Files
HexaWetter/api/app/services/warncells.py
2026-06-18 23:45:08 +02:00

94 lines
2.7 KiB
Python

from __future__ import annotations
import asyncio
import logging
from typing import Any
import httpx
from app.cache import cache_get, cache_set
from app.config import CACHE_TTL_GEOCODE, DWD_WMS_URL
from app.http_client import get_client
logger = logging.getLogger(__name__)
WFS_URL = f"{DWD_WMS_URL.rsplit('/wms', 1)[0]}/ows"
# Landkreise reicht fuer warnapp_landkreise/json/warnings.json
WFS_LAYERS = ("dwd:Warngebiete_Kreise",)
async def _wfs_intersects(layer: str, lat: float, lon: float) -> list[dict[str, Any]]:
params = {
"service": "WFS",
"version": "2.0.0",
"request": "GetFeature",
"typeName": layer,
"outputFormat": "application/json",
"count": 5,
"CQL_FILTER": f"INTERSECTS(SHAPE,POINT({lat} {lon}))",
}
client = get_client()
response = await client.get(WFS_URL, params=params, timeout=8.0)
response.raise_for_status()
payload = response.json()
results = []
for feature in payload.get("features", []):
props = feature.get("properties") or {}
cell_id = props.get("WARNCELLID")
if cell_id is None:
continue
results.append(
{
"warncell_id": str(cell_id),
"name": props.get("NAME"),
"short_name": props.get("KURZNAME"),
"layer": layer.split(":")[-1],
"state": props.get("BL"),
}
)
return results
def _related_cell_ids(cell_id: str) -> set[str]:
ids = {cell_id}
if len(cell_id) >= 9:
core = cell_id[1:]
ids.add(f"1{core}")
ids.add(f"9{core}")
if cell_id.startswith("9"):
ids.add(f"1{cell_id[1:]}")
elif cell_id.startswith("1"):
ids.add(f"9{cell_id[1:]}")
return ids
async def resolve_warncells(lat: float, lon: float) -> dict[str, Any]:
cache_key = f"warncell:{lat:.4f}:{lon:.4f}"
cached = await cache_get(cache_key)
if cached:
return cached
layer_results = await asyncio.gather(
*[_wfs_intersects(layer, lat, lon) for layer in WFS_LAYERS],
return_exceptions=True,
)
areas: list[dict[str, Any]] = []
for layer, result in zip(WFS_LAYERS, layer_results):
if isinstance(result, Exception):
logger.warning("WFS warncell lookup failed for %s: %s", layer, result)
continue
areas.extend(result)
cell_ids: set[str] = set()
for area in areas:
cell_ids.update(_related_cell_ids(area["warncell_id"]))
payload = {
"lat": lat,
"lon": lon,
"areas": areas,
"cell_ids": sorted(cell_ids),
}
await cache_set(cache_key, payload, CACHE_TTL_GEOCODE)
return payload