Fix billing downgrade recharge and suspension race

src/Exceptionless.Core/Billing/StripeEventHandler.cs

@@ -37,7 +37,7 @@ public async Task HandleEventAsync(Stripe.Event stripeEvent)
             }
             case "customer.subscription.deleted":
             {
-                await SubscriptionDeletedAsync((Subscription)stripeEvent.Data.Object);
+                await SubscriptionDeletedAsync((Subscription)stripeEvent.Data.Object, stripeEvent.Created);
                 break;
             }
             case "invoice.payment_succeeded":
@@ -121,7 +121,7 @@ private async Task SubscriptionUpdatedAsync(Subscription sub)
         await _organizationRepository.SaveAsync(org, o => o.Cache().Originals());
     }
 
-    private async Task SubscriptionDeletedAsync(Subscription sub)
+    private async Task SubscriptionDeletedAsync(Subscription sub, DateTime eventCreatedUtc)
     {
         var org = await _organizationRepository.GetByStripeCustomerIdAsync(sub.CustomerId);
         if (org is null)
@@ -132,6 +132,13 @@ private async Task SubscriptionDeletedAsync(Subscription sub)
 
         _logger.LogInformation("Stripe subscription deleted. Customer: {CustomerId} Org: {Organization} Org Name: {OrganizationName}", sub.CustomerId, org.Id, org.Name);
 
+        if (org.BillingChangeDate > DateTime.MinValue && eventCreatedUtc < org.BillingChangeDate)
+        {
+            _logger.LogInformation("Ignoring stale Stripe subscription deletion. Customer: {CustomerId} Org: {Organization} Event Created: {EventCreatedUtc} Billing Changed: {BillingChangeDate}",
+                sub.CustomerId, org.Id, eventCreatedUtc, org.BillingChangeDate);
+            return;
+        }
+
         var utcNow = _timeProvider.GetUtcNow().UtcDateTime;
         org.BillingChangeDate = utcNow;
         org.BillingStatus = BillingStatus.Canceled;

src/Exceptionless.Web/Api/Handlers/OrganizationHandler.cs

@@ -398,7 +398,7 @@ public async Task<Result<ChangePlanResult>> Handle(ChangeOrganizationPlan messag
                 {
                     var subs = await stripeBillingClient.ListSubscriptionsAsync(new SubscriptionListOptions { Customer = organization.StripeCustomerId });
                     foreach (var sub in subs.Where(s => !s.CanceledAt.HasValue))
-                        await stripeBillingClient.CancelSubscriptionAsync(sub.Id, new SubscriptionCancelOptions());
+                        await stripeBillingClient.CancelSubscriptionAsync(sub.Id, new SubscriptionCancelOptions { Prorate = true, InvoiceNow = true });
                 }
 
                 organization.BillingStatus = BillingStatus.Trialing;

tests/Exceptionless.Tests/Api/Endpoints/OrganizationEndpointTests.cs

@@ -1477,7 +1477,10 @@ public async Task ChangePlanAsync_FreePlanCancelsActiveStripeSubscriptions()
         Assert.NotNull(result);
         Assert.True(result.Success);
         Assert.Equal("cus_existing", StripeBillingClient.LastSubscriptionListOptions?.Customer);
-        Assert.Equal("sub_active", Assert.Single(StripeBillingClient.CanceledSubscriptions).SubscriptionId);
+        var canceledSubscription = Assert.Single(StripeBillingClient.CanceledSubscriptions);
+        Assert.Equal("sub_active", canceledSubscription.SubscriptionId);
+        Assert.True(canceledSubscription.Options.Prorate);
+        Assert.True(canceledSubscription.Options.InvoiceNow);
 
         var organization = await _organizationRepository.GetByIdAsync(SampleDataService.FREE_ORG_ID);
         Assert.NotNull(organization);

tests/Exceptionless.Tests/Api/Endpoints/StripeEndpointTests.cs

@@ -1,15 +1,27 @@
 using System.Net;
+using System.Security.Cryptography;
 using System.Text;
+using Exceptionless.Core;
+using Exceptionless.Core.Extensions;
+using Exceptionless.Core.Models;
+using Exceptionless.Core.Repositories;
 using Exceptionless.Core.Utility;
 using Exceptionless.Tests.Extensions;
 using FluentRest;
+using Foundatio.Repositories;
 using Xunit;
 
 namespace Exceptionless.Tests.Api.Endpoints;
 
 public class StripeEndpointTests : IntegrationTestsBase
 {
-    public StripeEndpointTests(ITestOutputHelper output, AppWebHostFactory factory) : base(output, factory) { }
+    private const string WebhookSigningSecret = "whsec_local_test";
+    private readonly IOrganizationRepository _organizationRepository;
+
+    public StripeEndpointTests(ITestOutputHelper output, AppWebHostFactory factory) : base(output, factory)
+    {
+        _organizationRepository = GetService<IOrganizationRepository>();
+    }
 
     protected override async Task ResetDataAsync()
     {
@@ -85,4 +97,72 @@ public async Task PostAsync_WithNonJsonContentType_ReturnsUnsupportedMediaType()
         // Assert
         Assert.Equal(HttpStatusCode.UnsupportedMediaType, response.StatusCode);
     }
+
+    [Theory]
+    [InlineData(BillingStatus.Trialing)]
+    [InlineData(BillingStatus.Active)]
+    public async Task PostAsync_WithStaleSubscriptionDeletedEvent_DoesNotOverwriteNewerBillingState(BillingStatus billingStatus)
+    {
+        // Arrange
+        var eventCreatedUtc = new DateTime(2026, 6, 22, 19, 3, 23, DateTimeKind.Utc);
+        var organization = await _organizationRepository.GetByIdAsync(SampleDataService.FREE_ORG_ID);
+        Assert.NotNull(organization);
+        organization.StripeCustomerId = "cus_existing";
+        organization.BillingChangeDate = eventCreatedUtc.AddSeconds(20);
+        organization.BillingStatus = billingStatus;
+        organization.RemoveSuspension();
+        await _organizationRepository.SaveAsync(organization, o => o.ImmediateConsistency());
+
+        /* language=json */
+        const string json = $$"""
+            {
+              "id": "evt_subscription_deleted",
+              "object": "event",
+              "created": 1782155003,
+              "data": {
+                "object": {
+                  "id": "sub_old",
+                  "object": "subscription",
+                  "customer": "cus_existing",
+                  "status": "canceled"
+                }
+              },
+              "livemode": false,
+              "pending_webhooks": 1,
+              "type": "customer.subscription.deleted"
+            }
+            """;
+
+        long signatureTimestamp = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
+        byte[] signatureBytes = HMACSHA256.HashData(
+            Encoding.UTF8.GetBytes(WebhookSigningSecret),
+            Encoding.UTF8.GetBytes($"{signatureTimestamp}.{json}")
+        );
+
+        var options = GetService<AppOptions>();
+        string? originalSigningSecret = options.StripeOptions.StripeWebHookSigningSecret;
+        options.StripeOptions.StripeWebHookSigningSecret = WebhookSigningSecret;
+        try
+        {
+            // Act
+            using var content = new StringContent(json, Encoding.UTF8, "application/json");
+            await SendRequestAsync(r => r
+                .Post()
+                .AppendPath("stripe")
+                .Content(content)
+                .Header("Stripe-Signature", $"t={signatureTimestamp},v1={Convert.ToHexStringLower(signatureBytes)}")
+                .StatusCodeShouldBeOk()
+            );
+        }
+        finally
+        {
+            options.StripeOptions.StripeWebHookSigningSecret = originalSigningSecret;
+        }
+
+        // Assert
+        organization = await _organizationRepository.GetByIdAsync(SampleDataService.FREE_ORG_ID, o => o.Cache(false));
+        Assert.NotNull(organization);
+        Assert.Equal(billingStatus, organization.BillingStatus);
+        Assert.False(organization.IsSuspended);
+    }
 }