feat(adminui): /hosts cluster-grouped Driver Instances section (#8)

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Hosts.razor

@@ -1,13 +1,23 @@
 @page "/hosts"
-@* Akka cluster topology: each member's NodeId (host:port), roles, leader status. v2 reshapes
+@* Two views, top to bottom. (1) Akka cluster topology: each member's NodeId (host:port), roles,
-   v1's "driver host" page — there are no per-driver host rows yet (driver-instance child actors
+   leader status — the cluster-membership view. (2) Driver instances: live driver-health grouped by
-   land with F7). For now this is the cluster-membership view; expand to per-driver rows when
+   cluster. The health feed (DriverHealthChanged) carries no per-Akka-member identity, so the rows
-   DriverHostActor starts spawning DriverInstanceActor children. *@
+   are cluster-scoped (keyed per driver instance across the cluster, not per member). The section
+   reads the in-process driver-health snapshot store directly + reloads its config from the ConfigDB. *@
 @attribute [Microsoft.AspNetCore.Authorization.Authorize]
 @rendermode RenderMode.InteractiveServer
 @using Akka.Actor
 @using Akka.Cluster
+@using Microsoft.EntityFrameworkCore
+@using Microsoft.Extensions.Logging
+@using ZB.MOM.WW.OtOpcUa.Configuration
+@using ZB.MOM.WW.OtOpcUa.AdminUI.Hosts
+@using ZB.MOM.WW.OtOpcUa.AdminUI.Hubs
+@using ZB.MOM.WW.OtOpcUa.Commons.Messages.Drivers
 @inject ActorSystem ActorSystem
+@inject IDriverStatusSnapshotStore DriverStore
+@inject IDbContextFactory<OtOpcUaConfigDbContext> DbFactory
+@inject Microsoft.Extensions.Logging.ILogger<Hosts> Logger
 @implements IDisposable
 
 <div class="d-flex justify-content-between align-items-center mb-3">
@@ -114,6 +124,90 @@ else
     </section>
 }
 
+<section class="panel notice rise" style="animation-delay:.16s">
+    Driver health is keyed per driver instance <em>across the cluster</em>, not per Akka member —
+    the health feed carries no per-member identity. These rows are therefore <strong>cluster-scoped</strong>:
+    one entry per configured driver instance, grouped under its cluster.
+</section>
+
+@if (_driverGroups is null)
+{
+    <p>Loading…</p>
+}
+else if (_driverGroups.Count == 0)
+{
+    <section class="panel notice rise" style="animation-delay:.2s">
+        No driver instances reporting yet.
+    </section>
+}
+else
+{
+    <section class="panel rise" style="animation-delay:.2s">
+        <div class="panel-head">Driver instances</div>
+        @foreach (var g in _driverGroups)
+        {
+            <div class="mb-3">
+                <div class="panel-head">Cluster <span class="mono">@g.ClusterId</span></div>
+                <div class="mb-2">
+                    @if (g.Nodes.Count == 0)
+                    {
+                        <span class="text-muted">—</span>
+                    }
+                    else
+                    {
+                        @foreach (var n in g.Nodes)
+                        {
+                            <span class="chip chip-idle me-1">@n.NodeId (@n.Host:@n.OpcUaPort)</span>
+                        }
+                    }
+                </div>
+                <div class="table-wrap">
+                    <table class="data-table">
+                        <thead>
+                            <tr>
+                                <th>Driver</th>
+                                <th>Type</th>
+                                <th>Status</th>
+                                <th>Last read</th>
+                                <th>Errors/5 min</th>
+                                <th>Last error</th>
+                            </tr>
+                        </thead>
+                        <tbody>
+                            @if (g.Drivers.Count == 0)
+                            {
+                                <tr>
+                                    <td colspan="6"><span class="text-muted">No drivers.</span></td>
+                                </tr>
+                            }
+                            else
+                            {
+                                @foreach (var d in g.Drivers)
+                                {
+                                    <tr>
+                                        <td>
+                                            @(d.Name ?? d.DriverInstanceId)
+                                            @if (d.Name is not null)
+                                            {
+                                                <span class="mono small">@d.DriverInstanceId</span>
+                                            }
+                                        </td>
+                                        <td>@(d.DriverType ?? "—")</td>
+                                        <td><span class="chip @DriverChipClass(d.State)">@d.State</span></td>
+                                        <td>@(d.LastSuccessfulReadUtc?.ToString("HH:mm:ss 'UTC'") ?? "—")</td>
+                                        <td class="numeric">@d.ErrorCount5Min</td>
+                                        <td><span class="text-muted small">@(d.LastError ?? "—")</span></td>
+                                    </tr>
+                                }
+                            }
+                        </tbody>
+                    </table>
+                </div>
+            </div>
+        }
+    </section>
+}
+
 @code {
     private const int RefreshIntervalSeconds = 5;
 
@@ -122,10 +216,23 @@ else
     private DateTime? _lastRefreshUtc;
     private Timer? _timer;
 
-    protected override void OnInitialized()
+    private IReadOnlyList<HostsClusterGroup>? _driverGroups;
+    private List<HostsNodeInfo> _nodes = new();
+    private List<HostsDriverInstanceInfo> _instances = new();
+
+    protected override async Task OnInitializedAsync()
     {
         Refresh();
-        _timer = new Timer(_ => InvokeAsync(() => { Refresh(); StateHasChanged(); }), null,
+        await LoadConfigAsync();
+        RebuildDriverGroups();
+        DriverStore.SnapshotChanged += OnSnapshotChanged;
+        _timer = new Timer(_ => InvokeAsync(async () =>
+            {
+                Refresh();
+                await LoadConfigAsync();
+                RebuildDriverGroups();
+                StateHasChanged();
+            }), null,
             TimeSpan.FromSeconds(RefreshIntervalSeconds),
             TimeSpan.FromSeconds(RefreshIntervalSeconds));
     }
@@ -138,6 +245,8 @@ else
         {
             await Task.Yield();
             Refresh();
+            await LoadConfigAsync();
+            RebuildDriverGroups();
         }
         finally
         {
@@ -146,6 +255,39 @@ else
         }
     }
 
+    // Load the per-cluster node + driver-instance config from the ConfigDB. Kept cheap and
+    // swallow-on-failure so a transient DB hiccup dims the enrichment (rows fall back to id/—)
+    // without crashing the page. The live health feed (the snapshot store) is independent of this.
+    private async Task LoadConfigAsync()
+    {
+        try
+        {
+            await using var db = await DbFactory.CreateDbContextAsync();
+            _nodes = await db.ClusterNodes.AsNoTracking()
+                .Select(n => new HostsNodeInfo(n.ClusterId, n.NodeId, n.Host, n.OpcUaPort))
+                .ToListAsync();
+            _instances = await db.DriverInstances.AsNoTracking()
+                .Select(d => new HostsDriverInstanceInfo(d.DriverInstanceId, d.ClusterId, d.Name, d.DriverType))
+                .ToListAsync();
+        }
+        catch (Exception ex)
+        {
+            Logger.LogWarning(ex, "/hosts: failed to load driver-instance config; rows show ids only.");
+            _nodes = new();
+            _instances = new();
+        }
+    }
+
+    // Re-project the cluster-grouped driver rows from the latest live snapshots + cached config.
+    private void RebuildDriverGroups()
+        => _driverGroups = HostsDriverView.Build(DriverStore.GetAll(), _nodes, _instances);
+
+    // Raised by the snapshot store on the bridge actor's thread for every driver instance. Rebuild
+    // from the cached config (cheap — no DB hit) and marshal onto the render sync context. A
+    // brand-new driver shows by id until the next config reload (timer/manual Refresh) enriches it.
+    private void OnSnapshotChanged(DriverHealthChanged _)
+        => InvokeAsync(() => { RebuildDriverGroups(); StateHasChanged(); });
+
     private void Refresh()
     {
         var cluster = Akka.Cluster.Cluster.Get(ActorSystem);
@@ -184,7 +326,22 @@ else
         _ => "chip-idle",
     };
 
-    public void Dispose() => _timer?.Dispose();
+    // Map DriverState string → chip CSS class (mirrors DriverStatusPanel.ChipClass).
+    private static string DriverChipClass(string? state) => state switch
+    {
+        "Healthy"      => "chip-ok",
+        "Degraded"     => "chip-warn",
+        "Connecting"   => "chip-warn",
+        "Reconnecting" => "chip-warn",
+        "Faulted"      => "chip-bad",
+        _              => "chip-idle",
+    };
+
+    public void Dispose()
+    {
+        _timer?.Dispose();
+        DriverStore.SnapshotChanged -= OnSnapshotChanged;
+    }
 
     private sealed record MemberRow(
         string Address,