from rest_framework import renderers


# IP address family designations
AF = {
    4: 'A',
    6: 'AAAA',
}


class BINDZoneRenderer(renderers.BaseRenderer):
    """
    Generate a BIND zone file from a list of DNS records.
        Required fields: `name`, `primary_ip`
    """
    media_type = 'text/plain'
    format = 'bind-zone'

    def render(self, data, media_type=None, renderer_context=None):
        records = []
        for record in data:
            if record.get('name') and record.get('primary_ip'):
                try:
                    records.append("{} IN {} {}".format(
                        record['name'],
                        AF[record['primary_ip']['family']],
                        record['primary_ip']['address'].split('/')[0],
                    ))
                except KeyError:
                    pass
        return '\n'.join(records)