Callsign → Route

"""Route detection response models for /routes/* endpoints."""from __future__ import annotationsfrom dataclasses import dataclass@dataclassclass RoutePair:    departure: str    arrival: str    airlines: list[str]    km: int    duration_min: int@dataclassclass CallsignRouteResponse:    """Exact callsign match from GET /routes/callsign/{callsign}."""    callsign: str    callsign_prefix: str    airline_code: str    departure_icao: str    arrival_icao: str    airports: list[str]    confidence: str    source: str    routes: list[RoutePair] | None = None@dataclassclass AirportRoutesResponse:    code: str    direction: str    count: int    routes: list[RoutePair]@dataclassclass RoutePairsResponse:    count: int    routes: list[RoutePair]@dataclassclass RouteGuess:    """Shape returned by route_guess() helper."""    callsign: str    departure: str | None    arrival: str | None    confidence: str    source: str

import osimport timefrom dataclasses import dataclassimport requestsHEADERS = {    "x-api-key": os.getenv("SKYLINK_API_KEY", "YOUR_API_KEY")}BASE = "https://data.skylinkapi.com/v3.1"CACHE: dict[str, tuple[dict, float]] = {}ROUTE_TTL = 86_400  # 24 h@dataclassclass RouteGuess:    callsign: str    departure: str | None    arrival: str | None    confidence: str    source: strdef fetch_route_by_callsign(callsign: str) -> dict:    callsign = callsign.upper().strip()    key = f"route:callsign:{callsign}"    cached = CACHE.get(key)    if cached and time.time() < cached[1]:        return cached[0]    try:        r = requests.get(            f"{BASE}/routes/callsign/{callsign}",            headers=HEADERS,            timeout=(10, 15),        )    except requests.Timeout as exc:        raise RuntimeError(f"SkyLink timeout resolving route for {callsign}") from exc    r.raise_for_status()    data = r.json()    CACHE[key] = (data, time.time() + ROUTE_TTL)    return datadef route_guess(callsign: str) -> RouteGuess | None:    data = fetch_route_by_callsign(callsign)    dep = data.get("departure_icao")    arr = data.get("arrival_icao")    if not dep and not arr:        routes = data.get("routes") or []        if not routes:            return None        top = routes[0]        dep, arr = top.get("departure"), top.get("arrival")    return RouteGuess(        callsign=data.get("callsign", callsign),        departure=dep,        arrival=arr,        confidence=data.get("confidence", "unknown"),        source=data.get("source", "vrs"),    )if __name__ == "__main__":    import json    from dataclasses import asdict    guess = route_guess("BAW178")    print(json.dumps(asdict(guess), indent=2) if guess else "Route not found")