"""Small SQLite foundation for durable state and future migration to PostgreSQL."""
import os, sqlite3, threading
from contextlib import contextmanager

class SQLiteStore:
    def __init__(self, path: str):
        self.path = path
        self._lock = threading.RLock()
        directory = os.path.dirname(os.path.abspath(path))
        os.makedirs(directory, exist_ok=True)
        with self.connect() as con:
            con.executescript('''
            PRAGMA journal_mode=WAL;
            PRAGMA synchronous=NORMAL;
            PRAGMA foreign_keys=ON;
            CREATE TABLE IF NOT EXISTS schema_meta(key TEXT PRIMARY KEY, value TEXT NOT NULL);
            CREATE TABLE IF NOT EXISTS audit_log(
              id INTEGER PRIMARY KEY AUTOINCREMENT, ts TEXT NOT NULL, actor TEXT,
              action TEXT NOT NULL, target TEXT, details TEXT
            );
            ''')
    @contextmanager
    def connect(self):
        con = sqlite3.connect(self.path, timeout=30, isolation_level=None)
        con.row_factory = sqlite3.Row
        try: yield con
        finally: con.close()