import pytest

from reactor_sim.control import ControlSystem
from reactor_sim import constants
from reactor_sim.state import CoreState


def _core_state() -> CoreState:
    return CoreState(
        fuel_temperature=300.0,
        neutron_flux=1e5,
        reactivity_margin=0.0,
        power_output_mw=0.0,
        burnup=0.0,
    )


def test_manual_rods_quantized_to_step():
    control = ControlSystem()
    control.manual_control = True
    core = _core_state()

    control.set_rods(0.333)
    assert control.rod_target == 0.325
    control.update_rods(core, dt=100.0)
    assert control.rod_fraction == pytest.approx(0.325, rel=1e-6)

    control.increment_rods(0.014)
    assert control.rod_target == pytest.approx(0.35)
    control.update_rods(core, dt=100.0)
    assert control.rod_fraction == pytest.approx(0.35, rel=1e-6)

    # Clamp upper bound
    control.set_rods(1.0)
    control.update_rods(core, dt=100.0)
    assert control.rod_fraction == 0.95


def test_dashboard_step_constant_exposed():
    assert constants.ROD_MANUAL_STEP == 0.025