"""
Database Configuration and Session Management
"""

from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
from sqlalchemy.orm import declarative_base
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

from app.core.config import settings

# Async engine for FastAPI
async_engine = create_async_engine(
    settings.DATABASE_URL,
    echo=settings.DEBUG,
    pool_pre_ping=True,
    pool_size=10,
    max_overflow=20,
)

# Async session factory
AsyncSessionLocal = async_sessionmaker(
    async_engine,
    class_=AsyncSession,
    expire_on_commit=False,
    autocommit=False,
    autoflush=False,
)

# Sync engine for Celery workers
sync_engine = create_engine(
    settings.DATABASE_URL_SYNC,
    echo=settings.DEBUG,
    pool_pre_ping=True,
    pool_size=5,
    max_overflow=10,
)

# Sync session factory
SyncSessionLocal = sessionmaker(
    sync_engine,
    autocommit=False,
    autoflush=False,
)

# Base class for models
Base = declarative_base()


async def init_db():
    """Initialize database (create tables if needed)."""
    # Tables are created by init.sql, but we can add migrations here
    pass


async def get_db() -> AsyncSession:
    """Dependency for getting async database session."""
    async with AsyncSessionLocal() as session:
        try:
            yield session
            await session.commit()
        except Exception:
            await session.rollback()
            raise
        finally:
            await session.close()


def get_sync_db():
    """Get sync database session for Celery workers."""
    db = SyncSessionLocal()
    try:
        yield db
        db.commit()
    except Exception:
        db.rollback()
        raise
    finally:
        db.close()