import json

from elac_plan.core import LocalProblem
from elac_plan.solver import LocalSolver


def test_solver_basic():
    solver = LocalSolver()
    lp = LocalProblem(
        id="lp1",
        asset="AAPL",
        venue="NYSE",
        objective="minimize_spread",
        constraints={"max_volume": 1000},
        price_target=150.0,
        tolerance=0.5,
    )
    delta = solver.solve(lp)
    assert isinstance(delta, type(solver.solve(lp)))
    payload = delta.to_json()
    # Basic sanity: json should be parseable and contain contract_id
    d = json.loads(payload)
    assert "contract_id" in d