from .models import Coupon

_COUPONS = {
    "SAVE10": Coupon(code="SAVE10", percent=0.10, min_subtotal=100.0),
}

def get_coupon(code: str | None) -> Coupon | None:
    if not code:
        return None
    return _COUPONS.get(code)

def cache_metadata() -> dict:
    # Diagnostic metadata only. Do not assume it is causal.
    return {"age_seconds": 301, "source": "local-fixture"}