"""Weather context for the map (server-26#237): NWS alerts + nearest-METAR wind.

Public-domain US Government data, cached server-side in app/internal/weather.py;
no licence gate (unlike 511NY / outage providers).
"""
from typing import Optional

from fastapi import APIRouter, HTTPException, Query

from app.internal import weather

router = APIRouter(prefix="/weather", tags=["weather"])


@router.get("/alerts")
async def get_alerts(
    south: Optional[float] = Query(None, ge=-90, le=90),
    west: Optional[float] = Query(None, ge=-180, le=180),
    north: Optional[float] = Query(None, ge=-90, le=90),
    east: Optional[float] = Query(None, ge=-180, le=180),
):
    """Active NWS alerts with polygons, optionally filtered to those intersecting a bbox.

    ``zone_only`` holds alerts whose zones could not be resolved to a polygon; it
    is never bbox-filtered (there is no shape to test) and never dropped.
    """
    box = (south, west, north, east)
    if any(v is not None for v in box) and any(v is None for v in box):
        raise HTTPException(400, "give all of south, west, north, east or none")
    if south is not None and (south > north or west > east):
        raise HTTPException(400, "bbox must satisfy south<=north and west<=east")
    feed = await weather.alerts.get()
    items = feed.alerts
    if south is not None:
        items = [a for a in items if weather.intersects(a.get("bbox"), south, west, north, east)]
    return {
        "alerts": items,
        "zone_only": feed.zone_only,
        "fetched_at": feed.fetched_at,
        "error": feed.error,
        "credit": weather.CREDIT,
    }


@router.get("/wind")
async def get_wind(
    lat: float = Query(..., ge=-90, le=90),
    lon: float = Query(..., ge=-180, le=180),
):
    """Wind from the nearest METAR station, or ``available: false`` with a reason."""
    return await weather.nearest_wind(lat, lon)