fix: add direct CronTimer reference refs NOISSUE

CronTimer/CronTimer.cs

@@ -0,0 +1,78 @@
+using System;
+using System.Threading;
+using NCrontab;
+
+public class CronTimer
+{
+    public const string UTC = "Etc/UTC";
+
+    static readonly TimeSpan InfiniteTimeSpan = TimeSpan.FromMilliseconds(Timeout.Infinite); // net 3.5
+
+    readonly CrontabSchedule schedule;
+    readonly TimeZoneInfo tzi;
+    readonly string id;
+    readonly Timer t;
+
+    public string tz { get; }
+    public string Expression { get; }
+    public event EventHandler<CronTimerEventArgs> OnOccurence;
+
+    public DateTime Next { get; private set; }
+
+    public CronTimer(string expression, string tz = UTC, bool includingSeconds = false)
+    {
+        Expression = expression;
+        this.tz = tz;
+        id = TimeZoneConverter.TZConvert.IanaToWindows(tz);
+        tzi = TimeZoneInfo.FindSystemTimeZoneById(id);
+        schedule = CrontabSchedule.Parse(expression, new CrontabSchedule.ParseOptions { IncludingSeconds = includingSeconds });
+        Next = TimeZoneInfo.ConvertTimeFromUtc(DateTime.UtcNow, tzi);
+        OnOccurence += OnOccurenceScheduleNext;
+        t = new Timer(s =>
+        {
+            var ea = new CronTimerEventArgs
+            {
+                At = Next
+            };
+            OnOccurence(this, ea);
+        }, null, InfiniteTimeSpan, InfiniteTimeSpan);
+    }
+
+    void OnOccurenceScheduleNext(object sender, EventArgs e)
+    {
+        var delay = CalculateDelay();
+        //Console.WriteLine($"Next for [{tz} {expression}] in {delay}.");
+        t.Change(delay, InfiniteTimeSpan);
+    }
+
+    public void Start()
+    {
+        var delay = CalculateDelay();
+        //Console.WriteLine($"Next for [{tz} {expression}] in {delay}.");
+        t.Change(delay, InfiniteTimeSpan);
+    }
+
+    TimeSpan CalculateDelay()
+    {
+        var nowUtc = DateTime.UtcNow;
+        Next = schedule.GetNextOccurrence(Next);
+        TimeSpan delay;
+        if (tz != UTC)
+        {
+            var nextUtc = TimeZoneInfo.ConvertTimeToUtc(Next, tzi);
+            delay = nextUtc - nowUtc;
+        }
+        else
+        {
+            delay = Next - nowUtc;
+        }
+        //Console.WriteLine($"Now: {nowUtc} [utc] {now} [{tz}], Next: {next} [{tz}] {nextUtc} [utc], Delay: {delay}");
+        if (delay < TimeSpan.Zero) delay = TimeSpan.Zero;
+        return delay;
+    }
+
+    public void Stop()
+    {
+        t.Change(InfiniteTimeSpan, InfiniteTimeSpan);
+    }
+}