feat: Implement Policy Engine Evaluation Service and Cache with unit tests

Temp commit to debug

src/Scanner/StellaOps.Scanner.WebService/Endpoints/HealthEndpoints.cs

@@ -1,12 +1,16 @@
-using System.Diagnostics;
+using System.Collections.Generic;
+using System.Diagnostics;
 using System.Text;
 using System.Text.Json;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Routing;
-using Microsoft.Extensions.Options;
-using StellaOps.Scanner.WebService.Diagnostics;
-using StellaOps.Scanner.WebService.Options;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using StellaOps.Scanner.WebService.Diagnostics;
+using StellaOps.Scanner.WebService.Options;
+using StellaOps.Scanner.Surface.Env;
+using StellaOps.Scanner.Surface.Validation;
 
 namespace StellaOps.Scanner.WebService.Endpoints;
 
@@ -56,27 +60,69 @@ internal static class HealthEndpoints
         return Json(document, StatusCodes.Status200OK);
     }
 
-    private static async Task<IResult> HandleReady(
-        ServiceStatus status,
-        HttpContext context,
-        CancellationToken cancellationToken)
-    {
-        ApplyNoCache(context.Response);
-
-        await Task.CompletedTask;
-
-        status.RecordReadyCheck(success: true, latency: TimeSpan.Zero, error: null);
-        var snapshot = status.CreateSnapshot();
-        var ready = snapshot.Ready;
-
-        var document = new ReadyDocument(
-            Status: ready.IsReady ? "ready" : "unready",
-            CheckedAt: ready.CheckedAt,
-            LatencyMs: ready.Latency?.TotalMilliseconds,
-            Error: ready.Error);
-
-        return Json(document, StatusCodes.Status200OK);
-    }
+    private static async Task<IResult> HandleReady(
+        ServiceStatus status,
+        ISurfaceValidatorRunner validatorRunner,
+        ISurfaceEnvironment surfaceEnvironment,
+        ILoggerFactory loggerFactory,
+        HttpContext context,
+        CancellationToken cancellationToken)
+    {
+        ApplyNoCache(context.Response);
+
+        ArgumentNullException.ThrowIfNull(loggerFactory);
+
+        var logger = loggerFactory.CreateLogger("Scanner.WebService.Health");
+        var stopwatch = Stopwatch.StartNew();
+        var success = true;
+        string? error = null;
+
+        try
+        {
+            var validationContext = SurfaceValidationContext.Create(
+                context.RequestServices,
+                "Scanner.WebService.ReadyCheck",
+                surfaceEnvironment.Settings,
+                properties: new Dictionary<string, object?>
+                {
+                    ["path"] = context.Request.Path.ToString()
+                });
+
+            await validatorRunner.EnsureAsync(validationContext, cancellationToken).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+        {
+            throw;
+        }
+        catch (SurfaceValidationException ex)
+        {
+            success = false;
+            error = ex.Message;
+        }
+        catch (Exception ex)
+        {
+            success = false;
+            error = ex.Message;
+            logger.LogError(ex, "Surface validation failed during ready check.");
+        }
+        finally
+        {
+            stopwatch.Stop();
+        }
+
+        status.RecordReadyCheck(success, stopwatch.Elapsed, error);
+        var snapshot = status.CreateSnapshot();
+        var ready = snapshot.Ready;
+
+        var document = new ReadyDocument(
+            Status: ready.IsReady ? "ready" : "unready",
+            CheckedAt: ready.CheckedAt,
+            LatencyMs: ready.Latency?.TotalMilliseconds,
+            Error: ready.Error);
+
+        var statusCode = success ? StatusCodes.Status200OK : StatusCodes.Status503ServiceUnavailable;
+        return Json(document, statusCode);
+    }
 
     private static void ApplyNoCache(HttpResponse response)
     {