from datetime import datetime

from robotproof_studio.contracts import PlanDelta
from robotproof_studio.audit import AuditLog


def make_delta(id_suffix: str) -> PlanDelta:
    return PlanDelta(delta_id=f"d-{id_suffix}", timestamp=datetime.utcnow().isoformat() + "Z", data={"val": id_suffix})


def test_audit_log_chain_and_detection():
    log = AuditLog()

    d1 = make_delta("1")
    d1.sign("tester")
    e1 = log.append(d1)

    d2 = make_delta("2")
    d2.sign("tester")
    e2 = log.append(d2)

    # chain should be valid
    assert log.verify_chain() is True

    # tamper with second entry's delta_id (simulates external tampering)
    log.entries[1].delta_id = "tampered"
    assert log.verify_chain() is False