import json


def parse_event(event):
    """
    :param event: event object received by lambda
    :return: tuple containing message and metadata from an event object
    """
    metadata = {}
    message = json.loads(event['Records'][0]['Sns']['Message'])
    if 'NotificationMetadata' in message.keys():
        metadata = json.loads(message['NotificationMetadata'])
    return message, metadata