO
 */

/* vim: set ts=4 sw=4: */
// +----------------------------------------------------------------------+
// | PHP Version 4                                                        |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2003 The PHP Group                                |
// +----------------------------------------------------------------------+
// | This source file is subject to version 3.0 of the PHP license,       |
// | that is bundled with this package in the file LICENSE, and is        |
// | available through the world-wide-web at the following url:           |
// | http://www.php.net/license/3_0.txt.                                  |
// | If you did not receive a copy of the PHP license and are unable to   |
// | obtain it through the world-wide-web, please send a note to          |
// | license@php.net so we can mail you a copy immediately.               |
// +----------------------------------------------------------------------+
// | Author: Vincent Blavet <vincent@phpconcept.net>                      |
// +----------------------------------------------------------------------+
//
// $Id: TTarFileExtractor.php 3188 2012-07-12 12:13:23Z ctrlaltca $

/**
 * TTarFileExtractor class
 *
 * @author Vincent Blavet <vincent@phpconcept.net>
 * @version $Id: TTarFileExtractor.php 3188 2012-07-12 12:13:23Z ctrlaltca $
 * @package System.IO
 * @since 3.0
 */
class TTarFileExtractor
{
    /**
    * @var string Name of the Tar
    */
    private $_tarname='';

    /**
    * @var file descriptor
    */
    private $_file=0;

    /**
    * @var string Local Tar name of a remote Tar (http:// or ftp://)
    */
    private $_temp_tarname='';

    /**
    * Archive_Tar Class constructor. This flavour of the constructor only
    * declare a new Archive_Tar object, identifying it by the name of the
    * tar file.
    *
    * @param    string  $p_tarname  The name of the tar archive to create
    * @access public
    */
    public function __construct($p_tarname)
    {
        $this->_tarname = $p_tarname;
    }

    public function __destruct()
    {
        $this->_close();
        // ----- Look for a local copy to delete
        if ($this->_temp_tarname != '')
            @unlink($this->_temp_tarname);
    }

    public function extract($p_path='')
    {
        return $this->extractModify($p_path, '');
    }

    /**
    * This method extract all the content of the archive in the directory
    * indicated by $p_path. When relevant the memorized path of the
    * files/dir can be modified by removing the $p_remove_path path at the
    * beginning of the file/dir path.
    * While extracting a file, if the directory path does not exists it is
    * created.
    * While extracting a file, if the file already exists it is replaced
    * without looking for last modification date.
    * While extracting a file, if the file already exists and is write
    * protected, the extraction is aborted.
    * While extracting a file, if a directory with the same name already
    * exists, the extraction is aborted.
    * While extracting a directory, if a file with the same name already
    * exists, the extraction is aborted.
    * While extracting a file/directory if the destination directory exist
    * and is write protected, or does not exist but can not be created,
    * the extraction is aborted.
    * If after extraction an extracted file does not show the correct
    * stored file size, the extraction is aborted.
    * When the extraction is aborted, a PEAR error text is set and false
    * is returned. However the result can be a partial extraction that may
    * need to be manually cleaned.
    *
    * @param string $p_path         The path of the directory where the
	*                               files/dir need to by extracted.
    * @param string $p_remove_path  Part of the memorized path that can be
	*                               removed if present at the beginning of
	*                               the file/dir path.
    * @return boolean               true on success, false on error.
    * @access public
    */
    protected function extractModify($p_path, $p_remove_path)
    {
        $v_result = true;
        $v_list_detail = array();

        if ($v_result = $this->_openRead()) {
            $v_result = $this->_extractList($p_path, $v_list_detail,
			                                "complete", 0, $p_remove_path);
            $this->_close();
        }

        return $v_result;
    }

    protected function _error($p_message)
    {
		throw new Exception($p_message);
    }

    private function _isArchive($p_filename=null)
    {
        if ($p_filename == null) {
            $p_filename = $this->_tarname;
        }
        clearstatcache();
        return @is_file($p_filename);
    }

    private function _openRead()
    {
        if (strtolower(substr($this->_tarname, 0, 7)) == 'http://') {

          // ----- Look if a local copy need to be done
          if ($this->_temp_tarname == '') {
              $this->_temp_tarname = uniqid('tar').'.tmp';
              if (!$v_file_from = @fopen($this->_tarname, 'rb')) {
                $this->_error('Unable to open in read mode \''
				              .$this->_tarname.'\'');
                $this->_temp_tarname = '';
                return false;
              }
              if (!$v_file_to = @fopen($this->_temp_tarname, 'wb')) {
                $this->_error('Unable to open in write mode \''
				              .$this->_temp_tarname.'\'');
                $this->_temp_tarname = '';
                return false;
              }
              while ($v_data = @fread($v_file_from, 1024))
                  @fwrite($v_file_to, $v_data);
              @fclose($v_file_from);
              @fclose($v_file_to);
          }

          // ----- File to open if the local copy
          $v_filename = $this->_temp_tarname;

        } else
          // ----- File to open if the normal Tar file
          $v_filename = $this->_tarname;

		$this->_file = @fopen($v_filename, "rb");

        if ($this->_file == 0) {
            $this->_error('Unable to open in read mode \''.$v_filename.'\'');
            return false;
        }

        return true;
    }

    private function _close()
    {
        //if (isset($this->_file)) {
        if (is_resource($this->_file))
		{
               @fclose($this->_file);
            $this->_file = 0;
        }

        // ----- Look if a local copy need to be erase
        // Note that it might be interesting to keep the url for a time : ToDo
        if ($this->_temp_tarname != '') {
            @unlink($this->_temp_tarname);
            $this->_temp_tarname = '';
        }

        return true;
    }

    private function _cleanFile()
    {
        $this->_close();

        // ----- Look for a local copy
        if ($this->_temp_tarname != '') {
            // ----- Remove the local copy but not the remote tarname
            @unlink($this->_temp_tarname);
            $this->_temp_tarname = '';
        } else {
            // ----- Remove the local tarname file
            @unlink($this->_tarname);
        }
        $this->_tarname = '';

        return true;
    }

    private function _readBlock()
    {
      $v_block = null;
      if (is_resource($this->_file)) {
              $v_block = @fread($this->_file, 512);
      }
      return $v_block;
    }

    private function _jumpBlock($p_len=null)
    {
      if (is_resource($this->_file)) {
          if ($p_len === null)
              $p_len = 1;

              @fseek($this->_file, @ftell($this->_file)+($p_len*512));
      }
      return true;
    }

    private function _readHeader($v_binary_data, &$v_header)
    {
        if (strlen($v_binary_data)==0) {
            $v_header['filename'] = '';
            return true;
        }

        if (strlen($v_binary_data) != 512) {
            $v_header['filename'] = '';
            $this->_error('Invalid block size : '.strlen($v_binary_data));
            return false;
        }

        // ----- Calculate the checksum
        $v_checksum = 0;
        // ..... First part of the header
        for ($i=0; $i<148; $i++)
            $v_checksum+=ord(substr($v_binary_data,$i,1));
        // ..... Ignore the checksum value and replace it by ' ' (space)
        for ($i=148; $i<156; $i++)
            $v_checksum += ord(' ');
        // ..... Last part of the header
        for ($i=156; $i<512; $i++)
           $v_checksum+=ord(substr($v_binary_data,$i,1));

        $v_data = unpack("a100filename/a8mode/a8uid/a8gid/a12size/a12mtime/"
		                 ."a8checksum/a1typeflag/a100link/a6magic/a2version/"
						 ."a32uname/a32gname/a8devmajor/a8devminor",
						 $v_binary_data);

        // ----- Extract the checksum
        $v_header['checksum'] = OctDec(trim($v_data['checksum']));
        if ($v_header['checksum'] != $v_checksum) {
            $v_header['filename'] = '';

            // ----- Look for last block (empty block)
            if (($v_checksum == 256) && ($v_header['checksum'] == 0))
                return true;

            $this->_error('Invalid checksum for file "'.$v_data['filename']
			              .'" : '.$v_checksum.' calculated, '
						  .$v_header['checksum'].' expected');
            return false;
        }

        // ----- Extract the properties
        $v_header['filename'] = trim($v_data['filename']);
        $v_header['mode'] = OctDec(trim($v_data['mode']));
        $v_header['uid'] = OctDec(trim($v_data['uid']));
        $v_header['gid'] = OctDec(trim($v_data['gid']));
        $v_header['size'] = OctDec(trim($v_data['size']));
        $v_header['mtime'] = OctDec(trim($v_data['mtime']));
        if (($v_header['typeflag'] = $v_data['typeflag']) == "5") {
          $v_header['size'] = 0;
        }
        return true;
    }

    private function _readLongHeader(&$v_header)
    {
      $v_filename = '';
      $n = floor($v_header['size']/512);
      for ($i=0; $i<$n; $i++) {
        $v_content = $this->_readBlock();
        $v_filename .= $v_content;
      }
      if (($v_header['size'] % 512) != 0) {
        $v_content = $this->_readBlock();
        $v_filename .= $v_content;
      }

      // ----- Read the next header
      $v_binary_data = $this->_readBlock();

      if (!$this->_readHeader($v_binary_data, $v_header))
        return false;

      $v_header['filename'] = $v_filename;

      return true;
    }

    protected function _extractList($p_path, &$p_list_detail, $p_mode,
	                      $p_file_list, $p_remove_path)
    {
    $v_result=true;
    $v_nb = 0;
    $v_extract_all = true;
    $v_listing = false;

    $p_path = $this->_translateWinPath($p_path, false);
    if ($p_path == '' || (substr($p_path, 0, 1) != '/'
	    && substr($p_path, 0, 3) != "../" && !strpos($p_path, ':'))) {
      $p_path = "./".$p_path;
    }
    $p_remove_path = $this->_translateWinPath($p_remove_path);

    // ----- Look for path to remove format (should end by /)
    if (($p_remove_path != '') && (substr($p_remove_path, -1) != '/'))
      $p_remove_path .= '/';
    $p_remove_path_size = strlen($p_remove_path);

    switch ($p_mode) {
      case "complete" :
        $v_extract_all = true;
        $v_listing = false;
      break;
      case "partial" :
          $v_extract_all = false;
          $v_listing = false;
      break;
      case "list" :
          $v_extract_all = false;
          $v_listing = true;
      break;
      default :
        $this->_error('Invalid extract mode ('.$p_mode.')');
        return false;
    }

    clearstatcache();

    while (strlen($v_binary_data = $this->_readBlock()) != 0)
    {
      $v_extract_file = false;
      $v_extraction_stopped = 0;

      if (!$this->_readHeader($v_binary_data, $v_header))
        return false;

      if ($v_header['filename'] == '') {
        continue;
      }

      // ----- Look for long filename
      if ($v_header['typeflag'] == 'L') {
        if (!$this->_readLongHeader($v_header))
          return false;
      }

      if ((!$v_extract_all) && (is_array($p_file_list))) {
        // ----- By default no unzip if the file is not found
        $v_extract_file = false;

        for ($i=0; $i<sizeof($p_file_list); $i++) {
          // ----- Look if it is a directory
          if (substr($p_file_list[$i], -1) == '/') {
            // ----- Look if the directory is in the filename path
            if ((strlen($v_header['filename']) > strlen($p_file_list[$i]))
			    && (substr($v_header['filename'], 0, strlen($p_file_list[$i]))
				    == $p_file_list[$i])) {
              $v_extract_file = true;
              break;
            }
          }

          // ----- It is a file, so compare the file names
          elseif ($p_file_list[$i] == $v_header['filename']) {
            $v_extract_file = true;
            break;
          }
        }
      } else {
        $v_extract_file = true;
      }

      // ----- Look if this file need to be extracted
      if (($v_extract_file) && (!$v_listing))
      {
        if (($p_remove_path != '')
            && (substr($v_header['filename'], 0, $p_remove_path_size)
			    == $p_remove_path))
          $v_header['filename'] = substr($v_header['filename'],
		                                 $p_remove_path_size);
        if (($p_path != './') && ($p_path != '/')) {
          while (substr($p_path, -1) == '/')
            $p_path = substr($p_path, 0, strlen($p_path)-1);

          if (substr($v_header['filename'], 0, 1) == '/')
              $v_header['filename'] = $p_path.$v_header['filename'];
          else
            $v_header['filename'] = $p_path.'/'.$v_header['filename'];
        }
        if (file_exists($v_header['filename'])) {
          if (   (@is_dir($v_header['filename']))
		      && ($v_header['typeflag'] == '')) {
            $this->_error('File '.$v_header['filename']
			              .' already exists as a directory');
            return false;
          }
          if (   ($this->_isArchive($v_header['filename']))
		      && ($v_header['typeflag'] == "5")) {
            $this->_error('Directory '.$v_header['filename']
			              .' already exists as a file');
            return false;
          }
          if (!is_writeable($v_header['filename'])) {
            $this->_error('File '.$v_header['filename']
			              .' already exists and is write protected');
            return false;
          }
          if (filemtime($v_header['filename']) > $v_header['mtime']) {
            // To be completed : An error or silent no replace ?
          }
        }

        // ----- Check the directory availability and create it if necessary
        elseif (($v_result
		         = $this->_dirCheck(($v_header['typeflag'] == "5"
				                    ?$v_header['filename']
									:dirname($v_header['filename'])))) != 1) {
            $this->_error('Unable to create path for '.$v_header['filename']);
            return false;
        }

        if ($v_extract_file) {
          if ($v_header['typeflag'] == "5") {
            if (!@file_exists($v_header['filename'])) {
                if (!@mkdir($v_header['filename'], PRADO_CHMOD)) {
                    $this->_error('Unable to create directory {'
					              .$v_header['filename'].'}');
                    return false;
                }
                chmod($v_header['filename'], PRADO_CHMOD);
            }
          } else {
              if (($v_dest_file = @fopen($v_header['filename'], "wb")) == 0) {
                  $this->_error('Error while opening {'.$v_header['filename']
				                .'} in write binary mode');
                  return false;
              } else {
                  $n = floor($v_header['size']/512);
                  for ($i=0; $i<$n; $i++) {
                      $v_content = $this->_readBlock();
                      fwrite($v_dest_file, $v_content, 512);
                  }
            if (($v_header['size'] % 512) != 0) {
              $v_content = $this->_readBlock();
              fwrite($v_dest_file, $v_content, ($v_header['size'] % 512));
            }

            @fclose($v_dest_file);

            // ----- Change the file mode, mtime
            @touch($v_header['filename'], $v_header['mtime']);
            // To be completed
            //chmod($v_header[filename], DecOct($v_header[mode]));
          }

          // ----- Check the file size
          clearstatcache();
          if (filesize($v_header['filename']) != $v_header['size']) {
              $this->_error('Extracted file '.$v_header['filename']
			                .' does not have the correct file size \''
							.filesize($v_header['filename'])
							.'\' ('.$v_header['size']
							.' expected). Archive may be corrupted.');
              return false;
          }
          }
        } else {
          $this->_jumpBlock(ceil(($v_header['size']/512)));
        }
      } else {
          $this->_jumpBlock(ceil(($v_header['size']/512)));
      }

      /* TBC : Seems to be unused ...
      if ($this->_compress)
        $v_end_of_file = @gzeof($this->_file);
      else
        $v_end_of_file = @feof($this->_file);
        */

      if ($v_listing || $v_extract_file || $v_extraction_stopped) {
        // ----- Log extracted files
        if (($v_file_dir = dirname($v_header['filename']))
		    == $v_header['filename'])
          $v_file_dir = '';
        if ((substr($v_header['filename'], 0, 1) == '/') && ($v_file_dir == ''))
          $v_file_dir = '/';

        $p_list_detail[$v_nb++] = $v_header;
      }
    }

        return true;
    }

    /**
     * Check if a directory exists and create it (including parent
     * dirs) if not.
     *
     * @param string $p_dir directory to check
     *
     * @return bool true if the directory exists or was created
     */
    protected function _dirCheck($p_dir)
    {
        if ((@is_dir($p_dir)) || ($p_dir == ''))
            return true;

        $p_parent_dir = dirname($p_dir);

        if (($p_parent_dir != $p_dir) &&
            ($p_parent_dir != '') &&
            (!$this->_dirCheck($p_parent_dir)))
             return false;

        if (!@mkdir($p_dir, PRADO_CHMOD)) {
            $this->_error("Unable to create directory '$p_dir'");
            return false;
        }
        chmod($p_dir,PRADO_CHMOD);

        return true;
    }

    protected function _translateWinPath($p_path, $p_remove_disk_letter=true)
    {
      if (substr(PHP_OS, 0, 3) == 'WIN') {
          // ----- Look for potential disk letter
          if (   ($p_remove_disk_letter)
		      && (($v_position = strpos($p_path, ':')) != false)) {
              $p_path = substr($p_path, $v_position+1);
          }
          // ----- Change potential windows directory separator
          if ((strpos($p_path, '\\') > 0) || (substr($p_path, 0,1) == '\\')) {
              $p_path = strtr($p_path, '\\', '/');
          }
      }
      return $p_path;
    }
}