import os
from io import BytesIO

import numpy as np

from amodem import send
from amodem import recv
from amodem import common
from amodem import dsp
from amodem import sampling

import logging
logging.basicConfig(level=logging.DEBUG,
                    format='%(asctime)s %(levelname)-12s %(message)s')

import pytest


class Args(object):
    def __init__(self, **kwargs):
        self.__dict__.update(kwargs)
        self.pylab = None


def run(size, chan=None, df=0, success=True):
    tx_data = os.urandom(size)
    tx_audio = BytesIO()
    send.main(Args(silence_start=1, silence_stop=1,
              input=BytesIO(tx_data), output=tx_audio))

    data = tx_audio.getvalue()
    data = common.loads(data)
    if chan is not None:
        data = chan(data)
    if df:
        sampler = sampling.Sampler(data, sampling.Interpolator())
        sampler.freq += df
        data = sampler.take(len(data))

    data = common.dumps(data)
    rx_audio = BytesIO(data)

    rx_data = BytesIO()
    result = recv.main(Args(skip=0, input=rx_audio, output=rx_data))
    rx_data = rx_data.getvalue()

    assert result == success
    if success:
        assert rx_data == tx_data


def test_small():
    run(1024, chan=lambda x: x)


def test_error():
    skip = 1 * send.config.Fs  # remove trailing silence
    run(1024, chan=lambda x: x[:-skip], success=False)


@pytest.fixture(params=[s*x for s in (+1, -1) for x in (0.1, 1, 10)])
def freq_err(request):
    return request.param * 1e-6


def test_timing(freq_err):
    run(1024, df=freq_err)


def test_lowpass():
    run(1024, chan=lambda x: dsp.lfilter(b=[0.9], a=[1.0, -0.1], x=x))


def test_highpass():
    run(1024, chan=lambda x: dsp.lfilter(b=[0.9], a=[1.0, 0.1], x=x))


def test_attenuation():
    run(5120, chan=lambda x: x * 0.1)


def test_low_noise():
    r = np.random.RandomState(seed=0)
    run(5120, chan=lambda x: x + r.normal(size=len(x), scale=0.0001))


def test_medium_noise():
    r = np.random.RandomState(seed=0)
    run(5120, chan=lambda x: x + r.normal(size=len(x), scale=0.001))


def test_large():
    run(54321, chan=lambda x: x)