microblog.pub/app/webmentions.py
2022-07-10 21:30:50 +02:00

132 lines
4.1 KiB
Python

from dataclasses import asdict
from dataclasses import dataclass
from typing import Any
from typing import Optional
from bs4 import BeautifulSoup # type: ignore
from fastapi import APIRouter
from fastapi import Depends
from fastapi import HTTPException
from fastapi import Request
from fastapi.responses import JSONResponse
from loguru import logger
from app.boxes import get_outbox_object_by_ap_id
from app.database import AsyncSession
from app.database import get_db_session
from app.database import now
from app.utils import microformats
from app.utils.url import check_url
from app.utils.url import is_url_valid
from app.utils.url import make_abs
router = APIRouter()
@dataclass
class Webmention:
actor_icon_url: str
actor_name: str
url: str
received_at: str
@classmethod
def from_microformats(
cls, items: list[dict[str, Any]], url: str
) -> Optional["Webmention"]:
for item in items:
if item["type"][0] == "h-card":
return cls(
actor_icon_url=make_abs(
item["properties"]["photo"][0], url
), # type: ignore
actor_name=item["properties"]["name"][0],
url=url,
received_at=now().isoformat(),
)
if item["type"][0] == "h-entry":
author = item["properties"]["author"][0]
return cls(
actor_icon_url=make_abs(
author["properties"]["photo"][0], url
), # type: ignore
actor_name=author["properties"]["name"][0],
url=url,
received_at=now().isoformat(),
)
return None
def is_source_containing_target(source_html: str, target_url: str) -> bool:
soup = BeautifulSoup(source_html, "html5lib")
for link in soup.find_all("a"):
h = link.get("href")
if not is_url_valid(h):
continue
if h == target_url:
return True
return False
@router.post("/webmentions")
async def webmention_endpoint(
request: Request,
db_session: AsyncSession = Depends(get_db_session),
) -> JSONResponse:
form_data = await request.form()
try:
source = form_data["source"]
target = form_data["target"]
if source == target:
raise ValueError("source URL is the same as target")
check_url(source)
check_url(target)
except Exception:
logger.exception("Invalid webmention request")
raise HTTPException(status_code=400, detail="Invalid payload")
logger.info(f"Received webmention {source=} {target=}")
mentioned_object = await get_outbox_object_by_ap_id(db_session, target)
if not mentioned_object:
logger.info(f"Invalid target {target=}")
raise HTTPException(status_code=400, detail="Invalid target")
maybe_data_and_html = await microformats.fetch_and_parse(source)
if not maybe_data_and_html:
logger.info("failed to fetch source")
raise HTTPException(status_code=400, detail="failed to fetch source")
data, html = maybe_data_and_html
if not is_source_containing_target(html, target):
logger.warning("target not found in source")
raise HTTPException(status_code=400, detail="target not found in source")
try:
webmention = Webmention.from_microformats(data["items"], source)
if not webmention:
raise ValueError("Failed to fetch target data")
except Exception:
logger.warning("Failed build Webmention for {source=} with {data=}")
return JSONResponse(content={}, status_code=200)
logger.info(f"{webmention=}")
if mentioned_object.webmentions is None:
mentioned_object.webmentions = [asdict(webmention)]
else:
mentioned_object.webmentions = [asdict(webmention)] + [
wm # type: ignore
for wm in mentioned_object.webmentions # type: ignore
if wm["url"] != source # type: ignore
]
await db_session.commit()
return JSONResponse(content={}, status_code=200)