up

src/Policy/StellaOps.Policy.Engine/BatchContext/BatchContextModels.cs

@@ -0,0 +1,31 @@
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Policy.Engine.BatchContext;
+
+internal sealed record BatchContextRequest(
+    [property: JsonPropertyName("tenant_id")] string TenantId,
+    [property: JsonPropertyName("policy_profile_hash")] string PolicyProfileHash,
+    [property: JsonPropertyName("knobs_version")] string KnobsVersion,
+    [property: JsonPropertyName("overlay_hash")] string OverlayHash,
+    [property: JsonPropertyName("items")] IReadOnlyList<BatchContextItem> Items,
+    [property: JsonPropertyName("options")] BatchContextOptions Options);
+
+internal sealed record BatchContextItem(
+    [property: JsonPropertyName("component_purl")] string ComponentPurl,
+    [property: JsonPropertyName("advisory_id")] string AdvisoryId);
+
+internal sealed record BatchContextOptions(
+    [property: JsonPropertyName("include_reachability")] bool IncludeReachability);
+
+internal sealed record BatchContextResponse(
+    [property: JsonPropertyName("context_id")] string ContextId,
+    [property: JsonPropertyName("expires_at")] string ExpiresAt,
+    [property: JsonPropertyName("knobs_version")] string KnobsVersion,
+    [property: JsonPropertyName("overlay_hash")] string OverlayHash,
+    [property: JsonPropertyName("items")] IReadOnlyList<BatchContextResolvedItem> Items);
+
+internal sealed record BatchContextResolvedItem(
+    [property: JsonPropertyName("component_purl")] string ComponentPurl,
+    [property: JsonPropertyName("advisory_id")] string AdvisoryId,
+    [property: JsonPropertyName("status")] string Status,
+    [property: JsonPropertyName("trace_ref")] string TraceRef);

src/Policy/StellaOps.Policy.Engine/BatchContext/BatchContextService.cs

@@ -0,0 +1,82 @@
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+
+namespace StellaOps.Policy.Engine.BatchContext;
+
+/// <summary>
+/// Creates deterministic batch context responses for advisory AI (POLICY-ENGINE-31-002).
+/// </summary>
+internal sealed class BatchContextService
+{
+    private readonly TimeProvider _timeProvider;
+
+    public BatchContextService(TimeProvider timeProvider)
+    {
+        _timeProvider = timeProvider ?? throw new ArgumentNullException(nameof(timeProvider));
+    }
+
+    public BatchContextResponse Create(BatchContextRequest request)
+    {
+        if (request is null) throw new ArgumentNullException(nameof(request));
+        if (request.Items is null || request.Items.Count == 0)
+        {
+            throw new ArgumentException("items are required", nameof(request.Items));
+        }
+
+        var sortedItems = request.Items
+            .OrderBy(i => i.ComponentPurl, StringComparer.Ordinal)
+            .ThenBy(i => i.AdvisoryId, StringComparer.Ordinal)
+            .ToList();
+
+        var status = request.Options?.IncludeReachability == true ? "pending-reachability" : "pending";
+        var resolved = sortedItems
+            .Select(i => new BatchContextResolvedItem(
+                i.ComponentPurl,
+                i.AdvisoryId,
+                status,
+                ComputeTraceRef(request.TenantId, i)))
+            .ToList();
+
+        var expires = _timeProvider.GetUtcNow().AddHours(1).ToString("O");
+        var contextId = ComputeContextId(request, sortedItems);
+
+        return new BatchContextResponse(
+            contextId,
+            ExpiresAt: expires,
+            KnobsVersion: request.KnobsVersion,
+            OverlayHash: request.OverlayHash,
+            Items: resolved);
+    }
+
+    private static string ComputeContextId(BatchContextRequest request, IReadOnlyList<BatchContextItem> sortedItems)
+    {
+        var canonical = new
+        {
+            tenant = request.TenantId,
+            profile = request.PolicyProfileHash,
+            knobs = request.KnobsVersion,
+            overlay = request.OverlayHash,
+            items = sortedItems.Select(i => new { i.ComponentPurl, i.AdvisoryId }).ToArray(),
+            includeReachability = request.Options?.IncludeReachability ?? false
+        };
+
+        var json = JsonSerializer.Serialize(canonical, new JsonSerializerOptions
+        {
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+            WriteIndented = false
+        });
+
+        Span<byte> hash = stackalloc byte[16];
+        SHA256.HashData(Encoding.UTF8.GetBytes(json), hash);
+        return Convert.ToHexString(hash);
+    }
+
+    private static string ComputeTraceRef(string tenant, BatchContextItem item)
+    {
+        var stable = $"{tenant}|{item.ComponentPurl}|{item.AdvisoryId}";
+        Span<byte> hash = stackalloc byte[12];
+        SHA256.HashData(Encoding.UTF8.GetBytes(stable), hash);
+        return Convert.ToHexString(hash);
+    }
+}