feature: Explainable Alerts

2026-06-25 00:25:31 +08:00
parent 279add1e45
commit 666d683d67
61 changed files with 9553 additions and 125 deletions
@@ -0,0 +1,26 @@
+public static class TrendContextBuilder
+{
+    public static TrendContext? BuildContext(
+        string observationCode,
+        IReadOnlyList<TrendHistoryEntry> history,
+        decimal currentValue)
+    {
+        if (history.Count < 2) return null;
+
+        var oldest = history.First();
+        var newest = history.Last();
+        var duration = newest.RecordedAt - oldest.RecordedAt;
+        if (duration <= TimeSpan.Zero || oldest.Value == 0) return null;
+
+        var pctChange = (double)((newest.Value - oldest.Value) / oldest.Value * 100m);
+        var direction = pctChange >= 0 ? "Increasing" : "Decreasing";
+
+        return new TrendContext
+        {
+            Parameter = TrendCalculator.DisplayName(observationCode),
+            PercentChange = Math.Round(Math.Abs(pctChange), 1),
+            Duration = duration,
+            Direction = direction
+        };
+    }
+}