import openmc

def test_tally_trigger(run_in_tmpdir):
    pincell = openmc.examples.pwr_pin_cell()

    # create a tally filter on the materials
    mat_filter = openmc.MaterialFilter(pincell.materials)

    # create a tally with triggers applied
    tally = openmc.Tally()
    tally.filters = [mat_filter]
    tally.scores = ['scatter']

    trigger = openmc.Trigger('rel_err', 0.05)
    trigger.scores = ['scatter']

    tally.triggers = [trigger]

    pincell.tallies = [tally]

    pincell.settings.trigger_active = True
    pincell.settings.trigger_max_batches = 100
    pincell.settings.trigger_batch_interval = 5

    sp_file = pincell.run()
    with openmc.StatePoint(sp_file) as sp:
        expected_realizations = sp.n_realizations

    # adding other scores to the tally should not change the
    # number of batches required to satisfy the trigger
    tally.scores = ['total', 'absorption', 'scatter']

    sp_file = pincell.run()

    with openmc.StatePoint(sp_file) as sp:
        realizations = sp.n_realizations

    assert realizations == expected_realizations


def test_tally_trigger_null_score(run_in_tmpdir):
    pincell = openmc.examples.pwr_pin_cell()

     # create a tally filter on the materials
    mat_filter = openmc.MaterialFilter(pincell.materials)

    # apply a tally with a score that be tallied in this model
    tally = openmc.Tally()
    tally.filters = [mat_filter]
    tally.scores = ['pair-production']

    trigger = openmc.Trigger('rel_err', 0.05)
    trigger.scores = ['pair-production']

    tally.triggers = [trigger]

    pincell.tallies = [tally]

    pincell.settings.trigger_active = True
    pincell.settings.trigger_max_batches = 50
    pincell.settings.trigger_batch_interval = 5

    sp_file = pincell.run()

    with openmc.StatePoint(sp_file) as sp:
        # verify that the tally mean is zero
        tally_out = sp.get_tally(id=tally.id)
        assert all(tally_out.mean == 0.0)

        # we expect that this simulation will run
        # up to the max allowed batches
        total_batches = sp.n_realizations + sp.n_inactive
        assert total_batches == pincell.settings.trigger_max_batches