from unittest.mock import MagicMock, patch

from app.backend_pre_start import init, logger
from sqlmodel import select


def test_init_successful_connection() -> None:
    engine_mock = MagicMock()

    session_mock = MagicMock()
    exec_mock = MagicMock(return_value=True)
    session_mock.configure_mock(**{"exec.return_value": exec_mock})

    with patch("sqlmodel.Session", return_value=session_mock), patch.object(
        logger, "info"
    ), patch.object(logger, "error"), patch.object(logger, "warn"):
        try:
            init(engine_mock)
            connection_successful = True
        except Exception:
            connection_successful = False

        assert (
            connection_successful
        ), "The database connection should be successful and not raise an exception."

        assert session_mock.exec.called_once_with(
            select(1)
        ), "The session should execute a select statement once."