import time
from nova_plan.planner import LocalProblem, simple_admm_step
from nova_plan.contracts import PlanDelta
from nova_plan.ledger import Ledger


def test_local_problem_evaluation_and_admm_step():
    # Simple local problem: minimize (x - s)^2 with x in [0, 10], shared_var s
    def objective(local_vars, shared):
        x = local_vars.get("x", 0.0)
        s = shared.get("x", 0.0)
        return (x - s) ** 2

    lp = LocalProblem(id="agent-1", objective=objective, variables={"x": 5.0}, constraints={"min": 0, "max": 10})
    shared = {"x": 7.0}

    # Evaluate
    val = lp.evaluate(shared)
    assert isinstance(val, float)

    # Perform a few ADMM-like steps
    for _ in range(3):
        simple_admm_step(lp, shared, rho=1.0)
        assert isinstance(lp.variables["x"], float)


def test_plan_delta_serialization():
    pd = PlanDelta(agent_id="agent-1", delta={"x": 1.0}, timestamp=time.time())
    s = pd.to_json() if hasattr(pd, "to_json") else None
    assert s is not None


def test_ledger_logging_and_anchor():
    ledger = Ledger()
    e = ledger.log("decision", "alloc-1", anchor="ground-link-001")
    assert e.anchor == "ground-link-001"
    assert ledger.last_anchor() == "ground-link-001"