microblog.pub/app/utils/webmentions.py

63 lines
1.7 KiB
Python
Raw Normal View History

2022-07-09 07:33:48 +00:00
from urllib.parse import urlparse
import httpx
from bs4 import BeautifulSoup # type: ignore
from loguru import logger
from app import config
from app.utils.url import is_url_valid
def _make_abs(url: str | None, parent: str) -> str | None:
if url is None:
return None
if url.startswith("http"):
return url
return (
urlparse(parent)._replace(path=url, params="", query="", fragment="").geturl()
)
async def _discover_webmention_endoint(url: str) -> str | None:
async with httpx.AsyncClient() as client:
try:
resp = await client.get(
url,
headers={
"User-Agent": config.USER_AGENT,
},
follow_redirects=True,
)
resp.raise_for_status()
except (httpx.HTTPError, httpx.HTTPStatusError):
logger.exception(f"Failed to discover webmention endpoint for {url}")
return None
for k, v in resp.links.items():
if k and "webmention" in k:
return _make_abs(resp.links[k].get("url"), url)
soup = BeautifulSoup(resp.text, "html5lib")
wlinks = soup.find_all(["link", "a"], attrs={"rel": "webmention"})
for wlink in wlinks:
if "href" in wlink.attrs:
return _make_abs(wlink.attrs["href"], url)
return None
async def discover_webmention_endpoint(url: str) -> str | None:
"""Discover the Webmention endpoint of a given URL, if any.
Passes all the tests at https://webmention.rocks!
"""
wurl = await _discover_webmention_endoint(url)
if wurl is None:
return None
if not is_url_valid(wurl):
return None
return wurl