decode_message

def decode_message(message: "StreamMessage[Any]") -> "DecodedMessage":
    """Decodes a message."""
    body: Any = getattr(message, "body", message)
    m: DecodedMessage = body

    if content_type := getattr(message, "content_type", False):
        with contextlib.suppress(ValueError):
            content_type = ContentTypes(cast("str", content_type))

        if content_type is ContentTypes.TEXT:
            m = body.decode()

        elif content_type is ContentTypes.JSON or (
            isinstance(content_type, str)
            and content_type.startswith(ContentTypes.JSON.value)
        ):
            m = json_loads(body)

    else:
        # content-type not set
        with suppress(json.JSONDecodeError, UnicodeDecodeError):
            m = json_loads(body)

    return m