import os
import sqlite3
from typing import Tuple, Optional

def resolve_db_path() -> Tuple[str, bool]:
    if os.path.isdir("/data"):
        return "/data/venus_hotel.db", True
    os.makedirs("./data", exist_ok=True)
    return "./data/venus_hotel.db", False

def get_conn(db_path: Optional[str] = None) -> sqlite3.Connection:
    if db_path is None:
        db_path, _ = resolve_db_path()

    conn = sqlite3.connect(db_path, check_same_thread=False, isolation_level=None)
    conn.row_factory = sqlite3.Row
    conn.execute("PRAGMA foreign_keys = ON;")
    conn.execute("PRAGMA journal_mode = WAL;")
    conn.execute("PRAGMA synchronous = NORMAL;")
    conn.execute("PRAGMA busy_timeout = 5000;")
    return conn