//=======================================================================
//			Copyright (C) XashXT Group 2007
//		       rundll.h - used for find engine library
//		       getting direct path or from environment
//======================================================================= 

#ifndef GETLIB_H
#define GETLIB_H

#define NDEBUG

#include <sys\types.h>
#include <windows.h>
#include <winreg.h>
#include <stdio.h>

#pragma comment( lib, "msvcrt" )
#pragma comment( linker, "/MERGE:.rdata=.text" )
#pragma comment( linker, "/FILEALIGN:512 /SECTION:.text, EWRX /IGNORE:4078" )

#define Run( prog ) int main( int argc, char **argv )\
{ return CreateMain32()( #prog, TRUE ); }

#define Run32( prog ) int WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow )\
{ return CreateMain32()( #prog, FALSE ); }

// engine entry point format
typedef int (*winmain_t)( char *hostname, int console );
char szSearch[5][1024];
char szFsPath[4096];
HINSTANCE	hmain;

void GetError( const char *errorstring )
{
	HINSTANCE user32_dll = LoadLibrary( "user32.dll" );
	static int (*pMessageBoxA)(HWND hWnd, LPCSTR lpText, LPCSTR lpCaption, UINT uType);	

	if(!errorstring) exit( 0 );

	if( user32_dll ) pMessageBoxA = (void *)GetProcAddress( user32_dll, "MessageBoxA" );
	if(pMessageBoxA) pMessageBoxA( 0, errorstring, "Xash Error", MB_OK|MB_SETFOREGROUND|MB_ICONSTOP );
	if( user32_dll ) FreeLibrary( user32_dll ); // no need anymore...

	exit( 1 );
}

BOOL GetBin( void )
{
	// grab direct path?
	return TRUE;
}

BOOL GetEnv( void )
{
	char *pEnvPath = getenv( "Xash3D" );
	if( !pEnvPath ) return FALSE;

	strcpy( szFsPath, pEnvPath );
	return TRUE;
}

BOOL GetReg( void )
{
	HINSTANCE advapi32_dll = LoadLibrary( "advapi32.dll" );
	static long( _stdcall *pRegOpenKeyEx )( HKEY, LPCSTR, DWORD, REGSAM, PHKEY );
	static long( _stdcall *pRegQueryValueEx )( HKEY, LPCSTR, LPDWORD, LPDWORD, LPBYTE, LPDWORD );
	static long( _stdcall *pRegCloseKey)(HKEY );
	DWORD	dwBufLen = 4096; // max env length
	HKEY	hKey;
	long	lRet;
	BOOL	result = FALSE;

	if( advapi32_dll )
	{
		pRegCloseKey = (void *)GetProcAddress( advapi32_dll, "RegCloseKey" );
		pRegOpenKeyEx = (void *)GetProcAddress( advapi32_dll, "RegOpenKeyExA" );
		pRegQueryValueEx = (void *)GetProcAddress( advapi32_dll, "RegQueryValueExA" );
	}
	else goto failure; 

	if( pRegCloseKey && pRegOpenKeyEx && pRegQueryValueEx )
	{
		lRet = pRegOpenKeyEx( HKEY_LOCAL_MACHINE, "System\\CurrentControlSet\\Control\\Session Manager\\Environment", 0, KEY_READ, &hKey );
  		if( lRet != ERROR_SUCCESS ) goto failure;
		lRet = pRegQueryValueEx( hKey, "Xash3D", NULL, NULL, (byte *)szFsPath, &dwBufLen );
		if( lRet != ERROR_SUCCESS ) goto failure;
		pRegCloseKey( hKey );
		result = TRUE;
	}
	else goto failure;

failure:
	if( advapi32_dll ) FreeLibrary( advapi32_dll ); // don't forget freeing
	return result;
}

void GetLibrary( void )
{
	int	i, count = 0;

	if( GetBin( ))
	{
		// assume run directory as XashDirectory
		strcpy( szSearch[count], "bin\\launch.dll" );
		count++;
	}

	if( GetEnv( ))
	{
		// get environment variable (e.g. compilers)
		sprintf( szSearch[count], "%s\\bin\\launch.dll", szFsPath );
		count++;
	}

	if( GetReg( ))
	{
		// get environment variable direct from registry (paranoid)
		sprintf( szSearch[count], "%s\\bin\\launch.dll", szFsPath );
		count++;
	}

	for( i = 0; i < count; i++ )
	{
		if( hmain = LoadLibrary( szSearch[i] ))
			break; // done
	}
}

winmain_t CreateMain32( void )
{
	winmain_t	main;
	
	GetLibrary();
	
	if( hmain ) 
	{
		main = (winmain_t)GetProcAddress( hmain, "CreateAPI" );
		if( !main ) GetError( "Unable to find entry point in launch.dll" );
		return main;
	}

	GetError( "Unable to load the launch.dll" );

	// make compiller happy
	return 0;
}

#endif//GETLIB_H