<?php
if (!defined('IN_CONTEXT')) die('access violation error!');

define('NUM_BIG_BLOCK_DEPOT_BLOCKS_POS', 0x2c);
define('SMALL_BLOCK_DEPOT_BLOCK_POS', 0x3c);
define('ROOT_START_BLOCK_POS', 0x30);
define('BIG_BLOCK_SIZE', 0x200);
define('SMALL_BLOCK_SIZE', 0x40);
define('EXTENSION_BLOCK_POS', 0x44);
define('NUM_EXTENSION_BLOCK_POS', 0x48);
define('PROPERTY_STORAGE_BLOCK_SIZE', 0x80);
define('BIG_BLOCK_DEPOT_BLOCKS_POS', 0x4c);
define('SMALL_BLOCK_THRESHOLD', 0x1000);
define('SIZE_OF_NAME_POS', 0x40);
define('TYPE_POS', 0x42);
define('START_BLOCK_POS', 0x74);
define('SIZE_POS', 0x78);
define('IDENTIFIER_OLE', pack("CCCCCCCC",0xd0,0xcf,0x11,0xe0,0xa1,0xb1,0x1a,0xe1));

function GetInt4d($data, $pos)
{
	$value = ord($data[$pos]) | (ord($data[$pos+1])	<< 8) | (ord($data[$pos+2]) << 16) | (ord($data[$pos+3]) << 24);
	if ($value>=4294967294)
	{
		$value=-2;
	}
	return $value;
}


class OLERead {
    var $data = '';
    
    
    function OLERead(){
        
        
    }
    
    function read($sFileName){
        
    	if(!is_readable($sFileName)) {
    		$this->error = 1;
    		return false;
    	}
    	
    	$this->data = @file_get_contents($sFileName);
    	if (!$this->data) { 
    		$this->error = 1; 
    		return false; 
   		}
   		if (substr($this->data, 0, 8) != IDENTIFIER_OLE) {
    		$this->error = 1; 
    		return false; 
   		}
        $this->numBigBlockDepotBlocks = GetInt4d($this->data, NUM_BIG_BLOCK_DEPOT_BLOCKS_POS);
        $this->sbdStartBlock = GetInt4d($this->data, SMALL_BLOCK_DEPOT_BLOCK_POS);
        $this->rootStartBlock = GetInt4d($this->data, ROOT_START_BLOCK_POS);
        $this->extensionBlock = GetInt4d($this->data, EXTENSION_BLOCK_POS);
        $this->numExtensionBlocks = GetInt4d($this->data, NUM_EXTENSION_BLOCK_POS);
 
        $bigBlockDepotBlocks = array();
        $pos = BIG_BLOCK_DEPOT_BLOCKS_POS;

	$bbdBlocks = $this->numBigBlockDepotBlocks;
        
            if ($this->numExtensionBlocks != 0) {
                $bbdBlocks = (BIG_BLOCK_SIZE - BIG_BLOCK_DEPOT_BLOCKS_POS)/4; 
            }
        
        for ($i = 0; $i < $bbdBlocks; $i++) {
              $bigBlockDepotBlocks[$i] = GetInt4d($this->data, $pos);
              $pos += 4;
        }
        
        
        for ($j = 0; $j < $this->numExtensionBlocks; $j++) {
            $pos = ($this->extensionBlock + 1) * BIG_BLOCK_SIZE;
            $blocksToRead = min($this->numBigBlockDepotBlocks - $bbdBlocks, BIG_BLOCK_SIZE / 4 - 1);

            for ($i = $bbdBlocks; $i < $bbdBlocks + $blocksToRead; $i++) {
                $bigBlockDepotBlocks[$i] = GetInt4d($this->data, $pos);
                $pos += 4;
            }   

            $bbdBlocks += $blocksToRead;
            if ($bbdBlocks < $this->numBigBlockDepotBlocks) {
                $this->extensionBlock = GetInt4d($this->data, $pos);
            }
        }

        $pos = 0;
        $index = 0;
        $this->bigBlockChain = array();
        
        for ($i = 0; $i < $this->numBigBlockDepotBlocks; $i++) {
            $pos = ($bigBlockDepotBlocks[$i] + 1) * BIG_BLOCK_SIZE;
            for ($j = 0 ; $j < BIG_BLOCK_SIZE / 4; $j++) {
                $this->bigBlockChain[$index] = GetInt4d($this->data, $pos);
                $pos += 4 ;
                $index++;
            }
        }

        $pos = 0;
	    $index = 0;
	    $sbdBlock = $this->sbdStartBlock;
	    $this->smallBlockChain = array();
	
	    while ($sbdBlock != -2) {
	
	      $pos = ($sbdBlock + 1) * BIG_BLOCK_SIZE;
	
	      for ($j = 0; $j < BIG_BLOCK_SIZE / 4; $j++) {
	        $this->smallBlockChain[$index] = GetInt4d($this->data, $pos);
	        $pos += 4;
	        $index++;
	      }
	
	      $sbdBlock = $this->bigBlockChain[$sbdBlock];
	    }

        
        $block = $this->rootStartBlock;
        $pos = 0;
        $this->entry = $this->__readData($block);
        
        $this->__readPropertySets();

    }
    
     function __readData($bl) {
        $block = $bl;
        $pos = 0;
        $data = '';
        
        while ($block != -2)  {
            $pos = ($block + 1) * BIG_BLOCK_SIZE;
            $data = $data.substr($this->data, $pos, BIG_BLOCK_SIZE);
	    $block = $this->bigBlockChain[$block];
        }
		return $data;
     }
        
    function __readPropertySets(){
        $offset = 0;
        while ($offset < strlen($this->entry)) {
              $d = substr($this->entry, $offset, PROPERTY_STORAGE_BLOCK_SIZE);
            
              $nameSize = ord($d[SIZE_OF_NAME_POS]) | (ord($d[SIZE_OF_NAME_POS+1]) << 8);
              
              $type = ord($d[TYPE_POS]);
        
              $startBlock = GetInt4d($d, START_BLOCK_POS);
              $size = GetInt4d($d, SIZE_POS);
        
            $name = '';
            for ($i = 0; $i < $nameSize ; $i++) {
              $name .= $d[$i];
            }
            
            $name = str_replace("\x00", "", $name);
            
            $this->props[] = array (
                'name' => $name, 
                'type' => $type,
                'startBlock' => $startBlock,
                'size' => $size);

            if (($name == "Workbook") || ($name == "Book")) {
                $this->wrkbook = count($this->props) - 1;
            }

            if ($name == "Root Entry") {
                $this->rootentry = count($this->props) - 1;
            }
            
            $offset += PROPERTY_STORAGE_BLOCK_SIZE;
        }   
        
    }
    
    
    function getWorkBook(){
    	if ($this->props[$this->wrkbook]['size'] < SMALL_BLOCK_THRESHOLD){

			$rootdata = $this->__readData($this->props[$this->rootentry]['startBlock']);
	        
			$streamData = '';
	        $block = $this->props[$this->wrkbook]['startBlock'];
	        $pos = 0;
		    while ($block != -2) {
      	          $pos = $block * SMALL_BLOCK_SIZE;
		          $streamData .= substr($rootdata, $pos, SMALL_BLOCK_SIZE);

			      $block = $this->smallBlockChain[$block];
		    }
			
		    return $streamData;
    		

    	}else{
    	
	        $numBlocks = $this->props[$this->wrkbook]['size'] / BIG_BLOCK_SIZE;
	        if ($this->props[$this->wrkbook]['size'] % BIG_BLOCK_SIZE != 0) {
	            $numBlocks++;
	        }
	        
	        if ($numBlocks == 0) return '';
	        
	        $streamData = '';
	        $block = $this->props[$this->wrkbook]['startBlock'];
	        $pos = 0;
	        while ($block != -2) {
	          $pos = ($block + 1) * BIG_BLOCK_SIZE;
	          $streamData .= substr($this->data, $pos, BIG_BLOCK_SIZE);
	          $block = $this->bigBlockChain[$block];
	        }   
	        return $streamData;
    	}
    }
    
}
?>