71 lines
3.1 KiB
Python
71 lines
3.1 KiB
Python
# routes/emoji_routes.py
|
|
# Same-origin emoji SVG proxy. The frontend rewrites emoji in chat to a
|
|
# <span class="emoji" style="--em:url('/api/emoji/<codepoints>.svg')">
|
|
# which uses the returned SVG as a CSS mask tinted to the text color, so emoji
|
|
# render as monochrome line icons (project rule: never colorful emoji). The
|
|
# black line-art SVGs are lazily fetched from the OpenMoji CDN on first use and
|
|
# cached on disk, so:
|
|
# - the client only ever talks to our own origin (no CDN dep, no CSP change),
|
|
# - the repo isn't bloated with thousands of SVG files,
|
|
# - it works offline once an emoji has been seen once.
|
|
# Unknown/unreachable codepoints return a transparent SVG (not 404), so the CSS
|
|
# mask shows nothing rather than a solid currentColor box.
|
|
import logging
|
|
import re
|
|
from pathlib import Path
|
|
|
|
import httpx
|
|
from fastapi import APIRouter
|
|
from fastapi.responses import FileResponse, Response
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
_CACHE_DIR = Path(__file__).resolve().parent.parent / "data" / "emoji_cache"
|
|
# OpenMoji "black" set = monochrome line-art SVGs. Filenames are the codepoints
|
|
# in UPPERCASE (FE0F dropped, same as we compute), '-' joined.
|
|
_OPENMOJI_BASE = "https://cdn.jsdelivr.net/npm/openmoji@15.0.0/black/svg"
|
|
# codepoints like "1f600" or "1f468-200d-1f469-200d-1f467" (lowercase hex, '-' joined)
|
|
_CODE_RE = re.compile(r"^[0-9a-f]{2,6}(?:-[0-9a-f]{2,6})*$")
|
|
_SVG_HEADERS = {"Cache-Control": "public, max-age=31536000, immutable"}
|
|
# Returned when a codepoint is unknown/unreachable: an empty (transparent) SVG,
|
|
# so the CSS mask renders nothing instead of a solid box. Not cached, so a later
|
|
# request can still pick up the real glyph once the CDN is reachable.
|
|
_BLANK_SVG = b'<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1 1"></svg>'
|
|
_BLANK_HEADERS = {"Cache-Control": "no-store"}
|
|
|
|
|
|
def setup_emoji_routes() -> APIRouter:
|
|
router = APIRouter(prefix="/api/emoji", tags=["emoji"])
|
|
|
|
def _blank() -> Response:
|
|
return Response(_BLANK_SVG, media_type="image/svg+xml", headers=_BLANK_HEADERS)
|
|
|
|
@router.get("/{code}.svg")
|
|
async def emoji_svg(code: str):
|
|
code = code.lower()
|
|
if not _CODE_RE.match(code):
|
|
return _blank()
|
|
|
|
_CACHE_DIR.mkdir(parents=True, exist_ok=True)
|
|
fp = _CACHE_DIR / f"{code}.svg"
|
|
if fp.exists():
|
|
return FileResponse(fp, media_type="image/svg+xml", headers=_SVG_HEADERS)
|
|
|
|
# First time we've seen this emoji — fetch the OpenMoji black SVG + cache
|
|
# it. OpenMoji filenames are the codepoints uppercased.
|
|
try:
|
|
async with httpx.AsyncClient(timeout=8.0) as client:
|
|
r = await client.get(f"{_OPENMOJI_BASE}/{code.upper()}.svg")
|
|
if r.status_code == 200 and b"<svg" in r.content[:256]:
|
|
try:
|
|
fp.write_bytes(r.content)
|
|
except Exception:
|
|
pass # cache write is best-effort
|
|
return Response(r.content, media_type="image/svg+xml", headers=_SVG_HEADERS)
|
|
except Exception as e:
|
|
logger.warning("emoji fetch %s failed: %s", code, e)
|
|
|
|
return _blank()
|
|
|
|
return router
|