Refactoring challenge

​

​

​

​

​

using Microsoft.AspNetCore.Mvc;

using System.Collections.Generic;

using System.Threading.Tasks;

​

public class Payment

{

    public int Id { get; set; }

    public decimal Amount { get; set; }

    public bool IsProcessed { get; set; }

}

​

public class PaymentService

{

    private readonly ILogger _logger;

    public List<Payment> Payments { get; } = new List<Payment>();

​

    public PaymentService()

    {

    }

​

    public Task<decimal> ProcessPaymentsAsync()

    {

        var validPayments = Payments.Where(p => p.Amount > 0 && !p.IsProcessed).ToList();

        decimal totalAmount = 0;

​

        var tasks = validPayments.Select(async payment =>

        {

            try

            {

                _logger.Log($"Processing Payment {payment.PaymentId}...");

                await Task.Delay(1000); // Simulate payment delay

                payment.IsProcessed = true;

                _logger.Log($"Payment {payment.PaymentId} processed.");

                return payment.Amount;

            }

            catch (Exception ex)

            {

                _logger.LogError($"Error processing Payment {payment.PaymentId}", ex);

                return 0;

            }

        });

​

        var results = await Task.WhenAll(tasks);

        totalAmount = results.Sum();

        _logger.Log($"Total Amount Processed: {totalAmount}");

​

        return totalAmount;

    }

}

​

​

[ApiController]

[Route("api/[controller]")]

public class PaymentController : ControllerBase

{

    private readonly PaymentService _paymentService;

​

    public PaymentController(PaymentService paymentService)

    {

        _paymentService = paymentService;

    }

​

    [HttpPut(“add")]

    public IActionResult AddPayment([FromBody] Payment payment)

    {

        if (payment == null || payment.Amount <= 0)

        {

            return BadRequest("Invalid payment details.");

        }

​

        _paymentService.Payments.Add(payment);

        return Ok("Payment added successfully.");

    }

​

    [HttpGet("process")]

    public async Task<IActionResult> ProcessPayments()

    {

        var totalAmount = await _paymentService.ProcessPaymentsAsync();

        return Ok($"Total amount processed: {totalAmount}");

    }

​

    [HttpGet("list")]

    public IActionResult GetPayments()

    {

        return Ok(_paymentService.Payments);

    }

}