If someone knocks on my door - activation for Alexa and camera.
Alexa asks who is it?
Camera takes a picture and checks it against the database of my friends and if possible identifies it.
Alexa records the response and if I have set my status (switch) to out, it will say please leave a message as I am not available right now. and if I have set my status to in, it will say notifying the owner and please wait.