Refactoring

backend/src/PostNordLotteriet.WebAPI/Controllers/ShipmentController.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Globalization;
 using Asp.Versioning;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
@@ -25,24 +24,22 @@ namespace PostNordLotteriet.WebAPI.Controllers
         [HttpGet("trackandtrace")]
         public IActionResult Get()
         {
-            DateTime currentDate = DateTime.Now;
-
-            if (_workDayService.IsNonWorkDay(currentDate))
+            if (_workDayService.IsNonWorkDay(DateTime.Now))
             {
-                DateTime nextWorkDay = _workDayService.GetNextWorkDay(currentDate);
-
-                Response.Headers.RetryAfter = nextWorkDay
-                    .ToUniversalTime()
-                    .ToString("R", CultureInfo.InvariantCulture);
-
                 return StatusCode(
                     StatusCodes.Status503ServiceUnavailable,
-                    new { message = "Ingen postutdelning på arbetsfria dagar." });
+                    new { message = "Ingen postutdelning när det är helg." });
             }
 
-            return Random.Shared.NextDouble() < 0.4
-                ? Ok(new { message = "Grattis! Försändelsen finns snart i en brevlåda nära dig." })
-                : BadRequest(new { message = "Tyvärr, ingen post idag." });
+            bool won = Random.Shared.NextDouble() < 0.4;
+
+            return Ok(new
+            {
+                won,
+                message = won
+                    ? "Grattis! Försändelsen finns snart i en brevlåda nära dig."
+                    : "Tyvärr, ingen post idag."
+            });
         }
     }
 }

backend/src/PostNordLotteriet.WebAPI/Extensions/RateLimiterExtensions.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Globalization;
 using System.Text.Json;
 using System.Threading.RateLimiting;
 using Microsoft.AspNetCore.Builder;
@@ -12,77 +11,63 @@ namespace PostNordLotteriet.WebAPI.Extensions
     public static class RateLimiterExtensions
     {
         // Adds a rate limiter with a custom error message in JSON format.
-        public static IServiceCollection AddPostNordLotterietRateLimiter(this IServiceCollection services)
+        public static IServiceCollection AddPostNordLotterietRateLimiter(
+            this IServiceCollection services)
         {
             services.AddRateLimiter(options =>
             {
-                options.AddPolicy(policyName: "fixed", httpContext =>
+                options.AddPolicy("fixed", httpContext =>
                 {
-                    // Disable rate limiter if today is a non-work day.
-                    if (httpContext.RequestServices.GetRequiredService<IWorkDayService>().IsNonWorkDay(DateTime.Now))
-                    {
-                        return RateLimitPartition.GetNoLimiter("NoLimiter");
-                    }
-                    else
-                    {
-                        return RateLimitPartition.GetFixedWindowLimiter(partitionKey: httpContext.Connection.RemoteIpAddress?.ToString()
-                            ?? "Unknown",
-                            factory: _ => new FixedWindowRateLimiterOptions
-                            {
-                                Window = TimeSpan.FromDays(1),
-                                PermitLimit = 1
-                            });
-                    }
-                });
-
-                options.RejectionStatusCode = StatusCodes.Status429TooManyRequests;
-
-                options.OnRejected = async (context, cancellationToken) =>
-                {
-                    HttpContext httpContext = context.HttpContext;
-
                     IWorkDayService workDayService =
                         httpContext.RequestServices.GetRequiredService<IWorkDayService>();
 
-                    DateTimeOffset now = DateTimeOffset.Now;
+                    DateTime now = DateTime.Now;
 
-                    DateTime nextWorkDay = workDayService.GetNextWorkDay(now.DateTime);
-
-                    // The next workday starts at midnight in the server's local time zone.
-                    DateTimeOffset nextWorkDayStart = new(
-                        nextWorkDay,
-                        now.Offset);
-
-                    DateTimeOffset nextAttempt = nextWorkDayStart;
-
-                    // Get the rate limiter's actual remaining lockout duration.
-                    if (context.Lease.TryGetMetadata(
-                            MetadataName.RetryAfter,
-                            out TimeSpan retryAfter))
+                    // Disable the rate limiter on non-work days.
+                    if (workDayService.IsNonWorkDay(now))
                     {
-                        DateTimeOffset limiterReset = now.Add(retryAfter);
-
-                        if (limiterReset > nextAttempt)
-                        {
-                            nextAttempt = limiterReset;
-                        }
+                        return RateLimitPartition.GetNoLimiter("NoLimiter");
                     }
 
-                    string formattedNextAttempt = nextAttempt.ToString(
-                        "dddd d MMMM 'klockan' HH:mm",
-                        CultureInfo.GetCultureInfo("sv-SE"));
+                    string ipAddress =
+                        httpContext.Connection.RemoteIpAddress?.ToString()
+                        ?? "Unknown";
 
-                    httpContext.Response.ContentType = "application/json";
+                    // Include today's date in the partition key so a new
+                    // partition is created automatically at midnight.
+                    string partitionKey = $"{ipAddress}:{now:yyyy-MM-dd}";
 
-                    httpContext.Response.Headers.RetryAfter = nextAttempt
-                        .ToUniversalTime()
-                        .ToString("R", CultureInfo.InvariantCulture);
-
-                    await httpContext.Response.WriteAsync(
-                        JsonSerializer.Serialize(new
+                    return RateLimitPartition.GetFixedWindowLimiter(
+                        partitionKey,
+                        _ => new FixedWindowRateLimiterOptions
                         {
-                            message = $"Posten delas ut en gång per arbetsdag. Gör ett nytt försök {formattedNextAttempt}."
-                        }),
+                            PermitLimit = 1,
+                            Window = TimeSpan.FromDays(1)
+                        });
+                });
+
+                options.RejectionStatusCode =
+                    StatusCodes.Status429TooManyRequests;
+
+                options.OnRejected = async (context, cancellationToken) =>
+                {
+                    DateTime now = DateTime.Now;
+                    DateTime nextMidnight = now.Date.AddDays(1);
+
+                    int retryAfterSeconds = (int)Math.Ceiling(
+                        (nextMidnight - now).TotalSeconds);
+
+                    context.HttpContext.Response.ContentType = "application/json";
+
+                    context.HttpContext.Response.Headers.RetryAfter = retryAfterSeconds.ToString();
+
+                    string response = JsonSerializer.Serialize(new
+                    {
+                        message = "Posten delas ut en gång om dagen. Gör ett nytt försök imorgon."
+                    });
+
+                    await context.HttpContext.Response.WriteAsync(
+                        response,
                         cancellationToken);
                 };
             });