DND and Auto Text Replies

Hello All. From what I can tell, the settings that I want are not yet available. But here we go anyways. Does anyone know how you can have text replies automatically go out when someone calls you (without your intervention)? What I want to do is set my phone on DND while I am at work and my phone automatically text anyone who calls OR texts by sending them a text message. That way I can let them know that they need to send me a text or email for a response when I am available. I am hoping there is a way. It would make my life easier.