Add a public way to register a pack upload separately from uploading a pack

[ioistired]

In Adhesive, I'd like to check if I've been rate limited before proceeding with the conversion process. I propose to separate the pack registration code:

signalstickers-client/signalstickers_client/classes/uploader.py

Lines 24 to 39 in 2d74c45

	# Register the pack and getting authorizations
	# - "Hey, I'm {USER} and I'd like to upload {nb_stickers} stickers"
	# - "Hey, no problem, here are your credentials for uploading content"
	register_req = await http.get(SERVICE_STICKER_FORM_URL.format(
	nb_stickers=pack.nb_stickers_with_cover),
	auth=(signal_user, signal_password),
	timeout=None,
	)
	if register_req.status_code == 401:
	raise RuntimeError("Invalid authentication")
	if register_req.status_code == 413:
	# Yes, it comes faster than you'll expect
	raise RuntimeError(
	"Service rate limit exceeded, please try again later.")
	pack_attrs = register_req.json()

Into a separate public function that returns pack_attrs and pack_key. The caller doesn't care about this data, and treats it as an opaque "token" object to be passed back to the upload code. For backwards compatibility and to maintain a simple API, upload_pack should remain as is with the same interface, wrapping the new function.

[romainricard]

So if I understand correctly, this is the kind of API you'd like?

pack = Pack()
client = StickersClient("foo", "bar")

# So instead of 
client.upload_pack(pack)

# You would do something like
try:
    registration = client.register(pack)
    client.upload_pack_from_registration(pack, registration)
except RateLimitException:
    ...

[ioistired]

In addition to, yea. client.upload_pack(pack) would be equivalent to client.upload_pack_from_registration(pack, client.register(pack)). What do you think?

[romainricard]

Yeah I meant in addition, sorry!
I've looked into Signal server code, and it does not seems that a method to get the rate limit status is available.

I can see the point of this use-case, so I'll try to do in the next days!