ios: stopped state for DB management, suspend quicker/instantly on app termination (#783)

* ios: stopped state for DB management, suspend quicker/instantly on app termination

* update terminateChat

apps/ios/Shared/AppDelegate.swift

@@ -75,6 +75,11 @@ class AppDelegate: NSObject, UIApplicationDelegate {
         }
     }
 
+    func applicationWillTerminate(_ application: UIApplication) {
+        logger.debug("AppDelegate: applicationWillTerminate")
+        terminateChat()
+    }
+
     private func receiveMessages(_ completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
         let complete = BGManager.shared.completionHandler {
             logger.debug("AppDelegate: completed BGManager.receiveMessages")

apps/ios/Shared/Model/SuspendChat.swift

@@ -16,6 +16,8 @@ let appSuspendTimeout: Int = 15 // seconds
 
 let bgSuspendTimeout: Int = 5 // seconds
 
+let terminationTimeout: Int = 3 // seconds
+
 private func _suspendChat(timeout: Int) {
     appStateGroupDefault.set(.suspending)
     apiSuspendChat(timeoutMicroseconds: timeout * 1000000)
@@ -25,9 +27,11 @@ private func _suspendChat(timeout: Int) {
 
 func suspendChat() {
     suspendLockQueue.sync {
+        if appStateGroupDefault.get() != .stopped {
             _suspendChat(timeout: appSuspendTimeout)
         }
     }
+}
 
 func suspendBgRefresh() {
     suspendLockQueue.sync {
@@ -37,17 +41,35 @@ func suspendBgRefresh() {
     }
 }
 
+func terminateChat() {
+    suspendLockQueue.sync {
+        switch appStateGroupDefault.get() {
+        case .suspending:
+            // suspend instantly if already suspending
+            _chatSuspended()
+            apiSuspendChat(timeoutMicroseconds: 0)
+        case .stopped: ()
+        default:
+            _suspendChat(timeout: terminationTimeout)
+        }
+    }
+}
+
 func chatSuspended() {
     suspendLockQueue.sync {
         if case .suspending = appStateGroupDefault.get() {
-            logger.debug("chatSuspended")
+            _chatSuspended()
+        }
+    }
+}
+
+private func _chatSuspended() {
+    logger.debug("_chatSuspended")
     appStateGroupDefault.set(.suspended)
     if ChatModel.shared.chatRunning == true {
         ChatReceiver.shared.stop()
     }
 }
-    }
-}
 
 func activateChat(appState: AppState = .active) {
     suspendLockQueue.sync {

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

@@ -223,6 +223,7 @@ struct DatabaseView: View {
                 try await apiStopChat()
                 ChatReceiver.shared.stop()
                 await MainActor.run { m.chatRunning = false }
+                appStateGroupDefault.set(.stopped)
             } catch let error {
                 await MainActor.run {
                     runChat = true
@@ -307,6 +308,7 @@ struct DatabaseView: View {
                 do {
                     try initializeChat(start: true)
                     m.chatDbChanged = false
+                    appStateGroupDefault.set(.active)
                 } catch let error {
                     fatalError("Error starting chat \(responseError(error))")
                 }
@@ -318,6 +320,7 @@ struct DatabaseView: View {
                 m.chatRunning = true
                 ChatReceiver.shared.start()
                 chatLastStartGroupDefault.set(Date.now)
+                appStateGroupDefault.set(.active)
             } catch let error {
                 runChat = false
                 alert = .error(title: "Error starting chat", error: responseError(error))

apps/ios/SimpleXChat/AppGroup.swift

@@ -23,6 +23,7 @@ public enum AppState: String {
     case bgRefresh
     case suspending
     case suspended
+    case stopped
 
     public var inactive: Bool {
         switch self {