add Notification Service Extension

DcCore/DcCore/Extensions/UserDefaults+Extensions.swift

@@ -3,7 +3,26 @@ public extension UserDefaults {
     static var hasExtensionAttemptedToSend = "hasExtensionAttemptedToSend"
     static var hasSavedKeyToKeychain = "hasSavedKeyToKeychain"
     static var upgradedKeychainEntry = "upgradedKeychainEntry_"
+    static var mainAppRunningKey = "mainAppRunning"
+    static var nseFetchingKey = "nseFetching"
+
     static var shared: UserDefaults? {
         return UserDefaults(suiteName: "group.chat.delta.ios")
     }
+
+    static var mainAppRunning: Bool {
+        return shared?.bool(forKey: mainAppRunningKey) ?? false
+    }
+
+    static func setMainAppRunning(_ value: Bool = true) {
+        shared?.setValue(value, forKey: mainAppRunningKey)
+    }
+
+    static var nseFetching: Bool {
+        return shared?.bool(forKey: nseFetchingKey) ?? false
+    }
+
+    static func setNseFetching(_ value: Bool = true) {
+        shared?.setValue(value, forKey: nseFetchingKey)
+    }
 }

DcCore/DcCore/Helper/Constants.swift

@@ -7,5 +7,4 @@ public struct Constants {
         static let deltachatImapEmailKey = "__DELTACHAT_IMAP_EMAIL_KEY__"
         static let deltachatImapPasswordKey = "__DELTACHAT_IMAP_PASSWORD_KEY__"
     }
-    public static let notificationIdentifier = "deltachat-ios-local-notifications"
 }

DcNotificationService/DcNotificationService.entitlements

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>com.apple.security.application-groups</key>
+	<array>
+		<string>group.chat.delta.ios</string>
+	</array>
+	<key>keychain-access-groups</key>
+	<array>
+		<string>$(AppIdentifierPrefix)group.chat.delta.ios</string>
+	</array>
+</dict>
+</plist>

DcNotificationService/Info.plist

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>NSExtension</key>
+	<dict>
+		<key>NSExtensionPointIdentifier</key>
+		<string>com.apple.usernotifications.service</string>
+		<key>NSExtensionPrincipalClass</key>
+		<string>$(PRODUCT_MODULE_NAME).NotificationService</string>
+	</dict>
+</dict>
+</plist>

DcNotificationService/NotificationService.swift

@@ -0,0 +1,98 @@
+import UserNotifications
+import DcCore
+
+class NotificationService: UNNotificationServiceExtension {
+    let dcAccounts = DcAccounts.shared
+
+    override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {
+        guard let bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent) else { return }
+
+        if UserDefaults.mainAppRunning {
+            contentHandler(silenceNotification(bestAttemptContent))
+            return
+        }
+        UserDefaults.setNseFetching()
+
+        // as we're mixing in notifications from accounts without PUSH and we cannot add multiple notifications,
+        // it is best to move everything to the same thread - and set just no threadIdentifier
+
+        dcAccounts.openDatabase(writeable: false)
+        let eventEmitter = dcAccounts.getEventEmitter()
+
+        if !dcAccounts.backgroundFetch(timeout: 25) {
+            UserDefaults.setNseFetching(false)
+            contentHandler(bestAttemptContent)
+            return
+        }
+        UserDefaults.setNseFetching(false)
+
+        var messageCount = 0
+        var uniqueChats: [String: String] = [:]
+        while true {
+            guard let event = eventEmitter.getNextEvent() else { break }
+            if event.id == DC_EVENT_ACCOUNTS_BACKGROUND_FETCH_DONE { break }
+            if event.id == DC_EVENT_INCOMING_MSG {
+                let dcContext = dcAccounts.get(id: event.accountId)
+                let chat = dcContext.getChat(chatId: event.data1Int)
+                if !UserDefaults.standard.bool(forKey: "notifications_disabled") && !chat.isMuted {
+                    let msg = dcContext.getMessage(id: event.data2Int)
+                    let sender = msg.getSenderName(dcContext.getContact(id: msg.fromContactId))
+                    bestAttemptContent.title = chat.isGroup ? chat.name : sender
+                    bestAttemptContent.body = (chat.isGroup ? "\(sender): " : "") + (msg.summary(chars: 80) ?? "")
+                    bestAttemptContent.userInfo["account_id"] = dcContext.id
+                    bestAttemptContent.userInfo["chat_id"] = chat.id
+                    bestAttemptContent.userInfo["message_id"] = msg.id
+
+                    uniqueChats["\(dcContext.id)-\(chat.id)"] = bestAttemptContent.title
+                    messageCount += 1
+                }
+            }
+        }
+
+        if messageCount == 0 {
+            dcAccounts.closeDatabase()
+            contentHandler(silenceNotification(bestAttemptContent))
+        } else {
+            bestAttemptContent.badge = dcAccounts.getFreshMessageCount() as NSNumber
+            dcAccounts.closeDatabase()
+            if messageCount > 1 {
+                bestAttemptContent.userInfo["message_id"] = nil
+                if uniqueChats.count == 1 {
+                    bestAttemptContent.body = String.localized(stringID: "n_messages", parameter: messageCount)
+                } else {
+                    bestAttemptContent.userInfo["open_as_overview"] = true // leaving chat_id as is removes the notification when one of the chats is opened (does not matter which)
+                    bestAttemptContent.title = uniqueChats.values.joined(separator: ", ")
+                    bestAttemptContent.body = String.localized(stringID: "n_messages_in_m_chats", parameter: messageCount, uniqueChats.count)
+                }
+            }
+            if #available(iOS 15.0, *) {
+                bestAttemptContent.relevanceScore = 1.0
+            }
+            UserDefaults.shared?.set(true, forKey: UserDefaults.hasExtensionAttemptedToSend) // force UI updates in case app was suspended
+            contentHandler(bestAttemptContent)
+        }
+    }
+
+    override func serviceExtensionTimeWillExpire() {
+        // Called just before the extension will be terminated by the system.
+        // Use this as an opportunity to deliver your "best attempt" at modified content, otherwise the original push payload will be used.
+
+        // For Delta Chat, it is just fine to do nothing - assume eg. bad network or mail servers not reachable,
+        // then a "You have new messages" is the best that can be done.
+        UserDefaults.setNseFetching(false)
+    }
+
+    private func silenceNotification(_ bestAttemptContent: UNMutableNotificationContent) -> UNMutableNotificationContent {
+        // with `com.apple.developer.usernotifications.filtering` entitlement,
+        // one can use `contentHandler(UNMutableNotificationContent())` to not display a notifcation
+        // and remove all "irrelevant" handling
+        bestAttemptContent.sound = nil
+        bestAttemptContent.body = String.localized("videochat_tap_to_open")
+        bestAttemptContent.userInfo["irrelevant"] = true
+        if #available(iOS 15.0, *) {
+            bestAttemptContent.interruptionLevel = .passive
+            bestAttemptContent.relevanceScore = 0.0
+        }
+        return bestAttemptContent
+    }
+}

RELEASE.md

@@ -29,6 +29,7 @@ in Xcode:
    b) increase the build number in the same dialog
    c) navigate to "DcShare / Build Settings / Versioning"
       and adapt "Marketing Version" and "Current Project Version"
+   d) same for "DcNotificationService"
 
 6. a) select "Any iOS Device (arm64)" in the toolbar
    b) select menu "Product/Archive"