Throws SyncValidationError when downloading corrupted Game or GameSave record

Delta.xcodeproj/project.pbxproj

@@ -201,6 +201,7 @@
 		D5A9C01D29DE058C00A8D610 /* VariableFastForward.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5A9C01C29DE058C00A8D610 /* VariableFastForward.swift */; };
 		D5AAF27729884F8600F21ACF /* CheatDevice.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5AAF27629884F8600F21ACF /* CheatDevice.swift */; };
 		D5ADD12229F33FBF00CE0560 /* Features.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5ADD12129F33FBF00CE0560 /* Features.swift */; };
+		D5CDCCEE2A859DC200E22131 /* SyncValidationError.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5CDCCEC2A859B2B00E22131 /* SyncValidationError.swift */; };
 		D5CDCCEF2A859E5300E22131 /* OSLog+Delta.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5CDCCC32A85765900E22131 /* OSLog+Delta.swift */; };
 		D5CDCCF02A859E5500E22131 /* UserDefaults+Delta.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5CDCCEA2A8593FC00E22131 /* UserDefaults+Delta.swift */; };
 		D5CDCCF12A859E7500E22131 /* ReviewSaveStatesViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5A1375A2A7D8F2600AB1372 /* ReviewSaveStatesViewController.swift */; };
@@ -478,6 +479,7 @@
 		D5ADD12129F33FBF00CE0560 /* Features.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Features.swift; sourceTree = "<group>"; };
 		D5CDCCC32A85765900E22131 /* OSLog+Delta.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "OSLog+Delta.swift"; sourceTree = "<group>"; };
 		D5CDCCEA2A8593FC00E22131 /* UserDefaults+Delta.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UserDefaults+Delta.swift"; sourceTree = "<group>"; };
+		D5CDCCEC2A859B2B00E22131 /* SyncValidationError.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SyncValidationError.swift; sourceTree = "<group>"; };
 		D5D78AE429F9BC3700E064F0 /* DSAirPlay.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DSAirPlay.swift; sourceTree = "<group>"; };
 		D5D78AE629F9D40A00E064F0 /* EnvironmentValues+FeatureOption.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "EnvironmentValues+FeatureOption.swift"; sourceTree = "<group>"; };
 		D5D797E5298D946200738869 /* Contributor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Contributor.swift; sourceTree = "<group>"; };
@@ -888,6 +890,7 @@
 			isa = PBXGroup;
 			children = (
 				BFAB9F7C219A43380080EC7D /* SyncManager.swift */,
+				D5CDCCEC2A859B2B00E22131 /* SyncValidationError.swift */,
 				BF1F45A321AF274D00EF9895 /* SyncResultViewController.swift */,
 				BF1F45AA21AF4B5800EF9895 /* SyncResultsViewController.storyboard */,
 			);
@@ -1660,6 +1663,7 @@
 				BF8CA9361F5F651900499FDD /* PopoverMenuController.swift in Sources */,
 				BFEF24F31F7DD4FD00454C62 /* SaveStateMigrationPolicy.swift in Sources */,
 				BF5942931E09BD1A0051894B /* NSFetchedResultsController+Conveniences.m in Sources */,
+				D5CDCCEE2A859DC200E22131 /* SyncValidationError.swift in Sources */,
 				BF4828881F90290F00028B97 /* Action.swift in Sources */,
 				BF6BF3271EB87EB8008E83CD /* PhotoLibraryImportOption.swift in Sources */,
 				BF5942661E09BBB10051894B /* LoadImageURLOperation.swift in Sources */,

Delta/Database/Model/Human/Game.swift

@@ -199,4 +199,14 @@ extension Game: Syncable
     public var syncableLocalizedName: String? {
         return self.name
     }
+    
+    public func awakeFromSync(_ record: AnyRecord) throws
+    {
+        guard let gameCollection = self.gameCollection else { throw SyncValidationError.incorrectGameCollection(nil) }
+        
+        if gameCollection.identifier != self.type.rawValue
+        {
+            throw SyncValidationError.incorrectGameCollection(gameCollection.name)
+        }
+    }
 }

Delta/Database/Model/Human/GameSave.swift

@@ -53,7 +53,9 @@ extension GameSave: Syncable
     
     public var syncableMetadata: [HarmonyMetadataKey : String] {
         guard let game = self.game else { return [:] }
-        return [.gameID: game.identifier, .gameName: game.name]
+        
+        // Use self.identifier to always link with exact matching game.
+        return [.gameID: self.identifier, .gameName: game.name]
     }
     
     public var syncableLocalizedName: String? {
@@ -66,4 +68,30 @@ extension GameSave: Syncable
         
         return self.game?.identifier != Game.melonDSBIOSIdentifier && self.game?.identifier != Game.melonDSDSiBIOSIdentifier
     }
+    
+    public func awakeFromSync(_ record: AnyRecord) throws
+    {
+        guard let game = self.game else { throw SyncValidationError.incorrectGame(nil) }
+        
+        if game.identifier != self.identifier
+        {
+            let fetchRequest = GameSave.fetchRequest()
+            fetchRequest.predicate = NSPredicate(format: "%K == %@", #keyPath(GameSave.identifier), game.identifier)
+            
+            if let misplacedGameSave = try self.managedObjectContext?.fetch(fetchRequest).first, misplacedGameSave.game == nil
+            {
+                // Relink game with its correct gameSave, in case we accidentally misplaced it.
+                // Otherwise, corrupted records might displace already-downloaded GameSaves
+                // due to automatic Core Data relationship propagation, despite us throwing error.
+                game.gameSave = misplacedGameSave
+            }
+            else
+            {
+                // Either there is no misplacedGameSave, or there is but it's linked to another game somehow.
+                game.gameSave = nil
+            }
+            
+            throw SyncValidationError.incorrectGame(game.name)
+        }
+    }
 }

Delta/Syncing/SyncResultViewController.swift

@@ -173,6 +173,15 @@ private extension SyncResultViewController
                             errorMessage = NSLocalizedString("The game for this item is missing. Please re-import the game to resume syncing its data.", comment: "")
                         }
                         
+                    case .other(_, let error as SyncValidationError):
+                        var message = error.failureReason ?? error.localizedDescription
+                        if let recoverySuggestion = error.recoverySuggestion
+                        {
+                            message += "\n\n" + recoverySuggestion
+                        }
+                        
+                        errorMessage = message
+                        
                     case .other(_, let error as NSError): errorMessage = error.localizedFailureReason ?? error.localizedDescription
                     default: errorMessage = error.failureReason
                     }
@@ -249,9 +258,7 @@ private extension SyncResultViewController
                 case .gameControllerInputMapping: group = .gameControllerInputMapping
                     
                 case .gameSave:
-                    guard let gameID = metadata?[.gameID] else { continue }
+                    let recordID = RecordID(type: SyncManager.RecordType.game.rawValue, identifier: error.record.recordID.identifier)
-                    
-                    let recordID = RecordID(type: SyncManager.RecordType.game.rawValue, identifier: gameID)
                     group = .game(recordID)
                     
                 case .saveState:
@@ -387,7 +394,11 @@ extension SyncResultViewController
             
         case .game:
             guard let error = section.errors.first as? RecordError else { return nil }
-            return error.record.localizedName
+            
+            let recordID = RecordID(type: SyncManager.RecordType.game.rawValue, identifier: error.record.recordID.identifier)
+            
+            let gameName = self.gameNamesByRecordID[recordID] // In case the remote record is corrupted, rely on local names.
+            return gameName ?? error.record.localizedName
             
         case .saveState(let gameID):
             guard let error = section.errors.first as? RecordError else { return nil }

Delta/Syncing/SyncValidationError.swift

@@ -0,0 +1,40 @@
+//
+//  SyncValidationError.swift
+//  Delta
+//
+//  Created by Riley Testut on 8/10/23.
+//  Copyright © 2023 Riley Testut. All rights reserved.
+//
+
+import Foundation
+
+enum SyncValidationError: LocalizedError
+{
+    case incorrectGame(String?)
+    case incorrectGameCollection(String?)
+    
+    var failureReason: String? {
+        switch self
+        {
+        case .incorrectGame(let name?):
+            return String(format: NSLocalizedString("The downloaded record is associated with the wrong game (%@).", comment: ""), name)
+        
+        case .incorrectGame(nil):
+            return NSLocalizedString("The downloaded record is not associated with a game.", comment: "")
+            
+        case .incorrectGameCollection(let name?):
+            return String(format: NSLocalizedString("The downloaded record is associated with the wrong game system (%@).", comment: ""), name)
+            
+        case .incorrectGameCollection(nil):
+            return NSLocalizedString("The downloaded record is not associated with a game system.", comment: "")
+        }
+    }
+    
+    var recoverySuggestion: String? {
+        switch self
+        {
+        case .incorrectGame: return NSLocalizedString("Try restoring an older version to resolve this issue.", comment: "")
+        case .incorrectGameCollection: return NSLocalizedString("Try restoring an older version, or manually re-import the game to resolve this issue.", comment: "")
+        }
+    }
+}