def aggregate_archivals_for_a_dataset(archivals):
    '''Returns aggregated archival info for a dataset, given the archivals for
    its resources (returned by get_for_package).

    :param archivals: A list of the archivals for a dataset's resources
    :type archivals: A list of Archival objects
    :returns: Archival dict about the dataset, with keys:
                status_id
                status
                reason
                is_broken
    '''
    archival_dict = {'status_id': None, 'status': None,
                     'reason': None, 'is_broken': None}
    for archival in archivals:
        # status_id takes the highest id i.e. pessimistic
        # reason matches the status_id
        if archival_dict['status_id'] is None or \
                archival.status_id > archival_dict['status_id']:
            archival_dict['status_id'] = archival.status_id
            archival_dict['reason'] = archival.reason

    if archivals:
        archival_dict['status'] = Status.by_id(archival_dict['status_id'])
        archival_dict['is_broken'] = \
            Status.is_status_broken(archival_dict['status_id'])
    return archival_dict