using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    // Here we have a feature that will preform two functions. First it will get a list of customers and print a message if there are any duplicates.

    // Second it will print all the customer names.

    //

    // Take a few minutes and look over the code and then describe what you think could be improved.

    public static void Main()

    {

        CustomerProvider provider = new CustomerProvider();

        var customers = provider.GetCustomers();

        var customersToCheck = MapToSimpleCustomer(customers).ToArray();

        var containsDuplicate = false;

        for(int idx=0; idx<customersToCheck.Count(); idx++)

        {

            var dupeCount = 0;

            for(int idx1=0; idx1<customersToCheck.Count(); idx1++)

            {

                if (customersToCheck[idx].FirstName == customersToCheck[idx1].FirstName && customersToCheck[idx].LastName == customersToCheck[idx1].LastName)

                {

                    dupeCount++;

                }

            }

            if (dupeCount > 1)

            {

                containsDuplicate = true;

            }

        }

        if (containsDuplicate)

        {

            Console.WriteLine("A duplicate name was found in the customer list.");

        }

        var customersToList = provider.GetCustomers();

        var customersToPrint = MapToSimpleCustomer(customers);

        customersToPrint.ForEach(customer => 

            {

                Console.WriteLine($"Customer: {customer.FirstName} {customer.LastName}");

            });

    }

    private static List<SimpleCustomer> MapToSimpleCustomer(List<CustomerDTO> customers)

    {

        return customers.Select(customer => new SimpleCustomer(customer.FirstName, customer.LastName)).ToList();

    }

}

​

public class SimpleCustomer 

{

    public SimpleCustomer(string firstName, string lastName)

    {

        FirstName = firstName;

        LastName = lastName;

    }

    public string FirstName {get; set;}

    public string LastName {get; set;}

}

​

public class CustomerProvider 

{

    CustomerRepository customerRepo = new CustomerRepository();

    public List<CustomerDTO> GetCustomers()

    {

        var customers = customerRepo.GetCustomers();

        return MapCustomers(customers);

    }

    private List<CustomerDTO> MapCustomers(List<Customer> customers)

    {

        var customersToMap = customers.ToArray();

        return customers.Select(customer => 

                                {

                                    var custDto = new CustomerDTO(customer.FirstName, customer.LastName);

                                    custDto.IsCurrent = customer.IsCurrent;

                                    custDto.Description = customer.Description;

                                    return custDto;

                                }).ToList();

    }

}

​

public class CustomerRepository 

{

    public List<Customer> GetCustomers()

    {

        // Test data for the purpose of this exercise

        // normally this data would be retreived via an API call

        var memberList =  new List<Customer>()

        {

            new Customer("Annie", "Lennox"),

            new Customer("Tina", "Turner"),

            new Customer("Ann", "Wilson"),

            new Customer("Dolly", "Parton"),

            new Customer("Bishop", "Briggs"),

            new Customer("Tracy", "Chapman"),

            new Customer("Ann", "wilson")

        };

        return memberList;

    }

}

​

public class CustomerDTO

{

    public CustomerDTO(string firstName, string lastName)

    {

        FirstName = firstName;

        LastName = lastName;

    }

    public string FirstName {get; set;}

    public string LastName {get; set;}

    public string IsCurrent {get; set;}

    public string Description {get; set;}

}

​

public class Customer

{

    public Customer(string firstName, string lastName)

    {

        FirstName = firstName;

        LastName = lastName;

    }

    public string FirstName {get; set;}

    public string LastName {get; set;}

    public string IsCurrent {get; set;}

    public string Description {get; set;}

}