Timeless refactor

src/Core/FileTime.Core.Abstraction/Timeline/PointInTime.cs

@@ -0,0 +1,41 @@
+namespace FileTime.Core.Timeline;
+
+public class PointInTime
+{
+    private readonly List<Difference> _differences;
+    public static readonly PointInTime Eternal = new PointInTime();
+    public static readonly PointInTime Present = new PointInTime();
+
+    public IReadOnlyList<Difference> Differences { get; }
+
+    private PointInTime() : this(new List<Difference>())
+    {
+    }
+
+    private PointInTime(IEnumerable<Difference> differences)
+    {
+        _differences = new List<Difference>(differences);
+        Differences = _differences.AsReadOnly();
+    }
+
+    private PointInTime(PointInTime previous, IEnumerable<Difference> differences)
+        : this(MergeDifferences(previous.Differences, differences))
+    {
+    }
+
+    public PointInTime WithDifferences(IEnumerable<Difference> differences) =>
+        new(this, differences);
+
+    private static List<Difference> MergeDifferences(IEnumerable<Difference> previouses,
+        IEnumerable<Difference> differences)
+    {
+        var merged = new List<Difference>();
+
+        merged.AddRange(previouses);
+        merged.AddRange(differences);
+
+        return merged;
+    }
+
+    public static PointInTime CreateEmpty() => new PointInTime();
+}