#!/usr/bin/env python3

# basé sur l'idée de Shivam Aggarwal sur https://shivama205.medium.com/audio-signals-comparison-23e431ed2207

# WTFL

import argparse

import subprocess 

import numpy 

import os

import sys

import time

import multiprocessing

def initialize():

    defaults = {

        'sample_time' : 500, # seconds to sample audio file for fingerprint calculation

        'span'        : 150, # number of points to scan cross correlation over

        'step'        : 1,   # step size (in points) of cross correlation

        'min_overlap' : 20,  # minimum number of points that must overlap in cross correlation

                             # exception is raised if this cannot be met

        'threshold'   : 80,  # %

        'processor'   : os.cpu_count(),

        'separator'   : ';'

    }

    def check_nproc(arg):

        try:

            n = int(arg)

        except ValueError:

            raise argparse.ArgumentTypeError("il faut un nombre entier")

        if n <  1 or n > os.cpu_count():

            raise argparse.ArgumentTypeError("{} n'est pas compris entre 1 et {:d}".format(n, os.cpu_count()))

        return n

    def check_threshold(arg):

        try:

            n = float(arg)

        except ValueError:

            raise argparse.ArgumentTypeError("il faut un nombre")

        if n <  0 or n > 100:

            raise argparse.ArgumentTypeError("{} n'est pas compris entre 0 et 100 inclus".format(n))

        return n

    parser = argparse.ArgumentParser(__file__)

    parser.add_argument("-i ", "--source-file",

            action   = 'append',

            nargs    = '+',

            help     = "répertoire ou fichier"

            )

    parser.add_argument("-t ", "--threshold",

            type    = check_threshold,

            default = defaults['threshold'],

            help    = "seuil en pourcentage sous lequel il est considéré qu'il n'y a pas de corrélation (défaut: %(default)d)"

            )

    parser.add_argument("-p ", "--processor",

            type    = check_nproc,

            default = defaults['processor'],

            help    = "le nombre de processus parallèles lancés (défaut: %(default)d)"

            )

    parser.add_argument("--sample-time",

            type    = int,

            default = defaults['sample_time'],

            help    = "seconds to sample audio file for fpcalc (défaut: %(default)d)"

            )

    parser.add_argument("--span",

            type    = int,

            default = defaults['span'],

            help    = "finesse en points pour scanner la corrélation (défaut: %(default)d)"

            )

    parser.add_argument("--step",

            type    = int,

            default = defaults['step'],

            help    = "valeur du pas en points de corrélation (défaut: %(default)d)"

            )

    parser.add_argument("--min-overlap",

            type    = int,

            default = defaults['min_overlap'],

            help    = "nombre minimal de points de correspondance (défaut %(default)d)"

            )

    parser.add_argument("--separator",

            type    = str,

            default = defaults['separator'],

            help    = "séparateur des champs de résultat (défaut '%(default)s')"

            )

    args = parser.parse_args()

    sources_files = {}

    for input_file in args.source_file:

        if os.path.isfile(input_file[0]):

            sources_files[input_file[0]] = 1

        elif os.path.isdir(input_file[0]):

            for root, dirs, files in os.walk(input_file[0]):

                for file in files:

                    if os.path.isfile(os.path.join(root, file)):

                        sources_files[os.path.join(root, file)] = 1

    dir(args)

    return list(sources_files.keys()), args

def prime(i, primes):

    for prime in primes:

        if not (i == prime or i % prime):

            return False

    primes.add(i)

    return i

def nPrimes(n):

    primes = set([2])

    i, p = 2, 0

    while True:

        if prime(i, primes):

            p += 1

            if p == n:

                return primes

        i += 1

def getPrimes(n, ids):

    a = 0

    b = 0

    _ids = list(ids)

    for i in range(len(_ids)):

        if n % _ids[i] == 0:

            a = _ids[i]

            b = n / _ids[i]

            break

    return a, int(b)

# calculate fingerprint

def calculate_fingerprints(filename):

    fpcalc_out = subprocess.getoutput('fpcalc -raw -length {} "{}"'.format(args.sample_time, filename))

    fingerprint_index = fpcalc_out.find('FINGERPRINT=') + 12

    return fpcalc_out[fingerprint_index:]

# returns correlation between lists

def correlation(listx, listy):

    if len(listx) == 0 or len(listy) == 0:

        # Error checking in main program should prevent us from ever being

        # able to get here.

        raise Exception('Empty lists cannot be correlated.')

    if len(listx) > len(listy):

        listx = listx[:len(listy)]

    elif len(listx) < len(listy):

        listy = listy[:len(listx)]

    covariance = 0

    for i in range(len(listx)):

        covariance += 32 - bin(listx[i] ^ listy[i]).count("1")

    covariance = covariance / float(len(listx))

    return covariance/32

# return cross correlation, with listy offset from listx

def cross_correlation(listx, listy, offset):

    if offset > 0:

        listx = listx[offset:]

        listy = listy[:len(listx)]

    elif offset < 0:

        offset = -offset

        listy = listy[offset:]

        listx = listx[:len(listy)]

    if min(len(listx), len(listy)) < args.min_overlap:

        # Error checking in main program should prevent us from ever being

        # able to get here.

        return 

    return correlation(listx, listy)

# cross correlate listx and listy with offsets from -span to span

def compare(listx, listy, span, step):

    if span > min(len(list(listx)), len(list(listy))):

        # Error checking in main program should prevent us from ever being

        # able to get here.

        raise Exception('span >= sample size: %i >= %i\n'

                        % (span, min(len(list(listx)), len(list(listy))))

                        + 'Reduce span, reduce crop or increase sample_time.')

    corr_xy = []

    for offset in numpy.arange(-span, span + 1, step):

        corr_xy.append(cross_correlation(listx, listy, offset))

    return corr_xy

def get_max_corr(corr, source, target):

    max_corr_index = corr.index(max(corr))

    max_corr_offset = -args.span + max_corr_index * args.step

# report matches

    if corr[max_corr_index] * 100 >= args.threshold:

        return corr[max_corr_index], max_corr_offset

def correlate(source, target):

    corr = compare(source, target, args.span, args.step)

    return get_max_corr(corr, source, target)

def get_tests_nbr(n):

    return n * n - n * ( n + 1 ) / 2

def get_ETA(start, total, done):

    now = time.time()

    return time.ctime(now + (now - start) / done * (total - done))

def eprint(*args, **kwargs):

    print(*args, file=sys.stderr, **kwargs)

def mp_calculate_fingerprints(key):

    try:

        ziques[key] = {

            'fingerprint': list(map(int, calculate_fingerprints(ziques[key]['path']).split(','))),

            'path': ziques[key]['path']

        }

    except:

        erreurs.append(ziques[key]['path'])

        del ziques[key]

        pass

def mp_correlate(key):

    try:

        c, o = correlate(

                ziques[comparaison[key]['a']]['fingerprint'],

                ziques[comparaison[key]['b']]['fingerprint'])

        comparaison[key] = {

            'a': comparaison[key]['a'],

            'b': comparaison[key]['b'],

            'correlation': c,

            'offset': o

        }

    except:

        del comparaison[key]

        pass

if __name__ == "__main__":

    global args

    source_files, args= initialize()

    if len(source_files) < 2:

        print("au moins deux fichiers sont nécessaires")

        sys.exit()

    ids = list(nPrimes(len(source_files)))

    total_ids = len(ids)

    manager = multiprocessing.Manager()

    ziques = manager.dict()

    comparaison = manager.dict()

    erreurs = manager.list()

    pool = multiprocessing.Pool(args.processor)

    for f in range(len(source_files)):

        ziques[ids[f]] = { 'path': source_files[f] }

    del source_files

    nb_erreurs = len(erreurs)

    start = time.time()

    for i, _ in enumerate(pool.imap_unordered(mp_calculate_fingerprints, ziques.keys()), 1):

        nb_erreurs = len(erreurs)

        print('calcul des empreintes{:s}: {:.1f}% (ETA {:s})'.format(

                    ("", " (" + str(nb_erreurs) + " erreur{})".format(("", "s")[nb_erreurs > 1]))[nb_erreurs > 0],

                    i / total_ids * 100, 

                    get_ETA(start, total_ids, i)),

                end='\r')

    sys.stdout.write("\033[K") #clear line

    print('calcul des empreintes terminé ({:d} fichiers traités{:s})'.format(

                len(ziques),

                ("", " et " + str(nb_erreurs) + " erreur{}".format(("", "s")[nb_erreurs > 1]))[nb_erreurs > 0]))

    if len(erreurs):

        print("Fichier{} en erreur:".format(("", "s")[len(erreurs) > 1]))

        for k in erreurs:

            print(k)

        print()

    erreurs[:] = [] # vide la liste d'erreurs

    nb_erreurs = len(erreurs)

    nb_tests = get_tests_nbr(len(ziques))

    done = 0

    start = time.time()

    for a in ziques.keys():

        for b in ziques.keys():

            id_correl = a * b

            if a == b or id_correl in comparaison:

                continue

            comparaison[id_correl] = {

                'a': a,

                'b': b

            }

            done += 1

        print("construction liste: {:.1f}% (ETA {:s})".format(

                    done / nb_tests * 100,

                    get_ETA(start, nb_tests, done)),

                end='\r')

    sys.stdout.write("\033[K") #clear line

    tests_nbr = len(comparaison)

    start = time.time()

    for i, _ in enumerate(pool.imap_unordered(mp_correlate, comparaison.keys()), 1):

        print('comparaisons: {:.1f}% (ETA {:s})'.format(

                    i / tests_nbr * 100,

                    get_ETA(start, tests_nbr, i),

                    len),

                end='\r')

    sys.stdout.write("\033[K") #clear line

    print('comparaison terminée:\n{0:d} comparaison{pluriel1} effectuée{pluriel1}\n{1} corrélation{pluriel2} trouvée{pluriel2} (seuil {2}%)'.format(

                tests_nbr,

                len(comparaison),

                args.threshold,

                pluriel1=("", "s")[tests_nbr > 1],

                pluriel2=("", "s")[len(comparaison) > 1],

                ))

    for k in comparaison.keys():

        print("{:s}{sep}{:s}{sep}{:.2f}%{sep}{:d}".format(

                    ziques[comparaison[k]['a']]['path'],

                    ziques[comparaison[k]['b']]['path'],

                    comparaison[k]['correlation'] * 100,

                    comparaison[k]['offset'],

                    sep = args.separator

                ))