"""Client for AirTrail's REST API (POST /api/flight/save, GET /api/flight/list).

Confirmed directly against AirTrail's source (johanohly/AirTrail):
- src/routes/api/flight/save/+server.ts
- src/lib/zod/flight.ts, src/lib/track/schema.ts, src/lib/db/types.ts

Deliberately does NOT touch AirTrail's Postgres database directly - the
documented API does everything this pipeline needs (including embedded
track data in one call) without needing DB credentials or trusting a
schema snapshot that could drift.
"""

import json
import urllib.error
import urllib.request
from datetime import date, datetime, timezone

import config
import models
import notifier

# IATA cabin compartment codes -> AirTrail SeatClasses ('economy', 'economy+',
# 'business', 'first', 'private'). Unmapped codes are left null rather than
# guessed.
COMPARTMENT_TO_SEATCLASS = {
    "F": "first", "A": "first", "P": "first",
    "J": "business", "C": "business", "D": "business", "I": "business", "Z": "business",
    "W": "economy+", "S": "economy+",
    "Y": "economy", "B": "economy", "H": "economy", "K": "economy", "L": "economy",
    "M": "economy", "N": "economy", "Q": "economy", "T": "economy", "V": "economy",
    "X": "economy", "G": "economy", "U": "economy", "O": "economy", "E": "economy",
}


class AirTrailError(Exception):
    pass


def _request(method: str, path: str, body: dict | None = None) -> dict:
    if not config.AIRTRAIL_BASE_URL or not config.AIRTRAIL_API_KEY:
        raise AirTrailError("AIRTRAIL_BASE_URL / AIRTRAIL_API_KEY not configured")

    url = f"{config.AIRTRAIL_BASE_URL}{path}"
    data = json.dumps(body).encode("utf-8") if body is not None else None
    req = urllib.request.Request(url, data=data, method=method)
    req.add_header("Authorization", f"Bearer {config.AIRTRAIL_API_KEY}")
    req.add_header("Content-Type", "application/json")

    try:
        with urllib.request.urlopen(req, timeout=30) as resp:
            return json.loads(resp.read().decode("utf-8"))
    except urllib.error.HTTPError as e:
        try:
            payload = json.loads(e.read().decode("utf-8"))
            message = payload.get("message") or payload.get("errors") or str(payload)
        except Exception:
            message = f"HTTP {e.code}"
        raise AirTrailError(f"AirTrail API error ({e.code}): {message}") from e
    except urllib.error.URLError as e:
        raise AirTrailError(f"failed to reach AirTrail: {e}") from e


def list_my_flights() -> list[dict]:
    result = _request("GET", "/api/flight/list?scope=mine")
    return result.get("flights", [])


def find_existing_flight(flight_number: str, flight_date: date) -> dict | None:
    if not flight_number:
        return None
    target = flight_date.isoformat()
    for flight in list_my_flights():
        if (flight.get("flightNumber") or "").strip().upper() != flight_number.strip().upper():
            continue
        departure = flight.get("departure")
        if departure and str(departure)[:10] == target:
            return flight
    return None


def downsample_track(
    coordinates: list[list[float]], times: list[int] | None, max_points: int = config.MAX_TRACK_POINTS
) -> tuple[list[list[float]], list[int] | None]:
    n = len(coordinates)
    if n <= max_points:
        return coordinates, times

    indices = [round(i * (n - 1) / (max_points - 1)) for i in range(max_points)]
    new_coords = [coordinates[i] for i in indices]
    new_times = [times[i] for i in indices] if times else None
    return new_coords, new_times


def build_save_payload(row: dict, existing_id: int | None) -> dict:
    flight_number = f"{row.get('operating_carrier_iata') or ''}{row.get('flight_number') or ''}"
    flight_date_str = row["flight_date"]

    payload = {
        "from": row["from_iata"],
        "to": row["to_iata"],
        "departure": f"{flight_date_str}T00:00:00.000+00:00",
        "datePrecision": "day",
        "flightNumber": flight_number or None,
        "airline": row.get("operating_carrier_icao"),
        "aircraft": None,
        "aircraftReg": None,
        "flightReason": None,
        "note": f"Imported via boarding-pass-pipeline (PNR {row.get('pnr') or 'unknown'})",
        "seats": [
            {
                "userId": "<USER_ID>",
                "guestName": None,
                "seat": None,
                "seatNumber": row.get("seat"),
                "seatClass": COMPARTMENT_TO_SEATCLASS.get((row.get("compartment") or "").upper()),
            }
        ],
    }

    coordinates = row.get("track_coordinates")
    if coordinates:
        times = row.get("track_times")
        coordinates, times = downsample_track(coordinates, times)
        payload["track"] = {
            "coordinates": coordinates,
            "sourceFormat": "kml",
            "sourceName": f"{flight_number} {flight_date_str}".strip(),
        }
        if times:
            payload["track"]["times"] = times
    else:
        payload["track"] = None

    if existing_id is not None:
        payload["id"] = existing_id

    return payload


def save_flight(payload: dict) -> dict:
    return _request("POST", "/api/flight/save", payload)


def approve_flight(flight_id: int) -> tuple[bool, str]:
    """Idempotent: shared by the review page's Approve button and the
    ntfy-callback route, so both paths behave identically."""
    row = models.get_flight(flight_id)
    if not row:
        return False, "flight not found"
    if row["status"] in ("approved", "rejected"):
        return True, f"already {row['status']}"

    existing_id = None
    try:
        flight_date = date.fromisoformat(row["flight_date"])
        existing = find_existing_flight(
            f"{row.get('operating_carrier_iata') or ''}{row.get('flight_number') or ''}",
            flight_date,
        )
        existing_id = existing["id"] if existing else None
        payload = build_save_payload(row, existing_id)
        result = save_flight(payload)
        if not result.get("success"):
            raise AirTrailError(result.get("message", "unknown AirTrail error"))
    except Exception as e:
        message = str(e)
        # A failed ntfy-triggered approve has no UI to surface this to.
        notifier.get_notifier().send(
            title=f"Approve failed: {row.get('flight_number') or 'flight'}",
            body=message[:200],
            url=notifier.flight_url(flight_id),
        )
        return False, message

    models.update_flight(
        flight_id,
        status="approved",
        approved_at=datetime.now(timezone.utc).isoformat(),
        airtrail_flight_id=result.get("id") or existing_id,
    )
    return True, "approved"


def reject_flight(flight_id: int) -> tuple[bool, str]:
    """Idempotent: shared by the review page's Reject button and the
    ntfy-callback route."""
    row = models.get_flight(flight_id)
    if not row:
        return False, "flight not found"
    if row["status"] in ("approved", "rejected"):
        return True, f"already {row['status']}"

    models.update_flight(
        flight_id, status="rejected", reviewed_at=datetime.now(timezone.utc).isoformat()
    )
    return True, "rejected"