import hashlib
import hmac
from typing import List, Optional, Tuple

from nacl.bindings import crypto_sign_seed_keypair

from ._settings import PBKDF_ITERATIONS
from ._utils import get_secure_random_number, is_basic_seed
from .bip39 import english


def mnemonic_is_valid(mnemo_words: List[str]) -> bool:
    return len(mnemo_words) == 24 and is_basic_seed(mnemonic_to_entropy(mnemo_words))


def mnemonic_to_entropy(mnemo_words: List[str], password: Optional[str] = None):
    # TODO: implement password
    sign = hmac.new((" ".join(mnemo_words)).encode(
        'utf-8'), bytes(0), hashlib.sha512).digest()
    return sign


def mnemonic_to_seed(mnemo_words: List[str], seed: str, password: Optional[str] = None):
    entropy = mnemonic_to_entropy(mnemo_words, password)
    return hashlib.pbkdf2_hmac("sha512", entropy, seed, PBKDF_ITERATIONS)


def mnemonic_to_private_key(mnemo_words: List[str], password: Optional[str] = None) -> Tuple[bytes, bytes]:
    """
    :rtype: (bytes(public_key), bytes(secret_key))
    """
    seed = mnemonic_to_seed(
        mnemo_words, 'TON default seed'.encode('utf-8'), password)
    return crypto_sign_seed_keypair(seed[:32])


def mnemonic_to_wallet_key(mnemo_words: List[str], password: Optional[str] = None) -> Tuple[bytes, bytes]:
    """
    :rtype: (bytes(public_key), bytes(secret_key))
    """
    _, priv_k = mnemonic_to_private_key(mnemo_words, password)
    return crypto_sign_seed_keypair(priv_k[:32])


def mnemonic_new(words_count: int = 24, password: Optional[str] = None) -> List[str]:
    while True:
        mnemo_arr = []

        for _ in range(words_count):
            idx = get_secure_random_number(0, len(english))
            mnemo_arr.append(english[idx])

        if not is_basic_seed(mnemonic_to_entropy(mnemo_arr)):
            continue

        break

    return mnemo_arr