import itertools
import string
from modes.hash_mode import HashMode


class CollisionsTest:
    """
    Грубый поиск коллизий: перебираем строки до max_len
    из заданного алфавита и проверяем, совпадут ли хэши.
    """

    def run(self, variant: str, max_len: int = 3, alphabet: str = "alnum", bytes: int = 16) -> dict:
        hasher = HashMode()
        seen = {}

        # выбор алфавита
        if alphabet == "alnum":
            chars = string.ascii_lowercase + string.digits
        elif alphabet == "alpha":
            chars = string.ascii_lowercase
        elif alphabet == "digits":
            chars = string.digits
        else:
            raise ValueError(f"Неизвестный алфавит: {alphabet}")

        for length in range(1, max_len + 1):
            for msg_tuple in itertools.product(chars, repeat=length):
                msg = "".join(msg_tuple)
                h = hasher.run(variant, msg, bytes=bytes)
                if h in seen:
                    return {
                        "collision_found": True,
                        "hash": h,
                        "messages": [seen[h], msg],
                    }
                seen[h] = msg

        return {"collision_found": False}