///////////////////////////////////////////////////////////////////////////////
//
// Credits:	TSCube (original source code) and Canterwood (xp style and more)
//
///////////////////////////////////////////////////////////////////////////////

#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <commctrl.h>
#include <commdlg.h>
#include "resource.h"

BOOL CALLBACK DialogProc (HWND, UINT, WPARAM, LPARAM) ;

HINSTANCE hInst;
OPENFILENAME ofn;

DWORD getCrc32(HANDLE);
int Patch(HWND);
	char szFileFilter[]="Executable Files "
						"*.*";

int WINAPI WinMain (HINSTANCE hInstance,
		HINSTANCE hPrevInstance,
		PSTR szCmdLine, 
		int iCmdShow)
{
	hInst = hInstance;
	InitCommonControls();
	DialogBoxParam(hInstance,MAKEINTRESOURCE(IDD_DIALOG),NULL,(DLGPROC)DialogProc,0);
	return 0;
}


BOOL CALLBACK DialogProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{

	switch (msg)
	{   

	case WM_COMMAND:
		 switch (LOWORD(wParam))
		 {

         case IDC_BROWSE :
			 ZeroMemory(&ofn,sizeof(ofn));
			 ofn.hwndOwner = hWnd;
			 ofn.hInstance = hInst;
			 ofn.lpstrFilter = szFileFilter;
			 ofn.nMaxFile = 512;
			 ofn.lpstrTitle = "Browse for...";
			 ofn.lpstrFile = "YTK Lite.exe";
			 ofn.nMaxFileTitle = 512;
			 ofn.Flags = OFN_FILEMUSTEXIST | OFN_PATHMUSTEXIST | OFN_LONGNAMES | OFN_EXPLORER | OFN_HIDEREADONLY;
			 ofn.lStructSize = sizeof(ofn);
			 if (GetOpenFileName(&ofn)){
			  SetWindowText(GetDlgItem(hWnd,IDC_FILE),ofn.lpstrFile);
			 }
			 break;

         case IDC_PATCH :
			Patch(hWnd);
			break;
 
		 case IDC_ABOUT :
MessageBox(hWnd,"Patch by: Ap0x\nPatch for: SomeFile v.1.0.0 \nWeb-site: http://ap0x.headcoders.net","About...",0x40);
			break;

		 case IDC_EXIT :
			EndDialog(hWnd, TRUE);
			break;
		 }
	return 0;
	break;

	case WM_CLOSE :
		EndDialog(hWnd,0);
	return 0 ;
	break;


	case WM_INITDIALOG :
		RECT DlgRect;
		RECT DesktopRect;
		HWND hWindow;

		SendMessage(hWnd, WM_SETICON, TRUE,(LPARAM)LoadIcon(hInst, MAKEINTRESOURCE(IDI_ICON)));
		SendDlgItemMessage(hWnd, IDC_FILE,EM_SETLIMITTEXT,512,0);
		SetDlgItemTextA (hWnd, IDC_FILE, "browse for file...");
		CheckDlgButton(hWnd,IDC_CHECK1,BST_CHECKED);
		GetWindowRect(hWnd,&DlgRect);			
		hWindow = GetDesktopWindow(); 
		GetWindowRect(hWindow,&DesktopRect);
			 
		int DlgHeight = DlgRect.bottom - DlgRect.top;
		int DlgWidth = DlgRect.right - DlgRect.left;
		int x=(DesktopRect.right+DesktopRect.left-DlgWidth)/2;
		int y =(DesktopRect.bottom+DesktopRect.top-DlgHeight)/2;
		MoveWindow(hWnd,x,y,DlgWidth,DlgHeight,FALSE);

	return 0 ;
	break;
	}
    
	return 0;
}

int Patch(HWND hWnd)
{
	char szName[800] = "";
	char szNameBackup[15] = "backup.bak";
	BYTE patched[111] = {0x08,0x09,0x09,0x09,0x09,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x09,0x09,0x08,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x09,0x09,0x08,0x09,0x08,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x08,0x09,0x09,0x08,0x09,0x09,0x09,0x08,0x09,0x08,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x09,0x09};
	LONG offset[111] = {0x17EE29,0x18095A,0x180A3A,0x180B0E,0x180C57,0x180D89,0x180ED5,0x180F0E,0x18124B,0x181280,0x18145F,0x181496,0x181566,0x181595,0x18167D,0x1816A9,0x181870,0x1818A6,0x181C92,0x181CBD,0x181D87,0x181DB0,0x181F76,0x181F7F,0x1820C7,0x1821BA,0x1821C3,0x182975,0x182A68,0x18466B,0x1846B3,0x184785,0x1847DA,0x184B21,0x184B7C,0x184C63,0x184C6C,0x185937,0x185975,0x185BBC,0x185C3D,0x185D18,0x185E01,0x185EFF,0x185FCD,0x187760,0x187798,0x187AC4,0x187B01,0x187BC8,0x187C1F,0x187DDC,0x187E1A,0x188002,0x188047,0x18F7E6,0x18F809,0x18FA12,0x18FA46,0x190DEA,0x190E19,0x190EF8,0x190F2A,0x19100C,0x19103C,0x191121,0x191156,0x192B62,0x192C33,0x192CF5,0x192D30,0x192E0C,0x192E2D,0x192F27,0x192FDF,0x19309C,0x19318D,0x193289,0x19338F,0x193810,0x193834,0x193920,0x193971,0x193B35,0x193B6D,0x193C33,0x193C61,0x194E78,0x195568,0x19559C,0x19560A,0x1956EE,0x1958EC,0x195922,0x195A0A,0x195A3B,0x195B34,0x195B3D,0x195D11,0x195F07,0x195FE5,0x1960CA,0x196532,0x196629,0x196759,0x196889,0x1969B7,0x196AA0,0x196B89,0x196C59,0x196D2D};
	DWORD number=111;
	DWORD crc32 = 0xD20DBF5E;
	// Create file name
	GetWindowText(GetDlgItem(hWnd,IDC_FILE),szName,GetWindowTextLength(GetDlgItem(hWnd,IDC_FILE))+1);
    
	// check CRC32 of file :
	HANDLE hFile = CreateFile(
		szName,
		GENERIC_READ | GENERIC_WRITE, 
		FILE_SHARE_READ, 
		NULL,
		OPEN_EXISTING,
		FILE_ATTRIBUTE_NORMAL,
		NULL);
                    
    if ( hFile == INVALID_HANDLE_VALUE )
    {
        MessageBox(hWnd,"I can't access file or patch it!","CRC error",MB_ICONEXCLAMATION);
        return 1;
    }

	if (getCrc32(hFile) != crc32)
	{
		MessageBox(hWnd,"Incorrect version or file already patched !","CRC error",MB_ICONEXCLAMATION);
		CloseHandle(hFile);
		return 1;
	}
	
	// create backup :
	if (IsDlgButtonChecked(hWnd,IDC_CHECK1)==BST_CHECKED)
	{
		
		if (!CopyFile(szName,szNameBackup,FALSE))
		{
			MessageBox(hWnd,"I can't find the original file !","Backup error",MB_ICONEXCLAMATION);
			CloseHandle(hFile);
			return 1;
		}
	}


	// Patch file
	DWORD nbWritten; // not used

 	for (DWORD i=0;i<number;i++)
	{
		SetFilePointer(hFile,offset[i],NULL,FILE_BEGIN); // rewind

		if(!WriteFile(hFile,&patched[i],1,&nbWritten,NULL))
		{
			MessageBox(hWnd,"Error while patching the file !","Patch aborted",MB_ICONEXCLAMATION);
			CloseHandle(hFile);
			if (IsDlgButtonChecked(hWnd,IDC_CHECK1)==BST_CHECKED) CopyFile(szNameBackup,szName,FALSE);
			return 1;
		}
	}

	CloseHandle(hFile);
	MessageBox(hWnd,"Patching was successfull !","Patch",MB_ICONINFORMATION);
	return 1;


}					




////////////////////////////////////////////////////////////////
// compute the CRC32 from a file
//
// argument : HANDLE of file
// return value : CRC32 of that file or 0 if error
//
// (based on source code by Craig Bruce (05-Dec-1994))
DWORD getCrc32(HANDLE hFile)
{
	//generate CRC constant table :
	DWORD crcTable[256];
	DWORD crcTmp1;
    
	for (int i=0; i<256; i++)
    {
        crcTmp1 = i;
        for (int j=8; j>0; j--)
        {
            if (crcTmp1&1) crcTmp1 = (crcTmp1 >> 1) ^ 0xEDB88320L;
            else crcTmp1 >>= 1;
        }

        crcTable[i] = crcTmp1;
    }


	//getfilesize :
	DWORD fileSize = GetFileSize(hFile,NULL);
	if (fileSize == 0xFFFFFFFF) return 0;


	//Compute CRC32 : 
	HANDLE hFileMapping = CreateFileMapping(
		hFile,
		NULL,PAGE_READONLY,
		0,
		0,
		NULL);
		
	if (!hFileMapping) return 0;

	BYTE* ptr = (BYTE*)MapViewOfFile(
		hFileMapping,
		FILE_MAP_READ,
		0,
		0,
		0);

	if (!ptr)
	{
		CloseHandle(hFileMapping);
		return 0;
	}

	BYTE* ptr_tmp = ptr; // save base pointer
	DWORD crcTmp2= 0xFFFFFFFF;

	while(fileSize--)
	{
		crcTmp2 = ((crcTmp2>>8) & 0x00FFFFFF) ^ crcTable[ (crcTmp2^(*ptr)) & 0xFF ];
		ptr++;
	}

	UnmapViewOfFile(ptr_tmp);
	CloseHandle(hFileMapping);
	return (crcTmp2^0xFFFFFFFF);
}