ios: fix background refresh crash, memoize migrateChatDatabase (#1103)

* ios: fix background refresh crash, memoize migrateChatDatabase

* store returned value

apps/ios/Shared/Model/BGManager.swift

@@ -82,12 +82,15 @@ class BGManager {
         }
         self.completed = false
         DispatchQueue.main.async {
-            do {
-                try initializeChat(start: true)
-            } catch let error {
-                fatalError("Failed to start or load chats: \(responseError(error))")
+            let m = ChatModel.shared
+            if (!m.chatInitialized) {
+                do {
+                    try initializeChat(start: true)
+                } catch let error {
+                    fatalError("Failed to start or load chats: \(responseError(error))")
+                }
             }
-            if ChatModel.shared.currentUser == nil {
+            if m.currentUser == nil {
                 completeReceiving("no current user")
                 return
             }

apps/ios/Shared/Model/ChatModel.swift

@@ -16,6 +16,7 @@ final class ChatModel: ObservableObject {
     @Published var onboardingStage: OnboardingStage?
     @Published var v3DBMigration: V3DBMigrationState = v3DBMigrationDefault.get()
     @Published var currentUser: User?
+    @Published var chatInitialized = false
     @Published var chatRunning: Bool?
     @Published var chatDbChanged = false
     @Published var chatDbEncrypted: Bool?

apps/ios/Shared/Model/SimpleXAPI.swift

@@ -734,6 +734,7 @@ func initializeChat(start: Bool, dbKey: String? = nil) throws {
     let _ = getChatCtrl(dbKey)
     try apiSetFilesFolder(filesFolder: getAppFilesDirectory().path)
     try apiSetIncognito(incognito: incognitoGroupDefault.get())
+    m.chatInitialized = true
     m.currentUser = try apiGetActiveUser()
     if m.currentUser == nil {
         m.onboardingStage = .step1_SimpleXInfo

apps/ios/Shared/SimpleXApp.swift

@@ -41,11 +41,13 @@ struct SimpleXApp: App {
                     chatModel.appOpenUrl = url
                 }
                 .onAppear() {
-                    do {
-                        chatModel.v3DBMigration = v3DBMigrationDefault.get()
-                        try initializeChat(start: chatModel.v3DBMigration.startChat)
-                    } catch let error {
-                        fatalError("Failed to start or load chats: \(responseError(error))")
+                    if (!chatModel.chatInitialized) {
+                        do {
+                            chatModel.v3DBMigration = v3DBMigrationDefault.get()
+                            try initializeChat(start: chatModel.v3DBMigration.startChat)
+                        } catch let error {
+                            fatalError("Failed to start or load chats: \(responseError(error))")
+                        }
                     }
                 }
                 .onChange(of: scenePhase) { phase in

apps/ios/Shared/Views/Database/DatabaseEncryptionView.swift

@@ -245,6 +245,7 @@ struct DatabaseEncryptionView: View {
     private func operationEnded(_ dbAlert: DatabaseEncryptionAlert) async {
         await MainActor.run {
             m.chatDbChanged = true
+            m.chatInitialized = false
             progressIndicator = false
             alert = dbAlert
         }

apps/ios/Shared/Views/Database/DatabaseView.swift

@@ -354,6 +354,7 @@ struct DatabaseView: View {
     private func operationEnded(_ dbAlert: DatabaseAlert) async {
         await MainActor.run {
             m.chatDbChanged = true
+            m.chatInitialized = false
             progressIndicator = false
             alert = dbAlert
         }

apps/ios/SimpleXChat/API.swift

@@ -10,6 +10,8 @@ import Foundation
 
 private var chatController: chat_ctrl?
 
+private var migrationResult: (Bool, DBMigrationResult)?
+
 public func getChatCtrl(_ useKey: String? = nil) -> chat_ctrl {
     if let controller = chatController { return controller }
     let dbPath = getAppDatabasePath().path
@@ -23,6 +25,7 @@ public func getChatCtrl(_ useKey: String? = nil) -> chat_ctrl {
 }
 
 public func migrateChatDatabase(_ useKey: String? = nil) -> (Bool, DBMigrationResult) {
+    if let res = migrationResult { return res }
     logger.debug("migrateChatDatabase \(storeDBPassphraseGroupDefault.get())")
     let dbPath = getAppDatabasePath().path
     var dbKey = ""
@@ -42,16 +45,17 @@ public func migrateChatDatabase(_ useKey: String? = nil) -> (Bool, DBMigrationRe
     var cPath = dbPath.cString(using: .utf8)!
     var cKey = dbKey.cString(using: .utf8)!
     let cjson = chat_migrate_db(&cPath, &cKey)!
-    let res = dbMigrationResult(fromCString(cjson))
+    let dbRes = dbMigrationResult(fromCString(cjson))
     let encrypted = dbKey != ""
-    if case .ok = res, useKeychain && encrypted && !setDatabaseKey(dbKey) {
-        return (encrypted, .errorKeychain)
-    }
-    return (encrypted, res)
+    let keychainErr = dbRes == .ok && useKeychain && encrypted && !setDatabaseKey(dbKey)
+    let result = (encrypted, keychainErr ? .errorKeychain : dbRes)
+    migrationResult = result
+    return result
 }
 
 public func resetChatCtrl() {
     chatController = nil
+    migrationResult = nil
 }
 
 public func sendSimpleXCmd(_ cmd: ChatCommand) -> ChatResponse {