from collections.abc import AsyncIterator
from typing import Annotated

from fastapi import Depends
from sqlalchemy.engine import make_url
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine

from app.config import settings


def normalize_async_url(url: str) -> str:
    """Translate libpq's `sslmode=` into the `ssl=` asyncpg understands.

    Hosted Postgres (Neon, Supabase) hands out sslmode= URLs, which asyncpg rejects outright.
    """
    parsed = make_url(url)
    if "asyncpg" not in parsed.drivername or "sslmode" not in parsed.query:
        return url
    query = dict(parsed.query)
    query["ssl"] = query.pop("sslmode")
    return parsed.set(query=query).render_as_string(hide_password=False)


engine = create_async_engine(normalize_async_url(settings.database_url), pool_pre_ping=True)
SessionLocal = async_sessionmaker(engine, expire_on_commit=False)


async def get_session() -> AsyncIterator[AsyncSession]:
    async with SessionLocal() as session:
        yield session


SessionDep = Annotated[AsyncSession, Depends(get_session)]