import itertools
import hashlib
import hmac


class NonceFinder:
    def __init__(self, data, difficulty, key):
        self.data = data
        self.difficulty = difficulty
        self.key = key

    @staticmethod
    def to_long(x):
        return sum(ord(b) << (8 * i) for i, b in enumerate(x))

    def verify_pow(self, nonce):
        self.data[0]['nonce'] = nonce
        # Использование HMAC с SHA-256
        combined_data = str(self.data).encode()
        hmac_result = hmac.new(self.key.encode(), combined_data, hashlib.sha256).hexdigest()
        return self.to_long(list(hmac_result)) % (1 << self.difficulty) == 0

    def create_pow(self):
        for nonce in itertools.count(0):
            if self.verify_pow(nonce):
                combined_data = str(self.data).encode()
                hmac_result = hmac.new(
                    self.key.encode(),
                    combined_data,
                    hashlib.sha256
                ).hexdigest()
                return nonce, hmac_result