import sqlite3
import time
from typing import Callable, TypeVar

T = TypeVar("T")


def run_tx(
    conn: sqlite3.Connection,
    fn: Callable[[sqlite3.Connection], T],
    retries: int = 5,
    delay: float = 0.2,
) -> T:
    last_exc = None

    for attempt in range(retries):
        try:
            result = fn(conn)
            conn.commit()
            return result
        except sqlite3.OperationalError as e:
            conn.rollback()
            last_exc = e
            if "locked" in str(e).lower():
                time.sleep(delay * (attempt + 1))
                continue
            raise

    raise last_exc