from hashlib import sha1, new
import os
from secrets import randbelow
from concurrent.futures import ProcessPoolExecutor
from itertools import takewhile
from functools import partial
from operator import ne
from random import shuffle, choices


RAND_SIZE = 128
N = 4 * 10 ** 7

def my_hash(s, k=-1):
    return int(sha1(s).hexdigest(), base=16)
    #return int(sha1(s).hexdigest(), base=16) >> (160 - k - 1)


template_message = "Прошу перевести 8000 руб 00 коп на счет №0101010{}. Клиент {}.RAND="
salt = b'=' + os.urandom(128)
case = 13

message = template_message.format(1, case).encode() + str(randbelow(10**6)).encode() + salt
new_message_template = template_message.format(1, case).encode()
message_hash = my_hash(message)

message_template = template_message.format(2, case).encode()
new_hashes = [my_hash(new_message_template + str(i).encode() + salt)
              for i in range(N)]

def calculate_collision1_for(k):
    message_hash_k = message_hash >> (160 - k - 1)
    #shuffle(new_hashes)
    return len(list(takewhile(partial(ne, message_hash_k),
                              (h >> (160 - k - 1) for h in choices(new_hashes, k=N))))) + 1

with ProcessPoolExecutor(max_workers=3) as pool:
    print(*zip(range(1, 25), pool.map(calculate_collision1_for, range(1, 25))), sep='\n')


hashes = [my_hash(message_template + str(i).encode() + salt)
              for i in range(N)]

def calculate_collision2_for(k):
    s1 = set()
    s2 = set()
    shuffle(hashes)
    shuffle(new_hashes)
    for h1, h2, i in zip(hashes, new_hashes, range(1, N+1)):
        h1 = h1 >> (160 - k - 1)
        h2 = h2 >> (160 - k - 1)
        if h1 in s2 or h2 in s1:
            print(k, i)
            return i
        s1.add(h1)
        s2.add(h2)
    return -1

with ProcessPoolExecutor(max_workers=3) as pool:
    print(*zip(range(1, 49), pool.map(calculate_collision2_for, range(1, 49))), sep='\n')