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"""Unit tests for the metrics measurement system: PA1, PA2, PF1.
"""

import unittest
import yaml
import os
import random

from lsst.utils import getPackageDir
from lsst.afw.table import SimpleCatalog
from lsst.faro.measurement import PA1Task, PA2Task, PF1Task

# Make sure measurements are deterministic
random.seed(8675309)

DATADIR = os.path.join(getPackageDir('faro'), 'tests', 'data')


class Pa1Test(unittest.TestCase):

    def load_data(self, key):
        '''Helper to load data to process and the expected value.'''
        cat_file, expected_file = self.file_map[key]
        catalog = SimpleCatalog.readFits(os.path.join(DATADIR, cat_file))
        with open(os.path.join(DATADIR, expected_file), 'r') as fh:
            expected = yaml.load(fh, Loader=yaml.FullLoader)
        return catalog, expected

    @classmethod
    def setUpClass(cls):
        '''This gets called once so can be used to set up
           state that is used by all test methods.'''
        super().setUpClass()
        cls.file_map = {('PA1', 'i'): ('matchedCatalogTract_0_i.fits.gz', 'PA1_expected_0_i.yaml'),
                        ('PA1', 'r'): ('matchedCatalogTract_0_r.fits.gz', 'PA1_expected_0_r.yaml'),
                        ('PA2', 'i'): ('matchedCatalogTract_0_i.fits.gz',
                                       'PA2_expected_0_i.yaml'),
                        ('PA2', 'r'): ('matchedCatalogTract_0_r.fits.gz',
                                       'PA2_expected_0_r.yaml'),
                        ('PF1', 'i'): ('matchedCatalogTract_0_i.fits.gz',
                                       'PF1_expected_0_i.yaml'),
                        ('PF1', 'r'): ('matchedCatalogTract_0_r.fits.gz',
                                       'PF1_expected_0_r.yaml')}

    @classmethod
    def tearDownClass(cls):
        '''Delete any variables set in setUpClass.'''
        del cls.file_map
        super().tearDownClass()

    def test_pa1(self):
        """Test calculation of pa1 on a known catalog."""
        config = PA1Task.ConfigClass()
        task = PA1Task(config=config)
        for band in ('i', 'r'):
            catalog, expected = self.load_data(('PA1', band))
            result = task.run(catalog, 'PA1')
            self.assertEqual(result.measurement, expected)

    def test_pa2(self):
        """Test calculation of pa2 on a known catalog."""
        config = PA2Task.ConfigClass()
        task = PA2Task(config=config)
        for band in ('i', 'r'):
            catalog, expected = self.load_data(('PA2', band))
            result = task.run(catalog, 'PA2')
            self.assertEqual(result.measurement, expected)

    def test_pf1(self):
        """Test calculation of pf1 on a known catalog."""
        config = PF1Task.ConfigClass()
        task = PF1Task(config=config)
        for band in ('i', 'r'):
            catalog, expected = self.load_data(('PF1', band))
            result = task.run(catalog, 'PF1')
            self.assertEqual(result.measurement, expected)


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