"""База данных: async engine, сессии, инициализация."""

from __future__ import annotations

from pathlib import Path

from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine

from app.config import settings

# Создаём каталог для БД, если SQLite
_db_path = settings.database_url.replace("sqlite+aiosqlite:///", "")
if _db_path != settings.database_url:
    Path(_db_path).parent.mkdir(parents=True, exist_ok=True)

engine = create_async_engine(settings.database_url, echo=False)
async_session_factory = async_sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)


async def get_db() -> AsyncSession:
    """FastAPI-зависимость: сессия БД."""
    async with async_session_factory() as session:
        try:
            yield session
            await session.commit()
        except Exception:
            await session.rollback()
            raise
        finally:
            await session.close()


async def init_db():
    """Создаёт таблицы при старте."""
    from app.models import Base  # noqa: F401 — импорт моделей для регистрации
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)