<?php

error_reporting(E_ERROR | E_PARSE);
set_time_limit(-1);
ini_set('max_input_time', '-1');
ini_set('max_execution_time', '0');
session_start();
ob_start();

require_once './config.php';
require_once './_pdo.php';
require_once "./src/D2Functions.php";
require_once './src/D2ItemData.php';
require_once './src/D2ItemDesc.php';
require_once './src/D2DocGenerator.php';

define('DB_FILE', "ironman-dev.db");
PDO_Connect("sqlite:" . DB_FILE);

$filename = "D:\Diablo II\MODS\ironman-dev\save\Test.d2s";
$fp = fopen($filename, "rb+");
$filesize = filesize($filename);
$pucData = unpack("C*",file_get_contents($filename));

 // ddump($pucData);


// ddump(fseek($fp, 1));
 
// pucData - pointer to the byte stream of the .d2s file
// iSize - number of bytes in the stream ( filesize )
function checksum($fp, $pucData, $iSize){
    // delete old checksum at offset 0x0C - byte 12
    fseek($fp, 12);
    // (I) unsigned integer (machine dependent size and byte order)
    fwrite($fp, pack('I', 0)); // produces 4 bytes 
    
    $uiCS = 0b00000000000000000000000000000000; 
    
    // this is the whole checksum calculation
    for ($j = 1; $j <= $iSize; ++$j ){
        $uiCS = (($uiCS << 1)|( $uiCS >> 31)) + decbin($pucData[$j]);
        // dump(decbin($pucData[$j]));
    }
    
    
    dump(decbin($uiCS));
    
    //fseek($fp, 12);
    //fwrite($fp, pack('I', $uiCS));     
}

fseek($fp, 347);
fwrite($fp, pack('C', 0xFD));
fseek($fp, 348);
fwrite($fp, pack('C', 0x9F));

checksum($fp, $pucData, $filesize);

fclose($fp);