Class MetaStringDecoder

python/pyfory/meta/metastring.py:71–256

Decodes MetaString objects back into their original plain text form.

class MetaStringDecoder:
    """
    Decodes MetaString objects back into their original plain text form.
    """

    def __init__(self, special_char1: str, special_char2: str):
        """
        Creates a MetaStringDecoder with specified special characters used for decoding.

        Args:
            special_char1 (str): The first special character used for encoding.
            special_char2 (str): The second special character used for encoding.
        """
        self.special_char1 = special_char1
        self.special_char2 = special_char2

    def decode(self, encoded_data: bytes, encoding: Encoding) -> str:
        """
        Decodes the encoded data using the specified encoding.

        Args:
            encoded_data (bytes): The data to decode.
            encoding (Encoding): The encoding type used for decoding.

        Returns:
            str: The decoded string.
        """
        if len(encoded_data) == 0:
            return ""
        return self.decode_with_encoding(encoded_data, encoding)

    def decode_with_encoding(self, encoded_data: bytes, encoding: Encoding) -> str:
        """
        Decodes the encoded data with the specified encoding.

        Args:
            encoded_data (bytes): The data to decode.
            encoding (Encoding): The encoding type.

        Returns:
            str: The decoded string.
        """
        if encoding == Encoding.LOWER_SPECIAL:
            return self._decode_lower_special(encoded_data)
        elif encoding == Encoding.LOWER_UPPER_DIGIT_SPECIAL:
            return self._decode_lower_upper_digit_special(encoded_data)
        elif encoding == Encoding.FIRST_TO_LOWER_SPECIAL:
            return self._decode_rep_first_lower_special(encoded_data)
        elif encoding == Encoding.ALL_TO_LOWER_SPECIAL:
            return self._decode_rep_all_to_lower_special(encoded_data)
        elif encoding == Encoding.UTF_8:
            return encoded_data.decode("utf-8")
        else:
            raise ValueError(f"Unexpected encoding flag: {encoding}")

    def _decode_lower_special(self, data: bytes) -> str:
        """
        Decodes data encoded with LOWER_SPECIAL encoding.