"""Data transformation functions."""

from availability_etl import constants


def transformed(dicts):
    """Generator of transformed data rows.

    Args:
        dicts (iterable): An iterable of data rows as dictionaries.

    Yields:
        dict: A dictionary with transformed row data.

    Raises:
        StopIteration: There are no more items to yield.
    """
    transformation_functions = [
        store_internal_id_to_storefront_url,
    ]
    for row in dicts:
        for transformation_function in transformation_functions:
            row = transformation_function(row)
        yield (row)


def store_internal_id_to_storefront_url(row_dict):
    """Transform store_internal_id to store-specific storefront_url.

    Args:
        row_dict (dict): Data row as a dictionary.

    Returns:
        dict: transformed row_dict.
    """
    store_internal_id = row_dict[constants.COLUMN_STORE_INTERNAL_ID]
    store_id = row_dict[constants.COLUMN_STORE_ID]
    storefront_url_pattern = constants.STOREFRONT_URLS_TEMPLATES[store_id]
    if store_internal_id:
        storefront_url = storefront_url_pattern.format(store_internal_id)
    else:
        storefront_url = constants.CSV_EMPTY_STR
    del row_dict[constants.COLUMN_STORE_INTERNAL_ID]
    row_dict[constants.COLUMN_STOREFRONT_URL] = storefront_url
    return row_dict