"""Unit-test fixtures for repository tests against the running dev database.

Repository tests roll back every test via a nested transaction so the shared
dev database stays clean. If the compose stack is not up, the tests are skipped.
"""

from __future__ import annotations

from collections.abc import AsyncIterator

import pytest
import pytest_asyncio
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
from sqlalchemy.pool import NullPool

_DB_URL = "postgresql+asyncpg://contract_check:contract_check@localhost:15432/contract_check"


@pytest_asyncio.fixture
async def db_session() -> AsyncIterator[AsyncSession]:
    """Open a rolled-back transaction against the dev database."""
    engine = create_async_engine(_DB_URL, poolclass=NullPool)
    try:
        async with engine.begin() as conn:
            trans = await conn.begin_nested()
            factory = async_sessionmaker(
                bind=conn,
                expire_on_commit=False,
                autoflush=False,
                autocommit=False,
            )
            session = factory()
            try:
                yield session
            finally:
                await session.close()
            await trans.rollback()
    except OSError as exc:
        pytest.skip(f"Postgres not reachable for repository tests: {exc}")
    finally:
        await engine.dispose()