import asyncpg

from onguard24.config import Settings


def normalize_dsn(url: str) -> str:
    if url.startswith("postgres://"):
        return url.replace("postgres://", "postgresql://", 1)
    return url


async def create_pool(settings: Settings) -> asyncpg.Pool | None:
    if not settings.database_url.strip():
        return None
    dsn = normalize_dsn(settings.database_url.strip())
    return await asyncpg.create_pool(dsn=dsn, min_size=1, max_size=10)