"""Functions to manage a users shopping cart items."""

from re import fullmatch


def add_item(current_cart, items_to_add):
    """Add items to shopping cart.

    :param current_cart: dict - the current shopping cart.
    :param items_to_add: iterable - items to add to the cart.
    :return: dict - the updated user cart dictionary.
    """
    # create a new cart with items_to_add if current_cart is empty
    # if current_cart == {}:
    #     current_cart = dict.fromkeys(items_to_add, 0)
    #     for item in items_to_add:
    #         current_cart[item] += 1
    #     return current_cart

    # (after doing this i realized that the bellow code also addresses the
    # concern of the current_cart being empty, so i commented out the code
    # above)

    # increment item by one if item already exists in current_cart,
    # otherwise add new item to current_cart with value of 1
    for item in items_to_add:
        current_cart[item] = current_cart.get(item, 0) + 1
    return current_cart


def read_notes(notes):
    """Create user cart from an iterable notes entry.

    :param notes: iterable of items to add to cart.
    :return: dict - a user shopping cart dictionary.
    """
    shopping_cart: dict = dict.fromkeys(notes, 0)
    for item in notes:
        shopping_cart[item] += 1
    return shopping_cart


def update_recipes(ideas, recipe_updates):
    """Update the recipe ideas dictionary.

    :param ideas: dict - The "recipe ideas" dict.
    :param recipe_updates: dict - dictionary with updates for the ideas section.
    :return: dict - updated "recipe ideas" dict.
    """
    ideas |= recipe_updates
    return ideas


def sort_entries(cart):
    """Sort a users shopping cart in alphabetically order.

    :param cart: dict - a users shopping cart dictionary.
    :return: dict - users shopping cart sorted in alphabetical order.
    """
    sorted_cart: dict = dict(sorted(cart.items()))
    return sorted_cart


def send_to_store(cart, aisle_mapping):
    """Combine users order to aisle and refrigeration information.

    :param cart: dict - users shopping cart dictionary.
    :param aisle_mapping: dict - aisle and refrigeration information dictionary.
    :return: dict - fulfillment dictionary ready to send to store.
    """
    fulfillment: dict[str, list] = {}
    for item in cart:
        fulfillment[item] = [cart[item],
                             aisle_mapping[item][0], aisle_mapping[item][1]]
    fulfillment = dict(sorted(fulfillment.items(), reverse=True))
    return fulfillment


def update_store_inventory(fulfillment_cart, store_inventory):
    """Update store inventory levels with user order.

    :param fulfillment cart: dict - fulfillment cart to send to store.
    :param store_inventory: dict - store available inventory
    :return: dict - store_inventory updated.
    """
    for item in fulfillment_cart:
        new_stock = store_inventory[item][0] - fulfillment_cart[item][0]
        store_inventory[item] = [
            "Out of Stock" if new_stock <= 0 else new_stock,
            store_inventory[item][1],
            store_inventory[item][2],
        ]
    return store_inventory