import re
import unittest

from damaris.experiments.Experiment import Experiment


def phase_of_state(state):
    "extracts the phase value from a state's XML content"
    match = re.search(r'phase="([-0-9.]+)"', state.content)
    assert match, "no phase in state: %s" % state.content
    return float(match.group(1))


class TestExperimentPhase(unittest.TestCase):
    def test_set_phase_negative_normalized(self):
        """Test that set_phase() normalizes negative phases to [0, 360)."""
        e = Experiment()
        for degrees, expected in ((-90, 270.0), (-45.5, 314.5),
                                  (-270, 90.0), (-360, 0.0)):
            e.set_phase(degrees)
            self.assertEqual(phase_of_state(e.state_list.list[-1]), expected)

    def test_set_phase_positive_unchanged(self):
        """Test that set_phase() passes positive phases through unchanged."""
        e = Experiment()
        for degrees, expected in ((0, 0.0), (90, 90.0), (270, 270.0),
                                  (45.5, 45.5)):
            e.set_phase(degrees)
            self.assertEqual(phase_of_state(e.state_list.list[-1]), expected)

    def test_set_frequency_negative_phase_normalized(self):
        """Test that set_frequency() normalizes a negative phase."""
        e = Experiment()
        e.set_frequency(85e6, -90)
        state = e.state_list.list[-1]
        self.assertEqual(phase_of_state(state), 270.0)
        self.assertIn('f="85000000.000000"', state.content)

    def test_rf_pulse_negative_phase_normalized(self):
        """Test that rf_pulse() normalizes a negative pulse phase."""
        e = Experiment(gating=1e-6, rf_sources=[1], rf_gates=[2])
        e.rf_pulse(length=1e-6, phase=-90, source=0)
        self.assertEqual(phase_of_state(e.state_list.list[0]), 270.0)


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