import numpy as np

from ase.calculators.emt import EMT
from ase.build import bulk
from ase.optimize import FIRE

a = bulk('Au')
a *= (2, 2, 2)

a[0].x += 0.5

a.set_calculator(EMT())

opt = FIRE(a, dtmax=1.0, dt=1.0, maxmove=100.0, downhill_check=False)
opt.run(fmax=0.001)
e1 = a.get_potential_energy()
n1 = opt.nsteps

a = bulk('Au')
a *= (2, 2, 2)

a[0].x += 0.5

a.set_calculator(EMT())

reset_history = []


def callback(a, r, e, e_last):
    reset_history.append([e - e_last])

opt = FIRE(a, dtmax=1.0, dt=1.0, maxmove=100.0, downhill_check=True,
           position_reset_callback=callback)
opt.run(fmax=0.001)
e2 = a.get_potential_energy()
n2 = opt.nsteps

assert abs(e1 - e2) < 1e-6
assert n2 < n1
assert (np.array(reset_history) > 0).all