About media sending. This is where stuff gets complicated IMHO.
Correct me if I'm wrong ( Cepi, Tarek? ) but first we need to upload the file to mms*.whatsapp.net farm of servers, which then returns a link?
After getting a link we submit it with all data including thumbnail and protocol id etc.
So link plus the rest of the data (thumb, media type, user id,etc) is finally sent as a message to the user.

First part is a problem for me since I can't fortell how to upload the file to bin-short.whatsapp.net server.

You are all welcome to help out.

Once this is done, everything is done.
Now get Cepi a new motherboard