import numpy as np
from scipy.integrate import solve_ivp

from gausse.physics.sensors import make_inductive_sensor_event, make_optical_sensor_event


def _ballistic(t, state):
    return [state[1], 0.0]


def test_optical_sensor_trigger_is_velocity_independent():
    x_sensor = 0.02
    trigger_xs = []
    for v in (1.0, 5.0, 20.0):
        event = make_optical_sensor_event(x_sensor)
        sol = solve_ivp(_ballistic, (0, 1.0), [-0.05, v], events=event)
        assert len(sol.t_events[0]) == 1
        trigger_xs.append(sol.y_events[0][0][0])
    assert np.allclose(trigger_xs, x_sensor, atol=1e-9)


def test_inductive_sensor_fires_earlier_at_higher_velocity():
    x_sensor = 0.02
    sensitivity = 0.05
    threshold = 0.3
    width = 0.005

    trigger_xs = []
    for v in (10.0, 20.0, 40.0):
        event = make_inductive_sensor_event(x_sensor, sensitivity, threshold, width)
        sol = solve_ivp(_ballistic, (0, 1.0), [-0.05, v], events=event)
        assert len(sol.t_events[0]) == 1
        trigger_xs.append(sol.y_events[0][0][0])

    # чем выше скорость, тем раньше (дальше от датчика, т.е. при меньшем x)
    # срабатывает индукционный датчик, т.к. sensitivity*v*bump(x) достигает
    # порога при меньшем bump(x), а значит при большем |x - x_sensor|
    assert trigger_xs[0] > trigger_xs[1] > trigger_xs[2]
    assert all(x < x_sensor for x in trigger_xs)


def test_inductive_sensor_never_fires_below_threshold_speed():
    x_sensor = 0.02
    sensitivity = 0.05
    threshold = 0.3
    width = 0.005
    # пиковый сигнал = sensitivity * v = 0.05 * 1.0 = 0.05 << порог 0.3
    event = make_inductive_sensor_event(x_sensor, sensitivity, threshold, width)
    sol = solve_ivp(_ballistic, (0, 1.0), [-0.05, 1.0], events=event)
    assert len(sol.t_events[0]) == 0