from typing import AsyncGenerator, Generator
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.asyncio import AsyncSession
from app.db.engine import engine, async_engine

# =========================
# SYNCHRONOUS SESSION
# =========================
SessionLocal = sessionmaker(
    bind=engine,
    autocommit=False,
    autoflush=False,
    future=True
)

def get_db() -> Generator:
    """
    Yield a synchronous SQLAlchemy session
    Usage: Depends(get_db)
    """
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()

# =========================
# ASYNCHRONOUS SESSION
# =========================
AsyncSessionLocal = sessionmaker(
    bind=async_engine,
    class_=AsyncSession,
    expire_on_commit=False,
    autocommit=False,
    autoflush=False,
    future=True
)

async def get_async_db() -> AsyncGenerator:
    """
    Yield an asynchronous SQLAlchemy session
    Usage: Depends(get_async_db)
    """
    async with AsyncSessionLocal() as session:
        yield session