"""GTFS-RT Trip Updates von opentransportdata.swiss holen und auf das Nötigste eindampfen."""
import httpx
from google.transit import gtfs_realtime_pb2 as pb

from . import config as C

CANCELED = pb.TripDescriptor.CANCELED


def parse(data: bytes, known_trips: dict):
    """-> (feed_version, {(trip_id, start_date): (ausgefallen, [(seq, ank, ank_absolut, abf, abf_absolut), ...])})
    ank/abf sind Verspätung in s, oder Unix-Zeit wenn *_absolut; None = keine Angabe."""
    feed = pb.FeedMessage()
    feed.ParseFromString(data)
    out = {}
    for e in feed.entity:
        if not e.HasField("trip_update"):
            continue
        tu = e.trip_update
        if tu.trip.trip_id not in known_trips:
            continue  # nicht Bahn
        upd = []
        for s in tu.stop_time_update:
            ev = []
            for name in ("arrival", "departure"):
                if s.HasField(name):
                    x = getattr(s, name)
                    ev += [x.time, True] if x.HasField("time") else [x.delay, False] if x.HasField("delay") else [None, False]
                else:
                    ev += [None, False]
            upd.append((s.stop_sequence, *ev))
        out[(tu.trip.trip_id, tu.trip.start_date)] = (tu.trip.schedule_relationship == CANCELED, upd)
    version = feed.header.feed_version if feed.header.HasField("feed_version") else None
    return version, out


def fetch(url: str, key: str = "") -> bytes:
    headers = {"User-Agent": C.USER_AGENT}
    if key:
        headers["Authorization"] = f"Bearer {key}"
    r = httpx.get(url, follow_redirects=True, timeout=30, headers=headers)
    r.raise_for_status()
    return r.content