working on difference calculations

Management/Services/Files/CourseDifferences.cs

@@ -0,0 +1,40 @@
+using LocalModels;
+
+public static class CourseDifferences
+{
+  public static NewCourseChanges GetNewChanges(LocalCourse newCourse, LocalCourse oldCourse)
+  {
+    if (newCourse == oldCourse)
+      return new NewCourseChanges();
+
+    var differentModules = newCourse.Modules
+      .Where(newModule =>
+        !oldCourse.Modules.Any(oldModule => oldModule.Equals(newModule))
+      )
+      .Select(newModule =>
+      {
+        var oldModule = oldCourse.Modules.FirstOrDefault(m => m.Name == newModule.Name);
+        if (oldModule == null)
+          return newModule;
+
+        var newAssignments = newModule.Assignments.Where(
+          newAssignment => !oldModule.Assignments.Any(oldAssignment => newAssignment == oldAssignment)
+        );
+        return newModule with { Assignments = newAssignments };
+      })
+      .ToArray();
+
+    return new NewCourseChanges
+    {
+      Settings = newCourse.Settings,
+      Modules = differentModules,
+    };
+  }
+
+}
+
+public record NewCourseChanges
+{
+  public IEnumerable<LocalModule> Modules { get; init; } = [];
+  public LocalCourseSettings? Settings { get; init; }
+}