feat(triggers): runtime expression trigger evaluation for scripts and alarms

src/ScadaLink.SiteRuntime/Actors/InstanceActor.cs

@@ -515,6 +515,10 @@ public class InstanceActor : ReceiveActor
                 continue;
             }
 
+            // Compile the trigger expression for Expression-triggered scripts.
+            var triggerExpression = CompileTriggerExpression(
+                script.TriggerType, script.TriggerConfiguration, $"script-trigger-{script.CanonicalName}");
+
             var props = Props.Create(() => new ScriptActor(
                 script.CanonicalName,
                 _instanceUniqueName,
@@ -524,6 +528,7 @@ public class InstanceActor : ReceiveActor
                 _sharedScriptLibrary,
                 _options,
                 _logger,
+                triggerExpression,
                 _healthCollector,
                 _serviceProvider));
 
@@ -559,6 +564,10 @@ public class InstanceActor : ReceiveActor
                 }
             }
 
+            // Compile the trigger expression for Expression-triggered alarms.
+            var triggerExpression = CompileTriggerExpression(
+                alarm.TriggerType, alarm.TriggerConfiguration, $"alarm-trigger-expr-{alarm.CanonicalName}");
+
             var props = Props.Create(() => new AlarmActor(
                 alarm.CanonicalName,
                 _instanceUniqueName,
@@ -568,6 +577,7 @@ public class InstanceActor : ReceiveActor
                 _sharedScriptLibrary,
                 _options,
                 _logger,
+                triggerExpression,
                 _healthCollector));
 
             var actorRef = Context.ActorOf(props, $"alarm-{alarm.CanonicalName}");
@@ -581,6 +591,47 @@ public class InstanceActor : ReceiveActor
             _instanceUniqueName, _scriptActors.Count, _alarmActors.Count);
     }
 
+    /// <summary>
+    /// Compiles the boolean trigger expression for an Expression-triggered
+    /// script or alarm. Returns null for non-Expression triggers, a blank
+    /// expression, or a compilation failure (logged) — in which case the
+    /// trigger is inert and the actor still starts.
+    /// </summary>
+    private Microsoft.CodeAnalysis.Scripting.Script<object?>? CompileTriggerExpression(
+        string? triggerType, string? triggerConfigJson, string compileName)
+    {
+        if (!string.Equals(triggerType, "Expression", StringComparison.OrdinalIgnoreCase))
+            return null;
+        if (string.IsNullOrEmpty(triggerConfigJson))
+            return null;
+
+        string? expression;
+        try
+        {
+            var doc = JsonSerializer.Deserialize<JsonElement>(triggerConfigJson);
+            expression = doc.TryGetProperty("expression", out var e) ? e.GetString() : null;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to read trigger expression config for {Name} on {Instance}",
+                compileName, _instanceUniqueName);
+            return null;
+        }
+
+        if (string.IsNullOrWhiteSpace(expression))
+            return null;
+
+        var result = _compilationService.CompileTriggerExpression(compileName, expression);
+        if (result.IsSuccess)
+            return result.CompiledScript;
+
+        _logger.LogError(
+            "Trigger expression for {Name} on {Instance} failed to compile: {Errors}",
+            compileName, _instanceUniqueName, string.Join("; ", result.Errors));
+        return null;
+    }
+
     /// <summary>
     /// Read-only access to current attribute count (for testing/diagnostics).
     /// </summary>