import asyncio
from typing import Optional

from fastapi import APIRouter, HTTPException, Query

from app.internal import ny511

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

# Per-layer cap per response. A statewide view is ~3k cameras; past this the
# map is unreadable anyway, and the client is told the list was cut.
MAX_ITEMS = 1500


def _feed_status(feed: "ny511._Feed") -> dict:
    return {"fetched_at": feed.fetched_at, "error": feed.error}


@router.get("/511")
async def get_511(
    south: float = Query(..., ge=-90, le=90),
    west: float = Query(..., ge=-180, le=180),
    north: float = Query(..., ge=-90, le=90),
    east: float = Query(..., ge=-180, le=180),
    layers: Optional[str] = Query("cameras,events", description="comma list: cameras, events"),
):
    if south > north or west > east:
        raise HTTPException(400, "bbox must satisfy south<=north and west<=east")
    wanted = {s.strip() for s in (layers or "").split(",") if s.strip()}
    feeds = {name: getattr(ny511, name) for name in ("cameras", "events") if name in wanted}
    await asyncio.gather(*(f.get() for f in feeds.values()))

    out: dict = {}
    for name, feed in feeds.items():
        hits = ny511.in_bbox(feed.items, south, west, north, east)
        out[name] = hits[:MAX_ITEMS]
        out[f"{name}_status"] = {**_feed_status(feed), "total_in_bbox": len(hits), "truncated": len(hits) > MAX_ITEMS}
    return out