rileytestut · CooperCorona · Aug 5, 2024
diff --git a/Delta.xcodeproj/project.pbxproj b/Delta.xcodeproj/project.pbxproj
@@ -253,6 +253,7 @@
 		D5EB601B2C0E6190007C543C /* Stream+Conveniences.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5EB601A2C0E6190007C543C /* Stream+Conveniences.swift */; };
 		D5F702FD2C24CE5300DCD271 /* UISceneSession+Delta.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5F702FC2C24CE5300DCD271 /* UISceneSession+Delta.swift */; };
 		D5F82FB82981D3AC00B229AF /* LegacySearchBar.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5F82FB72981D3AC00B229AF /* LegacySearchBar.swift */; };
+		DC1486CE2C604B130001E81C /* QuickSaveStackOptions.swift in Sources */ = {isa = PBXBuildFile; fileRef = DC1486CD2C604B130001E81C /* QuickSaveStackOptions.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -546,6 +547,7 @@
 		D5EB601A2C0E6190007C543C /* Stream+Conveniences.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Stream+Conveniences.swift"; sourceTree = "<group>"; };
 		D5F702FC2C24CE5300DCD271 /* UISceneSession+Delta.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UISceneSession+Delta.swift"; sourceTree = "<group>"; };
 		D5F82FB72981D3AC00B229AF /* LegacySearchBar.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LegacySearchBar.swift; sourceTree = "<group>"; };
+		DC1486CD2C604B130001E81C /* QuickSaveStackOptions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = QuickSaveStackOptions.swift; sourceTree = "<group>"; };
 		DC866E433B3BA9AE18ABA1EC /* libPods-Delta.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libPods-Delta.a"; sourceTree = BUILT_PRODUCTS_DIR; };
 /* End PBXFileReference section */
 
@@ -1193,6 +1195,8 @@
 				AC1C990F29F8B8C30020E6E4 /* ToastNotificationOptions.swift */,
 				D5147EC72A817B4A00D6CD64 /* ReviewSaveStatesOptions.swift */,
 				D5A287242C23A1AC009883C3 /* SkinDebugging.swift */,
+				AC1AE3092A69BD3A00956EB9 /* AlternateAppIcons.swift */,
+				DC1486CD2C604B130001E81C /* QuickSaveStackOptions.swift */,
 			);
 			path = Features;
 			sourceTree = "<group>";
@@ -1695,6 +1699,7 @@
 				BF34FA111CF1899D006624C7 /* CheatTextView.swift in Sources */,
 				D524F4A5273DEBB400D500B2 /* ServerManager+Delta.swift in Sources */,
 				D5AAF27729884F8600F21ACF /* CheatDevice.swift in Sources */,
+				DC1486CE2C604B130001E81C /* QuickSaveStackOptions.swift in Sources */,
 				BF1F45AD21AF57BA00EF9895 /* HarmonyMetadataKey+Keys.swift in Sources */,
 				BFD1EF402336BD8800D197CF /* UIDevice+Processor.swift in Sources */,
 				BF71CF871FE90006001F1613 /* AppIconShortcutsViewController.swift in Sources */,

diff --git a/Delta/Emulation/GameViewController.swift b/Delta/Emulation/GameViewController.swift
@@ -1310,17 +1310,33 @@ extension GameViewController
 
             do
             {
-                if let quickSaveState = try fetchRequest.execute().first
-                {
-                    self.update(quickSaveState)
-                }
-                else
-                {
+                if ExperimentalFeatures.shared.quickSaveStack.isEnabled {
+                    let quickSaveStates = try fetchRequest.execute()
+                    if let saveState = quickSaveStates.first, quickSaveStates.count >= ExperimentalFeatures.shared.quickSaveStack.size.rawValue {
+                        DatabaseManager.shared.performBackgroundTask { (context) in
+                            let temporarySaveState = context.object(with: saveState.objectID)
+                            context.delete(temporarySaveState)
+                            context.saveWithErrorLogging()
+                        }
+                    }
                     let saveState = SaveState(context: backgroundContext)
                     saveState.type = .quick
                     saveState.game = game
 
                     self.update(saveState)
+                } else {
+                    if let quickSaveState = try fetchRequest.execute().first
+                    {
+                        self.update(quickSaveState)
+                    }
+                    else
+                    {
+                        let saveState = SaveState(context: backgroundContext)
+                        saveState.type = .quick
+                        saveState.game = game
+
+                        self.update(saveState)
+                    }
                 }
             }
             catch
@@ -1340,7 +1356,7 @@ extension GameViewController
 
         do
         {
-            if let quickSaveState = try DatabaseManager.shared.viewContext.fetch(fetchRequest).first
+            if let quickSaveState = try DatabaseManager.shared.viewContext.fetch(fetchRequest).last
             {
                 self.load(quickSaveState)
             }

diff --git a/Delta/Experimental Features/ExperimentalFeatures.swift b/Delta/Experimental Features/ExperimentalFeatures.swift
@@ -57,6 +57,11 @@ struct ExperimentalFeatures: FeatureContainer
              description: "Visually show touches. Useful for screen recordings and tutorials.")
     var showTouches
 
+    @Feature(name: "Quick Save Stack",
+             description: "Maintain multiple quick saves in a stack.",
+             options: QuickSaveStatesOptions())
+    var quickSaveStack
+
     private init()
     {
         self.prepareFeatures()

diff --git a/Delta/Experimental Features/Features/QuickSaveStackOptions.swift b/Delta/Experimental Features/Features/QuickSaveStackOptions.swift
@@ -0,0 +1,25 @@
+//
+//  QuickSaveStackOptions.swift
+//  Delta
+//
+//  Created by Cooper Knaak on 8/4/24.
+//  Copyright © 2024 Riley Testut. All rights reserved.
+//
+
+import Foundation
+
+import DeltaFeatures
+
+struct QuickSaveStatesOptions
+{
+    enum Size: Int, CaseIterable, CustomStringConvertible, OptionValue, LocalizedOptionValue {
+        case two = 2
+        case four = 4
+        case eight = 8
+
+        var description: String { return "\(self.rawValue)" }
+    }
+
+    @Option(name: "Stack Size", values: Size.allCases)
+    var size = Size.two
+}
diff --git a/Delta/Settings/SettingsViewController.swift b/Delta/Settings/SettingsViewController.swift
@@ -122,6 +122,7 @@ class SettingsViewController: UITableViewController
         super.init(coder: aDecoder)
 
         NotificationCenter.default.addObserver(self, selector: #selector(SettingsViewController.settingsDidChange(with:)), name: Settings.didChangeNotification, object: nil)
+        NotificationCenter.default.addObserver(self, selector: #selector(SettingsViewController.experimentalSettingsDidChange(with:)), name: Settings.didChangeNotification, object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(SettingsViewController.externalGameControllerDidConnect(_:)), name: .externalGameControllerDidConnect, object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(SettingsViewController.externalGameControllerDidDisconnect(_:)), name: .externalGameControllerDidDisconnect, object: nil)
     }
@@ -594,7 +595,7 @@ private extension SettingsViewController
             {
                 self.tableView.selectRow(at: selectedIndexPath, animated: true, scrollPosition: .none)
             }
-            
+
         case .localControllerPlayerIndex, .preferredControllerSkin, .translucentControllerSkinOpacity, .respectSilentMode, .isButtonHapticFeedbackEnabled, .isThumbstickHapticFeedbackEnabled, .isAltJITEnabled: break
         default: break
         }
@@ -1030,3 +1031,67 @@ extension SettingsViewController: MFMailComposeViewControllerDelegate
         controller.dismiss(animated: true, completion: nil)
     }
 }
+
+// MARK: - ExperimentalFeatures.quickSaveStack
+
+private extension SettingsViewController {
+
+    @objc func experimentalSettingsDidChange(with notification: Notification) {
+        guard let settingsName = notification.userInfo?[Settings.NotificationUserInfoKey.name] as? Settings.Name else { return }
+        guard let settingsValue = notification.userInfo?[Settings.NotificationUserInfoKey.value] else { return }
+
+        switch settingsName
+        {
+        case ExperimentalFeatures.shared.quickSaveStack.settingsKey:
+            guard let isOn = settingsValue as? Bool else {
+                return
+            }
+            if !isOn {
+                // reset to 1. If it the feature was off and was turned on, there
+                // is only one save state, by definition, so 
+                deleteQuickSaveStack(count: 1)
+            }
+            break
+        case ExperimentalFeatures.shared.quickSaveStack.$size.settingsKey:
+            guard let newSize = settingsValue as? QuickSaveStatesOptions.Size else {
+                return
+            }
+            deleteQuickSaveStack(count: newSize.rawValue)
+            break
+
+        default: break
+        }
+    }
+
+    /// Deletes quick save database entries until there are no more than `count` remaining.
+    private func deleteQuickSaveStack(count:Int) {
+        let backgroundContext = DatabaseManager.shared.newBackgroundContext()
+        backgroundContext.performAndWait {
+            do {
+                let games = try Game.fetchRequest().execute()
+                for game in games {
+                    let fetchRequest = SaveState.fetchRequest(for: game, type: .quick)
+                    do {
+                        let quickSaveStates = try fetchRequest.execute()
+                        // quick saves are ordered earliest to latest. The top of the stack
+                        // is the end. Delete the first ones so the most recently related
+                        // ones remain.
+                        let toDelete = max(0, quickSaveStates.count - count)
+                        for i in 0..<toDelete {
+                            DatabaseManager.shared.performBackgroundTask { (context) in
+                                let temporarySaveState = context.object(with: quickSaveStates[i].objectID)
+                                context.delete(temporarySaveState)
+                                context.saveWithErrorLogging()
+                            }
+                        }
+                    }
+                    catch {
+                        print(error)
+                    }
+                }
+            } catch {
+                print(error)
+            }
+        }
+    }
+}