import unittest
import audioop
from speech_recognition import AudioSource
from mycroft.client.speech.mic import ResponsiveRecognizer

__author__ = 'seanfitz'


class MockStream(object):
    def __init__(self):
        self.chunks = []

    def inject(self, chunk):
        self.chunks.append(chunk)

    def read(self, chunk_size):
        result = self.chunks[0]
        if len(self.chunks) > 1:
            self.chunks = self.chunks[1:]
        return result


class MockSource(AudioSource):
    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_value, traceback):
        pass

    def __init__(self, stream=None):
        self.stream = stream if stream else MockStream()
        self.CHUNK = 1024
        self.SAMPLE_RATE = 16000
        self.SAMPLE_WIDTH = 2


class DynamicEnergytest(unittest.TestCase):
    def setUp(self):
        pass

    @unittest.skip('Disabled while unittests are brought upto date')
    def testMaxAudioWithBaselineShift(self):
        low_base = b"".join(["\x10\x00\x01\x00"] * 100)
        higher_base = b"".join(["\x01\x00\x00\x01"] * 100)

        source = MockSource()

        for i in xrange(100):
            source.stream.inject(low_base)

        source.stream.inject(higher_base)
        recognizer = ResponsiveRecognizer(None)

        sec_per_buffer = float(source.CHUNK) / (source.SAMPLE_RATE *
                                                source.SAMPLE_WIDTH)

        test_seconds = 30.0
        while test_seconds > 0:
            test_seconds -= sec_per_buffer
            data = source.stream.read(source.CHUNK)
            energy = recognizer.calc_energy(data, source.SAMPLE_WIDTH)
            recognizer.adjust_threshold(energy, sec_per_buffer)

        higher_base_energy = audioop.rms(higher_base, source.SAMPLE_WIDTH)
        # after recalibration (because of max audio length) new threshold
        # should be >= 1.5 * higher_base_energy
        delta_below_threshold = (
            recognizer.energy_threshold - higher_base_energy)
        min_delta = higher_base_energy * .5
        assert abs(delta_below_threshold - min_delta) < 1