import unittest

import numpy as np

from damaris.data.MeasurementResult import MeasurementResult


class TestMeasurementResult(unittest.TestCase):
    def test_add_zero_preserves_data(self):
        """mr + 0 must return a MeasurementResult with identical data."""
        mr = MeasurementResult("test_quantity")
        for i in range(3):
            mr[i] = float(i * i)
        mr2 = mr + 0
        self.assertIsInstance(mr2, MeasurementResult)
        self.assertEqual(mr2.quantity_name, "test_quantity")
        np.testing.assert_array_equal(mr2.get_xdata(), mr.get_xdata())
        np.testing.assert_array_equal(mr2.get_ydata(), mr.get_ydata())

    def test_add_zero_returns_independent_copy(self):
        """Changing the copy must not change the original."""
        mr = MeasurementResult("q")
        mr[1.0] = 5.0
        mr2 = mr + 0
        self.assertIsNot(mr2[1.0], mr[1.0])
        mr2[1.0] = mr2[1.0] + 100.0
        self.assertEqual(mr[1.0].mean(), 5.0)

    def test_add_nonzero_raises(self):
        mr = MeasurementResult("q")
        self.assertRaises(Exception, mr.__add__, 1)


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