feat(audit): multi-value filters across ManagementService, CLI and Central UI

src/ScadaLink.CentralUI/Components/Pages/Audit/AuditLogPage.razor.cs

@@ -80,33 +80,18 @@ public partial class AuditLogPage
             }
         }
 
-        string? site = null;
-        if (query.TryGetValue("site", out var siteValues))
-        {
-            var v = siteValues.ToString();
-            if (!string.IsNullOrWhiteSpace(v))
-            {
-                site = v.Trim();
-            }
-        }
+        // site/channel/status accept repeated params for symmetry with the
+        // multi-value export URL — a single ?site=/?channel=/?status= drill-in
+        // still works (one-element list). Unknown enum names are silently dropped.
+        IReadOnlyList<string>? sites = ParseStringList(query, "site");
 
-        AuditChannel? channel = null;
-        if (query.TryGetValue("channel", out var channelValues)
-            && Enum.TryParse<AuditChannel>(channelValues.ToString(), ignoreCase: true, out var parsedChannel))
-        {
-            channel = parsedChannel;
-        }
+        IReadOnlyList<AuditChannel>? channels = ParseEnumList<AuditChannel>(query, "channel");
 
         // Bundle E (M7-T13): the Health-dashboard Audit error-rate tile drills in
         // with ?status=Failed (and operators may craft URLs with Parked/Discarded).
         // Unknown values are silently dropped — the page still renders without
         // the constraint.
-        AuditStatus? status = null;
-        if (query.TryGetValue("status", out var statusValues)
-            && Enum.TryParse<AuditStatus>(statusValues.ToString(), ignoreCase: true, out var parsedStatus))
-        {
-            status = parsedStatus;
-        }
+        IReadOnlyList<AuditStatus>? statuses = ParseEnumList<AuditStatus>(query, "status");
 
         // Instance is UI-only — the filter contract has no matching column, so we
         // pass it as a separate seam to the filter bar.
@@ -123,20 +108,68 @@ public partial class AuditLogPage
         // auto-loads. Pure ?instance= deep links (UI-only) do not trigger auto-load
         // because the filter contract has no instance column — the user still needs
         // to refine + Apply for those.
-        if (correlationId is null && target is null && actor is null && site is null && channel is null && status is null)
+        if (correlationId is null && target is null && actor is null && sites is null && channels is null && statuses is null)
         {
             return;
         }
 
         _currentFilter = new AuditLogQueryFilter(
-            Channels: channel is { } ch ? new[] { ch } : null,
-            Statuses: status is { } st ? new[] { st } : null,
-            SourceSiteIds: site is { } siteId ? new[] { siteId } : null,
+            Channels: channels,
+            Statuses: statuses,
+            SourceSiteIds: sites,
             Target: target,
             Actor: actor,
             CorrelationId: correlationId);
     }
 
+    /// <summary>
+    /// Reads EVERY value of a (possibly repeated) query param and parses each as
+    /// <typeparamref name="TEnum"/>, dropping unparseable values silently. Returns
+    /// <c>null</c> when the param is absent or no value parsed.
+    /// </summary>
+    private static IReadOnlyList<TEnum>? ParseEnumList<TEnum>(
+        Dictionary<string, Microsoft.Extensions.Primitives.StringValues> query, string key)
+        where TEnum : struct, Enum
+    {
+        if (!query.TryGetValue(key, out var values))
+        {
+            return null;
+        }
+
+        var parsed = new List<TEnum>();
+        foreach (var raw in values)
+        {
+            if (Enum.TryParse<TEnum>(raw, ignoreCase: true, out var value))
+            {
+                parsed.Add(value);
+            }
+        }
+        return parsed.Count > 0 ? parsed : null;
+    }
+
+    /// <summary>
+    /// Reads EVERY value of a (possibly repeated) query param, trims each, and
+    /// drops blank entries. Returns <c>null</c> when absent or all-blank.
+    /// </summary>
+    private static IReadOnlyList<string>? ParseStringList(
+        Dictionary<string, Microsoft.Extensions.Primitives.StringValues> query, string key)
+    {
+        if (!query.TryGetValue(key, out var values))
+        {
+            return null;
+        }
+
+        var parsed = new List<string>();
+        foreach (var raw in values)
+        {
+            if (!string.IsNullOrWhiteSpace(raw))
+            {
+                parsed.Add(raw.Trim());
+            }
+        }
+        return parsed.Count > 0 ? parsed : null;
+    }
+
     private void HandleFilterChanged(AuditLogQueryFilter filter)
     {
         // Always reassign — the grid keys reloads on reference change, so even a
@@ -181,24 +214,39 @@ public partial class AuditLogPage
         }
 
         var parts = new List<KeyValuePair<string, string?>>(9);
-        // Task 8: the filter dimensions are multi-value now; the export query-string
-        // is still single-value, so emit the first selected value of each list.
-        // Task 9 widens the query-string contract to carry the full set.
+        // Task 9: the filter dimensions are multi-value end-to-end. Emit ONE
+        // repeated query-string key per selected value (channel=A&channel=B); the
+        // export endpoint's ParseFilter reads the full repeated set.
         if (filter.Channels is { Count: > 0 } channels)
         {
-            parts.Add(new("channel", channels[0].ToString()));
+            foreach (var channel in channels)
+            {
+                parts.Add(new("channel", channel.ToString()));
+            }
         }
         if (filter.Kinds is { Count: > 0 } kinds)
         {
-            parts.Add(new("kind", kinds[0].ToString()));
+            foreach (var kind in kinds)
+            {
+                parts.Add(new("kind", kind.ToString()));
+            }
         }
         if (filter.Statuses is { Count: > 0 } statuses)
         {
-            parts.Add(new("status", statuses[0].ToString()));
+            foreach (var status in statuses)
+            {
+                parts.Add(new("status", status.ToString()));
+            }
         }
-        if (filter.SourceSiteIds is { Count: > 0 } sourceSiteIds && !string.IsNullOrWhiteSpace(sourceSiteIds[0]))
+        if (filter.SourceSiteIds is { Count: > 0 } sourceSiteIds)
         {
-            parts.Add(new("site", sourceSiteIds[0]));
+            foreach (var site in sourceSiteIds)
+            {
+                if (!string.IsNullOrWhiteSpace(site))
+                {
+                    parts.Add(new("site", site));
+                }
+            }
         }
         if (!string.IsNullOrWhiteSpace(filter.Target))
         {