I have huge experience in javascript, ui framework and backend api.
Adding the message should be quite easy, the other piece will take a little bit longer.
the effort is to code, deploy, test the functionality. You will responsable to validate that the outcome respect your requirement.
The requirement need to be clear on the beginning to avoid any rework and any non satisfaction by you.
Let me know if you want to have further discussion.
For now have a good night and back to week end. :-)
Regards
gianluca