Rename Concelier Source modules to Connector

src/StellaOps.Concelier.Connector.Common/Cursors/TimeWindowCursorPlanner.cs

@@ -0,0 +1,50 @@
+namespace StellaOps.Concelier.Connector.Common.Cursors;
+
+/// <summary>
+/// Utility methods for computing sliding time-window ranges used by connectors.
+/// </summary>
+public static class TimeWindowCursorPlanner
+{
+    public static TimeWindow GetNextWindow(DateTimeOffset now, TimeWindowCursorState? state, TimeWindowCursorOptions options)
+    {
+        ArgumentNullException.ThrowIfNull(options);
+        options.EnsureValid();
+
+        var effectiveState = state ?? TimeWindowCursorState.Empty;
+
+        var earliest = now - options.InitialBackfill;
+        var anchorEnd = effectiveState.LastWindowEnd ?? earliest;
+        if (anchorEnd < earliest)
+        {
+            anchorEnd = earliest;
+        }
+
+        var start = anchorEnd - options.Overlap;
+        if (start < earliest)
+        {
+            start = earliest;
+        }
+
+        var end = start + options.WindowSize;
+        if (end > now)
+        {
+            end = now;
+        }
+
+        if (end <= start)
+        {
+            end = start + options.MinimumWindowSize;
+            if (end > now)
+            {
+                end = now;
+            }
+        }
+
+        if (end <= start)
+        {
+            throw new InvalidOperationException("Unable to compute a non-empty time window with the provided options.");
+        }
+
+        return new TimeWindow(start, end);
+    }
+}