import json
import secrets
from datetime import datetime, timezone

import db

JSON_FIELDS = {"track_coordinates", "track_times", "parse_warnings"}


def _now() -> str:
    return datetime.now(timezone.utc).isoformat()


def _row_to_dict(row) -> dict:
    if row is None:
        return None
    d = dict(row)
    for field in JSON_FIELDS:
        if d.get(field):
            try:
                d[field] = json.loads(d[field])
            except (TypeError, ValueError):
                d[field] = None
    return d


# --- settings -----------------------------------------------------------

def get_setting(key: str, default: str | None = None) -> str | None:
    with db.connect() as conn:
        row = conn.execute("SELECT value FROM settings WHERE key = ?", (key,)).fetchone()
        return row["value"] if row else default


def set_setting(key: str, value: str) -> None:
    with db.connect() as conn:
        conn.execute(
            "INSERT INTO settings (key, value) VALUES (?, ?) "
            "ON CONFLICT(key) DO UPDATE SET value = excluded.value",
            (key, value),
        )


def get_or_create_secret_key() -> str:
    existing = get_setting("secret_key")
    if existing:
        return existing
    new_key = secrets.token_hex(32)
    set_setting("secret_key", new_key)
    return new_key


DEFAULT_SETTINGS = {
    "notify_backend": "ntfy",
    "ntfy_server_url": "https://ntfy.sh",
    "ntfy_topic": "",
    "ntfy_auth_token": "",
    "daily_run_time": "03:00",
}


def get_all_settings() -> dict:
    return {key: get_setting(key, default) for key, default in DEFAULT_SETTINGS.items()}


# --- pending_flights ------------------------------------------------------

INSERT_FIELDS = [
    "image_path", "raw_bcbp", "passenger_name", "pnr", "from_iata", "to_iata",
    "from_icao", "to_icao", "operating_carrier_iata", "operating_carrier_icao",
    "flight_number", "julian_day", "flight_date", "known_departure_time",
    "compartment", "seat", "process_after", "parse_warnings", "error_message",
    "status",
]


def create_pending_flight(**fields) -> int:
    now = _now()
    cols = ["created_at", "updated_at"]
    vals = [now, now]
    for f in INSERT_FIELDS:
        if f in fields:
            v = fields[f]
            if f in JSON_FIELDS and v is not None:
                v = json.dumps(v)
            cols.append(f)
            vals.append(v)
    placeholders = ", ".join("?" for _ in cols)
    with db.connect() as conn:
        cur = conn.execute(
            f"INSERT INTO pending_flights ({', '.join(cols)}) VALUES ({placeholders})",
            vals,
        )
        return cur.lastrowid


def get_flight(flight_id: int) -> dict | None:
    with db.connect() as conn:
        row = conn.execute(
            "SELECT * FROM pending_flights WHERE id = ?", (flight_id,)
        ).fetchone()
        return _row_to_dict(row)


def list_flights(statuses: list[str] | None = None) -> list[dict]:
    with db.connect() as conn:
        if statuses:
            placeholders = ", ".join("?" for _ in statuses)
            rows = conn.execute(
                f"SELECT * FROM pending_flights WHERE status IN ({placeholders}) "
                "ORDER BY created_at DESC",
                statuses,
            ).fetchall()
        else:
            rows = conn.execute(
                "SELECT * FROM pending_flights ORDER BY created_at DESC"
            ).fetchall()
        return [_row_to_dict(r) for r in rows]


def list_due_flights(now_iso: str) -> list[dict]:
    with db.connect() as conn:
        rows = conn.execute(
            "SELECT * FROM pending_flights WHERE status = 'queued' AND process_after <= ?",
            (now_iso,),
        ).fetchall()
        return [_row_to_dict(r) for r in rows]


def update_flight(flight_id: int, **fields) -> None:
    if not fields:
        return
    cols = []
    vals = []
    for k, v in fields.items():
        if k in JSON_FIELDS and v is not None and not isinstance(v, str):
            v = json.dumps(v)
        cols.append(f"{k} = ?")
        vals.append(v)
    cols.append("updated_at = ?")
    vals.append(_now())
    vals.append(flight_id)
    with db.connect() as conn:
        conn.execute(
            f"UPDATE pending_flights SET {', '.join(cols)} WHERE id = ?", vals
        )