Generate id on Java side when not provided

Author: aurimasc

com.unity.mobile.notifications/Runtime/Android/AndroidNotificationCenter.cs

@@ -114,7 +114,7 @@ void CollectMethods(AndroidJavaClass clazz)
             setNotificationGroupAlertBehavior = JniApi.FindMethod(clazz, "setNotificationGroupAlertBehavior", "(Landroid/app/Notification$Builder;I)V", true);
             getNotificationGroupAlertBehavior = JniApi.FindMethod(clazz, "getNotificationGroupAlertBehavior", "(Landroid/app/Notification;)I", true);
             getNotificationChannelId = JniApi.FindMethod(clazz, "getNotificationChannelId", "(Landroid/app/Notification;)Ljava/lang/String;", true);
-            scheduleNotification = JniApi.FindMethod(clazz, "scheduleNotification", "(Landroid/app/Notification$Builder;)V", false);
+            scheduleNotification = JniApi.FindMethod(clazz, "scheduleNotification", "(Landroid/app/Notification$Builder;)I", false);
             createNotificationBuilder = JniApi.FindMethod(clazz, "createNotificationBuilder", "(Ljava/lang/String;)Landroid/app/Notification$Builder;", false);
         }
 
@@ -195,9 +195,9 @@ public void DeleteNotificationChannel(string channelId)
             self.Call("deleteNotificationChannel", channelId);
         }
 
-        public void ScheduleNotification(AndroidJavaObject notificationBuilder)
+        public int ScheduleNotification(AndroidJavaObject notificationBuilder)
         {
-            self.Call(scheduleNotification, notificationBuilder);
+            return self.Call<int>(scheduleNotification, notificationBuilder);
         }
 
         public bool CheckIfPendingNotificationIsRegistered(int id)
@@ -860,8 +860,11 @@ public static void OpenNotificationSettings(string channelId = null)
         /// </summary>
         public static AndroidJavaObject CreateNotificationBuilder(AndroidNotification notification, string channelId)
         {
-            int id = Math.Abs(DateTime.Now.ToString("yyMMddHHmmssffffff").GetHashCode()) + (new System.Random().Next(10000));
-            return CreateNotificationBuilder(id, notification, channelId);
+            AndroidJavaObject builder, extras;
+            CreateNotificationBuilder(notification, channelId, out builder, out extras);
+            if (extras != null)
+                extras.Dispose();
+            return builder;
         }
 
         /// <summary>

com.unity.mobile.notifications/Runtime/Android/Plugins/com/unity/androidnotifications/UnityNotificationManager.java

@@ -30,6 +30,7 @@
 
 import java.lang.Integer;
 import java.util.Calendar;
+import java.util.Random;
 import java.util.Set;
 import java.util.HashSet;
 import java.util.ArrayList;
@@ -300,12 +301,30 @@ public NotificationChannelWrapper[] getNotificationChannels() {
         }
     }
 
-    // This is called from Unity managed code to call AlarmManager to set a broadcast intent for sending a notification.
-    public void scheduleNotification(Notification.Builder notificationBuilder) {
-        int id = notificationBuilder.getExtras().getInt(KEY_ID, -1);
+    private int generateUniqueId() {
+        int id = 0;
+        Random random = new Random();
+        do {
+            id += random.nextInt(1000);
+        } while (mScheduledNotifications.containsKey(Integer.valueOf(id)));
+
+        return id;
+    }
+
+    public int scheduleNotification(Notification.Builder notificationBuilder) {
+        Bundle extras = notificationBuilder.getExtras();
+        int id;
+        if (extras.containsKey(KEY_ID))
+            id = notificationBuilder.getExtras().getInt(KEY_ID, -1);
+        else {
+            id = generateUniqueId();
+            extras.putInt(KEY_ID, id);
+        }
+
         // don't replace existing, only put null as placeholder so we properly report status as being scheduled
         mScheduledNotifications.putIfAbsent(Integer.valueOf(id), null);
         mBackgroundThread.enqueueNotification(id, notificationBuilder);
+        return id;
     }
 
     protected void performNotificationScheduling(int id, Notification.Builder notificationBuilder) {