import os
from typing import AsyncGenerator

from dotenv import load_dotenv
from sqlalchemy.ext.asyncio import (
    AsyncEngine,
    AsyncSession,
    async_sessionmaker,
    create_async_engine,
)
from sqlalchemy.orm import DeclarativeBase

load_dotenv()

DATABASE_URL = os.getenv("DATABASE_URL")
if not DATABASE_URL:
    raise ValueError("DATABASE_URL not found in .env")


engine: AsyncEngine = create_async_engine(
    DATABASE_URL,
    echo=True,
    pool_pre_ping=True,
)

async_session = async_sessionmaker(
    bind=engine,
    expire_on_commit=False,
)


class Base(DeclarativeBase):
    pass


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