"""
db/database.py — SQLAlchemy async engine and session management
"""
from __future__ import annotations
from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
from sqlalchemy.orm import DeclarativeBase
from utils.core.config import settings
from utils.core.logging_config import get_logger

logger = get_logger(__name__)

engine = create_async_engine(
    settings.db_path,
    echo=settings.debug,
    connect_args={"check_same_thread": False},
)

AsyncSessionLocal = async_sessionmaker(
    bind=engine,
    class_=AsyncSession,
    expire_on_commit=False,
    autoflush=False,
    autocommit=False,
)


class Base(DeclarativeBase):
    pass


async def create_tables():
    """Create all tables if they don't exist."""
    from utils.db.models import AnalysisResult, ResumeFile  # Ensure models are loaded
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)
    logger.info("Database tables created/verified")


async def get_db():
    """FastAPI dependency — provides an async DB session."""
    async with AsyncSessionLocal() as session:
        try:
            yield session
            await session.commit()
        except Exception:
            await session.rollback()
            raise
        finally:
            await session.close()