add fetch list of mosmix stations by radius

Author: p3t3r67x0

app/api/climate.py

@@ -7,6 +7,7 @@
 from ..dependencies import get_session
 from ..services.climate import (
     get_dwd_stations_by_municipality_key,
+    get_mosmix_geometries_by_lat_lng,
     get_mosmix_geometries_by_bbox,
     get_weather_service_stations,
     get_all_mosmix_stations
@@ -152,3 +153,53 @@ async def fetch_mosmix_geometries_by_bbox(
     geojson_data = FeatureCollection(features, crs=crs)
 
     return geojson_data
+
+
+@route_climate.get(
+    '/mosmix/radius',
+    response_model=dict,
+    tags=['Deutscher Wetterdienst'],
+    description=(
+        'Retrieves a list of German weather service stations within the '
+        'specified radius.'
+    ),
+    responses={
+        200: {'description': 'OK'},
+        400: {'description': 'Bad Request'},
+        404: {'description': 'Not Found'},
+        422: {'description': 'Unprocessable Entity'},
+    }
+)
+async def fetch_mosmix_geometries_by_lat_lng(
+    lat: float,
+    lng: float,
+    radius: float = Query(
+        default=5000,
+        ge=0,
+        le=100000,
+        description='Radius in meters'
+    ),
+    session: AsyncSession = Depends(get_session)
+):
+    rows = await get_mosmix_geometries_by_lat_lng(session, lat, lng, radius)
+
+    if len(rows) == 0:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f'No matches found for coordinates ({lat}, {lng})'
+        )
+
+    features = [
+        Feature(
+            id=row['station_id'],
+            geometry=row['geojson'],
+            properties={'station_name': row['station_name']},
+        )
+        for row in rows
+    ]
+
+    crs = {'type': 'name', 'properties': {
+        'name': 'urn:ogc:def:crs:OGC:1.3:CRS84'}}
+    geojson_data = FeatureCollection(features, crs=crs)
+
+    return geojson_data

app/services/climate.py

@@ -4,6 +4,7 @@
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.future import select
 from sqlalchemy.orm import aliased
+from geoalchemy2 import Geography as GEOGRAPHY
 
 from ..utils.validators import validate_not_none
 from ..utils.sanitizer import sanitize_string
@@ -143,3 +144,45 @@ async def get_mosmix_geometries_by_bbox(
     rows = result.mappings().all()
 
     return rows
+
+
+async def get_mosmix_geometries_by_lat_lng(
+    session: AsyncSession,
+    lat: float,
+    lng: float,
+    radius: float
+):
+    model = MosmixStation
+
+    geojson = cast(func.ST_AsGeoJSON(
+        model.wkb_geometry, 15), JSON).label('geojson')
+
+    point = func.ST_SetSRID(func.ST_MakePoint(
+        bindparam('lng'),
+        bindparam('lat')
+    ), 4326)
+
+    stmt = (
+        select(
+            model.station_id,
+            model.station_name,
+            geojson
+        )
+        .where(
+            func.ST_DWithin(
+                cast(model.wkb_geometry, GEOGRAPHY),
+                cast(point, GEOGRAPHY),
+                bindparam('radius')
+            ),
+            func.ST_IsValid(model.wkb_geometry)
+        )
+    )
+
+    result = await session.execute(
+        stmt,
+        {'lat': lat, 'lng': lng, 'radius': radius}
+    )
+
+    rows = result.mappings().all()
+
+    return rows