"""Lambda util shared module."""

import csv


from sosmodels import consts as sos_consts

import consts  # noqa

DB_FIELD_PATTERN = 'transactiontype_{tid}__{metric}'

csv.register_dialect(
    'escaped', delimiter=',', quotechar='"', escapechar='\\',
    quoting=csv.QUOTE_ALL)


def totals_as_dict(item_data, transactiontype_id):
    """Generate total metrics dict by transaction type.

    Args:
        item_data (dict): Representation
        transactiontype_id (int): Transaction type id value.

    Returns:
        dict: values for all total metrics.

    """
    totals = {
        metric: int(item_data[DB_FIELD_PATTERN.format(
            tid=transactiontype_id, metric=metric)])
        for metric in sos_consts.TOTAL_METRICS}
    return totals


def extract_triggered_key(lambda_event):
    """Get S3 bucket and key from lambda event.

    Args:
        lambda_event (dict): AWS Lambda event meta data object.

    Returns:
         (str, str): Tuple of bucket and key names.

    """
    record = lambda_event['Records'][0]['s3']
    return record['bucket']['name'], record['object']['key']


def object_is_file(s3_object):
    """Check if passed object is file (and not folder).

    Args:
        s3_object (str): S3 object suffix (file or folder).

    Returns:
        bool: True if object is file, otherwise False.

    """
    return s3_object[-1] != '/'


def identify_retailer(s3_key_url):
    """Identify store by key path.

    Args:
         s3_key_url (str): S3 key path.

    """
    for store in consts.AVAILABLE_STORES:
        if store in s3_key_url:
            return store


def identify_totals_type(s3_key_url):
    """Identify totals_type by key path.

    Args:
         s3_key_url (str): S3 key path.

    """
    for totals_type in consts.AVAILABLE_TOTALS_TYPES:
        if totals_type in s3_key_url:
            return totals_type