import numpy as np
import math
from scipy.io import wavfile
from scipy import stats

from acoustics.utils import _is_1d
from acoustics.signal import bandpass
from acoustics.bands import (_check_band_type, octave_low, octave_high, third_low, third_high)

import soundfile as sf
from multiprocessing import Pool

def t60_impulse(raw_signal,fs):  # pylint: disable=too-many-locals
    """
    Reverberation time from a WAV impulse response.
    :param file_name: name of the WAV file containing the impulse response.
    :param bands: Octave or third bands as NumPy array.
    :param rt: Reverberation time estimator. It accepts `'t30'`, `'t20'`, `'t10'` and `'edt'`.
    :returns: Reverberation time :math:`T_{60}`
    """
    bands =np.array([62.5 ,125, 250, 500,1000, 2000])

    if np.max(raw_signal)==0 and np.min(raw_signal)==0:
        print('came 1')
        return .5
    
    # fs, raw_signal = wavfile.read(file_name)
    band_type = _check_band_type(bands)

    # if band_type == 'octave':
    low = octave_low(bands[0], bands[-1])
    high = octave_high(bands[0], bands[-1])
    # elif band_type == 'third':
    #     low = third_low(bands[0], bands[-1])
    #     high = third_high(bands[0], bands[-1])

    
    init = -0.0
    end = -60.0
    factor = 1.0
    bands =bands[3:5]
    low = low[3:5]
    high = high[3:5]

    t60 = np.zeros(bands.size)

    for band in range(bands.size):
        # Filtering signal
        filtered_signal = bandpass(raw_signal, low[band], high[band], fs, order=8)
        abs_signal = np.abs(filtered_signal) / np.max(np.abs(filtered_signal))

        # Schroeder integration
        sch = np.cumsum(abs_signal[::-1]**2)[::-1]
        sch_db = 10.0 * np.log10(sch / np.max(sch))
        if math.isnan(sch_db[1]):
            print('came 2')
            return .5
        # print("leng sch_db ",sch_db.size)
        # print("sch_db ",sch_db)
        # Linear regression
        sch_init = sch_db[np.abs(sch_db - init).argmin()]
        sch_end = sch_db[np.abs(sch_db - end).argmin()]
        init_sample = np.where(sch_db == sch_init)[0][0]
        end_sample = np.where(sch_db == sch_end)[0][0]
        x = np.arange(init_sample, end_sample + 1) / fs
        y = sch_db[init_sample:end_sample + 1]
        slope, intercept = stats.linregress(x, y)[0:2]

        # Reverberation time (T30, T20, T10 or EDT)
        db_regress_init = (init - intercept) / slope
        db_regress_end = (end - intercept) / slope
        t60[band] = factor * (db_regress_end - db_regress_init)
    mean_t60 =(t60[1]+t60[0])/2
    # print("meant60 is ", mean_t60)
    if math.isnan(mean_t60):
        print('came 3')
        return .5
    return mean_t60

def t60_error(filename1,filename2):
    real_wave,fs = sf.read(filename1)
    fake_wave,fs = sf.read(filename2)

    channel = int(real_wave.size/len(real_wave))
    pool = Pool(processes=8)
    
    results =[]
    for n in range(channel):
        results.append(pool.apply_async(t60_parallel, args=(n,real_wave,fake_wave,fs,)))
    
    T60_error =0
    for result in results:
        T60_error =  T60_error + result.get()

    T60_error = T60_error/channel
    
    pool.close()
    pool.join()


    # T60_error = Parallel(n_jobs=64)(delayed(t60_parallel)(n, real_wave,fake_wave,fs) for n in range(channel))#np.random.randint(0,1023,size=channel))#
    # T60_error = sum(results)/channel
   
    # for n in range(channel):
    #     real_wave_single   = real_wave[:,n]
    #     fake_wave_single   = fake_wave[:,n]
    #     Real_T60_val = t60_impulse(real_wave_single,fs)
    #     Fake_T60_val = t60_impulse(fake_wave_single,fs)
    #     T60_diff = abs(Real_T60_val-Fake_T60_val)
    #     T60_error = T60_error + T60_diff
    # T60_error = T60_error/channel
    return str(T60_error)

def t60_parallel(n,real_wave,fake_wave,fs):
    real_wave_single   = real_wave[n,:]
    fake_wave_single   = fake_wave[n,:]
    Real_T60_val = t60_impulse(real_wave_single,fs)
    Fake_T60_val = t60_impulse(fake_wave_single,fs)
    T60_diff = abs(Real_T60_val-Fake_T60_val)

    return T60_diff







if __name__ == '__main__':
    t60_impulse('/home/anton/Desktop/gamma101/data/evaluation_all/SF1/Hotel_SkalskyDvur_ConferenceRoom2-MicID01-SpkID01_20170906_S-09-RIR-IR_sweep_15s_45Hzto22kHz_FS16kHz.v00.wav')