from typing import AsyncGenerator

from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
from sqlmodel import SQLModel, create_engine

from playlist_sync.config import settings

# For synchronous operations (e.g., simple migrations or scripts)
sync_engine = create_engine(
    settings.DATABASE_URL.replace("mysql+aiomysql://", "mysql+pymysql://"), echo=False
)

# For asynchronous operations (FastAPI/Worker)
async_engine = create_async_engine(settings.DATABASE_URL, echo=False)

AsyncSessionLocal = async_sessionmaker(
    async_engine, class_=AsyncSession, expire_on_commit=False
)


async def get_session() -> AsyncGenerator[AsyncSession, None]:
    async with AsyncSessionLocal() as session:
        yield session


async def init_db() -> None:
    async with async_engine.begin() as conn:
        # In a real migration, we wouldn't drop tables,
        # but for dev/testing setup this is useful.
        await conn.run_sync(SQLModel.metadata.create_all)