from __future__ import annotations

import os
from collections.abc import AsyncGenerator

from sqlalchemy.ext.asyncio import (
    AsyncSession,
    async_sessionmaker,
    create_async_engine,
)

DATABASE_URL = os.getenv(
    "DATABASE_URL",
    "postgresql+asyncpg://postgres:postgres@localhost:5432/data_db",
)

engine = create_async_engine(
    DATABASE_URL,
    echo=False,
    pool_size=10,
    max_overflow=20,
)

async_session_factory = async_sessionmaker(
    engine,
    class_=AsyncSession,
    expire_on_commit=False,
)


async def get_session() -> AsyncGenerator[AsyncSession, None]:
    async with async_session_factory() as session:
        try:
            yield session
            await session.commit()
        except Exception:
            await session.rollback()
            raise