Add Population Target and more deriveds

Stars Assistant/ViewModels/PlayerPlanetViewModel.cs

@@ -1,7 +1,9 @@
 using System.Collections.ObjectModel;
 using System.Reactive.Disposables;
+using System.Reactive.Linq;
 using Microsoft.EntityFrameworkCore;
 using ReactiveUI;
+using ReactiveUI.SourceGenerators;
 using StarsAssistant.Services;
 using Splat;
 
@@ -21,6 +23,12 @@ public partial class PlayerPlanetViewModel : ViewModelBase
             throw new InvalidOperationException("PlayerPlanet ViewModels can only be created for player planets.");
 
         Planet = planet;
+        PopulationTargetPercent = planet.PopulationTargetPercent;
+
+        _populationTargetHelper = this
+            .WhenAnyValue(vm => vm.PopulationTargetPercent)
+            .Select(popTgt => this.MaxPopulation * popTgt / 10000 * 100)
+            .ToProperty(this, vm => vm.PopulationTarget);
 
         this.WhenActivated((CompositeDisposable disposables) => 
         {
@@ -101,6 +109,9 @@ public partial class PlayerPlanetViewModel : ViewModelBase
 
     public int PctDamage => Planet.PctDamage ?? 0;
 
+    [Reactive]
+    private int _populationTargetPercent;
+
     #endregion
 
     #region Derived Properties
@@ -123,6 +134,9 @@ public partial class PlayerPlanetViewModel : ViewModelBase
 
     public int ResourcesFromFactories => GameEngine.ResourcesFromFactForPlayer(Population, Factories, Value);
 
+    [ObservableAsProperty]
+    private int _populationTarget;
+
     #endregion
 
 }