email support team when an installation turns to eror status

csharp/App/Backend/DataTypes/Methods/Installation.cs

@@ -1,5 +1,6 @@
 using InnovEnergy.App.Backend.Database;
 using InnovEnergy.App.Backend.Relations;
+using InnovEnergy.Lib.Mailer;
 using InnovEnergy.Lib.Utils;
 
 namespace InnovEnergy.App.Backend.DataTypes.Methods;
@@ -171,5 +172,39 @@ public static class InstallationMethods
 
         return true;
     }
-    
+
+    private const String SupportEmail = "support@inesco.energy";
+    private const String SupportName  = "inesco energy Support Team";
+
+    public static Task SendAlarmNotificationToSupport(this Installation installation, Int32 prevStatus)
+    {
+        var productName = ProductName(installation.Product);
+        var fromStatus  = StatusName(prevStatus);
+
+        var subject = $"[inesco energy] Alarm: {installation.Name}";
+        var body =
+            $"Installation \"{installation.Name}\" (ID {installation.Id}, {productName})\n" +
+            $"status changed from {fromStatus} to Alarm.\n\n" +
+            "Please check the Log tab on the Monitor to see detailed errors and warnings.\n";
+
+        return Mailer.Send(SupportName, SupportEmail, subject, body);
+    }
+
+    private static String StatusName(Int32 status) => status switch
+    {
+        -1 => "Offline",
+        0  => "Green",
+        1  => "Warning",
+        2  => "Alarm",
+        _  => "Unknown"
+    };
+
+    private static String ProductName(Int32 product) => product switch
+    {
+        2 => "Sodistore Home",
+        3 => "Sodistore Max",
+        4 => "Sodistore Grid",
+        5 => "Sodistore Pro",
+        _ => $"Product {product}"
+    };
 }