fix(kpi-history): backlogTotal trend records the real site-backlog aggregate instead of a hardwired zero

2026-07-09 07:51:55 -04:00
parent 1dd993ec2f
commit 1b53de1933
6 changed files with 271 additions and 3 deletions
@@ -0,0 +1,52 @@
+using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Kpi;
+
+namespace ZB.MOM.WW.ScadaBridge.HealthMonitoring.Kpi;
+
+/// <summary>
+/// Central <see cref="IAuditBacklogProvider"/> — sums the latest per-site
+/// <c>SiteAuditBacklog.PendingCount</c> across the in-memory
+/// <see cref="ICentralHealthAggregator"/>, the same aggregate the live
+/// Health-dashboard "Audit" backlog tile shows
+/// (<c>AuditLogQueryService.GetKpiSnapshotAsync</c>).
+/// </summary>
+/// <remarks>
+/// Registered only on the central node (where the aggregator lives), so the
+/// <see cref="ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Kpi.IKpiSampleSource"/>
+/// backing the <c>backlogTotal</c> trend records the real backlog instead of the
+/// append-only repository's hardwired zero. Best-effort: sites with no report or
+/// a null <c>SiteAuditBacklog</c> contribute nothing.
+/// </remarks>
+public sealed class CentralHealthAuditBacklogProvider : IAuditBacklogProvider
+{
+    private readonly ICentralHealthAggregator _aggregator;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="CentralHealthAuditBacklogProvider"/> class.
+    /// </summary>
+    /// <param name="aggregator">The central health aggregator whose per-site latest reports carry the backlog.</param>
+    public CentralHealthAuditBacklogProvider(ICentralHealthAggregator aggregator)
+    {
+        ArgumentNullException.ThrowIfNull(aggregator);
+        _aggregator = aggregator;
+    }
+
+    /// <inheritdoc />
+    public long GetPendingBacklogTotal()
+    {
+        // Ported verbatim from AuditLogQueryService.GetKpiSnapshotAsync: a null
+        // SiteAuditBacklog is "unknown" (contributes zero), and the `> 0` guard
+        // ignores any defensive negative/zero value so the tile and the history
+        // agree exactly.
+        long backlog = 0;
+        foreach (var state in _aggregator.GetAllSiteStates().Values)
+        {
+            var pending = state.LatestReport?.SiteAuditBacklog?.PendingCount;
+            if (pending is > 0)
+            {
+                backlog += pending.Value;
+            }
+        }
+
+        return backlog;
+    }
+}
@@ -63,6 +63,15 @@ public static class ServiceCollectionExtensions
        services.AddHostedService(sp => sp.GetRequiredService<CentralHealthAggregator>());
        services.AddHostedService<CentralHealthReportLoop>();

+        // Task 10 (arch-review 04): the central backlog aggregate for the Audit Log
+        // KPI *history*. Only the central node runs the aggregator, so this seam is
+        // registered here; the AuditLogKpiSampleSource resolves it (optional ctor
+        // param) and records the real cross-site backlog instead of the append-only
+        // repository's hardwired zero. Sites leave it unregistered → snapshot fallback.
+        services.AddSingleton<
+            Commons.Interfaces.Kpi.IAuditBacklogProvider,
+            Kpi.CentralHealthAuditBacklogProvider>();
+
        // "KPI History & Trends": per-site Site Health KPI sample source.
        // Reads the in-memory central aggregator (a singleton) rather than a
        // repository; registered Scoped to match the recorder's per-tick scope