"""Transformation and filtering functions for Alooma pipeline."""


art_relations_table_black_list = [
    'delivery_history_detail',
    'track_pricing_tier_country',
    'track_pricing_tier',
    'release_pricing_tier_country',
    'dig_sales',
    'processed_dig_sales',
    'dig_sales_detail',
    'vectorapi_auth_codes',
    'trackdown_media_access',
    'release_accounting',
    'dms_deletions',
    'script_status',    # no PK
    'standout_track',    # no PK
    'oa_logins',    # no PK
    'product_physical_reports_change_history',    # no PK
    'youtube_channel_video_remove_duplicates' # table truncated
    ]

art_relations_schema_black_list = dict(
    art_relations=art_relations_table_black_list,
    art_restore='*',
    cloudsearch='*',
    compilations='*',
    prod_maxwell='*',
    publishing='*',
    royalty_collections='*',
    sugarcrm='*',
    test='*',
    test1='*')

black_list = dict(
    art_relations_prod=art_relations_schema_black_list,
    art_relations_prod_dump=art_relations_schema_black_list)


events_to_clean = {
    'art_relations.track': ['track_name'],
    'art_relations.releases': ['vendor_catalog_number', 'release_name'],
    'art_relations.artist_info': ['name'],
    'art_relations.project': ['project_name', 'project_code'],
    'art_relations_log.project_log': ['project_name', 'project_code'],
    'art_relations.release_artist': ['artist_name']
}


def is_rollback_table(table):
    """Determine if a table is a rollback table.

    Args:
        table (str): table name.

    Returns:
        bool: is it rollback table or not
    """
    return table.upper().startswith('ROLLBACK')


def is_dbchangelog_table(table):
    """Determine if a table is a changelog table.

    Args:
        table (str): table name.

    Returns:
        bool: is it changelog table or not
    """
    return table.upper().startswith('DATABASECHANGELOG')


def is_table_black_listed(input_label, schema, table):
    """Determine if a table is blacklisted.

    Args:
        input_label (str): input label from event.
        schema (str): DB schema name.
        table (str): DB table name.

    Returns:
        bool: is table blacklisted or not.
    """
    if is_rollback_table(table):
        return True

    if is_dbchangelog_table(table):
        return True

    if input_label not in black_list:
        return False

    if schema not in black_list[input_label]:
        return False

    if '*' in black_list[input_label][schema]:
        return True

    return table in black_list[input_label][schema]


def clean_event_values(event):
    """Remove null byte codes at the start of select event fields.

    Event passed in is itself cleaned (since it is a dict).

    Args:
        dict (dict): Alooma event to clean.
            Assumes that event['_metadata']['event_type'] = <schema>.<table>
    """
    event_type = event['_metadata']['event_type']
    if event_type in events_to_clean:
        for field in events_to_clean[event_type]:
            # protect against when field is NULL
            if field in event and event[field] is not None:
                event[field] = event[field].strip(b'\0')


# TODO: add comment why do we need this manual overwrite.
DESCRIPTION_OVERRIDES = {
    'c831b479-1795-4392-8dff-b1f50cce5123': '<p>LOSFUOCOS was born in 2002 with the idea of playing some rock and roll and&nbsp;</p>\r\n<p>follow the trail of Scandinavian groups like the Hellacopters, Gluecifer or&nbsp;</p>\r\n<p>Turbonegro. The thing that united us is the desire to create our own sound derived from different musical influences: punk rock, hardcore and death metal.&nbsp;</p>\r\n<p>After many years, we have published a lot of material, we shared the stage&nbsp;</p>\r\n<p>with some of our favorite bands (Firebird, Imperial State Electric, the Dirtbombs, Thunder Express, Michael Davis of MC5, the Muggs) and now we are ready&nbsp;</p>\r\n<p>to start again with a new line-up and new songs between Sixties proto punk&nbsp;</p>\r\n<p>and Seventies hard rock .</p>\r\n<p>Stay tuned for more rock and roll!</p>\r\n<p>LOSFUOCOS are:</p>\r\n<p>PADO &ndash; Guitar + Lead Vocals</p>\r\n<p>DEN &ndash; Bass + Background Vocals</p>\r\n<p>GG &ndash; Guitar + Lead Vocals</p>\r\n<p>FRANK &ndash; Drums</p>'  # noqa
}


def transform(event):
    """Transform function.

    Args:
        event (dict): Alooma event.

    Returns:
        dict: Alooma event.
    """
    if event['_metadata']['input_label'] == 'SalesPlatform':
        event['_metadata']['schema'] = 'SALESPLATFORM_QA'

    if event['_metadata']['input_label'] == 'qa-ows-podcast':
        event['_metadata']['schema'] = 'qa_{}'.format(
            event['_metadata']['schema'])

    event_uuid = event['_metadata']['@uuid']

    if event['_metadata']['input_type'] == 'mongodb':
        schema = event['_metadata']['db']
    else:
        input_label = event['_metadata']['input_label']
        schema = event['_metadata']['schema']
        table = event['_metadata']['table']

        if is_table_black_listed(input_label, schema, table):
            return None

    if event_uuid in DESCRIPTION_OVERRIDES:
        event['description'] = DESCRIPTION_OVERRIDES[event_uuid]

    event['_metadata']['event_type'] = '{}.{}'.format(
        schema, event['_metadata']['event_type'])

    clean_event_values(event)

    return event