from __future__ import annotations

from collections.abc import AsyncGenerator

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

from cpv3.infrastructure.settings import get_settings


_settings = get_settings()
_database_url = _settings.get_database_url()

_engine_kwargs: dict[str, bool | int] = {
    "echo": _settings.debug,
    "pool_pre_ping": True,
}

if not _database_url.startswith("sqlite"):
    _engine_kwargs.update(
        {
            "pool_size": _settings.db_pool_size,
            "max_overflow": _settings.db_max_overflow,
            "pool_timeout": _settings.db_pool_timeout,
            "pool_recycle": _settings.db_pool_recycle_seconds,
        }
    )

_engine = create_async_engine(
    _database_url,
    **_engine_kwargs,
)

SessionLocal = async_sessionmaker(
    bind=_engine,
    class_=AsyncSession,
    expire_on_commit=False,
)


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