using System;

using System.Collections.Generic;

using System.Linq;

using System.Threading.Tasks;

​

public class Program

{

    private static List<SalesRecord> salesRecords = new();

    public static void Main()

    {

        var currentServiceProvider = "AWS";

        var accManager = GetAccountManager(currentServiceProvider);

​

        Console.WriteLine("Enter User ID:");

        var userId = Console.ReadLine();

        Console.WriteLine("Enter Password:");

        var password = Console.ReadLine();

​

        // Authenticate user

        var isAuthenticated = accManager.Authenticate(userId, password);

        if (!isAuthenticated)

        {

            Console.WriteLine("Invalid credentials. Exiting...");

            return;

        }

        var random = new Random();

        for (var i = 0; i < 10000; i++)

        {

            var item = i < 4000 ? "A" : i < 8000 ? "B" : "C";

            salesRecords.Add(new SalesRecord(item, random.Next(1, 100)));

        }

​

        // ... Propagate salesRecords with random quantities ...

​

​

        Console.WriteLine("Which item do you want to view? (A/B/C):");

        var chosenItem = Console.ReadLine();

​

        // Filter and sort salesRecords by quantity in descending order

        var filteredRecords = salesRecords.Where(record => record.Item == chosenItem)

                                          .OrderByDescending(record => record.Qty);

​

        // Print item codes and quantities

        foreach (var record in filteredRecords)

        {

            Console.WriteLine($"Item: {record.Item}, Quantity: {record.Qty}");

        }

    }

​

    public static IAccountManager GetAccountManager(string serviceProvider)

    {

        switch (serviceProvider)

        {

            case "AWS":

                return new AwsAccountManager(new AwsService());

            case "Azure":

                return new AzureAccountManager(new AzureService());

            default:

                throw new ArgumentException("Invalid service provider");

        }

    }

}

​

public struct SalesRecord

{

    public string Item { get; set; }

​

    public int Qty { get; set; }

​

    public SalesRecord(string item)

    {

        Item = item;

        Qty = 0;

    }

    public SalesRecord(string item, int qty)

    {

        Item = item;

        Qty = qty;

    }

}

​

public interface IAccountManager

{

    public bool Authenticate(string userId, string password);

}

​

// ... Implement the IAccountManager interface ...

public class AwsAccountManager : IAccountManager

{

    private readonly AwsService _awsService;

​

    public AwsAccountManager(AwsService awsService)

    {

        _awsService = awsService;

    }

​

    public bool Authenticate(string userId, string password)

    {

        return _awsService.Authenticate(userId, password);

    }

}

​

public class AzureAccountManager : IAccountManager

{

    private readonly AzureService _azureService;

​

    public AzureAccountManager(AzureService azureService)

    {

        _azureService = azureService;

    }

​

    public bool Authenticate(string userId, string password)

    {

        return _azureService.AuthUser(userId, password);

    }

}

​

​

// Do not modify below classes.

public class AwsService

{

    public bool Authenticate(string userId, string password)

    {

        return userId == "aws" && password == "abc123";

    }

​

    public bool DeleteUser(string userId)

    {

        return true;

    }

}

​

public class AzureService

{

    public bool AuthUser(string userId, string password)

    {

        return userId == "azure" && password == "abc321";

    }

​

    public bool RemoveUser(string userId)

    {

        return true;

    }

}

​