26 lines
881 B
C#
26 lines
881 B
C#
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
|
|
};
|
|
}
|
|
} |