#!/usr/bin/env python

# -*- coding: utf-8 -*-

"""

*TL;DR80

Separates presentation, application processing, and data management functions.

"""

class Data(object):

    """ Data Store Class """

    products = {

        'milk': {'price': 1.50, 'quantity': 10},

        'eggs': {'price': 0.20, 'quantity': 100},

        'cheese': {'price': 2.00, 'quantity': 10}

    }

    def __get__(self, obj, klas):

        print("(Fetching from Data Store)")

        return {'products': self.products}

class BusinessLogic(object):

    """ Business logic holding data store instances """

    data = Data()

    def product_list(self):

        return self.data['products'].keys()

    def product_information(self, product):

        return self.data['products'].get(product, None)

class Ui(object):

    """ UI interaction class """

    def __init__(self):

        self.business_logic = BusinessLogic()

    def get_product_list(self):

        print('PRODUCT LIST:')

        for product in self.business_logic.product_list():

            print(product)

        print('')

    def get_product_information(self, product):

        product_info = self.business_logic.product_information(product)

        if product_info:

            print('PRODUCT INFORMATION:')

            print('Name: {0}, Price: {1:.2f}, Quantity: {2:}'.format(

                product.title(), product_info.get('price', 0),

                product_info.get('quantity', 0)))

        else:

            print('That product "{0}" does not exist in the records'.format(

                product))

def main():

    ui = Ui()

    ui.get_product_list()

    ui.get_product_information('cheese')

    ui.get_product_information('eggs')

    ui.get_product_information('milk')

    ui.get_product_information('arepas')

if __name__ == '__main__':

    main()

### OUTPUT ###

# PRODUCT LIST:

# (Fetching from Data Store)

# cheese

# eggs

# milk

#

# (Fetching from Data Store)

# PRODUCT INFORMATION:

# Name: Cheese, Price: 2.00, Quantity: 10

# (Fetching from Data Store)

# PRODUCT INFORMATION:

# Name: Eggs, Price: 0.20, Quantity: 100

# (Fetching from Data Store)

# PRODUCT INFORMATION:

# Name: Milk, Price: 1.50, Quantity: 10

# (Fetching from Data Store)

# That product "arepas" does not exist in the records