From 422e5b7db211494d91b67753407053a99ca41d7a Mon Sep 17 00:00:00 2001
From: Joseph Doherty <dohejw01@gmail.com>
Date: Sun, 14 Jun 2026 03:27:03 -0400
Subject: [PATCH] refactor(alarms): harden ExtractTagAlarm severity parse
 (TryGetInt32) + trim projector prior-state (review nits)

---
 .../ZB.MOM.WW.OtOpcUa.OpcUaServer/Phase7Composer.cs      | 2 +-
 .../Drivers/DeploymentArtifact.cs                        | 2 +-
 .../Drivers/NativeAlarmProjector.cs                      | 9 +++------
 3 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/Phase7Composer.cs b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/Phase7Composer.cs
index b64db8e0..ddeae6b9 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/Phase7Composer.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/Phase7Composer.cs
@@ -469,7 +469,7 @@ public static class Phase7Composer
             var type = a.TryGetProperty("alarmType", out var tEl) && tEl.ValueKind == JsonValueKind.String
                 ? (tEl.GetString() ?? "AlarmCondition") : "AlarmCondition";
             var sev = a.TryGetProperty("severity", out var sEl) && sEl.ValueKind == JsonValueKind.Number
-                ? sEl.GetInt32() : 500;
+                && sEl.TryGetInt32(out var sv) ? sv : 500;
             return new EquipmentTagAlarmInfo(type, sev);
         }
         catch (JsonException) { return null; }
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DeploymentArtifact.cs b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DeploymentArtifact.cs
index 1407bbc0..5f59fa21 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DeploymentArtifact.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DeploymentArtifact.cs
@@ -666,7 +666,7 @@ public static class DeploymentArtifact
             var type = a.TryGetProperty("alarmType", out var tEl) && tEl.ValueKind == JsonValueKind.String
                 ? (tEl.GetString() ?? "AlarmCondition") : "AlarmCondition";
             var sev = a.TryGetProperty("severity", out var sEl) && sEl.ValueKind == JsonValueKind.Number
-                ? sEl.GetInt32() : 500;
+                && sEl.TryGetInt32(out var sv) ? sv : 500;
             return new EquipmentTagAlarmInfo(type, sev);
         }
         catch (JsonException) { return null; }
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/NativeAlarmProjector.cs b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/NativeAlarmProjector.cs
index 9cea1f3c..a7e2b75e 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/NativeAlarmProjector.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/NativeAlarmProjector.cs
@@ -12,8 +12,7 @@ namespace ZB.MOM.WW.OtOpcUa.Runtime.Drivers;
 /// </summary>
 public sealed class NativeAlarmProjector
 {
-    private readonly Dictionary<string, (bool Active, bool Acked, ushort Severity, string Message)> _prior =
-        new(StringComparer.Ordinal);
+    private readonly Dictionary<string, (bool Active, bool Acked)> _prior = new(StringComparer.Ordinal);
 
     /// <summary>Project an alarm transition onto the full condition snapshot for <paramref name="nodeId"/>.</summary>
     /// <param name="nodeId">The materialised condition node's id (the projection's state key).</param>
@@ -21,9 +20,7 @@ public sealed class NativeAlarmProjector
     /// <returns>The full Part 9 condition snapshot to write to the node.</returns>
     public AlarmConditionSnapshot Project(string nodeId, AlarmEventArgs e)
     {
-        var prev = _prior.TryGetValue(nodeId, out var p)
-            ? p
-            : (Active: false, Acked: true, Severity: (ushort)0, Message: string.Empty);
+        var prev = _prior.TryGetValue(nodeId, out var p) ? p : (Active: false, Acked: true);
         var sev = MapSeverity(e.Severity);
         var (active, acked) = e.Kind switch
         {
@@ -32,7 +29,7 @@ public sealed class NativeAlarmProjector
             AlarmTransitionKind.Clear => (false, prev.Acked),
             _ => (prev.Active, prev.Acked),
         };
-        _prior[nodeId] = (active, acked, sev, e.Message);
+        _prior[nodeId] = (active, acked);
         return new AlarmConditionSnapshot(
             Active: active, Acknowledged: acked, Confirmed: true, Enabled: true,
             Shelving: AlarmShelvingKind.Unshelved, Severity: sev, Message: e.Message);