# Licensed under a 3-clause BSD style license - see LICENSE.rst

"""Test geodetic representations"""
import pytest
from numpy.testing import assert_array_equal

from astropy.coordinates.representation import CartesianRepresentation

from astropy.coordinates.earth import (
    WGS84GeodeticRepresentation,
    GRS80GeodeticRepresentation,
    WGS72GeodeticRepresentation)

from astropy.units import allclose as quantity_allclose
from astropy import units as u


def test_cartesian_wgs84geodetic_roundtrip():
    # Test array-valued input in the process.
    s1 = CartesianRepresentation(x=[1, 3000.] * u.km,
                                 y=[7000., 4.] * u.km,
                                 z=[5., 6000.] * u.km)

    s2 = WGS84GeodeticRepresentation.from_representation(s1)

    s3 = CartesianRepresentation.from_representation(s2)

    s4 = WGS84GeodeticRepresentation.from_representation(s3)

    assert quantity_allclose(s1.x, s3.x)
    assert quantity_allclose(s1.y, s3.y)
    assert quantity_allclose(s1.z, s3.z)

    assert quantity_allclose(s2.lon, s4.lon)
    assert quantity_allclose(s2.lat, s4.lat)
    assert quantity_allclose(s2.height, s4.height)

    # Test initializer just for the sake of it.
    s5 = WGS84GeodeticRepresentation(s2.lon, s2.lat, s2.height)

    assert_array_equal(s2.lon, s5.lon)
    assert_array_equal(s2.lat, s5.lat)
    assert_array_equal(s2.height, s5.height)


def vvd(val, valok, dval, func, test, status):
    """Mimic routine of erfa/src/t_erfa_c.c (to help copy & paste)"""
    assert quantity_allclose(val, valok * val.unit, atol=dval * val.unit)


def test_geocentric_to_geodetic():
    """Test that we reproduce erfa/src/t_erfa_c.c t_gc2gd"""
    # Here, test the chain.  Direct conversion from Cartesian to
    # various Geodetic representations is done indirectly in test_earth.
    x, y, z = (2e6, 3e6, 5.244e6)

    status = 0  # help for copy & paste of vvd

    gc = CartesianRepresentation(x, y, z, u.m)
    gd = WGS84GeodeticRepresentation.from_cartesian(gc)
    e, p, h = gd.lon.to(u.radian), gd.lat.to(u.radian), gd.height.to(u.m)
    vvd(e, 0.9827937232473290680, 1e-14, "eraGc2gd", "e1", status)
    vvd(p, 0.97160184819075459, 1e-14, "eraGc2gd", "p1", status)
    vvd(h, 331.4172461426059892, 1e-8, "eraGc2gd", "h1", status)

    gd = gd.represent_as(GRS80GeodeticRepresentation)
    e, p, h = gd.lon.to(u.radian), gd.lat.to(u.radian), gd.height.to(u.m)
    vvd(e, 0.98279372324732907, 1e-14, "eraGc2gd", "e2", status)
    vvd(p, 0.97160184820607853, 1e-14, "eraGc2gd", "p2", status)
    vvd(h, 331.41731754844348, 1e-8, "eraGc2gd", "h2", status)

    gd = gd.represent_as(WGS72GeodeticRepresentation)
    e, p, h = gd.lon.to(u.radian), gd.lat.to(u.radian), gd.height.to(u.m)
    vvd(e, 0.98279372324732907, 1e-14, "eraGc2gd", "e3", status)
    vvd(p, 0.97160181811015119, 1e-14, "eraGc2gd", "p3", status)
    vvd(h, 333.27707261303181, 1e-8, "eraGc2gd", "h3", status)


def test_geodetic_to_geocentric():
    """Test that we reproduce erfa/src/t_erfa_c.c t_gd2gc"""
    # These tests are also done implicitly in test_earth.py.
    e = 3.1 * u.rad
    p = -0.5 * u.rad
    h = 2500.0 * u.m

    status = 0  # help for copy & paste of vvd

    gd = WGS84GeodeticRepresentation(e, p, h)
    xyz = gd.to_cartesian().get_xyz()
    vvd(xyz[0], -5599000.5577049947, 1e-7, "eraGd2gc", "0/1", status)
    vvd(xyz[1], 233011.67223479203, 1e-7, "eraGd2gc", "1/1", status)
    vvd(xyz[2], -3040909.4706983363, 1e-7, "eraGd2gc", "2/1", status)

    gd = GRS80GeodeticRepresentation(e, p, h)
    xyz = gd.to_cartesian().get_xyz()
    vvd(xyz[0], -5599000.5577260984, 1e-7, "eraGd2gc", "0/2", status)
    vvd(xyz[1], 233011.6722356703, 1e-7, "eraGd2gc", "1/2", status)
    vvd(xyz[2], -3040909.4706095476, 1e-7, "eraGd2gc", "2/2", status)

    gd = WGS72GeodeticRepresentation(e, p, h)
    xyz = gd.to_cartesian().get_xyz()
    vvd(xyz[0], -5598998.7626301490, 1e-7, "eraGd2gc", "0/3", status)
    vvd(xyz[1], 233011.5975297822, 1e-7, "eraGd2gc", "1/3", status)
    vvd(xyz[2], -3040908.6861467111, 1e-7, "eraGd2gc", "2/3", status)


def test_default_height_is_zero():
    gd = WGS84GeodeticRepresentation(10*u.deg, 20*u.deg)
    assert gd.lon == 10*u.deg
    assert gd.lat == 20*u.deg
    assert gd.height == 0*u.m


def test_non_angle_error():
    with pytest.raises(u.UnitTypeError):
        WGS84GeodeticRepresentation(20*u.m, 20*u.deg, 20*u.m)


def test_non_length_error():
    with pytest.raises(u.UnitTypeError, match='units of length'):
        WGS84GeodeticRepresentation(10*u.deg, 20*u.deg, 30)