import os
import sys
import unittest

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

try:
    import numpy as np
    import audio_engine
    HAVE_NUMPY = True
except Exception:  # numpy not installed — skip the array-shape tests
    HAVE_NUMPY = False


@unittest.skipUnless(HAVE_NUMPY, "numpy required")
class TestMatchChannels(unittest.TestCase):
    def test_mono_to_stereo(self):
        mono = np.zeros((100, 1), dtype=np.float32)
        out = audio_engine.match_channels(mono, 2)
        self.assertEqual(out.shape, (100, 2))

    def test_1d_treated_as_mono(self):
        out = audio_engine.match_channels(np.zeros(50, dtype=np.float32), 2)
        self.assertEqual(out.shape, (50, 2))

    def test_stereo_unchanged(self):
        st = np.zeros((10, 2), dtype=np.float32)
        out = audio_engine.match_channels(st, 2)
        self.assertEqual(out.shape, (10, 2))

    def test_downmix_truncates(self):
        five = np.zeros((10, 5), dtype=np.float32)
        out = audio_engine.match_channels(five, 2)
        self.assertEqual(out.shape, (10, 2))

    def test_mono_values_duplicated(self):
        mono = np.arange(4, dtype=np.float32).reshape(4, 1)
        out = audio_engine.match_channels(mono, 2)
        self.assertTrue(np.array_equal(out[:, 0], out[:, 1]))


@unittest.skipUnless(HAVE_NUMPY, "numpy required")
class TestAutoSelectDevice(unittest.TestCase):
    def test_prefers_cable_input(self):
        devices = [
            {"index": 0, "name": "Built-in Output", "channels": 2},
            {"index": 1, "name": "CABLE Input (VB-Audio Virtual Cable)", "channels": 2},
        ]
        self.assertEqual(audio_engine.auto_select_device(devices)["index"], 1)

    def test_linux_null_sink(self):
        devices = [
            {"index": 0, "name": "HDA Intel PCH", "channels": 2},
            {"index": 1, "name": "Null Output", "channels": 2},
        ]
        self.assertEqual(audio_engine.auto_select_device(devices)["index"], 1)

    def test_none_when_no_virtual(self):
        devices = [{"index": 0, "name": "Speakers", "channels": 2}]
        self.assertIsNone(audio_engine.auto_select_device(devices))

    def test_priority_order(self):
        # "cable input" outranks "virtual" even when virtual appears first
        devices = [
            {"index": 0, "name": "Some Virtual Thing", "channels": 2},
            {"index": 1, "name": "CABLE Input", "channels": 2},
        ]
        self.assertEqual(audio_engine.auto_select_device(devices)["index"], 1)


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