Fix crash when searching

Tusker/CoreData/MastodonCachePersistentStore.swift

@@ -78,8 +78,8 @@ class MastodonCachePersistentStore: NSPersistentContainer {
             if self.backgroundContext.hasChanges {
                 try! self.backgroundContext.save()
             }
-            completion?()
             statuses.forEach { self.statusSubject.send($0.id) }
+            completion?()
         }
     }
 
@@ -142,4 +142,27 @@ class MastodonCachePersistentStore: NSPersistentContainer {
         }
     }
     
+    func performBatchUpdates(_ block: @escaping (_ context: NSManagedObjectContext, _ addAccounts: ([Account]) -> Void, _ addStatuses: ([Status]) -> Void) -> Void, completion: (() -> Void)? = nil) {
+        backgroundContext.perform {
+            var updatedAccounts = [String]()
+            var updatedStatuses = [String]()
+            
+            block(self.backgroundContext, { (accounts) in
+                accounts.forEach { self.upsert(account: $0) }
+                updatedAccounts.append(contentsOf: accounts.map { $0.id })
+            }, { (statuses) in
+                statuses.forEach { self.upsert(status: $0, incrementReferenceCount: true) }
+                updatedStatuses.append(contentsOf: statuses.map { $0.id })
+            })
+
+            updatedAccounts.forEach(self.accountSubject.send)
+            updatedStatuses.forEach(self.statusSubject.send)
+            
+            if self.backgroundContext.hasChanges {
+                try! self.backgroundContext.save()
+            }
+            completion?()
+        }
+    }
+    
 }

Tusker/Screens/Conversation/ConversationTableViewController.swift

@@ -43,7 +43,6 @@ class ConversationTableViewController: EnhancedTableViewController {
     }
     
     deinit {
-        mastodonController.persistentContainer.status(for: mainStatusID)?.decrementReferenceCount()
         for (id, _) in statuses {
             mastodonController.persistentContainer.status(for: id)?.decrementReferenceCount()
         }

Tusker/Screens/Search/SearchResultsViewController.swift

@@ -116,10 +116,8 @@ class SearchResultsViewController: EnhancedTableViewController {
         }
         self.currentQuery = query
 
-        if self.dataSource.snapshot().numberOfItems == 0 {
         activityIndicator.isHidden = false
         activityIndicator.startAnimating()
-        }
 
         let request = Client.search(query: query, resolve: true, limit: 10)
         mastodonController.run(request) { (response) in
@@ -132,11 +130,25 @@ class SearchResultsViewController: EnhancedTableViewController {
 
             guard self.currentQuery == query else { return }
             
+            let oldSnapshot = self.dataSource.snapshot()
             var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
+            
+            self.mastodonController.persistentContainer.performBatchUpdates({ (context, addAccounts, addStatuses) in
+                // todo: reference count accounts
+//                oldSnapshot.itemIdentifiers(inSection: .accounts).forEach { (item) in
+//                    guard case let .account(id) = item else { return }
+//                    self.mastodonController.persistentContainer.account(for: id, in: context)?.decrementReferenceCount()
+//                }
+                
+                oldSnapshot.itemIdentifiers(inSection: .statuses).forEach { (item) in
+                    guard case let .status(id, _) = item else { return }
+                    self.mastodonController.persistentContainer.status(for: id, in: context)?.decrementReferenceCount()
+                }
+                
                 if self.onlySections.contains(.accounts) && !results.accounts.isEmpty {
                     snapshot.appendSections([.accounts])
                     snapshot.appendItems(results.accounts.map { .account($0.id) }, toSection: .accounts)
-                self.mastodonController.persistentContainer.addAll(accounts: results.accounts)
+                    addAccounts(results.accounts)
                 }
                 if self.onlySections.contains(.hashtags) && !results.hashtags.isEmpty {
                     snapshot.appendSections([.hashtags])
@@ -145,11 +157,15 @@ class SearchResultsViewController: EnhancedTableViewController {
                 if self.onlySections.contains(.statuses) && !results.statuses.isEmpty {
                     snapshot.appendSections([.statuses])
                     snapshot.appendItems(results.statuses.map { .status($0.id, .unknown) }, toSection: .statuses)
-                self.mastodonController.persistentContainer.addAll(statuses: results.statuses)
-                self.mastodonController.persistentContainer.addAll(accounts: results.statuses.map { $0.account })
+                    addStatuses(results.statuses)
+                    addAccounts(results.statuses.map { $0.account })
                 }
+            }, completion: {
+                DispatchQueue.main.async {
                     self.dataSource.apply(snapshot)
                 }
+            })
+        }
     }
     
     // MARK: - Table view delegate