Python OOP Retake Exam - 22 August 2022 - Food Orders App

# Python OOP Retake Exam - 22 August 2022 - Food Orders App

# https://judge.softuni.org/Contests/Practice/Index/3591#1
=============================================================================================
# file name: validator.py

class Validator:

    @staticmethod
    def raise_if_string_is_empty(string: str, error_msg: str):
        if string.strip() == '':
            raise ValueError(error_msg)

    @staticmethod
    def raise_if_phone_number_is_invalid(phone_number: str, error_msg):
        if len([n for n in phone_number if n.isdigit()]) != 10 or \
                phone_number[0] != '0':
            raise ValueError(error_msg)

    @staticmethod
    def raise_if_price_less_or_eq_zero(price: float, error_msg):
        if price <= 0:
            raise ValueError(error_msg)

    @staticmethod
    def raise_if_menu_is_less_than_5_dishes(menu, error_msg):
        if len(menu) < 5:
            raise Exception(error_msg)

    @staticmethod
    def find_client_by_phone_number(phone_number, client_list):
        client = [c for c in client_list if c.phone_number == phone_number]
        if client:
            return client[0]
        return None

    @staticmethod
    def raise_if_meal_name_not_in_menu(client_orders, menu):
        for meal, count in client_orders.items():
            if meal not in [m.name for m in menu]:
                raise Exception(f'{meal} is not on the menu!')

    @staticmethod
    def raise_if_qnt_is_wrong(client_orders, menu):
        all_qnt = [order.quantity for order in menu]
        all_products = [product.name for product in menu]
        all_types = [type(product).__name__ for product in menu]

        result1 = dict(zip(all_products, all_qnt))
        result2 = dict(zip(all_products, all_types))

        for meal, count in client_orders.items():
            if count > result1[meal]:
                raise Exception(f'Not enough quantity of {result2[meal]}: {meal}!')

    @staticmethod
    def remove_qnt_from_general_menu(general_menu, meal, qnt):
        for obj_meal in general_menu:
            if obj_meal.name == meal:
                obj_meal.quantity -= qnt

    @staticmethod
    def add_qnt_to_general_menu(general_menu, meal, qnt):
        for obj in general_menu:
            if obj.name == meal:
                obj.quantity += qnt

=============================================================================================
# file name: dessert.py

from project.meals.meal import Meal


class Dessert(Meal):

    def __init__(self, name: str, price: float, quantity=30):
        super().__init__(name, price, quantity)

    def details(self):
        return f'Dessert {self.name}: {self.price:.2f}lv/piece'

=============================================================================================
# file name: main_dish.py

from project.meals.meal import Meal


class MainDish(Meal):

    def __init__(self, name: str, price: float, quantity=50):
        super().__init__(name, price, quantity)

    def details(self):
        return f'Main Dish {self.name}: {self.price:.2f}lv/piece'

=============================================================================================
# file name: meal.py

from abc import ABC, abstractmethod

from project.helper.validator import Validator


class Meal(ABC):

    def __init__(self, name: str, price: float, quantity: int):
        self.name = name
        self.price = price
        self.quantity = quantity

    @property
    def name(self):
        return self.__name

    @name.setter
    def name(self, value):
        Validator.raise_if_string_is_empty(value, 'Name cannot be an empty string!')
        self.__name = value

    @property
    def price(self):
        return self.__price

    @price.setter
    def price(self, value):
        Validator.raise_if_price_less_or_eq_zero(value, 'Invalid price!')
        self.__price = value

    @abstractmethod
    def details(self):
        ...

=============================================================================================
# file name: starter.py

from project.meals.meal import Meal


class Starter(Meal):

    def __init__(self, name: str, price: float, quantity=60):
        super().__init__(name, price, quantity)

    def details(self):
        return f'Starter {self.name}: {self.price:.2f}lv/piece'

=============================================================================================
# file name: client.py

from project.helper.validator import Validator


class Client:
    def __init__(self, phone_number: str):
        self.phone_number = phone_number
        self.shopping_cart = []  # List to add OBJs by the client !
        self.bill = float(0.0)

    @property
    def phone_number(self):
        return self.__phone_number

    @phone_number.setter
    def phone_number(self, value):
        Validator.raise_if_phone_number_is_invalid(value, 'Invalid phone number!')
        self.__phone_number = value

=============================================================================================
# file name: food_orders_app.py

from project.client import Client
from project.helper.validator import Validator
from project.meals.dessert import Dessert
from project.meals.main_dish import MainDish
from project.meals.meal import Meal
from project.meals.starter import Starter


class FoodOrdersApp:
    def __init__(self):
        self.menu = []  # all the meals (objects)!
        self.clients_list = []  # all the clients (objects)!
        self.order = 0

    def register_client(self, client_phone_number: str):
        client = Client(client_phone_number)
        if [c for c in self.clients_list if c.phone_number == client_phone_number]:
            raise Exception('The client has already been registered!')
        self.clients_list.append(client)
        return f'Client {client_phone_number} registered successfully.'

    def add_meals_to_menu(self, *meals: Meal):
        for meal in meals:
            if type(meal).__name__ in ['Starter', 'MainDish', 'Dessert']:
                self.menu.append(meal)

    def show_menu(self):
        Validator.raise_if_menu_is_less_than_5_dishes(self.menu, 'The menu is not ready!')
        result = ''
        for meal in self.menu:
            result += meal.details() + '\n'
        return result.strip()

    def add_meals_to_shopping_cart(self, client_phone_number: str, **meal_names_and_quantities):
        client = None
        # Validate menu before adding items to the client!
        Validator.raise_if_menu_is_less_than_5_dishes(self.menu, 'The menu is not ready!')
        # searching for client , if not in the list -> auto-add it !
        client = Validator.find_client_by_phone_number(client_phone_number, self.clients_list)
        if client is None:
            client = Client(client_phone_number)
        self.clients_list.append(client)
        Validator.raise_if_meal_name_not_in_menu(meal_names_and_quantities, self.menu)
        Validator.raise_if_qnt_is_wrong(meal_names_and_quantities, self.menu)
        self.add_client_order_to_client_shopping_card(client, meal_names_and_quantities)
        print_names = [x.name for x in client.shopping_cart]
        return f"Client {client.phone_number} successfully ordered {', '.join(print_names)} for {client.bill:.2f}lv."

    def add_client_order_to_client_shopping_card(self, client: Client, client_order):
        class_mapper = {
            'Starter': Starter,
            'MainDish': MainDish,
            'Dessert': Dessert,
        }
        meal_names = []
        for meal, qnt in client_order.items():
            Validator.remove_qnt_from_general_menu(self.menu, meal, qnt)

            meal_names.append(meal)
            current_type = [type(obj).__name__ for obj in self.menu if obj.name == meal][0]
            current_price = [obj.price for obj in self.menu if obj.name == meal][0]
            current_meal_obj = class_mapper[current_type](meal, current_price, qnt)

            client.bill += current_price * qnt
            client.shopping_cart.append(current_meal_obj)

    def cancel_order(self, client_phone_number: str):
        client = Validator.find_client_by_phone_number(client_phone_number, self.clients_list)
        if len(client.shopping_cart) <= 0:
            raise Exception('There are no ordered meals!')
        else:
            for obj in client.shopping_cart:
                meal_name = obj.name
                meal_qnt = obj.quantity
                Validator.add_qnt_to_general_menu(self.menu, meal_name, meal_qnt)
        client.shopping_cart = []
        client.bill = 0
        return f"Client {client_phone_number} successfully canceled his order."

    def finish_order(self, client_phone_number: str):
        client = Validator.find_client_by_phone_number(client_phone_number, self.clients_list)
        if len(client.shopping_cart) <= 0:
            raise Exception('There are no ordered meals!')
        self.order += 1
        total_paid_money = client.bill
        client.shopping_cart = []
        client.bill = 0

        return f"Receipt #{self.order} with total amount of {total_paid_money:.2f}" \
               f" was successfully paid for {client_phone_number}."

    def __str__(self):
        result = f'Food Orders App has {len(self.menu)} meals on the menu ' \
               f'and {len(self.clients_list)} clients.'
        return result.strip()