From e37596f0f7cf6bafc97d59078400f0d6ff368deb Mon Sep 17 00:00:00 2001
From: Artal Druk <artald@wix.com>
Date: Thu, 13 Feb 2020 12:20:10 +0200
Subject: [PATCH] fix issue with UNUserNotificationCenterDelegate and the
 multicast delegate. the system completion handler needs to be called after
 all tasks are completed, otherwise they might be terminated.

---
 lib/ios/RNNotificationCenterMulticast.m | 49 +++++++++++++++++++++----
 1 file changed, 41 insertions(+), 8 deletions(-)

diff --git a/lib/ios/RNNotificationCenterMulticast.m b/lib/ios/RNNotificationCenterMulticast.m
index c1c6add..1cf2fcb 100644
--- a/lib/ios/RNNotificationCenterMulticast.m
+++ b/lib/ios/RNNotificationCenterMulticast.m
@@ -22,20 +22,53 @@
 
 - (void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions options))completionHandler
 {
-  for (id<UNUserNotificationCenterDelegate> delegate in delegates) {
-    if ([delegate respondsToSelector:@selector(userNotificationCenter:willPresentNotification:withCompletionHandler:)]) {
-      [delegate userNotificationCenter:center willPresentNotification:notification withCompletionHandler:completionHandler];
+  dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+    dispatch_group_t completionGroup = dispatch_group_create();
+      
+    __block UNNotificationPresentationOptions allOptions = UNNotificationPresentationOptionNone;
+    void (^myCompletion)(UNNotificationPresentationOptions);
+    myCompletion = ^(UNNotificationPresentationOptions options){
+      allOptions |= options;
+      dispatch_group_leave(completionGroup);
+    };
+    
+    for (id<UNUserNotificationCenterDelegate> delegate in delegates) {
+      if ([delegate respondsToSelector:@selector(userNotificationCenter:willPresentNotification:withCompletionHandler:)]) {
+        dispatch_group_enter(completionGroup);
+        [delegate userNotificationCenter:center willPresentNotification:notification withCompletionHandler:myCompletion];
+      }
     }
-  }
+    
+    dispatch_group_wait(completionGroup, dispatch_time(DISPATCH_TIME_NOW, 30 * NSEC_PER_SEC));
+
+    dispatch_async(dispatch_get_main_queue(), ^{
+      completionHandler(allOptions);
+    });
+  });
 }
 
 - (void)userNotificationCenter:(UNUserNotificationCenter *)center didReceiveNotificationResponse:(UNNotificationResponse *)response withCompletionHandler:(void(^)(void))completionHandler
 {
-  for (id<UNUserNotificationCenterDelegate> delegate in delegates) {
-    if ([delegate respondsToSelector:@selector(userNotificationCenter:didReceiveNotificationResponse:withCompletionHandler:)]) {
-      [delegate userNotificationCenter:center didReceiveNotificationResponse:response withCompletionHandler:completionHandler];
+  dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+    dispatch_group_t completionGroup = dispatch_group_create();
+      
+    void (^myCompletion)(void) = ^{
+      dispatch_group_leave(completionGroup);
+    };
+    
+    for (id<UNUserNotificationCenterDelegate> delegate in delegates) {
+      if ([delegate respondsToSelector:@selector(userNotificationCenter:didReceiveNotificationResponse:withCompletionHandler:)]) {
+        dispatch_group_enter(completionGroup);
+        [delegate userNotificationCenter:center didReceiveNotificationResponse:response withCompletionHandler:myCompletion];
+      }
     }
-  }
+    
+    dispatch_group_wait(completionGroup, dispatch_time(DISPATCH_TIME_NOW, 30 * NSEC_PER_SEC));
+
+    dispatch_async(dispatch_get_main_queue(), ^{
+      completionHandler();
+    });
+  });
 }
 
 - (void)userNotificationCenter:(UNUserNotificationCenter *)center openSettingsForNotification:(nullable UNNotification *)notification