"""Tests for DuckDB initialization and schema."""
import pytest
import duckdb

from backend.app import db as db_module


@pytest.fixture(autouse=True)
def fresh_db():
    """Use an in-memory DB for each test and reset global state."""
    db_module._conn = None
    yield
    db_module.close_db()
    db_module._conn = None


def test_init_creates_users_table():
    conn = db_module.init_db(":memory:")
    result = conn.execute(
        "SELECT table_name FROM information_schema.tables WHERE table_name = 'users'"
    ).fetchone()
    assert result is not None


def test_init_creates_refresh_tokens_table():
    conn = db_module.init_db(":memory:")
    result = conn.execute(
        "SELECT table_name FROM information_schema.tables WHERE table_name = 'refresh_tokens'"
    ).fetchone()
    assert result is not None


def test_init_is_idempotent():
    conn1 = db_module.init_db(":memory:")
    conn2 = db_module.init_db(":memory:")
    assert conn1 is conn2


def test_get_conn_raises_before_init():
    with pytest.raises(RuntimeError, match="not initialised"):
        db_module.get_conn()


def test_get_conn_returns_connection_after_init():
    db_module.init_db(":memory:")
    conn = db_module.get_conn()
    assert conn is not None


def test_close_db_resets_connection():
    db_module.init_db(":memory:")
    db_module.close_db()
    with pytest.raises(RuntimeError):
        db_module.get_conn()