feat(kpi): K13 — Notification Outbox trend charts (T11 first consumer)

src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Notifications/NotificationKpis.razor

@@ -4,9 +4,12 @@
 @using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Repositories
 @using ZB.MOM.WW.ScadaBridge.Commons.Messages.Notification
 @using ZB.MOM.WW.ScadaBridge.Commons.Types.Notifications
+@using ZB.MOM.WW.ScadaBridge.Commons.Types.Kpi
 @using ZB.MOM.WW.ScadaBridge.Communication
+@using ZB.MOM.WW.ScadaBridge.CentralUI.Services
 @inject CommunicationService CommunicationService
 @inject ISiteRepository SiteRepository
+@inject IKpiHistoryQueryService KpiHistory
 @inject ILogger<NotificationKpis> Logger
 
 <div class="container-fluid mt-3">
@@ -158,6 +161,39 @@
             </table>
         </div>
     }
+
+    @* ── Trends (T11: first KPI-history consumer) ── *@
+    <div class="d-flex justify-content-between align-items-center mt-4 mb-2" data-test="notification-trends">
+        <h5 class="mb-0">Trends</h5>
+        <div class="btn-group btn-group-sm" role="group" aria-label="Trend window">
+            <button type="button"
+                    class="btn @(_windowHours == 24 ? "btn-primary" : "btn-outline-secondary")"
+                    @onclick="() => SetWindowAsync(24)" disabled="@_trendsLoading">24h</button>
+            <button type="button"
+                    class="btn @(_windowHours == 168 ? "btn-primary" : "btn-outline-secondary")"
+                    @onclick="() => SetWindowAsync(168)" disabled="@_trendsLoading">7d</button>
+        </div>
+    </div>
+    <div class="row g-3">
+        <div class="col-lg-4 col-md-6">
+            <KpiTrendChart Title="Queue Depth"
+                           Points="@_queueDepthSeries"
+                           IsAvailable="@_trendsAvailable"
+                           ErrorMessage="@_trendsError" />
+        </div>
+        <div class="col-lg-4 col-md-6">
+            <KpiTrendChart Title="Parked"
+                           Points="@_parkedSeries"
+                           IsAvailable="@_trendsAvailable"
+                           ErrorMessage="@_trendsError" />
+        </div>
+        <div class="col-lg-4 col-md-6">
+            <KpiTrendChart Title="Delivered / interval"
+                           Points="@_deliveredSeries"
+                           IsAvailable="@_trendsAvailable"
+                           ErrorMessage="@_trendsError" />
+        </div>
+    </div>
 </div>
 
 @code {
@@ -175,6 +211,16 @@
 
     private bool _loading;
 
+    // ── Trends (T11: first KPI-history consumer) ──
+    // Window in hours: 24h (default) or 168h (7d). Toggling re-queries.
+    private int _windowHours = 24;
+    private bool _trendsLoading;
+    private bool _trendsAvailable = true;
+    private string? _trendsError;
+    private IReadOnlyList<KpiSeriesPoint>? _queueDepthSeries;
+    private IReadOnlyList<KpiSeriesPoint>? _parkedSeries;
+    private IReadOnlyList<KpiSeriesPoint>? _deliveredSeries;
+
     protected override async Task OnInitializedAsync()
     {
         try
@@ -195,10 +241,55 @@
         _loading = true;
         // Race-free despite all tasks mutating component fields: Blazor Server runs
         // every continuation on the circuit's single-threaded synchronization context.
-        await Task.WhenAll(LoadGlobalKpis(), LoadPerSiteKpis(), LoadPerNodeKpis());
+        await Task.WhenAll(LoadGlobalKpis(), LoadPerSiteKpis(), LoadPerNodeKpis(), LoadTrends());
         _loading = false;
     }
 
+    private async Task SetWindowAsync(int windowHours)
+    {
+        if (_windowHours == windowHours)
+        {
+            return;
+        }
+
+        _windowHours = windowHours;
+        await LoadTrends();
+    }
+
+    private async Task LoadTrends()
+    {
+        _trendsLoading = true;
+        try
+        {
+            var toUtc = DateTime.UtcNow;
+            var fromUtc = toUtc - TimeSpan.FromHours(_windowHours);
+
+            // Best-effort: one query failure must NOT break the page — on any
+            // exception the charts fall back to the unavailable placeholder while
+            // the KPI tiles above stay rendered.
+            _queueDepthSeries = await GetSeries("queueDepth", fromUtc, toUtc);
+            _parkedSeries = await GetSeries("parkedCount", fromUtc, toUtc);
+            _deliveredSeries = await GetSeries("deliveredLastInterval", fromUtc, toUtc);
+
+            _trendsAvailable = true;
+            _trendsError = null;
+        }
+        catch (Exception ex)
+        {
+            _trendsAvailable = false;
+            _trendsError = "Trend data unavailable.";
+            Logger.LogWarning(ex, "Failed to load notification-outbox KPI trend series.");
+        }
+        finally
+        {
+            _trendsLoading = false;
+        }
+    }
+
+    private Task<IReadOnlyList<KpiSeriesPoint>> GetSeries(string metric, DateTime fromUtc, DateTime toUtc) =>
+        KpiHistory.GetSeriesAsync(
+            KpiSources.NotificationOutbox, metric, KpiScopes.Global, scopeKey: null, fromUtc, toUtc);
+
     private async Task LoadGlobalKpis()
     {
         try