import sqlite3
from contextlib import contextmanager

import config

SCHEMA = """
CREATE TABLE IF NOT EXISTS pending_flights (
    id                      INTEGER PRIMARY KEY AUTOINCREMENT,
    created_at              TEXT NOT NULL,
    updated_at              TEXT NOT NULL,
    status                  TEXT NOT NULL DEFAULT 'queued'
                            CHECK (status IN ('queued','pending_review','track_unavailable',
                                               'approved','rejected','decode_failed')),
    image_path              TEXT NOT NULL,
    raw_bcbp                TEXT,
    passenger_name          TEXT,
    pnr                     TEXT,
    from_iata               TEXT,
    to_iata                 TEXT,
    from_icao               TEXT,
    to_icao                 TEXT,
    operating_carrier_iata  TEXT,
    operating_carrier_icao  TEXT,
    flight_number           TEXT,
    julian_day              INTEGER,
    flight_date             TEXT,
    known_departure_time    TEXT,
    compartment             TEXT,
    seat                    TEXT,
    process_after           TEXT,
    fetch_attempts          INTEGER NOT NULL DEFAULT 0,
    track_coordinates       TEXT,
    track_times             TEXT,
    track_point_count       INTEGER,
    flightaware_url         TEXT,
    takeoff_actual          TEXT,
    landing_actual          TEXT,
    gate_departure_scheduled TEXT,
    gate_departure_actual   TEXT,
    gate_arrival_scheduled  TEXT,
    gate_arrival_actual     TEXT,
    departure_utc_offset    TEXT,
    arrival_utc_offset      TEXT,
    schedule_error          TEXT,
    airtrail_flight_id      INTEGER,
    parse_warnings          TEXT,
    error_message           TEXT,
    reviewed_at             TEXT,
    approved_at             TEXT
);
CREATE INDEX IF NOT EXISTS idx_pending_flights_status_process_after
    ON pending_flights(status, process_after);

CREATE TABLE IF NOT EXISTS settings (
    key   TEXT PRIMARY KEY,
    value TEXT
);
"""


def get_connection() -> sqlite3.Connection:
    config.ensure_dirs()
    conn = sqlite3.connect(config.DB_PATH, timeout=30)
    conn.row_factory = sqlite3.Row
    conn.execute("PRAGMA journal_mode=WAL")
    conn.execute("PRAGMA foreign_keys=ON")
    return conn


@contextmanager
def connect():
    conn = get_connection()
    try:
        yield conn
        conn.commit()
    finally:
        conn.close()


# Columns added after the original schema. CREATE TABLE IF NOT EXISTS above
# is a no-op against an already-existing table, so anything added there
# needs a matching entry here too or it silently never appears on an
# upgraded (vs. freshly created) database.
MIGRATIONS = [
    ("takeoff_actual", "TEXT"),
    ("landing_actual", "TEXT"),
    ("gate_departure_scheduled", "TEXT"),
    ("gate_departure_actual", "TEXT"),
    ("gate_arrival_scheduled", "TEXT"),
    ("gate_arrival_actual", "TEXT"),
    ("departure_utc_offset", "TEXT"),
    ("arrival_utc_offset", "TEXT"),
    ("schedule_error", "TEXT"),
]


def _run_migrations(conn: sqlite3.Connection) -> None:
    existing = {row["name"] for row in conn.execute("PRAGMA table_info(pending_flights)")}
    for column, coltype in MIGRATIONS:
        if column not in existing:
            conn.execute(f"ALTER TABLE pending_flights ADD COLUMN {column} {coltype}")


def init_db() -> None:
    with connect() as conn:
        conn.executescript(SCHEMA)
        _run_migrations(conn)