<?php

/* vim: set expandtab tabstop=4 shiftwidth=4: */

// +----------------------------------------------------------------------+

// | PHP Version 4                                                        |

// +----------------------------------------------------------------------+

// | Copyright (c) 1997-2002 The PHP Group                                |

// +----------------------------------------------------------------------+

// | This source file is subject to version 2.02 of the PHP license,      |

// | that is bundled with this package in the file LICENSE, and is        |

// | available at through the world-wide-web at                           |

// | http://www.php.net/license/2_02.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: Xavier Noguer <xnoguer@php.net>                              |

// | Based on OLE::Storage_Lite by Kawai, Takanori                        |

// +----------------------------------------------------------------------+

//

// $Id: OLE.php,v 1.13 2007/03/07 14:38:25 schmidt Exp $





/**

* Array for storing OLE instances that are accessed from

* OLE_ChainedBlockStream::stream_open().

* @var  array

*/

$GLOBALS['_OLE_INSTANCES'] = array();



/**

* OLE package base class.

*

* @author   Xavier Noguer <xnoguer@php.net>

* @author   Christian Schmidt <schmidt@php.net>

* @category   PHPExcel

* @package    PHPExcel_Shared_OLE

*/

class PHPExcel_Shared_OLE

{

	const OLE_PPS_TYPE_ROOT   =      5;

	const OLE_PPS_TYPE_DIR    =      1;

	const OLE_PPS_TYPE_FILE   =      2;

	const OLE_DATA_SIZE_SMALL = 0x1000;

	const OLE_LONG_INT_SIZE   =      4;

	const OLE_PPS_SIZE        =   0x80;



	/**

	 * The file handle for reading an OLE container

	 * @var resource

	*/

	public $_file_handle;



	/**

	* Array of PPS's found on the OLE container

	* @var array

	*/

	public $_list = array();



	/**

	 * Root directory of OLE container

	 * @var OLE_PPS_Root

	*/

	public $root;



	/**

	 * Big Block Allocation Table

	 * @var array  (blockId => nextBlockId)

	*/

	public $bbat;



	/**

	 * Short Block Allocation Table

	 * @var array  (blockId => nextBlockId)

	*/

	public $sbat;



	/**

	 * Size of big blocks. This is usually 512.

	 * @var  int  number of octets per block.

	*/

	public $bigBlockSize;



	/**

	 * Size of small blocks. This is usually 64.

	 * @var  int  number of octets per block

	*/

	public $smallBlockSize;



	/**

	 * Reads an OLE container from the contents of the file given.

	 *

	 * @acces public

	 * @param string $file

	 * @return mixed true on success, PEAR_Error on failure

	*/

	public function read($file)

	{

		$fh = fopen($file, "r");

		if (!$fh) {

			throw new PHPExcel_Reader_Exception("Can't open file $file");

		}

		$this->_file_handle = $fh;



		$signature = fread($fh, 8);

		if ("\xD0\xCF\x11\xE0\xA1\xB1\x1A\xE1" != $signature) {

			throw new PHPExcel_Reader_Exception("File doesn't seem to be an OLE container.");

		}

		fseek($fh, 28);

		if (fread($fh, 2) != "\xFE\xFF") {

			// This shouldn't be a problem in practice

			throw new PHPExcel_Reader_Exception("Only Little-Endian encoding is supported.");

		}

		// Size of blocks and short blocks in bytes

		$this->bigBlockSize = pow(2, self::_readInt2($fh));

		$this->smallBlockSize  = pow(2, self::_readInt2($fh));



		// Skip UID, revision number and version number

		fseek($fh, 44);

		// Number of blocks in Big Block Allocation Table

		$bbatBlockCount = self::_readInt4($fh);



		// Root chain 1st block

		$directoryFirstBlockId = self::_readInt4($fh);



		// Skip unused bytes

		fseek($fh, 56);

		// Streams shorter than this are stored using small blocks

		$this->bigBlockThreshold = self::_readInt4($fh);

		// Block id of first sector in Short Block Allocation Table

		$sbatFirstBlockId = self::_readInt4($fh);

		// Number of blocks in Short Block Allocation Table

		$sbbatBlockCount = self::_readInt4($fh);

		// Block id of first sector in Master Block Allocation Table

		$mbatFirstBlockId = self::_readInt4($fh);

		// Number of blocks in Master Block Allocation Table

		$mbbatBlockCount = self::_readInt4($fh);

		$this->bbat = array();



		// Remaining 4 * 109 bytes of current block is beginning of Master

		// Block Allocation Table

		$mbatBlocks = array();

		for ($i = 0; $i < 109; ++$i) {

			$mbatBlocks[] = self::_readInt4($fh);

		}



		// Read rest of Master Block Allocation Table (if any is left)

		$pos = $this->_getBlockOffset($mbatFirstBlockId);

		for ($i = 0; $i < $mbbatBlockCount; ++$i) {

			fseek($fh, $pos);

			for ($j = 0; $j < $this->bigBlockSize / 4 - 1; ++$j) {

				$mbatBlocks[] = self::_readInt4($fh);

			}

			// Last block id in each block points to next block

			$pos = $this->_getBlockOffset(self::_readInt4($fh));

		}



		// Read Big Block Allocation Table according to chain specified by

		// $mbatBlocks

		for ($i = 0; $i < $bbatBlockCount; ++$i) {

			$pos = $this->_getBlockOffset($mbatBlocks[$i]);

			fseek($fh, $pos);

			for ($j = 0 ; $j < $this->bigBlockSize / 4; ++$j) {

				$this->bbat[] = self::_readInt4($fh);

			}

		}



		// Read short block allocation table (SBAT)

		$this->sbat = array();

		$shortBlockCount = $sbbatBlockCount * $this->bigBlockSize / 4;

		$sbatFh = $this->getStream($sbatFirstBlockId);

		for ($blockId = 0; $blockId < $shortBlockCount; ++$blockId) {

			$this->sbat[$blockId] = self::_readInt4($sbatFh);

		}

		fclose($sbatFh);



		$this->_readPpsWks($directoryFirstBlockId);



		return true;

	}



	/**

	 * @param  int  block id

	 * @param  int  byte offset from beginning of file

	 * @access public

	 */

	public function _getBlockOffset($blockId)

	{

		return 512 + $blockId * $this->bigBlockSize;

	}



	/**

	* Returns a stream for use with fread() etc. External callers should

	* use PHPExcel_Shared_OLE_PPS_File::getStream().

	* @param   int|PPS   block id or PPS

	* @return  resource  read-only stream

	*/

	public function getStream($blockIdOrPps)

	{

		static $isRegistered = false;

		if (!$isRegistered) {

			stream_wrapper_register('ole-chainedblockstream',

				'PHPExcel_Shared_OLE_ChainedBlockStream');

			$isRegistered = true;

		}



		// Store current instance in global array, so that it can be accessed

		// in OLE_ChainedBlockStream::stream_open().

		// Object is removed from self::$instances in OLE_Stream::close().

		$GLOBALS['_OLE_INSTANCES'][] = $this;

		$instanceId = end(array_keys($GLOBALS['_OLE_INSTANCES']));



		$path = 'ole-chainedblockstream://oleInstanceId=' . $instanceId;

		if ($blockIdOrPps instanceof PHPExcel_Shared_OLE_PPS) {

			$path .= '&blockId=' . $blockIdOrPps->_StartBlock;

			$path .= '&size=' . $blockIdOrPps->Size;

		} else {

			$path .= '&blockId=' . $blockIdOrPps;

		}

		return fopen($path, 'r');

	}



	/**

	 * Reads a signed char.

	 * @param   resource  file handle

	 * @return  int

	 * @access public

	 */

	private static function _readInt1($fh)

	{

		list(, $tmp) = unpack("c", fread($fh, 1));

		return $tmp;

	}



	/**

	 * Reads an unsigned short (2 octets).

	 * @param   resource  file handle

	 * @return  int

	 * @access public

	 */

	private static function _readInt2($fh)

	{

		list(, $tmp) = unpack("v", fread($fh, 2));

		return $tmp;

	}



	/**

	 * Reads an unsigned long (4 octets).

	 * @param   resource  file handle

	 * @return  int

	 * @access public

	 */

	private static function _readInt4($fh)

	{

		list(, $tmp) = unpack("V", fread($fh, 4));

		return $tmp;

	}



	/**

	* Gets information about all PPS's on the OLE container from the PPS WK's

	* creates an OLE_PPS object for each one.

	*

	* @access public

	* @param  integer  the block id of the first block

	* @return mixed true on success, PEAR_Error on failure

	*/

	public function _readPpsWks($blockId)

	{

		$fh = $this->getStream($blockId);

		for ($pos = 0; ; $pos += 128) {

			fseek($fh, $pos, SEEK_SET);

			$nameUtf16 = fread($fh, 64);

			$nameLength = self::_readInt2($fh);

			$nameUtf16 = substr($nameUtf16, 0, $nameLength - 2);

			// Simple conversion from UTF-16LE to ISO-8859-1

			$name = str_replace("\x00", "", $nameUtf16);

			$type = self::_readInt1($fh);

			switch ($type) {

			case self::OLE_PPS_TYPE_ROOT:

				$pps = new PHPExcel_Shared_OLE_PPS_Root(null, null, array());

				$this->root = $pps;

				break;

			case self::OLE_PPS_TYPE_DIR:

				$pps = new PHPExcel_Shared_OLE_PPS(null, null, null, null, null,

								   null, null, null, null, array());

				break;

			case self::OLE_PPS_TYPE_FILE:

				$pps = new PHPExcel_Shared_OLE_PPS_File($name);

				break;

			default:

				continue;

			}

			fseek($fh, 1, SEEK_CUR);

			$pps->Type    = $type;

			$pps->Name    = $name;

			$pps->PrevPps = self::_readInt4($fh);

			$pps->NextPps = self::_readInt4($fh);

			$pps->DirPps  = self::_readInt4($fh);

			fseek($fh, 20, SEEK_CUR);

			$pps->Time1st = self::OLE2LocalDate(fread($fh, 8));

			$pps->Time2nd = self::OLE2LocalDate(fread($fh, 8));

			$pps->_StartBlock = self::_readInt4($fh);

			$pps->Size = self::_readInt4($fh);

			$pps->No = count($this->_list);

			$this->_list[] = $pps;



			// check if the PPS tree (starting from root) is complete

			if (isset($this->root) &&

				$this->_ppsTreeComplete($this->root->No)) {



				break;

			}

		}

		fclose($fh);



		// Initialize $pps->children on directories

		foreach ($this->_list as $pps) {

			if ($pps->Type == self::OLE_PPS_TYPE_DIR || $pps->Type == self::OLE_PPS_TYPE_ROOT) {

				$nos = array($pps->DirPps);

				$pps->children = array();

				while ($nos) {

					$no = array_pop($nos);

					if ($no != -1) {

						$childPps = $this->_list[$no];

						$nos[] = $childPps->PrevPps;

						$nos[] = $childPps->NextPps;

						$pps->children[] = $childPps;

					}

				}

			}

		}



		return true;

	}



	/**

	* It checks whether the PPS tree is complete (all PPS's read)

	* starting with the given PPS (not necessarily root)

	*

	* @access public

	* @param integer $index The index of the PPS from which we are checking

	* @return boolean Whether the PPS tree for the given PPS is complete

	*/

	public function _ppsTreeComplete($index)

	{

		return isset($this->_list[$index]) &&

			   ($pps = $this->_list[$index]) &&

			   ($pps->PrevPps == -1 ||

				$this->_ppsTreeComplete($pps->PrevPps)) &&

			   ($pps->NextPps == -1 ||

				$this->_ppsTreeComplete($pps->NextPps)) &&

			   ($pps->DirPps == -1 ||

				$this->_ppsTreeComplete($pps->DirPps));

	}



	/**

	* Checks whether a PPS is a File PPS or not.

	* If there is no PPS for the index given, it will return false.

	*

	* @access public

	* @param integer $index The index for the PPS

	* @return bool true if it's a File PPS, false otherwise

	*/

	public function isFile($index)

	{

		if (isset($this->_list[$index])) {

			return ($this->_list[$index]->Type == self::OLE_PPS_TYPE_FILE);

		}

		return false;

	}



	/**

	* Checks whether a PPS is a Root PPS or not.

	* If there is no PPS for the index given, it will return false.

	*

	* @access public

	* @param integer $index The index for the PPS.

	* @return bool true if it's a Root PPS, false otherwise

	*/

	public function isRoot($index)

	{

		if (isset($this->_list[$index])) {

			return ($this->_list[$index]->Type == self::OLE_PPS_TYPE_ROOT);

		}

		return false;

	}



	/**

	* Gives the total number of PPS's found in the OLE container.

	*

	* @access public

	* @return integer The total number of PPS's found in the OLE container

	*/

	public function ppsTotal()

	{

		return count($this->_list);

	}



	/**

	* Gets data from a PPS

	* If there is no PPS for the index given, it will return an empty string.

	*

	* @access public

	* @param integer $index    The index for the PPS

	* @param integer $position The position from which to start reading

	*                          (relative to the PPS)

	* @param integer $length   The amount of bytes to read (at most)

	* @return string The binary string containing the data requested

	* @see OLE_PPS_File::getStream()

	*/

	public function getData($index, $position, $length)

	{

		// if position is not valid return empty string

		if (!isset($this->_list[$index]) || ($position >= $this->_list[$index]->Size) || ($position < 0)) {

			return '';

		}

		$fh = $this->getStream($this->_list[$index]);

		$data = stream_get_contents($fh, $length, $position);

		fclose($fh);

		return $data;

	}



	/**

	* Gets the data length from a PPS

	* If there is no PPS for the index given, it will return 0.

	*

	* @access public

	* @param integer $index    The index for the PPS

	* @return integer The amount of bytes in data the PPS has

	*/

	public function getDataLength($index)

	{

		if (isset($this->_list[$index])) {

			return $this->_list[$index]->Size;

		}

		return 0;

	}



	/**

	* Utility function to transform ASCII text to Unicode

	*

	* @access public

	* @static

	* @param string $ascii The ASCII string to transform

	* @return string The string in Unicode

	*/

	public static function Asc2Ucs($ascii)

	{

		$rawname = '';

		for ($i = 0; $i < strlen($ascii); ++$i) {

			$rawname .= $ascii{$i} . "\x00";

		}

		return $rawname;

	}



	/**

	* Utility function

	* Returns a string for the OLE container with the date given

	*

	* @access public

	* @static

	* @param integer $date A timestamp

	* @return string The string for the OLE container

	*/

	public static function LocalDate2OLE($date = null)

	{

		if (!isset($date)) {

			return "\x00\x00\x00\x00\x00\x00\x00\x00";

		}



		// factor used for separating numbers into 4 bytes parts

		$factor = pow(2, 32);



		// days from 1-1-1601 until the beggining of UNIX era

		$days = 134774;

		// calculate seconds

		$big_date = $days*24*3600 + gmmktime(date("H",$date),date("i",$date),date("s",$date),

											 date("m",$date),date("d",$date),date("Y",$date));

		// multiply just to make MS happy

		$big_date *= 10000000;



		$high_part = floor($big_date / $factor);

		// lower 4 bytes

		$low_part = floor((($big_date / $factor) - $high_part) * $factor);



		// Make HEX string

		$res = '';



		for ($i = 0; $i < 4; ++$i) {

			$hex = $low_part % 0x100;

			$res .= pack('c', $hex);

			$low_part /= 0x100;

		}

		for ($i = 0; $i < 4; ++$i) {

			$hex = $high_part % 0x100;

			$res .= pack('c', $hex);

			$high_part /= 0x100;

		}

		return $res;

	}



	/**

	* Returns a timestamp from an OLE container's date

	*

	* @access public

	* @static

	* @param integer $string A binary string with the encoded date

	* @return string The timestamp corresponding to the string

	*/

	public static function OLE2LocalDate($string)

	{

		if (strlen($string) != 8) {

			return new PEAR_Error("Expecting 8 byte string");

		}



		// factor used for separating numbers into 4 bytes parts

		$factor = pow(2,32);

		list(, $high_part) = unpack('V', substr($string, 4, 4));

		list(, $low_part) = unpack('V', substr($string, 0, 4));



		$big_date = ($high_part * $factor) + $low_part;

		// translate to seconds

		$big_date /= 10000000;



		// days from 1-1-1601 until the beggining of UNIX era

		$days = 134774;



		// translate to seconds from beggining of UNIX era

		$big_date -= $days * 24 * 3600;

		return floor($big_date);

	}

}

