# Licensed under a 3-clause BSD style license - see LICENSE.rst
# -*- coding: utf-8 -*-
"""Test desitarget.brightmask.
"""
import unittest
from pkg_resources import resource_filename
import os
import sys
import fitsio
import numpy as np
import numpy.lib.recfunctions as rfn
from glob import glob
import healpy as hp
import tempfile
import shutil

from desitarget import brightmask, io
from desitarget.targetmask import desi_mask, targetid_mask

from desiutil import brick

_macos = sys.platform == 'darwin'


class TestBRIGHTMASK(unittest.TestCase):

    @classmethod
    def setUpClass(cls):
        # ADM set up the necessary environment variables.
        cls.gaiadir_orig = os.getenv("GAIA_DIR")
        testdir = 'desitarget.test'
        os.environ["GAIA_DIR"] = resource_filename(testdir, 't4')
        cls.tychodir_orig = os.getenv("TYCHO_DIR")
        os.environ["TYCHO_DIR"] = resource_filename(testdir, 't4/tycho')
        cls.uratdir_orig = os.getenv("URAT_DIR")
        os.environ["URAT_DIR"] = resource_filename(testdir, 't4/urat')

        # ADM a temporary output directory to test writing masks.
        cls.maskdir = tempfile.mkdtemp()

        # ADM allowed HEALPixels in the Tycho directory.
        pixnum = []
        fns = sorted(glob(os.path.join(os.environ["TYCHO_DIR"], 'healpix', '*fits')))
        for fn in fns:
            data, hdr = fitsio.read(fn, "TYCHOHPX", header=True)
            nside = hdr["HPXNSIDE"]
            theta, phi = np.radians(90-data["DEC"]), np.radians(data["RA"])
            pixnum.append(list(set(hp.ang2pix(nside, theta, phi, nest=True))))
        cls.pixnum = [i for eachlist in pixnum for i in eachlist]
        cls.nside = nside

        # ADM pick a faint maglim (as unit tests deal with few objects).
        cls.maglim = 20.
        # ADM also pick a reasonable epoch at which to make the mask.
        cls.maskepoch = 2025.5

        # ADM an example mask, made from all of the test HEALPixels.
        cls.allmx = brightmask.make_bright_star_mask(
            numproc=1, nside=cls.nside, pixels=cls.pixnum,
            maglim=cls.maglim, maskepoch=cls.maskepoch)

        # ADM read in some targets.
        targdir = resource_filename(testdir, 't')
        fn = os.path.join(targdir, 'sweep-320m005-330p000.fits')
        ts = fitsio.read(fn)
        # ADM targets are really sweeps objects, so add target fields.
        zs = np.zeros(len(ts))
        targs = rfn.append_fields(ts, ["DESI_TARGET", "TARGETID"], [zs, zs],
                                  usemask=False, dtypes='>i8')
        cls.targs = rfn.append_fields(targs, "BRICK_OBJID", zs, usemask=False,
                                      dtypes='>i4')
        cls.targs["BRICK_OBJID"] = cls.targs["OBJID"]

        # ADM mask_targets checks for unique TARGETIDs, so create some.
        cls.targs["TARGETID"] = np.arange(len(cls.targs))

        # ADM invent a mask with various testing properties.
        cls.mask = np.zeros(3, dtype=brightmask.maskdatamodel.dtype)
        cls.mask["DEC"] = [0, 70, 35]
        cls.mask["IN_RADIUS"] = [1, 20, 10]
        cls.mask["E1"] = [0., 0., -0.3]
        cls.mask["E2"] = [0., 0., 0.5]
        cls.mask["TYPE"] = ['PSF', b'PSF ', 'PSF ']

    @classmethod
    def tearDownClass(cls):
        # ADM remove the temporary output directory.
        if os.path.exists(cls.maskdir):
            shutil.rmtree(cls.maskdir)

        # ADM reset the environment variables.
        if cls.gaiadir_orig is not None:
            os.environ["GAIA_DIR"] = cls.gaiadir_orig
        if cls.tychodir_orig is not None:
            os.environ["TYCHO_DIR"] = cls.tychodir_orig
        if cls.uratdir_orig is not None:
            os.environ["URAT_DIR"] = cls.uratdir_orig

    def test_make_bright_star_mask(self):
        """Test the construction of a bright star mask.
        """
        # ADM test making the mask in an individual pixel.
        mx = brightmask.make_bright_star_mask_in_hp(
            self.nside, self.pixnum[0],
            maglim=self.maglim, maskepoch=self.maskepoch)

        # ADM check that running across all pixels contains the subset
        # ADM of masks in the single pixel.
        self.assertTrue(len(set(mx["REF_ID"]) - set(self.allmx["REF_ID"])) == 0)
        self.assertTrue(len(set(self.allmx["REF_ID"]) - set(mx["REF_ID"])) > 0)

    @unittest.skipIf(_macos, "Skipping parallel test that fails on macOS.")
    def test_make_bright_star_mask_parallel(self):
        """Check running the mask-making code in parallel.
        """
        # ADM run on two processors.
        two = brightmask.make_bright_star_mask(
            numproc=2, nside=self.nside, pixels=self.pixnum,
            maglim=self.maglim, maskepoch=self.maskepoch)

        # ADM check that running in parallel recovers the same masks as
        # ADM running on one processor.
        one = self.allmx[np.argsort(self.allmx["REF_ID"])]
        two = two[np.argsort(two["REF_ID"])]
        self.assertTrue(np.all(one == two))

    def test_mask_write(self):
        """Test that masks are written to file correctly.
        """
        # ADM some meaningless magnitude limits and mask epochs.
        ml, me = 62.3, 2062.3
        # ADM a keyword dictionary to write to the output file header.
        extra = {'BLAT': 'blat', 'FOO': 'foo'}

        # ADM test writing without HEALPixel-split.
        _, mxdir = io.write_masks(self.maskdir, self.allmx, maglim=ml,
                                  maskepoch=me, extra=extra)

        # ADM test writing with HEALPixel-split.
        _, mxdir = io.write_masks(self.maskdir, self.allmx, maglim=ml,
                                  maskepoch=me, extra=extra, nside=self.nside)

        # ADM construct the output directory and file name.
        mxd = io.find_target_files(self.maskdir, flavor="masks",
                                   maglim=ml, epoch=me)
        mxfn = io.find_target_files(self.maskdir, flavor="masks",
                                    maglim=ml, epoch=me, hp=self.pixnum[0])

        # ADM check the output directory is as expected.
        self.assertEqual(mxdir, mxd)

        # ADM check all of the files were made in the correct place.
        fns = sorted(glob(os.path.join(mxdir, "masks-hp*fits")))
        self.assertEqual(len(fns), len(self.pixnum)+1)

        # ADM check the extra kwargs were written to the header.
        for key in extra:
            hdr = fitsio.read_header(mxfn, "MASKS")
            self.assertEqual(hdr[key].rstrip(), extra[key])

    def test_mask_targets(self):
        """Test that targets in masks are flagged accordingly.
        """
        # ADM create the output mask directory.
        _, mxdir = io.write_masks(self.maskdir, self.allmx, maglim=self.maglim,
                                  maskepoch=self.maskepoch, nside=self.nside)

        # ADM make targets with the same coordinates as the masks.
        # ADM remembering to select masks that actually have a radius.
        ii = self.allmx["IN_RADIUS"] > 0
        targs = self.targs.copy()
        targs["RA"] = self.allmx["RA"][ii][:len(targs)]
        targs["DEC"] = self.allmx["DEC"][ii][:len(targs)]

        # ADM add mask information to DESI_TARGET.
        mxt = brightmask.mask_targets(targs, mxdir, nside=self.nside,
                                      pixlist=self.pixnum)

        # ADM all the targs should have been masked.
        nmasked = np.sum(mxt["DESI_TARGET"] & desi_mask["IN_BRIGHT_OBJECT"] != 0)
        self.assertEqual(nmasked, len(targs))

        # ADM and we should have added some safe targets that will be
        # ADM "near" bright objects.
        is_nbo = mxt["DESI_TARGET"] & desi_mask["NEAR_BRIGHT_OBJECT"] != 0
        self.assertTrue(np.all(is_nbo))

    def test_non_mask_targets(self):
        """Test targets that are NOT in masks are flagged accordingly.
        """
        # ADM create the output mask directory.
        _, mxdir = io.write_masks(self.maskdir, self.allmx, maglim=self.maglim,
                                  maskepoch=self.maskepoch, nside=self.nside)

        # ADM update DESI_TARGET for any targets in masks.
        mxtargs = brightmask.mask_targets(self.targs, mxdir, nside=self.nside,
                                          pixlist=self.pixnum)

        # ADM none of the targets should be in a mask.
        self.assertTrue(np.all(mxtargs["DESI_TARGET"] == 0))

    def test_safe_locations(self):
        """Test SAFE/BADSKY locations are equidistant from mask centers.
        """
        # ADM append SAFE locations around the perimeter of the mask.
        safes = brightmask.get_safe_targets(self.targs, self.mask)
        targs = np.concatenate([self.targs, safes])
        # ADM restrict to just SAFE locations.
        skybitset = ((targs["TARGETID"] & targetid_mask.SKY) != 0)
        safes = targs[np.where(skybitset)]
        # ADM for each mask location check that every safe location is
        # ADM equidistant from the mask center.
        from astropy.coordinates import SkyCoord
        from astropy import units as u
        c = SkyCoord(safes["RA"]*u.deg, safes["DEC"]*u.deg)
        for i in range(2):
            cent = SkyCoord(self.mask[i]["RA"]*u.deg, self.mask[i]["DEC"]*u.deg)
            sep = cent.separation(c)
            # ADM only things close to mask i
            w = np.where(sep < np.min(sep)*1.002)
            # ADM are these all the same distance to high precision?
            self.assertTrue(np.max(sep[w] - sep[w[0]]) < 1e-15*u.deg)

    def test_targetid(self):
        """Test SKY/RELEASE/BRICKID/OBJID are set correctly in TARGETID
        and DESI_TARGET for SAFE/BADSKY locations.
        """
        # ADM append SAFE locations around the perimeter of the mask.
        safes = brightmask.get_safe_targets(self.targs, self.mask)
        targs = np.concatenate([self.targs, safes])

        # ADM first check the SKY and BADSKY bits are appropriately set.
        skybitset = ((targs["TARGETID"] & targetid_mask.SKY) != 0)
        badskybitset = ((targs["DESI_TARGET"] & desi_mask.BAD_SKY) != 0)
        self.assertTrue(np.all(skybitset == badskybitset))

        # ADM now check that the other bits are in the correct locations
        # ADM first restrict to the ~half-dozen targets in BRICK 521233.
        bid = 521233
        ii = targs["BRICKID"] == bid
        targs = targs[ii]

        # ADM check that the TARGETIDs are unique.
        s = set(targs["TARGETID"])
        self.assertEqual(len(s), len(targs["TARGETID"]))

        # ADM the TARGETIDs as a binary string.
        bintargids = [np.binary_repr(targid) for targid in targs["TARGETID"]]

        # ADM check the DR is set (in a way unlike the normal bit-setting
        # in brightmask.py). Release should be zero for SAFE locations.
        rmostbit = targetid_mask.RELEASE.bitnum
        lmostbit = targetid_mask.RELEASE.bitnum + targetid_mask.RELEASE.nbits
        drbitset = int(bintargids[0][-lmostbit:-rmostbit], 2)
        drbitshould = targs["RELEASE"][0]
        self.assertEqual(drbitset, drbitshould)
        self.assertEqual(drbitset, 0)

        # ADM check that the BRICKIDs are as restricted/requested.
        rmostbit = targetid_mask.BRICKID.bitnum
        lmostbit = targetid_mask.BRICKID.bitnum + targetid_mask.BRICKID.nbits
        brickidset = np.array(
            [int(bintargid[-lmostbit:-rmostbit], 2) for bintargid in bintargids])
        self.assertTrue(np.all(brickidset == bid))


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


def test_suite():
    """Allows testing of only this module with the command:

        python setup.py test -m desitarget.test.test_brightmask
    """
    return unittest.defaultTestLoader.loadTestsFromName(__name__)
