first commit

services/csharp/example/Features/Auth/Logout.cs

@@ -0,0 +1,28 @@
+using MediatR;
+using Microsoft.AspNetCore.Http;
+using SequenceAuth.Lib;
+
+namespace SequenceAuth.Example.Features.Auth;
+
+public record LogoutCommand() : IRequest;
+
+public class LogoutCommandHandler(ISequenceStore sequenceStore, IHttpContextAccessor httpContextAccessor, Microsoft.Extensions.Options.IOptions<SequenceAuthOptions> options) : IRequestHandler<LogoutCommand>
+{
+    public async Task Handle(LogoutCommand request, CancellationToken cancellationToken)
+    {
+        var userIdStr = httpContextAccessor.HttpContext?.Items[options.Value.UserIdItemKey]?.ToString();
+        var isUserIdPresent = string.IsNullOrEmpty(userIdStr);
+        
+        _ = isUserIdPresent switch
+        {
+            false => await ProcessLogout(userIdStr!),
+            true => 0
+        };
+    }
+
+    private async Task<int> ProcessLogout(string userId)
+    {
+        await sequenceStore.InvalidateUserSessionsAsync(userId);
+        return 1;
+    }
+}