chore: correct namespaces and hiearchy

src/TrackApi/TrackQrApi/Features/Billing/Endpoints/CreatePortalSessionEndpoint.cs

@@ -0,0 +1,60 @@
+using System.Security.Claims;
+using FastEndpoints;
+using FluentValidation;
+using TrackQrApi.Features.Auth.Common;
+using TrackQrApi.Features.Billing.Common;
+using TrackQrApi.Features.Billing.Services;
+
+namespace TrackQrApi.Features.Billing.Endpoints;
+
+public class CreatePortalSessionValidator : Validator<PortalSessionRequest>
+{
+    public CreatePortalSessionValidator()
+    {
+        RuleFor(x => x.ReturnUrl).NotEmpty().Must(BeValidUrl);
+    }
+
+    private static bool BeValidUrl(string url)
+    {
+        return Uri.TryCreate(url, UriKind.Absolute, out var uri)
+               && (uri.Scheme == Uri.UriSchemeHttp || uri.Scheme == Uri.UriSchemeHttps);
+    }
+}
+
+public class CreatePortalSessionEndpoint(IStripeService stripeService)
+    : Endpoint<PortalSessionRequest, PortalSessionResponse>
+{
+    public override void Configure()
+    {
+        Post("/billing/portal");
+    }
+
+    public override async Task HandleAsync(PortalSessionRequest req, CancellationToken ct)
+    {
+        var userId = Guid.Parse(User.FindFirstValue(ClaimTypes.NameIdentifier)!);
+
+        try
+        {
+            var portalUrl = await stripeService.CreateCustomerPortalSessionAsync(
+                userId,
+                req.ReturnUrl,
+                ct);
+
+            await HttpContext.Response.SendAsync(new PortalSessionResponse(portalUrl), cancellation: ct);
+        }
+        catch (InvalidOperationException ex)
+        {
+            await HttpContext.Response.SendAsync(
+                new MessageResponse(ex.Message),
+                400,
+                cancellation: ct);
+        }
+        catch (Exception ex)
+        {
+            await HttpContext.Response.SendAsync(
+                new MessageResponse($"Failed to create portal session: {ex.Message}"),
+                500,
+                cancellation: ct);
+        }
+    }
+}