Write a C# code that creates objects and classes with their member functions for Vistaflyer, an Australian airlines loyalty program. You are asked to write an inheritance hierarchy discount system that benefits Vistaflyer members program to calculate their profit. A brief about Vistaflyer is that it is useful for those who fly on Australian Airlines (its partners like Virgin Singapore and Air New Zealand) frequently. Vistaflyer miles can be earned through credit cards, flying and bonus miles promotions. The miles can be redeemed for award flights in all categories. It has three types of memberships namely Basic, Elite Silver and Elite Gold. When registered for the first time, all the customers get instant access to the basic membership level of Vistaflyer. In 2020, Australia airlines offers a flat 10%, 20% and 30% discount to its Basic, Elite silver and Elite Gold members respectively for all services provided. Customers without membership receive no discounts. The students must implement basic OOPs concepts such as Inheritance, Polymorphism and Encapsulation. You can make your own assumptions, not necessarily the same values which are provided above.

Inheritance:

Base class: Create an inheritance hierarchy to represent various types of memberships. Use Vistaflyer as the base class of the hierarchy, then include derived classes Basic, Elite Silver and Elite Gold that derives from Vistaflyer. Base class Vistaflyer should have data members representing name, membership, flight, price for flight, number of passengers for the members. The constructor should initialize these data members. Ensure that flight price and number of passengers contain positive values. Vistaflyer should include a public member function calculateCost() that returns a double indicating the cost by multiplying the price for flight by the number of passengers.

Derived class: Basic, Elite Silver and Elite Gold should inherit the functionality of base class Vistaflyer, but also include a data member that represents a discount that the reward program has offered recently. All the derived classs constructor should receive a value to initialize this data member. In 2020, Australia Airlines offers a flat 10%, 20% and 30% discount to its Basic, Elite Silver and Elite gold members respectively for all services provided. All the derived members should redefine calculateCost() so that it applies the discount to the booked flights. It shall compute the total bill if a customer purchases y tickets for a price of $x for each flight for their visit using Vistaflyer.

Your system shall consist of four classes: Base class, Derived class (including Basic, Elite Silver and Elite Golden)

Polymorphism:

Implement a method display () that displays all the records of the system. Another form of the method display (string cust_name) that displays records related to the customers name passed in the argument.

Encapsulation: Define the instance variables private/public so that they cannot/can be accessed from outside the class. Implement getter and setter method for the variables in the program. Write a program that implements basic object-oriented concepts including encapsulation, polymorphism, and inheritance. Also, the program is expected to get the basic input from the user based on Console.

You need to do the following tasks:

1. Write the C# classes with suggested data members and functions.

2. Write the base and derived classes for implementing inheritance in the program.

3. Implement polymorphism and encapsulation to check for accessibility of data members and different form of the data member.

4. Write the main logic that takes input from the user members with their bookings.

5. Write the code to display the output.

6. Advanced topic: Create a windows form, by considering the same scenario, where you need to create a layout which will describe the Welcome Page with some submit buttons and few different controls. You are free to use any basic controls from the toolbox to design this layout.

Code related guidelines: Your C# console-based application should include the following:

1. The code should have a consistent, professional, and well-organized appearance.

2. Code should compile without errors.

3. Choose meaningful identifiers names.

4. The developed system takes inputs and handles the error in friendly manner.

5. Your code must adhere to OOPS concepts with implementation guidelines including modularity, reusability, extensibility, maintainability, and adaptability