#!/usr/bin/env python

from collections import Mapping
import os

import numpy as np
import pytest
import openmc.data


def test_data_library(tmpdir):
    lib = openmc.data.DataLibrary.from_xml()
    for f in lib.libraries:
        assert sorted(f.keys()) == ['materials', 'path', 'type']

    f = lib.get_by_material('U235')
    assert f['type'] == 'neutron'
    assert 'U235' in f['materials']

    f = lib.get_by_material('c_H_in_H2O')
    assert f['type'] == 'thermal'
    assert 'c_H_in_H2O' in f['materials']

    filename = str(tmpdir.join('test.xml'))
    lib.export_to_xml(filename)
    assert os.path.exists(filename)

    new_lib = openmc.data.DataLibrary()
    directory = os.path.dirname(os.environ['OPENMC_CROSS_SECTIONS'])
    new_lib.register_file(os.path.join(directory, 'H1.h5'))
    assert new_lib.libraries[-1]['type'] == 'neutron'
    new_lib.register_file(os.path.join(directory, 'c_Zr_in_ZrH.h5'))
    assert new_lib.libraries[-1]['type'] == 'thermal'


def test_linearize():
    """Test linearization of a continuous function."""
    x, y = openmc.data.linearize([-1., 1.], lambda x: 1 - x*x)
    f = openmc.data.Tabulated1D(x, y)
    assert f(-0.5) == pytest.approx(1 - 0.5*0.5, 0.001)
    assert f(0.32) == pytest.approx(1 - 0.32*0.32, 0.001)


def test_thin():
    """Test thinning of a tabulated function."""
    x = np.linspace(0., 2*np.pi, 1000)
    y = np.sin(x)
    x_thin, y_thin = openmc.data.thin(x, y)
    f = openmc.data.Tabulated1D(x_thin, y_thin)
    assert f(1.0) == pytest.approx(np.sin(1.0), 0.001)


def test_atomic_mass():
    assert openmc.data.atomic_mass('H1') == 1.00782503223
    assert openmc.data.atomic_mass('U235') == 235.043930131
    with pytest.raises(KeyError):
        openmc.data.atomic_mass('U100')


def test_atomic_weight():
    assert openmc.data.atomic_weight('C') == 12.011115164862904
    with pytest.raises(ValueError):
        openmc.data.atomic_weight('Qt')


def test_water_density():
    dens = openmc.data.water_density
    # These test values are from IAPWS R7-97(2012).  They are actually specific
    # volumes so they need to be inverted.  They also need to be divided by 1000
    # to convert from [kg / m^3] to [g / cm^3].
    assert dens(300.0, 3.0) == pytest.approx(1e-3/0.100215168e-2, 1e-6)
    assert dens(300.0, 80.0) == pytest.approx(1e-3/0.971180894e-3, 1e-6)
    assert dens(500.0, 3.0) == pytest.approx(1e-3/0.120241800e-2, 1e-6)


def test_gnd_name():
    assert openmc.data.gnd_name(1, 1) == 'H1'
    assert openmc.data.gnd_name(40, 90) == ('Zr90')
    assert openmc.data.gnd_name(95, 242, 0) == ('Am242')
    assert openmc.data.gnd_name(95, 242, 1) == ('Am242_m1')
    assert openmc.data.gnd_name(95, 242, 10) == ('Am242_m10')


def test_zam():
    assert openmc.data.zam('H1') == (1, 1, 0)
    assert openmc.data.zam('Zr90') == (40, 90, 0)
    assert openmc.data.zam('Am242') == (95, 242, 0)
    assert openmc.data.zam('Am242_m1') == (95, 242, 1)
    assert openmc.data.zam('Am242_m10') == (95, 242, 10)
    with pytest.raises(ValueError):
        openmc.data.zam('garbage')