"""
OpenSky Network API worker — enriches fr24_ext.schedule with icao24 + actual times.
"""
import logging
import time
from datetime import date, datetime, timezone
from typing import Dict, List, Optional
from functools import wraps

import requests
import psycopg2

from config import config

log = logging.getLogger(__name__)

OPENSKY_BASE = "https://opensky-network.org/api/flights"


# ── retry decorator ───────────────────────────────────────────────────────────

def retry(max_retries: int = 3, base_delay: float = 10.0):
    def decorator(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            for attempt in range(max_retries):
                try:
                    return func(*args, **kwargs)
                except requests.RequestException as e:
                    if attempt < max_retries - 1:
                        wait = base_delay * (2 ** attempt)
                        log.warning("Retry %d/%d after %.0fs: %s", attempt + 1, max_retries, wait, e)
                        time.sleep(wait)
                    else:
                        raise
        return wrapper
    return decorator


# ── API fetch ─────────────────────────────────────────────────────────────────

@retry(max_retries=3, base_delay=10.0)
def fetch_opensky_flights(icao: str, begin_ts: int, end_ts: int, direction: str) -> List[Dict]:
    """
    Fetch arrivals or departures from OpenSky for one airport/day.
    direction: 'arrival' | 'departure'
    """
    url = f"{OPENSKY_BASE}/{direction}"
    params = {"airport": icao, "begin": begin_ts, "end": end_ts}

    auth = None
    if config.OPENSKY_USERNAME and config.OPENSKY_PASSWORD:
        auth = (config.OPENSKY_USERNAME, config.OPENSKY_PASSWORD)

    resp = requests.get(url, params=params, auth=auth, timeout=60)

    # 404 means no data for this period — not an error
    if resp.status_code == 404:
        return []

    resp.raise_for_status()
    return resp.json() or []


# ── DB enrichment ─────────────────────────────────────────────────────────────

def enrich_flights(conn, opensky_flights: List[Dict], airport_iata: str, direction: str) -> int:
    """
    Update icao24 + actual_at on existing schedule rows matched by callsign.
    Match window: ±3 hours around the OpenSky actual time.
    """
    if not opensky_flights:
        return 0

    enriched = 0
    with conn.cursor() as cur:
        for flight in opensky_flights:
            icao24 = (flight.get("icao24") or "").strip().lower()
            callsign = (flight.get("callsign") or "").strip()

            if not icao24 or not callsign:
                continue

            # actual time: lastSeen for arrivals, firstSeen for departures
            actual_ts = (
                flight.get("lastSeen") if direction == "arrival"
                else flight.get("firstSeen")
            )
            if not actual_ts:
                continue

            actual_at = datetime.fromtimestamp(actual_ts, tz=timezone.utc)

            cur.execute(
                """
                UPDATE fr24_ext.schedule
                SET
                    icao24    = %s,
                    actual_at = %s,
                    source    = CASE WHEN source = 'yandex' THEN 'merged' ELSE source END
                WHERE airport_iata = %s
                  AND direction    = %s
                  AND flight_number = %s
                  AND scheduled_at BETWEEN %s - INTERVAL '3 hours'
                                       AND %s + INTERVAL '3 hours'
                """,
                (icao24, actual_at, airport_iata, direction, callsign, actual_at, actual_at),
            )
            enriched += cur.rowcount

    return enriched


# ── main entry ────────────────────────────────────────────────────────────────

def enrich_day(target_date: date, conn) -> int:
    """Enrich all airports for one day. Returns total rows updated."""
    # Unix timestamps for start/end of the day (UTC)
    day_start = int(datetime(target_date.year, target_date.month, target_date.day,
                             tzinfo=timezone.utc).timestamp())
    day_end = day_start + 86400

    total = 0

    for airport_iata, airport_info in config.AIRPORTS.items():
        icao = airport_info["icao"]
        log.info("OpenSky: enriching %s (%s) for %s", airport_iata, icao, target_date)

        for direction in ("arrival", "departure"):
            try:
                flights = fetch_opensky_flights(icao, day_start, day_end, direction)
                count = enrich_flights(conn, flights, airport_iata, direction)
                total += count
                log.info("OpenSky: %s %s → %d rows enriched", airport_iata, direction, count)
            except Exception as e:
                log.error("OpenSky: failed %s %s: %s", airport_iata, direction, e)

            time.sleep(config.OPENSKY_RATE_LIMIT_SEC)

    conn.commit()
    return total