"""Offline ledger from Qwen guide; dated Singapore rates, no API calls."""
from decimal import Decimal

def token_bill(ordinary, cached, output):
    counts = (ordinary, cached, output)
    if any(type(n) is not int or n < 0 for n in counts):
        raise ValueError("Token counts must be non-negative integers")
    rates = (Decimal("0.15"), Decimal("0.016"), Decimal("0.47"))
    return sum((Decimal(n) * r / Decimal(1_000_000)
                for n, r in zip(counts, rates)), Decimal("0"))

def accepted_cost(model_cost, review_minutes, hourly_rate, accepted):
    if type(accepted) is not int or accepted <= 0:
        raise ValueError("Accepted count must be a positive integer")
    money = tuple(Decimal(str(x))
                  for x in (model_cost, review_minutes, hourly_rate))
    if any(not x.is_finite() or x < 0 for x in money):
        raise ValueError("Costs and review values must be finite and non-negative")
    model, minutes, rate = money
    return (model + minutes * rate / Decimal(60)) / Decimal(accepted)

assert token_bill(12_000_000, 8_000_000, 2_000_000) == Decimal("2.868")
assert token_bill(20_000_000, 0, 2_000_000) == Decimal("3.94")
assert accepted_cost("2.868", 75, 24, 100) == Decimal("0.32868")
assert token_bill(0, 0, 0) == 0

for invalid in (-1, 1.5, True):
    try:
        token_bill(invalid, 0, 0)
    except ValueError:
        pass
    else:
        raise AssertionError("Invalid token count was accepted")

print("token bill:", token_bill(12_000_000, 8_000_000, 2_000_000))
print("accepted artifact cost:", accepted_cost("2.868", 75, 24, 100))