webfinger.py

from rest_framework import serializers


async def lookup(name, session):
    username, domain = name.split("@")
    response = await session.get(
        "https://{}/.well-known/webfinger".format(domain),
        params={"resource": "acct:{}".format(name)},
    )
    response.raise_for_status()
    return await response.json()


class AccountLinkSerializer(serializers.Serializer):
    rel = serializers.CharField()
    href = serializers.URLField()
    type = serializers.CharField()


class WebfingerSerializer(serializers.Serializer):
    links = serializers.ListField(child=AccountLinkSerializer(), min_length=1)


def get_links(payload):
    serializer = WebfingerSerializer(data=payload)
    serializer.is_valid(raise_exception=True)
    links = {}
    for link in serializer.validated_data["links"]:
        if link["rel"] != "self":
            continue

        if link["type"] == "application/activity+json":
            links["activitypub"] = link["href"]

    return links