traveling from Canada to New Delhi with Indian Passport and I have 17 hours layover in Shanghai

Hi Sir/Mam,

I'm traveling from Canada to India(New Delhi) with Indian Passport and I have 17 hours layover in Pudong Airport.
do I need transit visa to go out to do sight-seeing and come back to catch my flight ?

If yes , can I apply online from Canada ?

Please advise ...
Regards
Harshita