import hashlib
import bech32

# https://liaoxuefeng.com/books/blockchain/bitcoin/segwit/index.html

def hash160(data):
    """
    计算输入数据的SHA-160哈希值。

    参数:
    data (bytes): 输入数据

    返回:
    bytes: SHA-160哈希值
    """
    return hashlib.new('ripemd160', hashlib.sha256(data).digest()).digest()

def encodeSegwit(data_bytes, hrp="fst"):
    """
    将字节数据编码为Bech32格式。

    参数:
    hrp (str): 人类可读部分 (Human-readable part)
    data_bytes (bytes): 要编码的数据

    返回:
    str: Bech32编码后的字符串
    """

    # 将字节转换为5位整数列表
    data_ints = bech32.convertbits(hash160(data_bytes), 8, 5)
    if not data_ints:
        raise ValueError("Failed to convert bytes to 5-bit integers")

    return bech32.bech32_encode(hrp, data_ints)


def verifySegwit(bech32_str):
    """
    验证Bech32编码的字符串是否有效。

    参数:
    bech32_str (str): Bech32编码的字符串

    返回:
    bool: 如果字符串有效则返回True，否则返回False
    """
    try:
        hrp, data_ints = bech32.bech32_decode(bech32_str)
        if not hrp or not data_ints:
            return False

        # 将5位整数列表转换回字节
        data_bytes = bech32.convertbits(data_ints, 5, 8, False)
        if not data_bytes:
            return False

        return True
    except Exception as e:
        print(f"Verification failed: {e}")
        return False


# 示例用法
if __name__ == "__main__":
    message = b"Hello, Bech32!"

    encoded = encodeSegwit(message)
    print(f"Encoded: {encoded}")

    is_valid = verifySegwit(encoded)
    print(f"Is valid: {is_valid}")