Improve env setup script

setup_env.bat

@@ -1,6 +1,36 @@
-@set /p "choice=Install PyInstaller so you can build an EXEcutable? (y/n) "
-python -m venv env
-%CD%/env/scripts/pip install wheel
-%CD%/env/scripts/pip install -r %CD%/requirements.txt
-if "%choice%" == "y" %CD%/env/scripts/pip install pyinstaller
-%CD%/env/scripts/python %CD%/env/scripts/pywin32_postinstall.py -install -silent
+@echo off
+set /p "choice=Install PyInstaller so you can build an EXEcutable? (y/n) "
+set dirpath=%~dp0
+if "%dirpath:~-1%" == "\" set dirpath=%dirpath:~0,-1%
+git -v > nul
+if %errorlevel% NEQ 0 goto NOGIT
+if not exist "%dirpath%\env" (
+    echo:
+    echo Creating the env folder...
+    python -m venv "%dirpath%\env"
+    if %errorlevel% NEQ 0 goto NOPYTHON
+)
+echo:
+echo Installing requirements.txt...
+"%dirpath%\env\scripts\pip" install wheel
+"%dirpath%\env\scripts\pip" install -r "%dirpath%\requirements.txt"
+echo:
+echo Installing PyInstaller...
+if "%choice%" == "y" "%dirpath%\env\scripts\pip" install pyinstaller
+"%dirpath%\env\scripts\python" "%dirpath%\env\scripts\pywin32_postinstall.py" -install -silent
+goto DONE
+:NOPYTHON
+echo:
+echo No python executable found in path!
+pause
+goto END
+:NOGIT
+echo:
+echo No git executable found in path!
+pause
+goto END
+:DONE
+echo:
+echo All done!
+pause
+:END