import json
from bexproof.policy import load_policy, evaluate_policy


def test_policy_load_with_blocks_selects_latest_version():
    policy_text = json.dumps({
        "blocks": [
            {"version": 1, "rules": {"latency_budget_ms": 5}},
            {"version": 2, "rules": {"latency_budget_ms": 3, "price_improvement_min": 0.0005}},
        ]
    })
    policy = load_policy(policy_text)
    assert policy.version == 2
    assert policy.rules.get("latency_budget_ms") == 3
    # Ensure evaluate_policy works with the loaded policy
    log = {"order_id": "ORDX", "venue": "VENUEX", "latency_ms": 3, "price_improvement": 0.001}
    assert evaluate_policy(log, policy) is True