import pytest

from astropy.tests.helper import assert_quantity_allclose
from astropy.units import allclose as quantity_allclose
from astropy import units as u
from astropy.coordinates import Longitude, Latitude, EarthLocation
from astropy.coordinates.sites import get_builtin_sites, get_downloaded_sites, SiteRegistry


def test_builtin_sites():
    reg = get_builtin_sites()

    greenwich = reg['greenwich']
    lon, lat, el = greenwich.to_geodetic()
    assert_quantity_allclose(lon, Longitude('0:0:0', unit=u.deg),
                             atol=10*u.arcsec)
    assert_quantity_allclose(lat, Latitude('51:28:40', unit=u.deg),
                             atol=1*u.arcsec)
    assert_quantity_allclose(el, 46*u.m, atol=1*u.m)

    names = reg.names
    assert 'greenwich' in names
    assert 'example_site' in names

    with pytest.raises(KeyError) as exc:
        reg['nonexistent site']
    assert exc.value.args[0] == "Site 'nonexistent site' not in database. Use the 'names' attribute to see available sites."


@pytest.mark.remote_data(source='astropy')
def test_online_sites():
    reg = get_downloaded_sites()

    keck = reg['keck']
    lon, lat, el = keck.to_geodetic()
    assert_quantity_allclose(lon, -Longitude('155:28.7', unit=u.deg),
                             atol=0.001*u.deg)
    assert_quantity_allclose(lat, Latitude('19:49.7', unit=u.deg),
                             atol=0.001*u.deg)
    assert_quantity_allclose(el, 4160*u.m, atol=1*u.m)

    names = reg.names
    assert 'keck' in names
    assert 'ctio' in names

    with pytest.raises(KeyError) as exc:
        reg['nonexistent site']
    assert exc.value.args[0] == "Site 'nonexistent site' not in database. Use the 'names' attribute to see available sites."

    with pytest.raises(KeyError) as exc:
        reg['kec']
    assert exc.value.args[0] == "Site 'kec' not in database. Use the 'names' attribute to see available sites. Did you mean one of: 'keck'?'"


@pytest.mark.remote_data(source='astropy')
# this will *try* the online so we have to make it remote_data, even though it
# could fall back on the non-remote version
def test_EarthLocation_basic():
    greenwichel = EarthLocation.of_site('greenwich')
    lon, lat, el = greenwichel.to_geodetic()
    assert_quantity_allclose(lon, Longitude('0:0:0', unit=u.deg),
                             atol=10*u.arcsec)
    assert_quantity_allclose(lat, Latitude('51:28:40', unit=u.deg),
                             atol=1*u.arcsec)
    assert_quantity_allclose(el, 46*u.m, atol=1*u.m)

    names = EarthLocation.get_site_names()
    assert 'greenwich' in names
    assert 'example_site' in names

    with pytest.raises(KeyError) as exc:
        EarthLocation.of_site('nonexistent site')
    assert exc.value.args[0] == "Site 'nonexistent site' not in database. Use EarthLocation.get_site_names to see available sites."


def test_EarthLocation_state_offline():
    EarthLocation._site_registry = None
    EarthLocation._get_site_registry(force_builtin=True)
    assert EarthLocation._site_registry is not None

    oldreg = EarthLocation._site_registry
    newreg = EarthLocation._get_site_registry()
    assert oldreg is newreg
    newreg = EarthLocation._get_site_registry(force_builtin=True)
    assert oldreg is not newreg


@pytest.mark.remote_data(source='astropy')
def test_EarthLocation_state_online():
    EarthLocation._site_registry = None
    EarthLocation._get_site_registry(force_download=True)
    assert EarthLocation._site_registry is not None

    oldreg = EarthLocation._site_registry
    newreg = EarthLocation._get_site_registry()
    assert oldreg is newreg
    newreg = EarthLocation._get_site_registry(force_download=True)
    assert oldreg is not newreg


def test_registry():
    reg = SiteRegistry()

    assert len(reg.names) == 0

    names = ['sitea', 'site A']
    loc = EarthLocation.from_geodetic(lat=1*u.deg, lon=2*u.deg, height=3*u.km)
    reg.add_site(names, loc)

    assert len(reg.names) == 2

    loc1 = reg['SIteA']
    assert loc1 is loc

    loc2 = reg['sIte a']
    assert loc2 is loc


def test_non_EarthLocation():
    """
    A regression test for a typo bug pointed out at the bottom of
    https://github.com/astropy/astropy/pull/4042
    """
    class EarthLocation2(EarthLocation):
        pass

    # This lets keeps us from needing to do remote_data
    # note that this does *not* mess up the registry for EarthLocation because
    # registry is cached on a per-class basis
    EarthLocation2._get_site_registry(force_builtin=True)

    el2 = EarthLocation2.of_site('greenwich')
    assert type(el2) is EarthLocation2
    assert el2.info.name == 'Royal Observatory Greenwich'


def check_builtin_matches_remote(download_url=True):
    """
    This function checks that the builtin sites registry is consistent with the
    remote registry (or a registry at some other location).

    Note that current this is *not* run by the testing suite (because it
    doesn't start with "test", and is instead meant to be used as a check
    before merging changes in astropy-data)
    """
    builtin_registry = EarthLocation._get_site_registry(force_builtin=True)
    dl_registry = EarthLocation._get_site_registry(force_download=download_url)

    in_dl = {}
    matches = {}
    for name in builtin_registry.names:
        in_dl[name] = name in dl_registry
        if in_dl[name]:
            matches[name] = quantity_allclose(builtin_registry[name].geocentric, dl_registry[name].geocentric)
        else:
            matches[name] = False

    if not all(matches.values()):
        # this makes sure we actually see which don't match
        print("In builtin registry but not in download:")
        for name in in_dl:
            if not in_dl[name]:
                print('    ', name)
        print("In both but not the same value:")
        for name in matches:
            if not matches[name] and in_dl[name]:
                print('    ', name, 'builtin:', builtin_registry[name], 'download:', dl_registry[name])
        assert False, "Builtin and download registry aren't consistent - failures printed to stdout"


def test_meta_present():
    reg = get_builtin_sites()

    greenwich = reg['greenwich']
    assert greenwich.info.meta['source'] == ('Ordnance Survey via '
           'http://gpsinformation.net/main/greenwich.htm and UNESCO')