import gzip
import base64


def decompress(data):
    """
    Decodes a Base64 bytes (or string) input and decompresses it using Gzip
    :param data: Base64 (bytes) data to be decoded
    :return: Decompressed and decoded bytes
    """

    if isinstance(data, bytes):
        source = data
    elif isinstance(data, str):
        source = bytes(data, encoding='utf-8')
    else:
        raise RuntimeError("Compression is only supported for strings and bytes")

    return gzip.decompress(base64.b64decode(source))