from Cryptodome.Cipher import AES
from binascii import b2a_hex,a2b_hex
from Cryptodome import Random


class AesEncryption(object):
    def __init__(self, key, mode=AES.MODE_CFB):
        self.key = self.check_key(key)
        # 金鑰key長度必須為16,24或者32bytes的長度
        self.mode = mode
        self.iv = Random.new().read(AES.block_size)

    def check_key(self, key):
        '檢測key的長度是否為16,24或者32bytes的長度'
        try:
            if isinstance(key, bytes):
                assert len(key) in [16, 24, 32]
                return key
            elif isinstance(key, str):
                assert len(key.encode()) in [16, 24, 32]
                return key.encode()
            else:
                raise Exception(f'金鑰必須為str或bytes,不能為{type(key)}')
        except AssertionError:
            print('輸入的長度不正確')

    def check_data(self,data):
        '檢測加密的資料型別'
        if isinstance(data, str):
            data = data.encode()
        elif isinstance(data, bytes):
            pass
        else:
            raise Exception(f'加密的資料必須為str或bytes,不能為{type(data)}')
        return data
    def encrypt(self, data):
        ' 加密函式 '
        data = self.check_data(data)
        cryptor = AES.new(self.key, self.mode,self.iv)
        return b2a_hex(cryptor.encrypt(data)).decode()

    def decrypt(self,data):
        ' 解密函式 '
        data = self.check_data(data)
        cryptor = AES.new(self.key, self.mode,self.iv)
        return cryptor.decrypt(a2b_hex(data)).decode()

if __name__ == '__main__':
    key = input('請輸入key:')
    data = '你真帥'
    aes = AesEncryption(key)
    e = aes.encrypt(data)  # 呼叫加密函式
    d = aes.decrypt(e)  # 呼叫解密函式
    print(e)
    print(d)