import hashlib

def hash_file(filepath):
    BUF_SIZE = 65 * 1024

    sha = hashlib.sha256()

    with open(filepath, 'rb') as f:
        while True:
            data = f.read(BUF_SIZE)
            if not data:
                break
            sha.update(data)
    return sha.hexdigest()

def hash_bytes(data):
    sha = hashlib.sha256()
    sha.update(data)
    return sha.hexdigest()

def hash_string(data:str): 
    sha = hashlib.sha256() 
    sha.update(str(data).encode('utf-8')) 
    return sha.hexdigest()

# ---------------
import datetime
import string
import itertools
import random

def get_nonce(characters, lenght):
    yield from itertools.product(*([characters] * lenght)) 

def count_leading_zeros(text):
    n = 0
    for i in range(len(text)):
        if text[:i] == "0" * i:
            n = i
        else:
            break
    return n

def mine_user(data, force=4, nonce_lenght=4):
    characters = '[@_!#$%^&*()<>?/\|}{~:]'+string.ascii_letters+string.digits
    while True: 
        for x in get_nonce(characters, nonce_lenght):
            nonce = ''.join(x)+random.choice(characters)
            hash = hash_string(data+ nonce)
            leading_zeros = count_leading_zeros(hash)
            if leading_zeros >= force:
                return nonce
        

def test():
    print(datetime.datetime.now(), "EXECUTING HASH TEST - MINE USER")
    public_key_str = "A4DZSk+TlR+4w39MbiIAQbti+N0H1QlJEhRH2DI6Iubj"
    nonce, hash = mine_user(public_key_str)

    print(nonce, hash)
    
# test()

# A4DZSk+TlR+4w39MbiIAQbti+N0H1QlJEhRH2DI6Iubj
# 8
# eYnU*@
# [/Q#7r