text: # Licensed under a 3-clause BSD style license - see LICENSE.rst
  
  import os
  import warnings
  from pathlib import Path
  
  import pytest
  import numpy as np
  
  from astropy.tests.helper import assert_quantity_allclose
  from astropy.utils.data import get_pkg_data_filename
  from astropy.utils.iers import iers
  from astropy import units as u
  from astropy.table import QTable
  from astropy.time import Time, TimeDelta
  
  CI = os.environ.get('CI', False)
  
  FILE_NOT_FOUND_ERROR = getattr(__builtins__, 'FileNotFoundError', OSError)
  
  try:
      iers.IERS_A.open('finals2000A.all')  # check if IERS_A is available
  except OSError:
      HAS_IERS_A = False
  else:
      HAS_IERS_A = True
  
  IERS_A_EXCERPT = get_pkg_data_filename(os.path.join('data', 'iers_a_excerpt'))
  
  
  def setup_module():
      # Need auto_download so that IERS_B won't be loaded and cause tests to
      # fail. Files to be downloaded are handled appropriately in the tests.
      iers.conf.auto_download = True
  
  
  def teardown_module():
      # This setting is to be consistent with astropy/conftest.py
      iers.conf.auto_download = False
  
  
  class TestBasic():
      """Basic tests that IERS_B returns correct values"""
  
      @pytest.mark.parametrize('iers_cls', (iers.IERS_B, iers.IERS))
      def test_simple(self, iers_cls):
          """Test the default behaviour for IERS_B and IERS."""
          # Arguably, IERS itself should not be used at all, but it used to
          # provide IERS_B by default so we check that it continues to do so.
          # Eventually, IERS should probably be deprecated.
          iers_cls.close()
          assert iers_cls.iers_table is None
          iers_tab = iers_cls.open()
          assert iers_cls.iers_table is not None
          assert iers_cls.iers_table is iers_tab
          assert isinstance(iers_tab, QTable)
          assert isinstance(iers_tab, iers.IERS_B)
          assert (iers_tab['UT1_UTC'].unit / u.second).is_unity()
          assert (iers_tab['PM_x'].unit / u.arcsecond).is_unity()
          assert (iers_tab['PM_y'].unit / u.arcsecond).is_unity()
          jd1 = np.array([2456108.5, 2456108.5, 2456108.5, 2456109.5, 2456109.5])
          jd2 = np.array([0.49999421, 0.99997685, 0.99998843, 0., 0.5])
          ut1_utc = iers_tab.ut1_utc(jd1, jd2)
          assert isinstance(ut1_utc, u.Quantity)
          assert (ut1_utc.unit / u.second).is_unity()
          # IERS files change at the 0.1 ms level; see gh-6981
          assert_quantity_allclose(ut1_utc, [-0.5868211, -0.5868184, -0.5868184,
                                             0.4131816, 0.41328895] * u.s,
                                   atol=0.1*u.ms)
          # should be future-proof; surely we've moved to another planet by then
          with pytest.raises(IndexError):
              ut1_utc2, status2 = iers_tab.ut1_utc(1e11, 0.)
          # also check it returns the right status
          ut1_utc2, status2 = iers_tab.ut1_utc(jd1, jd2, return_status=True)
          assert np.all(status2 == iers.FROM_IERS_B)
          ut1_utc4, status4 = iers_tab.ut1_utc(1e11, 0., return_status=True)
          assert status4 == iers.TIME_BEYOND_IERS_RANGE
  
          # check it works via Time too
          t = Time(jd1, jd2, format='jd', scale='utc')
          ut1_utc3 = iers_tab.ut1_utc(t)
          assert_quantity_allclose(ut1_utc3, [-0.5868211, -0.5868184, -0.5868184,
                                              0.4131816, 0.41328895] * u.s,
                                   atol=0.1*u.ms)
  
          # Table behaves properly as a table (e.g. can be sliced)
          assert len(iers_tab[:2]) == 2
  
      def test_open_filename(self):
          iers.IERS_B.close()
          iers.IERS_B.open(iers.IERS_B_FILE)
          assert iers.IERS_B.iers_table is not None
          assert isinstance(iers.IERS_B.iers_table, QTable)
          iers.IERS_B.close()
          with pytest.raises(FILE_NOT_FOUND_ERROR):
              iers.IERS_B.open('surely this does not exist')
  
      def test_open_network_url(self):
          iers.IERS_A.close()
          iers.IERS_A.open(Path(IERS_A_EXCERPT).as_uri())
          assert iers.IERS_A.iers_table is not None
          assert isinstance(iers.IERS_A.iers_table, QTable)
          iers.IERS_A.close()
  
  
  class TestIERS_AExcerpt():
      def test_simple(self):
          # Test the IERS A reader. It is also a regression tests that ensures
          # values do not get overridden by IERS B; see #4933.
          iers_tab = iers.IERS_A.open(IERS_A_EXCERPT)
  
          assert (iers_tab['UT1_UTC'].unit / u.second).is_unity()
          assert 'P' in iers_tab['UT1Flag']
          assert 'I' in iers_tab['UT1Flag']
          assert 'B' in iers_tab['UT1Flag']
          assert np.all((iers_tab['UT1Flag'] == 'I') |
                        (iers_tab['UT1Flag'] == 'P') |
                        (iers_tab['UT1Flag'] == 'B'))
  
          assert (iers_tab['dX_2000A'].unit / u.marcsec).is_unity()
          assert (iers_tab['dY_2000A'].unit / u.marcsec).is_unity()
          assert 'P' in iers_tab['NutFlag']
          assert 'I' in iers_tab['NutFlag']
          assert 'B' in iers_tab['NutFlag']
          assert np.all((iers_tab['NutFlag'] == 'P') |
                        (iers_tab['NutFlag'] == 'I') |
                        (iers_tab['NutFlag'] == 'B'))
  
          assert (iers_tab['PM_x'].unit / u.arcsecond).is_unity()
          assert (iers_tab['PM_y'].unit / u.arcsecond).is_unity()
          assert 'P' in iers_tab['PolPMFlag']
          assert 'I' in iers_tab['PolPMFlag']
          assert 'B' in iers_tab['PolPMFlag']
          assert np.all((iers_tab['PolPMFlag'] == 'P') |
                        (iers_tab['PolPMFlag'] == 'I') |
                        (iers_tab['PolPMFlag'] == 'B'))
  
          t = Time([57053., 57054., 57055.], format='mjd')
          ut1_utc, status = iers_tab.ut1_utc(t, return_status=True)
          assert status[0] == iers.FROM_IERS_B
          assert np.all(status[1:] == iers.FROM_IERS_A)
          # These values are *exactly* as given in the table, so they should
          # match to double precision accuracy.
          assert_quantity_allclose(ut1_utc,
                                   [-0.4916557, -0.4925323, -0.4934373] * u.s,
                                   atol=0.1*u.ms)
  
          dcip_x, dcip_y, status = iers_tab.dcip_xy(t, return_status=True)
          assert status[0] == iers.FROM_IERS_B
          assert np.all(status[1:] == iers.FROM_IERS_A)
          # These values are *exactly* as given in the table, so they should
          # match to double precision accuracy.
          print(dcip_x)
          print(dcip_y)
          assert_quantity_allclose(dcip_x,
                                   [-0.086, -0.093, -0.087] * u.marcsec,
                                   atol=1.*u.narcsec)
          assert_quantity_allclose(dcip_y,
                                   [0.094, 0.081, 0.072] * u.marcsec,
                                   atol=1*u.narcsec)
  
          pm_x, pm_y, status = iers_tab.pm_xy(t, return_status=True)
          assert status[0] == iers.FROM_IERS_B
          assert np.all(status[1:] == iers.FROM_IERS_A)
          assert_quantity_allclose(pm_x,
                                   [0.003734, 0.004581, 0.004623] * u.arcsec,
                                   atol=0.1*u.marcsec)
          assert_quantity_allclose(pm_y,
                                   [0.310824, 0.313150, 0.315517] * u.arcsec,
                                   atol=0.1*u.marcsec)
  
          # Table behaves properly as a table (e.g. can be sliced)
          assert len(iers_tab[:2]) == 2
  
  
  @pytest.mark.skipif('not HAS_IERS_A')
  class TestIERS_A():
  
      def test_simple(self):
          """Test that open() by default reads a 'finals2000A.all' file."""
          # Ensure we remove any cached table (gh-5131).
          iers.IERS_A.close()
          iers_tab = iers.IERS_A.open()
          jd1 = np.array([2456108.5, 2456108.5, 2456108.5, 2456109.5, 2456109.5])
          jd2 = np.array([0.49999421, 0.99997685, 0.99998843, 0., 0.5])
          ut1_utc, status = iers_tab.ut1_utc(jd1, jd2, return_status=True)
          assert np.all(status == iers.FROM_IERS_B)
          assert_quantity_allclose(ut1_utc, [-0.5868211, -0.5868184, -0.5868184,
                                             0.4131816, 0.41328895] * u.s,
                                   atol=0.1*u.ms)
          ut1_utc2, status2 = iers_tab.ut1_utc(1e11, 0., return_status=True)
          assert status2 == iers.TIME_BEYOND_IERS_RANGE
  
          tnow = Time.now()
  
          ut1_utc3, status3 = iers_tab.ut1_utc(tnow, return_status=True)
          assert status3 == iers.FROM_IERS_A_PREDICTION
          assert ut1_utc3 != 0.
  
  
  class TestIERS_Auto():
  
      def setup_class(self):
          """Set up useful data for the tests.
          """
          self.N = 40
          self.ame = 30.0
          self.iers_a_file_1 = get_pkg_data_filename(
              os.path.join('data', 'finals2000A-2016-02-30-test'))
          self.iers_a_file_2 = get_pkg_data_filename(
              os.path.join('data', 'finals2000A-2016-04-30-test'))
          self.iers_a_url_1 = Path(self.iers_a_file_1).as_uri()
          self.iers_a_url_2 = Path(self.iers_a_file_2).as_uri()
          self.t = Time.now() + TimeDelta(10, format='jd') * np.arange(self.N)
  
      def teardown_method(self, method):
          """Run this after every test.
          """
          iers.IERS_Auto.close()
  
      def test_interpolate_error_formatting(self):
          """Regression test: make sure the error message in
          IERS_Auto._check_interpolate_indices() is formatted correctly.
          """
          with iers.conf.set_temp('iers_auto_url', self.iers_a_url_1):
              with iers.conf.set_temp('iers_auto_url_mirror', self.iers_a_url_1):
                  with iers.conf.set_temp('auto_max_age', self.ame):
                      with pytest.raises(ValueError) as err:
                          iers_table = iers.IERS_Auto.open()
                          with warnings.catch_warnings():
                              # Ignoring this if it comes up -- IERS_Auto predictive
                              # values are older than 30.0 days but downloading the
                              # latest table did not find newer values
                              warnings.simplefilter('ignore', iers.IERSStaleWarning)
                              iers_table.ut1_utc(self.t.jd1, self.t.jd2)
          assert str(err.value) == iers.INTERPOLATE_ERROR.format(self.ame)
  
      def test_auto_max_age_none(self):
          """Make sure that iers.INTERPOLATE_ERROR's advice about setting
          auto_max_age = None actually works.
          """
          with iers.conf.set_temp('iers_auto_url', self.iers_a_url_1):
              with iers.conf.set_temp('auto_max_age', None):
                  iers_table = iers.IERS_Auto.open()
                  delta = iers_table.ut1_utc(self.t.jd1, self.t.jd2)
          assert isinstance(delta, np.ndarray)
          assert delta.shape == (self.N,)
          assert_quantity_allclose(delta, np.array([-0.2246227]*self.N)*u.s)
  
      def test_auto_max_age_minimum(self):
          """Check that the minimum auto_max_age is enforced.
          """
          with iers.conf.set_temp('iers_auto_url', self.iers_a_url_1):
              with iers.conf.set_temp('auto_max_age', 5.0):
                  with pytest.raises(ValueError) as err:
                      iers_table = iers.IERS_Auto.open()
                      _ = iers_table.ut1_utc(self.t.jd1, self.t.jd2)
          assert str(err.value) == 'IERS auto_max_age configuration value must be larger than 10 days'
  
      def test_no_auto_download(self):
          with iers.conf.set_temp('auto_download', False):
              t = iers.IERS_Auto.open()
          assert type(t) is iers.IERS_B
  
      @pytest.mark.remote_data
      def test_simple(self):
  
          with iers.conf.set_temp('iers_auto_url', self.iers_a_url_1):
  
              dat = iers.IERS_Auto.open()
              assert dat['MJD'][0] == 57359.0 * u.d
              assert dat['MJD'][-1] == 57539.0 * u.d
  
              # Pretend we are accessing at a time 7 days after start of predictive data
              predictive_mjd = dat.meta['predictive_mjd']
              dat._time_now = Time(predictive_mjd, format='mjd') + 7 * u.d
  
              # Look at times before and after the test file begins.  0.1292905 is
              # the IERS-B value from MJD=57359.  The value in
              # finals2000A-2016-02-30-test has been replaced at this point.
              assert np.allclose(dat.ut1_utc(Time(50000, format='mjd').jd).value, 0.1293286)
              assert np.allclose(dat.ut1_utc(Time(60000, format='mjd').jd).value, -0.2246227)
  
              # Now pretend we are accessing at time 60 days after start of predictive data.
              # There will be a warning when downloading the file doesn't give new data
              # and an exception when extrapolating into the future with insufficient data.
              dat._time_now = Time(predictive_mjd, format='mjd') + 60 * u.d
              assert np.allclose(dat.ut1_utc(Time(50000, format='mjd').jd).value, 0.1293286)
              with pytest.warns(iers.IERSStaleWarning, match='IERS_Auto predictive '
                                'values are older') as warns, \
                   pytest.raises(ValueError, match='interpolating from IERS_Auto '
                                 'using predictive values'):
                  dat.ut1_utc(Time(60000, format='mjd').jd)
              assert len(warns) == 1
  
              # Warning only if we are getting return status
              with pytest.warns(iers.IERSStaleWarning, match='IERS_Auto '
                                'predictive values are older') as warns:
                  dat.ut1_utc(Time(60000, format='mjd').jd, return_status=True)
              assert len(warns) == 1
  
              # Now set auto_max_age = None which says that we don't care how old the
              # available IERS-A file is.  There should be no warnings or exceptions.
              with iers.conf.set_temp('auto_max_age', None):
                  dat.ut1_utc(Time(60000, format='mjd').jd)
  
          # Now point to a later file with same values but MJD increased by
          # 60 days and see that things work.  dat._time_now is still the same value
          # as before, i.e. right around the start of predictive values for the new file.
          # (In other words this is like downloading the latest file online right now).
          with iers.conf.set_temp('iers_auto_url', self.iers_a_url_2):
  
              # Look at times before and after the test file begins.  This forces a new download.
              assert np.allclose(dat.ut1_utc(Time(50000, format='mjd').jd).value, 0.1293286)
              assert np.allclose(dat.ut1_utc(Time(60000, format='mjd').jd).value, -0.3)
  
              # Now the time range should be different.
              assert dat['MJD'][0] == 57359.0 * u.d
              assert dat['MJD'][-1] == (57539.0 + 60) * u.d
  
  
  @pytest.mark.remote_data
  def test_IERS_B_parameters_loading_into_IERS_Auto():
      A = iers.IERS_Auto.open()
      B = iers.IERS_B.open()
  
      ok_A = A["MJD"] <= B["MJD"][-1]
      assert not np.all(ok_A), "IERS B covers all of IERS A: should not happen"
  
      # We only overwrite IERS_B values in the IERS_A table that were already
      # there in the first place.  Better take that into account.
      ok_A &= np.isfinite(A["UT1_UTC_B"])
  
      i_B = np.searchsorted(B["MJD"], A["MJD"][ok_A])
  
      assert np.all(np.diff(i_B) == 1), "Valid region not contiguous"
      assert np.all(A["MJD"][ok_A] == B["MJD"][i_B])
      # Check that values are copied correctly.  Since units are not
      # necessarily the same, we use allclose with very strict tolerance.
      for name in ("UT1_UTC", "PM_x", "PM_y", "dX_2000A", "dY_2000A"):
          assert_quantity_allclose(
              A[name][ok_A], B[name][i_B], rtol=1e-15,
              err_msg=("Bug #9206 IERS B parameter {} not copied over "
                       "correctly to IERS Auto".format(name)))
  
  
  # Issue with FTP, rework test into previous one when it's fixed
  @pytest.mark.skipif("CI", reason="Flaky on CI")
  @pytest.mark.remote_data
  def test_iers_a_dl():
      iersa_tab = iers.IERS_A.open(iers.IERS_A_URL, cache=False)
      try:
          # some basic checks to ensure the format makes sense
          assert len(iersa_tab) > 0
          assert 'UT1_UTC_A' in iersa_tab.colnames
      finally:
          iers.IERS_A.close()
  
  
  @pytest.mark.remote_data
  def test_iers_a_dl_mirror():
      iersa_tab = iers.IERS_A.open(iers.IERS_A_URL_MIRROR, cache=False)
      try:
          # some basic checks to ensure the format makes sense
          assert len(iersa_tab) > 0
          assert 'UT1_UTC_A' in iersa_tab.colnames
      finally:
          iers.IERS_A.close()
  
  
  @pytest.mark.remote_data
  def test_iers_b_dl():
      iersb_tab = iers.IERS_B.open(iers.IERS_B_URL, cache=False)
      try:
          # some basic checks to ensure the format makes sense
          assert len(iersb_tab) > 0
          assert 'UT1_UTC' in iersb_tab.colnames
      finally:
          iers.IERS_B.close()
  