import io
import os
import tempfile
import unittest

import numpy as np
import tables

from damaris.data.MeasurementResult import MeasurementResult, read_from_hdf


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)

    def test_get_lineplotdata_returns_means(self):
        """get_lineplotdata must return the accumulated means, not self.y."""
        mr = MeasurementResult("test_quantity")
        for i in range(3):
            mr[float(i)] = float(i * i)
        k, v = mr.get_lineplotdata()
        self.assertIsInstance(k, np.ndarray)
        self.assertIsInstance(v, np.ndarray)
        self.assertEqual(k.shape, v.shape)
        np.testing.assert_array_equal(v, mr.get_ydata())
        np.testing.assert_array_equal(v, [0.0, 1.0, 4.0])

    def test_get_lineplotdata_empty(self):
        """get_lineplotdata of an empty result must return empty arrays."""
        mr = MeasurementResult("q")
        k, v = mr.get_lineplotdata()
        self.assertEqual(k.shape[0], 0)
        self.assertEqual(v.shape[0], 0)

    def test_write_to_csv(self):
        mr = MeasurementResult("q")
        mr[1.0] = 5.0
        mr[2.0] = 7.0
        buf = io.StringIO()
        mr.write_to_csv(buf)
        lines = buf.getvalue().splitlines()
        self.assertEqual(lines[0], "# quantity:q")
        self.assertEqual(lines[1], "# x y ysigma n")
        self.assertEqual(len(lines), 4)
        self.assertEqual(lines[2].split()[3], "1")
        self.assertEqual(lines[3].split()[3], "1")

    def test_write_to_hdf_roundtrip(self):
        mr = MeasurementResult("q")
        mr[1.0] = 5.0
        mr[2.0] = 7.0
        with tempfile.TemporaryDirectory() as tmpdir:
            path = os.path.join(tmpdir, "test.h5")
            with tables.open_file(path, mode="w") as h5file:
                mr.write_to_hdf(h5file, "/", "mr", "test result")
            with tables.open_file(path, mode="r") as h5file:
                mr2 = read_from_hdf(h5file.get_node("/mr"))
        self.assertIsNotNone(mr2)
        self.assertEqual(mr2.quantity_name, "q")
        np.testing.assert_array_equal(mr2.get_xdata(), mr.get_xdata())
        np.testing.assert_array_equal(mr2.get_ydata(), mr.get_ydata())


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