import torch
import torchani
import unittest
import os
import pickle

path = os.path.dirname(os.path.realpath(__file__))
N = 97


class TestAEV(unittest.TestCase):

    def setUp(self, dtype=torchani.default_dtype):
        aev_computer = torchani.SortedAEV(dtype=dtype,
                                          device=torch.device('cpu'))
        self.radial_length = aev_computer.radial_length
        self.aev = torch.nn.Sequential(
            torchani.PrepareInput(aev_computer.species, aev_computer.device),
            aev_computer
        )
        self.tolerance = 1e-5

    def _test_molecule(self, coordinates, species, expected_radial,
                       expected_angular):
        species, aev = self.aev((species, coordinates))
        radial = aev[..., :self.radial_length]
        angular = aev[..., self.radial_length:]
        radial_diff = expected_radial - radial
        radial_max_error = torch.max(torch.abs(radial_diff)).item()
        angular_diff = expected_angular - angular
        angular_max_error = torch.max(torch.abs(angular_diff)).item()
        self.assertLess(radial_max_error, self.tolerance)
        self.assertLess(angular_max_error, self.tolerance)

    def testGDB(self):
        for i in range(N):
            datafile = os.path.join(path, 'test_data/{}'.format(i))
            with open(datafile, 'rb') as f:
                coordinates, species, radial, angular, _, _ = pickle.load(f)
                self._test_molecule(coordinates, species, radial, angular)


if __name__ == '__main__':
    unittest.main()
