"""Connexion et sessions de base de données async."""
from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
from backend.config.settings import get_settings
from backend.database.models import Base

settings = get_settings()

# Convertir l'URL SQLite en version async
DB_URL = settings.database_url
if DB_URL.startswith("sqlite:///"):
    DB_URL = DB_URL.replace("sqlite:///", "sqlite+aiosqlite:///")

engine = create_async_engine(DB_URL, echo=settings.debug, pool_pre_ping=True)
AsyncSessionLocal = async_sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)


async def init_db():
    """Crée toutes les tables si elles n'existent pas."""
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)


async def get_db():
    """Dépendance FastAPI - fournit une session DB."""
    async with AsyncSessionLocal() as session:
        try:
            yield session
            await session.commit()
        except Exception:
            await session.rollback()
            raise
        finally:
            await session.close()