authenticator.bat

@SETLOCAL ENABLEEXTENSIONS 
@SETLOCAL ENABLEDELAYEDEXPANSION
@REM // ENABLEDELAYEDEXPANSION would allow !var! to expand the  variable var at execution time.
@REM // The variables is usually expanded at input time, but when inside of a FOR loop, its assigned with value during initialization.
@REM // This expansion of variable at the input time, causes counter variables not to increment or decrement in FOR loop.

@REM // Parent Directory of Authenticator App
@SET parent=%~dp0

@REM //  Get the path of python executable
@REM //  If more than one path of python.exe exists, select the 1st one
@SET /A once=0
@FOR /F "usebackq delims=" %%i IN (`where python.exe`) DO (
	@IF /I !once! EQU 0 (		
		@SET pypaths=%%i
		@SET /A once=1
	)	
)
@REM @echo %pypaths%
@cd %parent%

@REM // For Supporting “double-click” execution from Windows Explorer
@SET /A noninteractive=0
@REM ECHO %CMDCMDLINE% | FINDSTR /L /I %COMSPEC% >NUL 2>&1
@ECHO %CMDCMDLINE% | FINDSTR /L /I %parent% >NUL 2>&1
@REM ECHO ERRORLEVEL=%ERRORLEVEL%
@IF %ERRORLEVEL% == 0 SET /A noninteractive=1

@REM //	Run the app
"%pypaths%" authenticator.py

@IF ERRORLEVEL 1 (
	@REM //	If Some Error occured running the app
	@REM //	Re Run the app to capture the error
	"%pypaths%" authenticator.py 2>NUL | findstr /L /I "pip3 install pycryptodome"
	@IF ERRORLEVEL 0 (
		@REM //	If Crypto module is not installed
		@ECHO Installing Crypto Library
		pip3 install pycryptodome
		
		@IF ERRORLEVEL 0 (
			@REM //	After successful installation of Crypto Library
			@REM //	Run the app again
			"%pypaths%" authenticator.py
		)
	)		
)


@IF /I !noninteractive! EQU 1 (
	REM //  Paused the CMD.exe to show the output before exiting 
	@REM // For bat script, double clicked from Win Explorer
	@PAUSE
)

@ENDLOCAL
@EXIT /B 0