"""insights gets its own engines, separate from common.db's shared default,
so pool sizing here can be tuned independently of sanctions/notifier/audit
(which also import common.db).

Two pools, selected per-request: a generous default, and a small one used
whenever unbounded_cache is on -- every request is then a guaranteed fresh
miss needing a real connection, and under concurrent load that alone is
enough demand to exhaust a small pool. This is a realistic capacity limit
that emerges under load, not a 14th named chaos flag."""
from sqlalchemy.ext.asyncio import async_sessionmaker

from common.db import make_engine

normal_engine = make_engine(pool_size=20, max_overflow=10)
starved_engine = make_engine(pool_size=5, max_overflow=3, pool_timeout=0.5)

NormalSession = async_sessionmaker(normal_engine, expire_on_commit=False)
StarvedSession = async_sessionmaker(starved_engine, expire_on_commit=False)

# Exposed for readyz's connectivity check.
engine = normal_engine


def session_factory(starved: bool):
    return StarvedSession() if starved else NormalSession()