import json

from cosmosmesh_privacy_preserving_federated.catopt_bridge import LocalProblem, SharedVariable, DualVariable, CatOptBridge


def test_round_trip_construction():
    lp = LocalProblem(
        problem_id="test-problem",
        objective="maximize throughput",
        variables=["x"],
        constraints=["x >= 0"],
        version=1,
    )
    sv = [SharedVariable(name="s", value=3.14, version=1)]
    dv = [DualVariable(name="d", value=2.718, version=1)]

    msg = CatOptBridge.build_round_trip(problem=lp, shared=sv, duals=dv)
    # Basic sanity checks on the envelope
    assert isinstance(msg, dict)
    assert msg.get("kind") == "RoundTrip"
    payload = msg.get("payload")
    assert isinstance(payload, dict)
    assert payload.get("object")["id"] == lp.problem_id
    # ensure morphisms present
    morphisms = payload.get("morphisms")
    assert isinstance(morphisms, list)
    assert any(isinstance(m, dict) and m.get("name") == "s" for m in morphisms)