from gravityweave.receipt import MutualFeasibilityReceipt


def test_receipt_create_and_verify():
    key = b"node-secret"
    prop_hash = "deadbeefcafebabe"
    invariants = ["fuel_bound", "power_bound"]

    r = MutualFeasibilityReceipt.create(proposal_hash=prop_hash,
                                        invariant_ids=invariants,
                                        decision="ok",
                                        uncertainty=0.1,
                                        round_nonce=1,
                                        signer="nodeA",
                                        key=key)

    assert r.proposal_hash == prop_hash
    assert r.decision == "ok"
    assert r.verify(key) is True

    ser = r.serialize()
    # ensure compact size under 512 bytes
    assert len(ser) <= 512

    r2 = MutualFeasibilityReceipt.deserialize(ser)
    assert r2.receipt_id == r.receipt_id
    # verify with same key
    assert r2.verify(key) is True


def test_receipt_tamper_detection():
    key = b"k"
    r = MutualFeasibilityReceipt.create(proposal_hash="h", invariant_ids=["i"], decision="ok",
                                        signer="s", key=key)
    ser = r.serialize()
    # tamper with serialized bytes
    s2 = ser.replace(b"ok", b"deny")
    r2 = MutualFeasibilityReceipt.deserialize(s2)
    assert r2.verify(key) is False