Fixes always showing non-featured apps last in FeaturedViewController

AltStoreCore/Model/DatabaseManager.swift

@@ -188,11 +188,15 @@ public extension DatabaseManager
             {
                 // Randomize source order
                 let fetchRequest = Source.fetchRequest()
-                let sources = try context.fetch(fetchRequest)
+                fetchRequest.relationshipKeyPathsForPrefetching = [#keyPath(Source._apps)]
                 
+                let sources = try context.fetch(fetchRequest)
                 for source in sources
                 {
                     source.featuredSortID = UUID().uuidString
+                    
+                    // Randomize app order
+                    self.updateAppFeaturedSortIDs(for: source)
                 }
                 
                 try context.save()
@@ -201,23 +205,43 @@ public extension DatabaseManager
             {
                 Logger.main.error("Failed to update source order. \(error.localizedDescription, privacy: .public)")
             }
-            
-            do
-            {
-                // Randomize app order
-                let fetchRequest = StoreApp.fetchRequest()
-                let apps = try context.fetch(fetchRequest)
-                
-                for app in apps
-                {
-                    app.featuredSortID = UUID().uuidString
-                }
-                
-                try context.save()
+        }
+    }
+    
+    private func updateAppFeaturedSortIDs(for source: Source)
+    {
+        let featuredAppSlots = 5
+        
+        // Filter out already installed apps.
+        var featuredApps = Set(source.effectiveFeaturedApps.filter { $0.installedApp == nil }.prefix(featuredAppSlots)) // Take just first 5 featured apps
+        var otherApps = source.apps.filter { $0.installedApp == nil && !featuredApps.contains($0) }
+        
+        let remainingSlots = featuredAppSlots - featuredApps.count
+        
+        // Fill in remaining featured app slots with random uninstalled apps.
+        for _ in 0 ..< remainingSlots
+        {
+            guard let index = otherApps.indices.randomElement() else {
+                // No remaining apps, so stop filling in slots.
+                break
             }
-            catch
+            
+            let randomApp = otherApps[index]
+            
+            featuredApps.insert(randomApp)
+            otherApps.remove(at: index)
+        }
+        
+        for storeApp in source.apps
+        {
+            if featuredApps.contains(storeApp)
             {
-                Logger.main.error("Failed to update app order. \(error.localizedDescription, privacy: .public)")
+                storeApp.featuredSortID = UUID().uuidString
+            }
+            else
+            {
+                // Prepend "_" to ensure it's sorted after featuredApps.
+                storeApp.featuredSortID = "_" + UUID().uuidString
             }
         }
     }