Android service Ionic

I developed a native app a time ago. Now I want to try to make it an hybrid app by using Ionic v3.
I have translate almost half of my native app, but now I have a problem.

In my native app I have a service, is there any way to use it in ionic?
I read about background-mode but I need to use my service. I read also about cordova plugins, but I’m not figure out how to solve this problem.

Could someone suggest to me a way ?

After a while of research I got a solution. I used background mode plugin, and I run all the operations I need inside it.
IMPORTANT: the current version of the plugin works fine in background but not show the notification, because it doesn’t support channel introduced in Android O.

Read here to find a way to fix it: