import os
from unittest import TestCase

import numpy as np
from   numpy.testing import assert_allclose

from math_utils.array_utils import array_reflect as ar
from nr_analysis_axi import null, invars

class TestNull(TestCase):

    def setUp(self):
        datafile = os.path.splitext(__file__)[0] + '.npz'

        self.data = np.load(datafile)
        self.t   = ar(self.data['t'], -1)
        self.x   = ar(self.data['x'], -1)
        self.gxx = ar(ar(self.data['gxx'], axis = 1), axis = 0)
        self.gtt = ar(ar(self.data['gtt'], axis = 1), axis = 0)

    def test_null_geodesics(self):
        g = null.null_geodesics(self.t, self.x, self.gxx, self.gtt, integrate_times = [0.1])[0]

        l = self.data['l']

        assert_allclose(g(l), self.data['g'], 1e-12)