Merge pull request 'Added PayfastPaymentConfirmationReceivedEvent' (#57) from payments into master

Reviewed-on: #57

LiteCharms.Features.MidrandBooks/Payments/Events/Handlers/PayfastPaymentConfirmationReceivedEventHandler.cs

@@ -0,0 +1,81 @@
+using LiteCharms.Features.Hasher;
+using LiteCharms.Features.MidrandBooks.Orders;
+
+namespace LiteCharms.Features.MidrandBooks.Payments.Events.Handlers;
+
+public sealed class PayfastPaymentConfirmationReceivedEventHandler(PaymentService paymentService,
+    HashService hashService, OrderService orderService, ILogger<PayfastPaymentConfirmationReceivedEvent> logger) : 
+    INotificationHandler<PayfastPaymentConfirmationReceivedEvent>
+{
+    public async ValueTask Handle(PayfastPaymentConfirmationReceivedEvent notification, CancellationToken cancellationToken)
+    {
+        var hashResult = hashService.DecodeLongIdHash(notification.Payload?.MPaymentId!);
+        if (hashResult.IsFailed)
+        {
+            logger.LogError("Failed to decode payment ID hash: {Hash}. Errors: {Errors}", notification.Payload?.MPaymentId, string.Join(", ", hashResult.Errors.Select(e => e.Message)));
+            throw new Exception($"Failed to decode payment ID hash: {notification.Payload?.MPaymentId}.");
+        }
+
+        var orderResult = await orderService.GetOrderAsync(hashResult.Value, cancellationToken);
+        if (orderResult.IsFailed)
+        {
+            logger.LogError("Failed to retrieve order for payment ID: {PaymentId}. Errors: {Errors}", notification.Payload?.MPaymentId, string.Join(", ", orderResult.Errors.Select(e => e.Message)));
+            throw new Exception($"Failed to retrieve order for payment ID: {notification.Payload?.MPaymentId}.");
+        }
+
+        var paymentResult = await paymentService.GetOrderPaymentAsync(orderResult.Value.CustomerId, cancellationToken);
+        if (paymentResult.IsFailed)
+        {
+            logger.LogError("Failed to retrieve payment for order ID: {OrderId}. Errors: {Errors}", orderResult.Value.Id, string.Join(", ", paymentResult.Errors.Select(e => e.Message)));
+            throw new Exception($"Failed to retrieve payment for order ID: {orderResult.Value.Id}.");
+        }
+
+        var isAlreadyProcessed = await paymentService.HasLedgerEntryAsync(orderResult.Value.Id, paymentResult.Value.Id, 1, cancellationToken);
+
+        if (isAlreadyProcessed.IsFailed)
+        {
+            logger.LogError("Failed to check existing ledger entry for order ID: {OrderId} and payment ID: {PaymentId}. Errors: {Errors}", orderResult.Value.Id, paymentResult.Value.Id, string.Join(", ", isAlreadyProcessed.Errors.Select(e => e.Message)));
+            throw new Exception($"Failed to check existing ledger entry for order ID: {orderResult.Value.Id} and payment ID: {paymentResult.Value.Id}.");
+        }
+
+        if (isAlreadyProcessed.Value)
+        {
+            logger.LogInformation("Payment confirmation for payment ID: {PaymentId} has already been processed. Skipping.", notification.Payload?.MPaymentId);
+            return;
+        }
+
+        var ledgerResult = await paymentService.WriteLedgerEntryAsync(new Models.CreateLedgerEntry
+        {
+            CustomerId = orderResult.Value.CustomerId,
+            OrderId = orderResult.Value.Id,
+            PaymentId = paymentResult.Value.Id,
+            Status = LedgerStatuses.Received,
+            PaymentGatewayId = 1,
+            PaymentGatewayReference = notification.CorrelationId,
+        }, cancellationToken);
+
+        if (ledgerResult.IsFailed)
+        {
+            logger.LogError("Failed to write ledger entry for payment ID: {PaymentId}. Errors: {Errors}", notification.Payload?.MPaymentId, string.Join(", ", ledgerResult.Errors.Select(e => e.Message)));
+            throw new Exception($"Failed to write ledger entry for payment ID: {notification.Payload?.MPaymentId}.");   
+        }
+
+        var paymentCompletedResult = await paymentService.CompletePaymentAsync(paymentResult.Value.Id, PaymentStatuses.Paid, cancellationToken);
+        if (paymentCompletedResult.IsFailed)
+        {
+            logger.LogError("Failed to complete payment for order ID: {OrderId}. Errors: {Errors}", orderResult.Value.Id, string.Join(", ", paymentCompletedResult.Errors.Select(e => e.Message)));
+            throw new Exception($"Failed to complete payment for order ID: {orderResult.Value.Id}.");
+        }
+
+        var orderCompletedResult = await orderService.UpdateOrderStatusAsync(orderResult.Value.Id, OrderStatus.Completed, cancellationToken);
+        if (orderCompletedResult.IsFailed)
+        {
+            logger.LogError("Failed to update order status to Completed for order ID: {OrderId}. Errors: {Errors}", orderResult.Value.Id, string.Join(", ", orderCompletedResult.Errors.Select(e => e.Message)));
+            throw new Exception($"Failed to update order status to Completed for order ID: {orderResult.Value.Id}.");
+        }
+
+        logger.LogInformation("Received Payfast payment confirmation for payment ID: {PaymentId}", notification.Payload?.MPaymentId);
+
+        // TODO: Publish MediatR notifications or queue downstream Quartz jobs (Discord, Shipping, Customer Email, Royalties)
+    }
+}

LiteCharms.Features.MidrandBooks/Payments/Events/PayfastPaymentConfirmationReceivedEvent.cs

@@ -0,0 +1,22 @@
+using LiteCharms.Features.Abstractions;
+using LiteCharms.Features.Models;
+
+namespace LiteCharms.Features.MidrandBooks.Payments.Events;
+
+public sealed class PayfastPaymentConfirmationReceivedEvent : EventBase, IEvent
+{
+    public string Name { get; set; } = nameof(PayfastPaymentConfirmationReceivedEvent);
+
+    public PayfastWebhookPayload? Payload { get; set; }
+
+    public PayfastPaymentConfirmationReceivedEvent() { }
+
+    private PayfastPaymentConfirmationReceivedEvent(PayfastWebhookPayload? payload, string paymentId)
+    {
+        Payload = payload;
+        CorrelationId = paymentId;
+    }
+
+    public static PayfastPaymentConfirmationReceivedEvent Create(PayfastWebhookPayload? payload, string paymentId) =>
+        new(payload, paymentId);
+}

LiteCharms.Features.MidrandBooks/Payments/PaymentService.cs

@@ -7,6 +7,27 @@ namespace LiteCharms.Features.MidrandBooks.Payments;
 
 public sealed class PaymentService(IDbContextFactory<MidrandBooksDbContext> contextFactory) : IService
 {
+    public async ValueTask<Result<Payment>> GetOrderPaymentAsync(long orderId, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            var payment = await context.Payments.AsNoTracking()
+                .Where(p => p.OrderId == orderId)
+                .OrderByDescending(p => p.Id)
+                .FirstOrDefaultAsync(cancellationToken);
+
+            return payment is not null
+                ? Result.Ok(payment.ToModel())
+                : Result.Fail<Payment>("Could not find payment for the order");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<Payment>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
     public async ValueTask<Result<Refund>> GetRefundAsync(long refundId, CancellationToken cancellationToken = default)
     {
         try
@@ -95,6 +116,25 @@ public sealed class PaymentService(IDbContextFactory<MidrandBooksDbContext> cont
         }
     }
 
+    public async ValueTask<Result<bool>> HasLedgerEntryAsync(long orderId, long paymentId, long gatewayId, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            var exists = await context.Ledger.AnyAsync(l =>
+                l.OrderId == orderId &&
+                l.PaymentId == paymentId &&
+                l.PaymentGatewayId == gatewayId, cancellationToken);
+
+            return Result.Ok(exists);
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
     public async ValueTask<Result> WriteLedgerEntryAsync(CreateLedgerEntry request, CancellationToken cancellationToken = default)
     {
         try